Microbiology exam 1, Micro ch 8-13 study quiz, Micro ch 16-19, Micro ch 20-26
How can opportunistic pathogens cause infections?
1. introduction into sterile tissues 2. infection of persons w/ underlying conditions that increase susceptibility 3. infection in immunocompromised patients
Assume a cell is grown in a culture medium containing radioactively labeled thymidine. After three cell divisions, what percentage of the cells would contain the radioactive label?
100%
Place the following infections in order of increasing tissue involvement and severity: septicemia folliculitis cellulitis furuncle
2,4,3,1
Programmed cell death is also called ____________.
Apoptosis
Which of the following statements is true regarding chickenpox and shingles?
A child who is not immune to chickenpox may get it following exposure to a patient with shingles.
Which of the following would be an example of disease transmission via indirect contact?
A student sneezes in her text booklet. The instructor grades it and catches her cold.
The most frequent diagnostic test used to confirm an HIV infection is
APTIMA assay (Western Blotting)
which of the following would you predict to be a feedback inhibitor of the glycolytic enzyme phosphofructokinase
ATP
which of the folowing processes occurs in bacterial plasma membranes but NOT in eukaryotic plasma membranes
ATP synthesis
Which of the following is NOT a reservoir of infection?
All are reservoirs of infection - a sick person -a healthy person -a hospital -a sick animal
What cells have class II MHC molecules on their plasma membranes?
Antigen-presenting molecules (APCs) - including B cells
The presence of inflamed lymph vessels that are visible as red streaks under the skin, running along the armor the leg from the site of the infection is called...
lymphangitis
Which of these structures are NOT part of the mononuclear phagocytic system?
lymphocytes
which of the following is not a step in binary fission
lysis of the existing cell wall
Assume you mix red blood cells, antibodies against the red blood cells, and complement in a test tube. What would you expect to see?
lysis of the red blood cells
chemotaxis refers to the ability of microorganisms to
move toward or away from chemical stimuli
Which non-specific defense mechanism is mismatched with its associated body structure or body fluid?
mucociliary escalator intestines
The most frequently used portal of entry for pathogens is the
mucous membranes of the respiratory tract
Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use?
mucous membranes only
with a light microscope, which of the following would allow discrimination between eukaryotes and prokaryotes
observation of nuclei
unlike chemiosis in eukaryotes, prokaryotes chemiosmosis
occurs at the plasma membrane and not the mitochondria
infestation by lice is called
pediculosis
A 23-year-old woman comes to the emergency room complaining of low abdominal pain and a fever. As she walks into the examination room, she is slightly stooped over and says that even walking is painful. She indicates that intercourse has been painful for the past week and evidence of purulent vaginal discharge is noted during a pelvic exam. What is the most likely diagnosis?
pelvic inflammatory disease
why is penicillin selectively toxic to bacterial cells but harmless to human cells
penicillin specifically weakens peptidoglycan, which is found only in bacterial cells
Heterotrophs use organic molecules as energy and carbon sources. To provide 5 carbon intermediates needed for synthesis of nucleic acids, the cell utilizes the
pentose phosphate pathway
Which of the following is the third stage of a disease?
period of illness
During the bacteriophage lysogenic cycle, __________.
phage DNA is inserted into the host chromosome
Ingesting lactic acid bacteria to prevent colonization by intestinal pathogens such as Salmonella enterica during antibiotic therapy is an example of __________.
probiotics
Some actinomycetes are similar to filamentous fungi because they __________.
produce asexual reproductive spores
Neutrophils with defective lysosomes are unable to
produce toxic oxygen products.
In the blue-white screening procedure, bacteria that are transformed with recombinant plasmid and cultured in media containing ampicillin and X-gal will __________.
produce white colonies
Which of the following is NOT an advantage of obtaining the protein product called human growth hormone by recombinant DNA technology rather than extraction from cadavers?
production of endotoxins
prion is an infectious
protein
What organic compound are exotoxins?
proteins
eukaryotes
protists, fungi, plants, animals
an organism displays some growth at 4C and at 25C. However, it grows best at 20C. The organism would be classifed as a
psychrotroph
if the decolourizing step was deleted, gram negative cells will appear
purple
The bacterial species that is the leading cause of peptic ulcer disease is...
pylori
all of the following are potential end- products of fermentation EXCEPT
pyruivc acid
An 85-year-old man has been experiencing weight loss, night sweats, and a dry cough for several months; recently, he has begun coughing up sputum with tinges of blood in it. Following a chest X-ray showing some white spots on his lungs, an AFB stain and culture were ordered, and both were positive for the presence of AFB. He has been PPD positive since his twenties. Which of the following most accurately describes his current situation?
reactivation tuberculosis
Which of the following cytopathic effects is cytocidal?
release of enzymes from lysosomes
An 8-week-old infant has been brought to the ER because of difficulty breathing. Chest sounds and a chest X-ray indicate an acute bronchiolitis. Oxygen saturation is poor. What is the most likely diagnosis?
respiratory syncytial virus (RSV)
A frameshift mutation in a gene encoding a protein usually __________.
results in the production of a nonfunctional peptide
Viruses that use RNA as a template for transcribing DNA include __________.
retroviridae
An autoimmune complication that sometimes occurs in people 4-18 years of age from an initial Streptococcal infection and causes symptoms such as arthritis, fever, joint nodules, and damage to heart valves is called...
rheumatic fever
All of the following cause lower respiratory tract infections EXCEPT __________.
rhinovirus
Most common cold viruses (30-50%) are species of..
rhinoviruses
A virus may contain any of any of the following EXCEPT (a) __________.
ribosomes
Which would be the most UNLIKELY location to find adhesin molecules on a newly discovered bacterium?
ribosomes
which of the following pairs is MISMATCHED
ribosomes, storage
gram negative cells contain a periplasmic space that is
rich in degradative enzymes
Which of the following drugs inhibits the synthesis of mRNA in bacteria?
rifampin
The viral disease German measles is also known as
rubella
What three components in perspiration have antimicrobial properties?
salt - inhibits many microorganisms lysozyme - breaks down cell wall antimicrobial peptides
micrscopy that is used to study the structure of slimy accumulation of bacteria on an IV catheter tip
scanning acoustic
microscopy for viewing the shape and arrangement of pili
scanning electron
When Streptococcus pyogenes produces an erythrogenic toxin, the resulting infection is known as...
scarlet fever
The occurrence of streptococcal bronchopneumonia in an individual recovering from influenza is an example of a __________.
secondary infection
overuse and misuse of antibiotics has
selected for antibiotic- resistant strains of bacteria and increased their frequency bith in the hospital and community
Martin Lewis agar is an enriched media (containing heated blood) designed for the growth of Neisseria gonorrhea. Antibiotics are added to suppress the growth of normal microbiota that may be found in patient specimens, yet permit the growth of Neisseria gonorrhea. This medium would best be described as
selective media
Endotoxins in sterile injectable drugs could cause
septic shock symptoms.
An acute illness that is associated with the presence and persistence of pathogenic microorganisms or their toxins in the blood is termed....
septicemia
Blood poisoning, also called ___________ is a systemicinfection arising from the multiplication of pathogens in the blood.
septicemia
In polio virus replication, the function of the antisense (- strand) RNA is to __________.
serve as a template for the production of sense (+ strand) RNA
When sepsis results in the uncontrolled drop of blood pressure and organs fail, the patient has progressed into a condition called...
severe sepsis
An example of a latent virus infection is __________.
shingles
The disease caused by reactivation of latent herpesvirus varicella-zoster is called
shingles
Which of the following is NOT a possible result of rubeola?
shingles
Which of the following may result from systemic anaphylaxis?
shock
a good cloning vector ____
should have a gene or genes that allows for selection of transformed host cells
Of what value are siderophores?
siderophores gather iron for the bacteria by taking away the iron from iron-transport proteins of the cell.
All of the following are iron-binding proteins found in humans EXCEPT
siderophorin.
characteristics of bacteria
simple, single celled, lack membrane bound nucleus
an antiseptic is used to remove microbes from
skin before an injection
Two major nonliving reservoirs of infectious disease are _________ and _________.
soil, water
Which of these answers is true for trematodes?
they have more than one intermediate host
Normal microbiota provide protection from infection in each of the following ways EXCEPT
they produce lysozyme
An infection caused by Candida albicans found in the oral cavities of infants is called
thursh
A physician receives a lab report indicating that acid-fast bacilli were found in sputum from a patient with a lower respiratory tract infection. The physician suspects __________.
tuberculosis
which of the follwing is NOT a method used for the direct measurement of microbial growth
turbidity
Typhoid Mary was famous for starting several outbreaks of typhoid fever in the early part of the twentieth century because she was a carrier of the bacteria that caused the disease.What is species of bacteria that causes typhoid fever?
typhi
After the attachment and entry of a virus into a host cell, what is the next step in the multiplication of animal viruses?
uncoating
in negative staining procedure, the bacterial cells would appear
unstained in a coloured background
One of the most important reasons to diagnose and treat strep throat is that __________.
untreated strep throat may contribute to the development of rheumatic fever
Which of the following descriptions does NOT pertain to mycoplasmal pneumonia?
usually a life-threatening illness in adolescence
The rise in herd immunity amongst a population can be directly attributed to
vaccinations
The number of antibody binding sites on an antibody is known as its _____________.
valence
the smallpox virus is also known as the __ virus
variola
Cytopathic effects are changes in host cells due to
viral infections
As a health care worker, you are keenly aware of how important it is to avoid harming patients. You worry about inadvertently transmitting an infectious disease to an already compromised individual. According to the CDC, what is the most important thing you can do to avoid this?
wash my hands before interacting with any patient
characteristic of water accounts for its excellent solvent properties
water has a negatively chartged portion and a postively charged portion
acid fast bacteria differ from non acidic by presence of
waxy material in their cell
Which of the following can be used to diagnose infections by detecting specific antibodies in a patient's serum?
western blotting and ELISA
Pertussis is characterized by __________.
whooping type cough
All of the following are prion diseases EXCEPT __________.
wiles- davidoff syndrome
the valence of oxygen is 2. that means that O
will form up to 2 bonds
auxotrophs ____
will not grow on a plate that lacks the growth factor, but will grow on a complete medium that contains the growth factor
when placed in water, phospholipids will orient themsleves
with phosphates associated with water and lipids clustered away from the water
The following may be listed on the ingredient list of your favorite snack food. Which of these products is NOT antimicrobial?
xanthan
Unicellular, nonfilamentous fungi are known as __________.
yeasts
A nucleoside analog used to treat HIV infection is __________.
zidovudine
In general, a disease that is transmitted by contact with an infected animal is called...
zoonotic
What type of pathogen causes classical hemorrhagic fevers such as chikungunya fever, yellow fever, and dengue?
zoonotic
A fungus that produces sporangiospores and zygospores and has hyphae without cross-walls would be classified in the category __________.
zygomycota
The bacterial species most commonly involved in gas gangrene is..
C. perfringens
Complement component C3, in the classical pathway, is split by __________.
C2aC4b
The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway after the point in the cascade where the activation of ________ takes place.
C3
Which of the following statements is NOT true of the classical pathway of complement activation?
C3 is the first component to be activated.
Multiple sclerosis and insulin-dependent diabetes mellitus are example of which type of autoimmune reaction?
Cell-mediated
Which of the following does NOT pertain to Streptococcus mutans?
Cells lyse on contact with fluoride.
Which of the following statements concerning cellular immunity is FALSE?
Cellular immunity involves cells that recognize antigens and make specific antibodies against them.
All of the following methods are used for diagnosis of syphilis EXCEPT __________.
Gram staining
The influenza virus has two types of rapidly mutating antigenic projections called HA and NA spikes that are associated with its outer membrane. Strains of the virus are identified by the variation of the spikes.What do the abbreviations, HA and NA, stand for?
HA- hemagglutinin NA- neuraminidase
All of the following protect the skin and mucous membranes from infection EXCEPT
HCI
Why would it be especially difficult to develop an effective vaccine for HIV?
HIV changes more rapidly than once a year
Systemic lupus erythematosus and rheumatoid arthritis are example of which type of autoimmune reaction?
Immune Complex
Which of these statements is NOT true for bacterial capsules?
Immune system antibodies are not produced against a capsule.
List three modes of action of antimicrobial peptides.
Inhibiting cell wall synthesis, forming pores in the PM, and destroying DNA and RNA
Where in the adult body are the cells involved with humoral immunity created and mature?
Initially produced in fetal liver, after 3 months - creation and maturation is red bone marrow
New mother's often shield their babies from other sick children, so that their child doesn't contract the microbe and get sick. According to the hygiene hypothesis, what negative result may occur?
It lowers immune tolerance and the body's ability to cope with harmless antigens, such as food or pollen.
Which of the following statements is NOT true of nitric oxide (NO)?
It is of little value in killing microbes or tumor cells.
Which of the following statements is NOT true of diphtheria?
It is readily treated with antibiotics.
Which of the following is NOT characteristic of mumps?
It is spread via the fecal-oral route.
Which of the following does NOT pertain to Staphylococcus aureus, which causes food poisoning?
It is transmitted by contaminated drinking water.
How are exotoxins are released from a bacterial cell?
They are secreted by the bacterium into the surrounding medium or released following lysis. They are secreted to the outside of the bacterial cells that produce them.
Which of the following statements concerning immunological memory is true?
The memory response is due to production of long-lived cells that can respond very rapidly upon second exposure.
Which statement is NOT true of endotoxins?
They are eliminated from the body as a result of antitoxin production.
Which of the following statements in NOT true of plasmids?
They are essential for survival of the organism in most situations.
Which of the following statements is NOT true of the genus Mycoplasma ?
They are obligate intracellular pathogens.
Which of the following statements is NOT true of A-B exotoxins?
They are produced only by gram-negative bacteria.
Explain how endotoxins are released from the bacterial cell.
They are released during bacterial multiplication and when gram-negative bacteria die and their cell walls undergo lysis
What is the principal function of both alpha-and beta interferon?
To interfere with viral multiplication
Which of the following statements is NOT true of brucellosis?
Transmission occurs via mosquitoes.
Black death, or more commonly, the plague is caused by the gram-negative rod-shaped bacteria...
Yersina pestis
The resistance to reinfection with measles virus following recovery from measles infection is called __________.
adaptive immunity
Which of the following is NOT a step in Southern blotting?
addition of heat- stable DNA polymerase
The stage of phagocytosis in which the phagocyte's plasma membrane attaches to the surface of the microbe is called __________.
adherence
The fimbriae of Neisseria gonorrhea and enteropathogenic E. coli are examples of
adhesins and ligands.
Which of these substances are most important in the establishment of biofilms?
adhesions
The mold, Aspergillus flavus, grows on peanuts and produces a toxin called ___________that when ingested can be altered to a mutagenic compound.
aflatoxin
Which of the following are possible strategies for treating viral infections?
all of the listed strategies are correct
Emergence of infectious diseases can be attributed to all of the following EXCEPT
all of these can be attributed -climatic changes -ease of travel -antibiotic resistance -new strains of previously known agents
Which of the following does NOT pertain to vaginitis?
always sexually transmitted
The process of making multiple copies of a DNA molecule is referred to as __________.
amplification
the proton motive force is
an electrochemical gradient formed across a membrane
What is a compromised host?
an individual whose resistance to infection is impaired by disease, therapy, or burns
Which antibodies will be in the serum of a person with blood type B, Rh+?
aniti - A
Clostridium difficile-associated diarrhea is usual caused by long term use of...
antibiotics, especially fluoroquinolones
Which of the following is/are NOT used in DNA fingerprinting?
antibodies
Which of these molecules or structures is/are NOT associated with innate immunity?
antibodies
microbes are NOT responsible for
antibody production
Which item is from the patient in a direct ELISA test?
antigen
The classical pathway for complement activation is initiated by
antigen-antibody reactions
The ability of some microbes, such as Trypanosoma or Giardia to alter their surface molecules and evade destruction by the host's antibodies is called
antigenic variation
Which of the following are best described as short chains of amino acids that are very stable and can have a variety of different antimicrobial activities, such as forming pores in bacterial plasma membranes and inhibiting cell wall synthesis?
antimicrobial peptides
Members of the genus Clostridium display the following properties: gram-positive bacilli endospore formation anaerobic growth Which of the following would be appropriate for the culture of members of this genus?
both a blood agar plate in an anaerobic jar and sodium thioglycate broth
In which of the following patterns of disease does the patient experience no signs or symptoms?
both incubaion and convalescence
Which of the following diseases is NOT spread by droplet infection?
botulism
microscopy used to visualize stained specimens
brightfiled
enzymes are important in living organisms bbecause they
bring together reactants or properly orient a molecule for a reaction
Which of the following types of antibiotics is most likely to be associated with the development of a superinfection?
broad spectrum anitbiotics
A periodontal disease that results in inflammation and bleeding of the gums is called...
gingivitis
Which of the following is NOT caused by HSV-1?
canker sores
Some tribes in New Guinea have suffered from a transmissible spongiform encephalitis called kuru. How did the people belonging to these tribes contact the causative agent?
cannibalism
Some people can harbor pathogens and transmit them to others without exhibiting any signs of illness. These people are called ___________, and they are considered a human reservoir of infection.
carriers
Complement proteins work act in a ____________where one reaction triggers another, which in turn triggers another.
cascade
The aerobic, gram-negative bacteria, Bartonella henselae, causes...
cat scratch disease
A variant form of Creutzfeldt-Jakob Disease (vCJD)was discovered in certain individuals living in Great Britain. How did the individuals contract vCJD?
cattle that are affected with mad cow
Which of the following is NOT a characteristic of members of the domain Archaea?
cause disease in humans
Which one molecule could provide the carbon source, the energy source, and the electron source for a chemoheterotroph
glucose
The swelling associated with inflammation decreases when the fluid
goes into lymph capillaries.
Which one of the following does NOT contribute to the incidence of nosocomial infections?
gram negative cell walls
An antimicrobial drug that inhibits peptidoglycan synthesis is most likely to be effective against __________.
gram positve bacteria
Consider the following three common agents of bacterial meningitis: Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae type B. Which of the following would be most helpful in differentiating these three agents?
gram-stain morphology
competitive inhibition of enzyme action involves
competition with the substrate for binding at the active site
Women who have a healthy population of Lactobacillus spp. as part of the normal vaginal microbiota are less likely to get yeast infections. Which of the following terms is used to explain this observation?
competitive exclusion
After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT
complement
Which of the following is found normally in serum?
complement
The serum from patients with hepatitis B contain three distinct particles. What particle is the largest, infectious, and capable of replication?
complete virion
a culture medium consisting of agar, peptone, and beef-heart extract is a
complex medium
pinkeye by lice is called
conjuctivitis
Which of the following is NOT involved in the production of sexual spores in fungi?
conjugation
Staphylococcal food poisoning is most likely to result from __________.
consumption of staphylococcal enterotoxin in potato salad that has been left at room temperature
In a direct ELISA test to screen for drugs in a patient's urine, what is the third step in the test process?
enzyme-labeled antibodies against the drug being tested is added
Group A streptococci are synonymous with what species of beta-hemolytic streptococci?
group A strepococci
Your lab partner tells you the bacteria are moving in his Gram-stained smear. You can conclude that
he didnt fix the smear
If one is examining a blood smear from a patient with a parasitic worm infection, which of the following leukocytes would be found in increased numbers?
eosinophils
Which of the following is involved in resistance to parasitic helminths?
eosinophils
The graph in the figure shows the incidence of polio in the United States. The period between 1945 and 1955 indicates a(n)
epidemic level
The science that deals with when diseases occur and how they are transmitted is called
epidemiology
One of the most serious infections of the upper respiratory system is __________.
epiglottitis
Inflammation of the cartilaginous flap-like structure that prevents ingested material from entering the larynx is called...
epilottitis
Antibodies recognize and interact with specific regions on antigens called __________.
epitopes or antigenic determinants
The ascomycete fungus, Claviceps purpurea,grows on certain grains and produces a toxin called ___________that mimics the effect of LSD.
ergot
Which of the following antibiotics is a common choice to treat streptococcal infections in children?
erythromycin
Which of the following antibiotics is frequently used as an alternative for those who are allergic to penicillin?
erythromycin
A skin rash that arises from disease conditions is called
exanthem
an organism that grows both in the presence and the absence of oxygen and uses oxygen when its available is call a
facultative anaerobe
Worldwide, how do humans usually contract rabies?
in saliva from the bite of an infected animal, especially dogs
Which of the following is an effect of opsonization?
increased adherence of phagocytes to microorganisms
One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in
increased susceptibility to disease
Which of these disease stages is most likely to be altered in length if the number of infecting organisms at the start of the infection is very high?
incubation period
Which of the following does NOT correctly represent a stage of syphilis?
incubation: 3- to 5-day incubation period
Which of the following tests is MOST useful in determining the presence of AIDS antibodies?
indirect ELISA
An infection transmitted by a handkerchief or tissue is transmitted by __________.
indirect contact
A needlestick is an example of
indirect contact transmission by fomite
Which of the following mechanisms is used by gram-negative bacteria to cross the blood-brain barrier?
inducing TNF
Which answer is true of hepatitis A but NOT hepatitis B?
fecal-oral; spread via water and food
"Mad cow disease" is caused by which type pathogen?
feed supplements containing meat and bone meal contaminated with prions from sheep infected with scrapie
All of the following are effects of histamine EXCEPT
fever
Bacteria, their toxins, and viruses can reset the hypothalamus, the body's "thermostat", to a higher than normal temperature. The result of resetting the hypothalamus is ____________.
fever
All of the following are true of hypersensitivity EXCEPT
it occurs when an individual is exposed to an allergen for the first time.
The three main species of bacteria that are responsible for the majority of cases of bacterial meningitis possess a capsule. How does the bacterial capsule protect the bacteria?
it protects them from phagocytosis as they replicate in the bloodstream, from which they might enter the cerebrospinal fluid
Which of the following statements about sebum is NOT true?
it raises the pH of skin
Not a step in translation
joining of the Okazaki fragments
__________ is/are always present in an individual's blood. However, in the absence of infection, it is in an inactive form.
kinins
Swimmer's itch is caused by __________.
larvae of schistosomes
A disease in which the causative agent remains inactive for a time before producing symptoms is referred to as
latent
All of the following are exclusively sexually transmitted infections (STIs) EXCEPT __________.
leptospirosis
all of the following are found in the cell walls of gram positive bacteria EXCEPT
lipid A
the lipid portion of lipopolysaccharide (LPS) is called....
lipid A
The alternative pathway for complement activation is initiated by
lipid-carbohydrate complexes and C3.
What organic compound are endotoxins?
lipopolysaccharides
Which disease may be transmitted by contaminated dairy products?
listeriosis
Focal infections initially start out as
local infections
in which phase of growth curve is the population-doubling time fastest
log phase
what phase of the cell cycle is extended in a chemostat
log phase
Which of these viral cytopathic effects is most likely to be associated with the development of cancer?
loss of contact inhibition
A patient has flu like symptoms and a bull's-eye rash on his leg. Investigation reveals that he had been hiking in Connecticut and was bitten by two ticks. What is the diagnosis?
lyme disease
Which disease is NOT caused by an obligatory intracellular bacterium?
lyme disease
Why are carriers important reservoirs of infection?
Carriers are more important in populations than are cases because the infectious agent is maintained for a long time and it is not as easy to identify carriers in order to eliminate them from a herd and thereby control a disease
Define cytopathic effects, and give five examples
Cause the macromolecular synthesis to cease, cause cell's lysosomes to release enzymes and destroy cell, the production of an inclusion body, formation of a large multinucleate cell called a syncytium, change cell function without visually changing cell, production of interferons, antigenic variation, chromosomal changes, and loss of contact inhibition.
Non-gonococcal urethritis is commonly caused by __________.
Chlamydia trachomatis
Give several examples of emerging infectious diseases.
*GENETIC RECOMBINATION new strains such as cholerae recombination *GLOBAL WARMING and change of weather patterns-malaria *TRAVEL known diseases such as west nile may spread to new areas *MIGRATION AND CHANGE IN ECOSYSTEM previously unrecognized infections b/c of- hemorrhagic fever *ANIMAL CONTROL-lyme disease increasing from killing animal predators
Explain some exceptions to Koch's postulates.
-Some pathogens can cause several disease conditions -Some pathogens cause disease only in humans -Some microbes have never been cultured
List Koch's postulates.
-The same pathogen must be present in every case of the disease. -The pathogen must be isolated from the diseased host and grown in pure culture. -The pathogen from the pure culture must cause the disease when it's inoculated into a healthy, susceptible laboratory animal. -The pathogen must be isolated from the inoculated animal and must be shown to be the original organism.
List three portals of entry, and describe how microorganisms(MO) gain access through each.
1. Mucous membranes -MO are inhaled into the nose or mouth in drops of moisture and dust particles - microorganisms can gain access to the GI tract in food and water via contaminated fingers -MO gain access in genitourinary through sexual contraction 2.Skin -MO gain access to the body through openings in the skin, such as hair follicles and sweat gland ducts 3.Parenteral route(direct deposition beneath the skin or membranes) -MO gain access to the body when they are deposited directly into the tissue beneath the skin or into mucous membranes when these barriers are penetrated or injured
if a single bacterium replicated every 30 minutes, how many bacteria would be present in 2 hours
16
Streptococcus bacteria lack an electron transport chain. How many molecules of ATP can a Streptococcus cell net from one molecule of glucose
2
Which blood transfusions in the table are incompatible?
235
You have a 200 mg/ml antibiotic solution. You prepare serial dilutions (1:2, 1:4, etc.) of the antibiotic; the first tube contains 100 mg/ml. You then inoculate each tube with Salmonella. Bacteria grow in tubes 4, 5, and 6. You subculture bacteria from tubes 1 through 3 to nutrient broth. Growth occurs in the tube 3 subculture. You can conclude that the MIC is
25 mg/ml
alcohol is most effecive when used as a ___ solution
70%
The DRT for a particular bacterial species at 60°C is 30 minutes. How long would it take at this temperature to remove 99.9% of this bacterial population?
90 minutes
Which of the following statements correctly differentiates a genomic library from a cDNA library?
A genomic library contains fragments of the entire DNA in an organism's genome. A cDNA library contains the coding sequences of eukaryotic genes (minus the introns).
Which of these events is an example of contact transmission?
A person drinks from a cup used by another individual.
Which of the following results in comparatively long-lasting immunity?
A person survives an infectious disease.
Which of these statements is true about transduction?
A virus is required for transfer of genetic material.
A newly identified bacterial pathogen has been shown to cause disease in humans, disrupting the production of some proteins by interfering with the function of the endoplasmic reticulum of liver cells. Under specific growth conditions, this bacterial strain secretes a protein that appears to be responsible for the pathology of the disease. This protein is composed of two polypeptide chains, one of which binds to a receptor on the surface of liver cells, stimulating the uptake of the protein by endocytosis. Once inside the cell, the other polypeptide component interferes with the activity of ribosomes bound to the endoplasmic reticulum. This bacterial protein will most likely be classified as a/an __________.
A-B toxin
Which of the following is NOT a membrane-disrupting toxin?
A-B toxin
Assuming Rh compatibility is present, individuals with which of the following blood types would be able to receive donor blood from any of the four blood types (A, B, AB, and O)?
AB
Which of the following is a eukaryotic pathogen that infects the eye?
Acanthamoeba
What microbe structure do pathogens use to bind to host cell receptors?
Adherence or adhesion
The strength of the bond between antigen and antibody is called ____________.
Affinity
Which of the following diseases is NOT caused by a prion?
African sleeping sickness
Which of the following can contribute to postoperative infections?
All of the answers are correct -normal microbiota on the operating room staff -errors in aseptic technique -using syringes more than once -antibiotic resistance
If a patient has a positive tuberculin skin test, it means that __________.
All of the listed choices are possible regarding a patient with a positive tuberculin skin test.
Which of the following can be prevented by cooking food?
All of the listed choices can be prevented by cooking food.
Which one of the following is NOT a zoonosis?
All of these are zoonoses -cat scratch disease -rabies -tapeworm -hantavirus pulmonary syndrome
Which of the following does NOT pertain to E. coli?
All pathogenic strains invade mucosal cells and cause lesions.
Under what conditions does hemolytic disease of the newborn occur?
An Rh- woman would have to give birth to a Rh+ baby from a Rh+ father, and then have a subsequent Rh+ pregnancy, resulting in the anti-Rh antibodies to cross the placenta and destroy the fetal RBCs by producing large numbers of immature RBCs called erythroblasts
Which of the following would be an example of an infection initiated via the parenteral route?
An individual contracts hepatitis B from an accidental stick with a contaminated needle.
After learning that 40 hospital employees developed nausea and vomiting, the hospital infection control officer determined that 39 ill people ate green beans in the hospital cafeteria, compared to 34 healthy people who ate in the cafeteria the same day but did not eat green beans in the hospital cafeteria. What type of epidemiology is this?
Analytical
Systemic anaphylaxis is also called
Anaphylactic shock
What is the genus of the mosquito vector transmits the infective agent of malaria?
Anopheles
Which of the following is NOT true of salmonellosis?
Antibiotic therapy is required for all patients.
Which of the following statements is NOT true about botulism?
Antibiotics are the first choice of treatment.
Why do antibiotics sometimes aggravate septic shock?
Antibiotics may cause the lysis of more bacteria and the release of more endotoxin.
What do Type III hypersensitivity reactions usually involve?
Antibodies against soluble antigens circulating in the serum
Which answer is NOT true for adherence of a phagocyte to a microbe?
Antibody molecules attached to the microbe will limit adherence.
Which of these statements is NOT true of antibody molecules?
Antibody molecules can directly destroy antigens.
Cyclosporine is a drug sometimes used to prevent transplant rejection after organ transplant surgery. This drug specifically disrupts cell-mediated immunity by cytotoxic T cells. Which of these events can be predicted based on this information?
Antibody production will NOT be disrupted in the recipient.
Explain how artificially acquired active immunity develops.
Artficially acquired active - antigens are intriduced in vaccines; body produces antibdies and specialized lymphocytes
Which organisms are the most important group of disease vectors?
Arthropods
Explain how artificially acquired passive immunity is attained.
Artificially acquired passive - preformed antibodies in immune serum are introduced by injection
Explain the result of having an infection with a bacterial species that secrete siderophores.
As a result of infection it is secreted by both macrophages and hepatocytes, enterobactin being scavenged from the extracellular space.
Which of these statements is NOT true?
Attachment of animal viruses to host cells is random and nonspecific.
Historically, three main species of bacteria are responsible for the majority of cases of bacterial meningitis. Name the species that is associated with meningococcal meningitis.
B,C,Y
Which one of the following is NOT correctly matched to its vector?
Babesia microti; flea
Which of the following is an endospore-forming bacterium?
Bacillus
Which of the following statements concerning phagocytosis is true?
Bacteria are digested when the phagosome fuses with a lysosome.
The genus of the bacterium that causes pertussis is....
Bordetella pertussis
All of the following can form filaments EXCEPT __________.
Borrelia
The genus of spirochete bacteria that causes both relapsing fever and Lyme disease is...
Borrelia
The LD50 of botulinum toxin is 0.03 ng/kg; the LD50 of Salmonella toxin is 12 mg/kg. Which is the more potent toxin?
Botulinum
What is the function of lysozyme?
Breaking down cell walls of gram postive bacteria and to a lesser extent, breaks chemical bonds on peptidoglcan, which destroys cell walls
through metabolism, pathogens often produce acids that interfere with their own growth. _____ are added to media to control pH changes
Buffers
Which of the following statements is NOT true of yellow fever?
Burkitt's lymphoma may develop.
A healthy immune system destroys cancer cells with
CTLs and activated macrophages.
American trypanosomiasis, caused by the protozoa, Trypanosoma cruzi, is also known as...
Chagas disease
List the three main steps that occur in the process of phagocytosis.
Chemotaxis and Adherence, Ingestion, and Digestion
A patient has a rapid onset of fever, chills, labored breathing, and sore throat. He recently returned from Mexico, where he drank local water and stayed in an air-conditioned room. Several weeks ago, he purchased a parrot. After a physical exam, his physician prescribes tetracycline. What is the cause of the patient's illness?
Chlamydia psittaci
The mycotoxin that causes ergot poisoning and can induce LSD-like symptoms is produced by...
Claviceps purpurea
A hyperbaric chamber is sometimes used to treat wounds infected with __________.
Clostridium perfringens
Does Clostridium perfringens cause a communicable disease?
Clostridium perfringens cannot be transmitted from body to body
The pathogenicity of which of the following is NOT the result of lysogeny?
Clostridium tetani
T cells are classified by certain glycoproteins on their surface called ____________.
Clusters of differniation
There are two main vaccines for polio. What type of vaccine is the Sabin vaccine?
Contains living attenuated strains of the virus
An epidemiologist is involved in a hepatitis outbreak in a community. She traces the source of all cases to food served in a local restaurant. What health recommendations should be made to customers who ate at the restaurant?
Customers should be offered passive immunization with immune globulin.
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years. The etiologic agent of the disease in the situation is
Coxiella burnetii
The etiological agent of Q fever is the obligate intracellular bacterial parasite named...
Coxiella burnetii
Which answer is NOT true of bacterial photosynthesis and/or photosynthetic bacteria?
Cyanobacteria deposit sulfur derived from the splitting of hydrogen sulfide outside of the cells.
Superantigens nonspecifically stimulate the proliferation of certain immune cells called T-cells that release an enormous amount of what chemical?
Cytokines
Grave's disease and Myasthenia gravis are example of which type of autoimmune reaction?
Cytotoxic
Which of the following could be a choice to track the source of hospital-acquired infections?
DNA fingerprinting
What is a live attenuate vaccine?
Deliberate weakening, called attenuation, can lead to the production of live attenuate vaccines. When the practice of cell culture for producing viruses for study came into use, it was realized an extended period of cell culture was, itself, a means to attenuate pathogenic viruses
Clostridium difficileis currently the leading cause of nosocomial infections. What is the most common infection associate with C. difficile?
Diarrhea after abdominal surgery
Explain the differences between direct vs indirect agglutination tests.
Direct - detects antibodies against relatively large cellular antigens, such as those on red blood cells, bacteria, and fungi. Usually done in plastic microtiter plates, which have many shallow wells. The amount of particulate antigen in each well is the same, but the amount of serum that contains antibodies is diluted, so that each successive well has half the antibodies of the previous well. Indirect - the antibody reacts with the soluble antigen adhering to the particles do in the direct agglutination tests. The same principle can be applied in reverse by using particles coated with antibodies to detect the antigens against which they are specific.
Explain the differences in what is being detected by using a direct vs indirect FA test.
Direct - microorganism in a clinical specimen Indirect - used to detect the presence of a specific antibody in serum following exposure to a microorganism
How does toxigenicity differ from direct damage?
Direct damage is the damage done to the host as pathogens by using the host cell for nutrients and excreting waste. Toxigenicity is the ability for a bacteria to produce toxin.
Which of these statements is true concerning foodborne botulism in older children and adults?
Disease results from consuming botulism toxin in improperly preserved foods.
A person that has contracted the flu sneezes without covering his/her mouth. What route of disease transmission is caused by sneezing?
Droplet transmission
How does Escherichia coli cause membrane ruffling?
E. Coli releases invasins which alters the host's actin and form ruffling due the the disruption of the cytoskeleton.
Which diagnostic test has antibodies adsorbed to a microtiter plate well that can detect a specific antigen in a patient's blood?
ELISA Direct does antigens Indirect does antibodies
Which of the following is used to diagnose West Nile encephalitis?
ELISA test for IgM antibodies
The most common species of bacteria that causes traveler's diarrhea is...
ETEC
Which of these statements is NOT true of translation?
Each amino acid is coded for by a single codon.
Which of these events leads to all of the others in a pyrogenic (fever) response?
Endotoxin is released from the cell wall of gram-negative bacteria.
Amebic dysentery is spread mostly by food or water contaminated with cysts of the protozoan called...
Entamoeba histolytica
All of the following cause diarrhea EXCEPT __________.
Enterobius vermicularis
Which of these answers is true of the Apicomplexa?
Enzyme-containing organelles are present at one end.
Which of these bacteria is NOT associated with foodborne illness?
Erwinia
The majority of traveler's diarrhea cases are caused by __________.
Escherichia coli
Which microorganism is responsible for approximately 75% of all UTIs and half of the nosocomial infections of the urinary tract?
Escherichia coli
Which of the following is an INCORRECT match regarding motility?
Euglenozoa; nonmotile
Differentiate an exotoxin from an endotoxin.
Exotoxins are produce within the bacteria, and are usually pretty potent. Endotoxins are components of the cell wall called lipopolysaccharides that break off when the cell dyes, usually not as potent as exotoxins.
What type of pathogens are humoral immunity responses generally targeted against?
Extracellular - in blood or body fluids
Which of the following is NOT true of typhoid fever?
Fluid and electrolyte replacement are the primary treatments.
Identify one virulence factor that contributes to the pathogenicity of each of the following: fungi, protozoa, helminths, and algae.
Fungi: Secretion of proteases, and toxins Protozoan: Waste products, antigenic variation Helminths: Waste products, presence Algae: Toxins
Which type of bacteria are more susceptible to MAC-mediated cytolysis?
Gram negative
Examples of microbial antagonism
For example, the normal bacterial microbiota of the adult human vagina maintains a local pH of about 4. The presence of normal microbiota inhibits the overgrowth of the yeast Candida albicans, which can grow when the balance be- tween normal microbiota and pathogens is upset and when pH is altered. If the bacterial population is eliminated by antibiotics, excessive douching, or deodorants, the pH of the vagina reverts to nearly neutral, and C. albicans can flourish and become the dom- inant microorganism there. This condition can lead to a form of vaginitis (vaginal infection). Another example of microbial antagonism occurs in the large intestine. E. coli cells produce bacteriocins, proteins that inhibit the growth of other bacteria of the same or closely re- lated species, such as pathogenic Salmonella and Shigella. A bac- terium that makes a particular bacteriocin is not killed by that bacteriocin but may be killed by other ones. Bacteriocins are used in medical microbiology to help identify different strains of bacteria. Such identification helps determine whether severaloutbreaks of an infectious disease are caused by one or more strains of a bacterium. A final example involves another bacterium, Clostridium difficile (difʹfi-sē-il), also in the large intestine. The normal microbiota of the large intestine effectively inhibit C. difficile, possibly by making host receptors unavailable, competing for available nutrients, or producing bacteriocins. However, if the normal microbiota are eliminated (for example, by antibiotics), C. difficile can become a problem. This microbe is responsible for nearly all gastrointestinal infections that follow antibiotic therapy, from mild diarrhea to severe or even fatal colitis (in- flammation of the colon).
Coccidioides immitis, the etiological agent of coccidioidomycosis, is a dimorphic fungus. What is a dimorphic fungus?
Fungi which can exist as mold/hyphal/filamentous form or as yeast
The most abundant Ig in the blood serum is __________.
G
For the peptide with the amino acid sequence, proline-alanine-glycine (pro-ala-gly), the DNA template strand could have the sequence __________.
GGC CGA CCG
A clinical microbiologist detects clue cells from a vaginal swab of a patient. These cells are diagnostic of infection associated with __________.
Gardnerella vaginalis
You see flagellated cells in a microscopic examination of feces from a patient with diarrhea. You conclude that the etiology is__________.
Giardia
What protozoan is being looked in an individual who has a prolonged diarrheal disease when performing the "string test"? PS: YUCK!
Giardiasis intestinalis
What species of gram-negative pneumonia-causing coccobacilli is commonly associated with patients having conditions such as alcoholism and poor nutrition?
Haemophilus influenzae
Leprosy is also called
Hansen's disease
What is immunological component is necessary for contact dermatitis from poison ivy to display itself as a rash on your skin?
Haptens that combine with proteins (particularly the amino acid lysine)
Which of the following is an example of a helical bacterium that does NOT make a complete twist?
Helicobacter
A double-stranded, enveloped DNA virus that contains reverse transcriptase belongs to which family?
Hepadnaviridae
The antibodies found in mucus, saliva, and tears are
IgA
What antibody is found in saliva?
IgA
What class of antibody appears in the plasma first in response to primary infection?
IgA
The antibodies that can bind to large parasites are
IgE
What class of antibody increases during parasite infections and some allergic reactions?
IgE
What immunoglobulin class is responsible for inducing anaphylactic reactions?
IgE
During the secondary response of humoral immunity, immunoglobulins undergo class switching. What class of antibody is generally produced during the secondary response?
IgG
The desensitization injections for allergy treatments are aimed at producing __________.
IgG
What class of antibody is involved in the response of ABO blood group antigens on the surface of red blood cells?
IgM
The causative agent of botulism can grow in sealed canned food products. What causes the symptoms of botulism to occur?
In anaerobic environments, such as sealed cans, the microorganisms produce an exotoxin. This neurotoxin is highly specific for the synaptic end of the nerve, where it blocks the release of acetylcholine
Which of the following events does NOT occur in diseases transmitted by vectors?
In biological transmission, the vector multiplies in the human host.
Explain how natural killer cells (NK cells) differ from CTL cells.
In contrast to CTLs, NK cells are not immunologically specific, that is, they do not need to be stimulated by an antigen
Food poisoning can be divided into two categories: food infection and food intoxication. On the basis of toxin production by bacteria, explain the difference between these two categories.
In food infection, microorganism itself causes the illness. In food intoxication, the toxic the microorganism produces causes the illness.
A form of innate immunity can be provided when normal microbiota and host cells have certain interactions. An example of this is when the normal microbiota function as microbial antagonists. What is the result of microbial antagonism?
In microbial antagonism, the normal microbiota prevent pathogens from colonizing the host by competing with them for nutrients, by producing substances that are harmful to pathogens, and by alteriing cinditions that affect the survival of pathogens, such as pH and oxygen
The Salk polio vaccine is an example of which type of vaccine?
Inactivated killed vaccine
Distinguish the incidence from the prevalence of a disease.
Incidence - the number of people in a population who develop a disease during a particular time period Prevalence - the number of people in a population who develop a disease at a specified time, regardless of when it first appeared
Which of the following statements is NOT true of tuberculosis?
Infection has been greatly reduced because of mass immunization.
What type of pathogens are cell-mediated immunity responses generally targeted against?
Intercellular
Cytokines that serve as communicators between leukocytes (=white blood cells, WBCs) are called ___________.
Interleukins
There are two main vaccines for polio. What type of vaccine is the Salk vaccine?
It consists of viruses of all three types that have been inactivated by treatment with formalin
Why is the bacterium that causes syphilis an exception to Koch's postulates?
It has a unique culture requirement. Virulent strains of Treponema pallidum have never been cultured on artificial media.
Explain how antigenic variation would negatively affect the protection gained by the influenza vaccine.
It makes it harder to make a vaccination that is up to date with the alteration
Why would it be important to administer cyclosporine to a patient after receiving an allograft?
It suppresses the secretion of interleukin-2 (IL-2)
Why are Type IV delayed reactions delayed for a day or more?
It takes a long time for the participating T-cells and macrophages to migrate to and accumulate near the foreign antigens
An example of descriptive epidemiology is __________.
John Snow's study of the London cholera outbreak from 1848 to 1849
What protein in the epidermis is involved with the first line of defense in innate immunity?
Keratin
Which of the following is NOT true of the polymerase chain reaction (PCR)?
Large amounts of DNA must be isolated from the source organism.
If an endospore producing organism has an ID50 for the following routes of entry, which transmission route would be the least likely route to cause an infection? Which transmission route would be the most likely route to cause an infection? Ingestion:ID50of 1500-5000 endospores; Skin penetration ID50of 10,000-15,000 endospores; inhalation: ID50 50-100 endospores
Least: skin Most: inhalation
Which member of the gammaproteobacteria is a potential cause of pneumonia and can be found in warm-water supply lines and air conditioning cooling towers?
Legionella
An outbreak of pneumonia occurs in a wing of a hospital housing kidney-transplant patients. The source of infection is traced to the water supply of the air conditioner. This case describes transmission of which of the following?
Legionella pneumophila
Legionella pneumophila is the etiological agent of legionellosis. What is another name for legionellosis?
Legionnaires' disease
Which of the following pairs is NOT a correct match?
Leishmania spp.; water
In 2012, the morbidity of West Nile encephalitis was 5674, and the mortality was 286. The morbidity of listeriosis was 121, and the mortality was 13. Which disease is more likely to be fatal?
Listeriosis Killed 13/121, where West Nile killed 286/5674
The disease that is acquired by an infection with a certain spirochete that is transmitted by the Ixodes tick and exhibits an unusual rash that looks like a bull's-eye is called...
Lyme disease/borreliosis
Which statement regarding the lymphatic system is true?
Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces.
CD8+ cells bind to ____________ molecules, which are located on all nucleated cells
MHC class 1 molecules
CD4+ cells bind to ____________ molecules located on B cells and APCs.
MHC class 2 molecules
What is a predisposing factor?
Makes the body more susceptible to a disease and may alter the course of the disease
Which type of microbe causes dandruff?
Malassezia furfur
What cells have class I MHC molecules on their plasma membranes?
Mammalian nucleated cells
What interacting factors result in nosocomial infections?
Many hospital patients have compromised immune systems, so they are less able to fight off infections. In some cases, patients develop infections due to poor conditions at a hospital or a healthcare facility, or due to hospital staff not following proper procedures. Some patients acquire nosocomial infections by interacting with other patients. Others encounter bacteria, fungi, parasites, or viruses in their hospital environment.
Which of the following statements is NOT true of inflammation?
Many neutrophils can be found at the site of chronic inflammation.
The incubation period for a cold is 3 days, and the period of disease is usually 5 days. If the person next to you has a cold, when will you know whether you contracted it?
Mild symptoms will occurs in 4 days
What is the advantage of producing hybridoma cell lines that produce monoclonal antibodies (Mabs) over culturing B-cells to produce antibodies?
Monoclonal antibodies are uniform, are highly specific, and can be produced in large quantities. They have enormous importance as diagnostic tools.
Which of the following best describes why antibiotic administration is inappropriate for most of the common upper respiratory tract infections?
Most are caused by viruses.
Which of the following statements is NOT true of pelvic inflammatory disease?
Most infections are resolved without treatment.
Which of the following statements is NOT true of base substitutions?
Mutations rarely involve base substitutions.
Capsules play a role in the virulence of all of the following EXCEPT __________.
Mycobacterium tuberculosis
The genus of the bacterium that causes tuberculosis is...
Mycobacterium tuberculosis
A 90-year-old patient is diagnosed with pneumonia. Microscopic examination shows a bacterial agent that lacks cell walls. What is the etiological cause of the patient's pneumonia?
Mycoplasma pneumoniae
Some respiratory diseases are best diagnosed by a gram-stained smear and/or culture, while others are best diagnosed by specific antigen testing or by detecting IgM antibodies. Which of the following respiratory diseases is best diagnosed by doing a specific IgM titer?
Mycoplasma pneumoniae
which of the following is a likely outcome, based on the unique cell structure of membranes of the genusd Mycoplasma
Mycroplasma speices have a very flexible cells that can pass through bacteriologic filters
Which answer is true for bacterial destruction by phagocytosis?
Myeloperoxidase in lysosomes is involved in the formation of HOCl.
During glycolysis, electrons from the oxidation of glucose are transferred to
NAD+
in an enzyme reaction involving oxidation of a substrate, which of the following would be required
NAD+
Which white blood cells releases perforins and granzymes?
NK Cells
Primary amebic encephalitis is caused by the freshwater protozoan called
Naegleria fowleri
Explain how naturally acquired passive immunity is attained.
Natually acquired passive immunity - involves the natural transfer of antibodies from mother to her infant
Explain how naturally acquired active immunity develops.
Naturally acquired active immunity - develops when a person is exposed to antigens through everday life, becomes ill, and then recovers
Which of these bacteria is NOT in the phylum Actinobacteria?
Neisseria
Ophthalmia neonatorum is a serious form of conjunctivitis caused by the bacteria
Neisseria gonorrhoea
A 20-year-old male reports to an STI clinic with symptoms of painful urination. A Gram stain of urethral exudate reveals gram-negative diplococci inside leukocytes. What is the causative agent of the patient's symptoms?
Neisseria gonorrhoeae
Which of these statements about gonorrhea is true?
Neisseria gonorrhoeae can disseminate from the genital area to the joints, causing arthritis.
An otherwise healthy 19-year-old college student was admitted to the emergency room with a fever, bad headache, and a stiff neck, symptoms suggestive of meningitis. A spinal tap was done. The CSF was cloudy, and the cell count on the fluid was 500 WBC/ml. The differential WBC count of the CSF showed predominantly neutrophils. The CSF glucose was decreased, and the CSF protein was elevated. The Gram stain showed gram-negative diplococci. The most likely etiologic agent is __________.
Neisseria meningitidis
Vaccination is recommended to prevent epidemic meningitis among college students and military recruits resulting from infection with __________.
Neisseria meningitidis
Which of the following bacteria are INCORRECTLY matched with gram reaction and morphology?
Neisseria; gram-positive coccus
Which of the following bacteria does NOT fix nitrogen?
Nitrobacter
Would you expect a bacterium to make coagulase and kinase simultaneously?
No, coagulase are bacterial enzymes that coagulate the fibrogen in blood and convert it into fibrin and kinase breaks down fibrin.
Microbiota vs Transient Microbiota
Normal - permanently colonize the host and do not cause disease under normal conditions Transient - may be present for days, weeks, or months (a short time)
Germ-free (gnotobiotic) animals often are more susceptible to infections and serious disease than are animals with a typical complement of normal microbiota. Based on this observation, which of the following would be an appropriate conclusion?
Normal microbiota stimulate the development of the immune system.
Which of the following does NOT pertain to dental caries?
Normal mouth microbiota act as first-line nonspecific defenses.
How are nosocomial infections primarily transmitted, and how can they be prevented
Nosocomial infections are transmitted by direct contact between staff members and patients and between patients. Prevention of nosocomial infections: Using aseptic techniques, handling contaminated materials carefully, insisting on frequent hand washing, educate on infection control basics, and use isolation rooms.
Which of the following is NOT a treatment for papillomas?
acyclovir treatment
What is herd immunity?
Outbreaks are limited to sporadic cases because there are not enough susceptible individuals to support the spread of epidermis
What bacteria cause otitis externa (swimmer's ear)?
P. aeruginosa
Which of the following is frequently the cause of infection following animal bites?
Pasteurella multocida
What are the objectives of pathology?
Pathology is the study of disease. It is concerned with etiology(the cause), pathogenesis(the manner in which a disease develops),and the structural and functional changes brought about by disease and their effects on the body.
the sequencing of RNA
can yield information about evolutionary relatedness
Which of the following statements is NOT true for Pelagibacter?
Pelagibacter's photosynthetic capability makes it a key producer in marine ecosystems.
Which of the following does NOT pertain to leptospirosis?
Penicillin A is the preferred drug for treatment.
What genera of parasitic protozoan causes malaria?
Plasmodium
Most cases of Burkitt's lymphoma occur in individuals who are infected with EB virus and __________.
Plasmodium species
Pneumocystis jirovecii is the etiological agent of pneumocystis pneumonia. What type of pathogen is Pneumocystis jirovecii?
Pneumocystis jirovecii
Use Figure 18.10 The Complement Fixation Test on page 507 to answer the following: What would positive AND negative complement fixation reactions look like?
Positive - Antigen + Complement + Serum with antibody against antigen > complement fixation > sheep red blood cell (RBC) + Antibody to sheep RBC > No hemolysis (complement tied up in antigen-antibody reaction) Negative - Antigen + Complement + Serum without antibody > No complement fixation > Sheep red blood cell (RBC) + Antibody to sheep RBC > Hemolysis (uncombined complement available)
which is not correctly matched
Poxviridae; chickenpox
How would a drug that binds mannose on human cells affect a pathogenic bacterium?
Prevent the bacterium from attaching on the cell; unable to bind to the host cell
What is the end goal of thymic selection.
Preventing the body from attacking its own tissues
List two ways that HIV, the virus that causes AIDS, evades phagocytosis.
Prevents the fusion of phagosomes with a lysozome and the proper acidification of digestive enzymes. The micobes then multiply within the phagocyte, almost completely filling it.
All of the following cause conjunctivitis EXCEPT __________.
Propionibacterium
Moderate acne arises from certain bacteria metabolizing glycerol found in sebum which leads to an inflammatory response. Which bacterial species is commonly the cause of moderate acne?
Propionibacterium acnes
Ibuprofen and aspirin are frequently used to alleviate by inhibiting _____________ production.
Prostaglandin
A bacterium isolated from the soil has the following characteristics: it is a gram-negative straight rod, it is aerobic and motile, it produces water-soluble pigment, and it readily grows on several common laboratory media. Ribosomal RNA analysis places this bacterium with the gammaproteobacteria. This organism is most likely in the genus __________.
Pseudomonas
Washwater containing Pseudomonas was sterilized and used to wash cardiac catheters. Three patients developed fever, chills, and hypotension following cardiac catheterization. The water and catheters were sterile. Why did the patients show these reactions? How should the water have been tested?
Pseudomonas = gram neg bacteria There must have been endotoxins released. The bacteria was killed but the toxin was still present
Which microorganism is responsible for otitis externa?
Pseudomonas aeruginosa
Which of the following may produce infections of the skin with blue-green pus?
Pseudomonas aeruginosa
viruses possess genetic material comprised of DNA or ___
RNA
Which of the following might specifically be used as part of a reverse-genetics approach to studying a gene?
RNA interference
Which of these enzymes is necessary for the replication of a + strand RNA virus?
RNA-dependent RNA polymerase
What are Negri bodies, where are they located, and the presence of them diagnose what infection?
Rabies virus produces inclusion bodies (Negri bodies) in the cytoplasm of the cell of nerve cells, and their presence in animal brain tissue has been used as one diagnostic tools for rabies. Negri bodies are associated with measles virus, vaccinia virus, smallpox virus, herpesvirus, and adenoviruses
Recently, a new parasitic helminth was described in a 3-year-old boy. The only unusual part of his history was that he played in a shed frequented by raccoons. To diagnose the child's behavioral changes and loss of speech and motor skills, doctors did MRIs and CT scans. The data collected from these scans suggested the presence of larval helminths in his brain. Which of the following is the most likely scenario?
Raccoons are the definitive hosts, and humans are accidental intermediate hosts.
Which virus is probably the most common cause of viral respiratory disease in infants?
Respiratory Syncytial Virus
Which of these statements is true for restriction enzymes?
Restriction enzymes are useful in genetic engineering when they make staggered cuts in DNA.
The bacteria, Rickettsia rickettsia, causes a disease called...
Rocky mountain spotted fever
Which group B streptococci is the most common cause of neonatal sepsis?
S. agalactiae
What is the etiological agent of pneumococcal pneumonia?
S. pneumoniae
What beta-hemolytic streptococci is the cause of erysipelas, necrotizing fasciitis, and streptococcal toxic shock syndrome?
S. pyogens
Which of these vaccines has actually been implicated in causing the disease it is designed to prevent?
Sabin oral polio vaccine
The genus of bacteria that causes gastroenteritis and has developed the ability to survive and reproduce in eggs is called...
Salmonellosis
The amnestic response in adaptive immunity is also known as the ____________ response.
Secondary
Severe dysentery caused by Shigella dysenteriae occurs by the release of an unusually virulant toxin called...
Shiga toxin
In mice, the LD50 for staphylococcal enterotoxin is 1350 ng/kg, and the LD50 for Shiga toxin is 250 ng/kg. Which of the following statements is true?
Shiga toxin is more lethal than staphylococcal enterotoxin
Some bacteria can overcome the actions of iron-binding proteins by secreting proteins called _______________ that function to take away the iron from iron-binding proteins.
Siderophores
Describe how antigenic variation help bacteria evade host defenses.
Some pathogens can alter their surface antigens by the process of antigenic variation. By the time the body mounts an immune response against a pathogen, the pathogen has already altered its antigens and is unaffected by the antibodies
Which organism is NOT correctly matched to its motility?
Spirillum; axial filaments
Which bacterium is associated with impetigo, scalded skin syndrome, and toxic shock syndrome?
Staphylcocci
A 22-year-old female college student visits the campus health center, complaining of low pelvic pain, dysuria, and hematuria. A clean-catch urine specimen is collected and upon culture, it grows more than 100,000 colony-forming units per millimeter of a catalase-positive, coagulase-negative, gram-positive cocci. What is the most likely identification of this etiologic agent?
Staphylococcus saprophyticus
Where in the adult body do the cells involved with cell-mediated immunity mature?
Stem cells of the bone marrow
The LD50 of Vibrio choleraeis 108 cells through the oral route. If the bacterial cells are ingested with bicarbonate, the LD50 drops to 104. Which of these explanations is the most likely?
Stomach acid decreases the virulence of Vibrio cholerae
Which of the following is NOT normal skin microbiota?
Streptococcus
The CDC recommends that pregnant women be tested and offered antibiotic therapy before delivery if they are vaginal carriers of __________.
Streptococcus agalactiae
One of the most important cariogenic bacterium is...
Streptococcus mutans
About 2/3rds of pneumonia (typical pneumonia) is caused by a species of bacteria. Name the bacterial genus that causes typical pneumonia.
Streptococcus pneumoniae
What group A streptococcus is the cause of strep throat?
Streptococcus pyogens
Which subset of T helper cells are involved in stimulating antibody production, activating macrophages and delayed hypersensitivity reactions?
TH1
The beef and pork tapeworms are caused by infection with what genus of helminth?
Taenia
Beef is checked for cysticerci to prevent transmission of __________.
Taenia saginata
What fluid does the lacrimal apparatus produce?
Tears
What is the CDC's function?
The Centers for Disease Control and Prevention (CDC) is a federal agency that conducts and supports health promotion, prevention and preparedness activities in the United States, with the goal of improving overall public health.
Explain the function of the MAC complex.
The MAC complex creates a hole in a pathogen's membrane and makes transmembrane channels, allowing for the flow of extracellular fluid.
Which of the following is NOT true for the slide agglutination test?
The absence of agglutination indicates that the antibody reacted with the antigen.
What would occur if a person with Type O blood is given a transfusion with Type AB blood?
The anti-A and anti-B antibodies would react in the recipient's serum. This antigen-antibody reaction activates complement, which in turn causes lysis of the donor's red blood cells (RBC) as the enter the recipient's body.
Which answer is NOT true of the inflammatory process?
The area becomes red because of a decrease in capillary diameter.
Describe the function of toll-like receptors located on phagocyte membranes.
The binding of PAMPs to TLRs not only initiates phagocytosis, but also induces the phagocyte to release specific cytokines that recruit additional phagocytes
What function do capsules and M proteins have in common?
The both add to a bacteria's virulence.
Explain how certain encapsulated bacteria evade host defenses.
The capsule resists the host's defenses by impairing phagocytosis, the process by which certain cells of the body engulf and destroy microbes.
Define chemotaxis
The chemical attraction of phagocytes to microorganisms
Which of the following is a possible outcome of an HIV infection?
The disease does not progress to AIDS. Infection may initially be asymptomatic. There may be persistent yeast infections. Virions may remain latent. *All of the answers are correct.*
Many vaccines provide years of protection against a disease. Why doesn't the influenza vaccine offer more than a few months of protection?
The influenza virus exhibits antigenic variation so that it alters its surface antigens so the antibodies formed from the previous vaccination do not bind to the new antigens.
What is the benefit of our normal microbiota exhibiting microbial antagonism (competitive exclusion) with other foreign bacteria?
The normal bacteria can prevent the overgrowth of harmful organisms, such as the yeast Candida albicans
Which of the following is NOT necessary to satisfy Koch's postulates?
The organism must cause disease through toxin production.
Koch's postulates established criteria for proving that a specific organism causes a specific disease. Which of the following is NOT one of the criteria given by Koch's postulates?
The pathogen must be isolated from inoculated animals and must be different from the original organism
Which of the following statements about the development of infectious diseases is correct?
The period of convalescence is the time during which the person regains health and fully recovers
Which of these answers is NOT true for positive (direct) selection?
The procedure detects altered genotypes regardless of the phenotype.
List 3 advantages of nucleic acid vaccines
The protein antigens are carried to the red bone marrow and stimulate both humoral and cellular immunity. They also tend to be expressed for extended times, with good immunological memory. The gene gun would eliminate the need for large supplies of syringes and needles, and these vaccines would not require refrigeration. Manufacturing operations costs could be lowered.
What are R factors responsible for
The resistance of some microorganism to antibiotics
Which are the most often used portals of exit?
The respiratory and gastrointestinal tract.
Which of these answers is a potential concern of using T-independent antigens as vaccines?
These antigens will be ineffective in producing an immune response in infants.
Why would a Nanopatch vaccine be especially important in Africa?
They administer a dry formulation of a vaccine. This would be helpful because Africa has faulty refrigeration
Which of the following statements is NOT true of dichotomous keys?
They always show evolutionary relationships of organisms.
What do the following diseases have in common? Scalded skin syndrome Toxic shock syndrome Staphylococcal food poisoning
They are all caused by exotoxins produced by strains of Staphylococcus aureus.
Which of the following statements does NOT pertain to genital warts?
They are caused by a disease of the tropics that is uncommon in the United States.
Which of the following statements about fixed macrophages is FALSE?
They develop from neutrophils
Which of the following statements is true of members of the order Lactobacillales?
They do not perform aerobic or anaerobic respiration.
Explain how viruses gain access to their target cells.
They have attachment sites for receptors on their target cells. When such attachment site is brought together with appropriate receptor, the virus can bind to and penetrate cell
Which statement is NOT true of cladograms?
They make dichotomous keys useless.
Which of the following statements is NOT true of antigens?
They often have a molecular weight of less than 10,000
Which is NOT true of the rickettsias?
They reproduce by fragmentation.
Which of the following statements does NOT pertain to urinary tract infections (UTIs)?
They typically begin in kidneys and descend to the bladder and urethra.
What do Type II hypersensitivity reactions usually involve?
They usually involve the activation of complement by the combination of IgG or IgM antibodies with an antigenic cell
Which of the following is NOT a member of Domain Archaea?
Thiomargarita
During the Southern blotting technique, what is the purpose of transferring the DNA fragments from the gel to a nitrocellulose filter?
This step attaches the DNA fragments to a permanent substrate, which then can be probed.
Which of the following is NOT true of the Western blot?
This technique identifies signature rRNA sequences of microbes.
Which of the following occurs first, setting in motion the remaining events?
Toll-like receptors (TLRs) on macrophages and dendritic cells attach to pathogen-associated microbial patterns (PAMPS) on invading microorganisms.
The drug Flagyl is commonly used to treat an STD caused by __________.
Trichomonas vaginalis
Whipworm infestation is caused by the nematode worm called..
Trichuris trichiura
Packages of milk and coffee creamers may be stored without refrigeration if they have been sterilized by
UHT treatment
In which of the following diseases can gender be considered a viable predisposing factor?
UTI
What is a subunit vaccine?
Use only those antigenic fragments of a microorganism that best stimulate an immune response
Cholera is a serious gastrointestinal disease that has the characteristic symptomology of a severe form of diarrhea known as "rice water stools". What is the genus of the bacteria that causes cholera?
Vibrio
Which of the following toxins and descriptions do NOT match?
Vibrio enterotoxin: a superantigen that destroys epithelial cells
Reservoirs for rabies include all of the following EXCEPT __________.
mosquitos
How does herd immunity develop?
When many immune people are present in a community
What is the cause of an autoimmune disease?
When the action of the immune system is in response to self-antigens and cause damage to one's own organs
Why are toxoids good candidates for vaccines?
When toxins are injected into the body as a vaccine, they stimulate antitoxin production so that immunity is produced.
All of the following are antiprotozoan drugs EXCEPT __________.
Your Answer: mebendazole
Which of the following antibiotics inhibits protein synthesis?
Your Answer: streptomycin
How are zoonoses transmitted to humans?
Zoonoses are diseases transmitted from animals to humans
In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes
a decrease in blood pressure
To what does the term viral species refer?
a group of viruses sharing the same genetic information and structure
Which of the following is a fomite
a hypodermic needle
Which of the following is NOT included in Domain Eukarya?
a photosynthetic bacterium
crystal violet is
a primary stain
In an immunodiffusion test to diagnose the fungal disease histoplasmosis, a patient's serum is placed in a well in an agar plate. In a positive test, a precipitate forms as the serum diffuses from the well and meets material diffusing from a second well. In this test process, what is the most likely identity of the material in the second well?
a purified fungal antigen
All of the following are potentially predisposing conditions for vaginitis EXCEPT __________.
a vaginal pH of 4.5 or lower
a solution with a pH below 7
acidic
A nosocomial infection is
acquired during the course of hospitalization
Which of these eukaryotic molecules/structures can be responsible for movement of bacteria within host cells?
actin molecules
A population of bacterial cells has been placed in a very nutrient-poor environment with extremely low concentrations of sugars and amino acids. Which kind of membrane transport becomes crucial in this environment?
active transport
List two examples of acute and chronic diseases.
acute - influenza chronic - tuberculosis, hepatitis B
A useful way of defining the scope of a disease is in terms of its severity or duration. A(n) __________ disease is one that develops rapidly but lasts for a short time while a(n) ____________ disease develops more slowly, but is likely to continue or recur for long periods.
acute, chronic
A unicellular microorganism has been isolated from an acidic sulfur-rich hot spring in Yellowstone Park. Its cell wall lacks peptidoglycan and has no nucleus or other membranous organelles. What is the most likely classification of this microorganism?
archaea
DNA probes ____
are DNA fragments
fungal spores ___
are considered "reproductive" spores
Interferons ___________.
are host-specific but not virus-specific
Bacillus anthracis causes the deadly disease anthrax. Organisms of the genus Bacillus may form endospores. This bacterium would be suitable for biological warfare because endospores
are resistant to high temperatures, UV light, and desication
When two DNA pieces cut with the same restriction enzyme are combined, sticky ends will __________.
associate by complementary base pairing and hydrogen bonds
normal microbacteria are NOT
associated with disease
micrscope uses a metal and diamond probe that is gently forced down along the surface of a specimen
atomic force
Live weakened polio virus can be used directly in a(n)
attenuated whole-agent vaccine
What type of vaccine is the live, weakened measles virus?
attenuated whole-agent vaccine
Which component in the figure came from the patient in this indirect ELISA test?
b
The presence of bacteria in the bloodstream is referred to as __________.
bacteremia
which term refers to an agent that inhibits bacterial growth
bacteriostatic
If DNA ligase were NOT used in the creation of a recombinant plasmid, __________.
base-pairing would occur but the sugar phosphate backbone would not be connected
How might penicillin use result in candidiasis?
because the fungus is not affected by antibacterial drugs, antibiotics can suppress the normal bacteria microbiota
All of the following are characteristics of the varicella-zoster virus EXCEPT __________.
benign skin growths
All of the following are examples of microbial control using heavy metals EXCEPT __________.
benzoyl peroxide used for acne treatment
when a bacterial cell reproduces by splitting into two daughter cells, the process is called
binary fission
a bioprocess using naturally occuring bacteria to remove arsenic has been developed. this is an example of ___
bioremdation
In a healthy human, resident microorganisms would be found in all of the following areas EXCEPT the __________.
bloodstream
A chill is a sign that
body temperature is rising.
Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by
boiling food prior to consumption.
A man found living in a rat-infested building develops a high fever and swollen lymph nodes, called buboes, in the armpit and groin. A gram-negative bacillus is isolated from the patient, and the rats are found to be infested with Xenopsylla cheopis. What is the disease?
bubonic plaque
For the introduction of a genetically modified plasmid into E. coli, __________.
calcium chloride and heat shock can be used
Activation of the complement cascade __________
can cause the infecting microbe to be killed by lysis
In E. coli, Hfr cells __________.
can pass main chromosome genes to a recipient cell
Diarrhea caused by Clostridium difficile __________.
can result in life-threatening inflammation of the colon
Which of the following does NOT contribute to the symptoms of a fungal disease?
cell walls
during the lag phase
cells are engaged in intense enzymatic activity
The current first choice of antibiotic for bacterial meningitis is __________.
cephalosporin
The diagnosis of bacterial meningitis is accomplished by performing a spinal tap (lumbar puncture) and gram staining the sample. What fluid is collected during a lumbar puncture?
cerebrospinal fluid
The diagnosis of bacterial meningitis requires a sample of __________.
cerebrospinal fluid
symptoms of disease differ from signs of disease because symptoms are
changes felt by the patients
A family of cytokines that were named for functioning to interfere with viral infections in host cells are called ___________.
chemo kines
A Thiobacilus bacterium uses the Calvin Benson cycle to reduce CO2 and the oxidation of sulfide ions for energy. This organism is a
chemoautotroph
organisms that use carbon dioxide as a carbon source and ammonia or hydrogen sulfide as energy sources are called
chemoautotrophs
Fungi are __________.
chemoheterotrophs
Which of the following is mismatched
chemotaxis chemical degradation inside a phagolysosome
an initial infection with herpesvirus varicella - zoster causes
chickenpox
Naegleria encephalitis is commonly acquired by __________.
children swimming in ponds and streams
which of the following is NOT a structure of prokaryotic cells
chloroplast
A Nigerian tourist is hospitalized with a fever and chills that occur in 48-hour cycles. A blood smear reveals circular rings within the erythrocytes. What is the treatment of choice for this patient?
chloroquine
Which of the following is the drug of choice for the treatment of malaria?
chloroquine
Which disease would be potentially propagated in an environment without functional plumbing and in which drinking water is contaminated with sewage?
cholera
The mycotoxin, aflatoxin, that is produced by Aspergillus flavus has been found in many foods, but it most associated with...
cirrhosis of the liver and cancer of the liver in India and Africa
in the capsule stain using India ink, capsules are distinguished as
clear halos
Which drug would be used to treat athlete's foot?
clotrimazole
Which enzyme is NOT produced by deep-tissue streptococcal infections?
coagulase
Which of the following is NOT a characteristic of Streptococcus?
coagulase-positive
Human herpesvirus 1 and 2 cause painful, short-lived vesicles that occur near the outer red margin of the lips that are commonly known as
cold sores or fever blisters
Give an example of contact transmission, vehicle transmission, mechanical transmission, and biological transmission.
contact transmission - direct: requires close association between the infected and a susceptible host. indirect: spreads to a host be a nonliving object called a fomite vehicle - the transmission of disease agents by a medium such as food, water, air, blood, bodily fluids mechanical - passive transport of pathogens on an insect's feet or other body parts biological - pathogen reproduces in the vector, transmitted via bites or feces
Toxoplasmosis is most commonly contracted by __________.
contact with cat feces
the nuclear area of bacterial cell
contains the bacterial chromosome
The epidermis __________
contains the protein keratin
Cell lines derived from transformed (cancerous) cells are called __________.
continuous cell lines
Which method is best for controlling African trypanosomiasis?
control the vector
all of the following are required for generation of ATP by chemiosis EXCEPT
conversion of pyruvic acid to lactic acid
Two bacteria with the same percentage of guanine plus cytosine __________.
could be related
an exposure to ___ protects against infection with smallpox
cowpox
Which of the following begins as a lung infection but may cause meningitis in immunosuppressed individuals?
cryptococcosis
Which of the following would be the most appropriate way of testing whether a skin lesion is caused by a dermatophyte?
culture scrapings of the lesion periphery on Sabouraud's agar
Recombinant DNA technology is used for all of the following EXCEPT ________.
culturing unknown organisms
The ID50 for cutaneous anthrax due to Bacillus anthracis is 10 to 50 endospores, while the ID50 for inhalation anthrax is 10,000 to 20,000 endospores. This means that __________.
cutaneous anthrax is easier to acquire than inhalation anthrax
Most naturally occurring anthrax infections are __________.
cutaneous infections from endospore entry at a skin lesion
Which of the following is NOT a disease of the reproductive system?
cystitis
Which of the following pairs is NOT a correct match?
cystitis; inflammation of urethra
Superantigens produce intense immune responses by stimulating lymphocytes to produce
cytokines.
Symptoms of delayed cell-mediated reactions are due to
cytokines.
Marburg, Lassa, and ebola viruses cause...
death
the table shows the ID50 for Staphylococcus aureus in wounds with and without the administration of ampicillin before surgery. Based on the data, the administration of ampicillin before surgery
decreases the risk of staphylococcal infection.
A 34-year-old Caucasian male is being examined in the emergency room of a Boston hospital, complaining of a high fever and severe muscle pain and joint pain. He returned to Boston two days ago, after spending 10 days traveling throughout Brazil on business. He indicated that he was bitten by mosquitoes several times while on the trip. Which of the following is the most likely diagnosis?
dengue fever
A type of biofilm that is intimately involved in dental caries is called...
dental plaque
The genus ____________ is associated with ringworm and athlete's foot.
dermatomycoses, tinea?
Direct fluorescent-antibody techniques are frequently used to __________.
detect microorganisms in a clinical sample
A key difference between classification methods and identification methods is that classification methods are designed to __________.
determine evolutionary relationships of organisms
A unicellular alga with cell walls containing pectin and silica is isolated from coastal waters. It is capable of photosynthesis and stores oil for energy. This alga is most likely a __________.
diatom
At least 50 different types of Papillomavirus cause
different kinds of warts
blood agar used to observe hemolysis or cleaning around Steptococcus pyogenes colonies is an example of
differential media
You note that the body temperature of one of your patients is starting to increase. As a result, you can infer that all of the following may be occurring in this patient EXCEPT __________.
dilation of blood vessels
Saxitoxin is produced by __________.
dinoflagellates
Part of the normal immunization program in the United States is an immunization that protects children against three different diseases called DTaP. Which three diseases are encompassed in the DTaP vaccine?
diphtheria, tetanus, and pertussis
The DTaP immunization is for __________.
diphtheria, tetanus, and pertussis
Which of the following is a test to determine a patient's blood type by mixing the patient's red blood cells with antisera?
direct agglutination reaction
all of the following methods are used for food preservation EXCEPT
direct flaming
You are an epidemiologist studying an emerging disease reported over the past three years in Wisconsin, Minnesota, and Michigan. You have noticed a seasonal pattern of disease, with new cases appearing in late April through September and peaking in July. No new cases appear during late fall or the winter months. This pattern is suggestive of __________.
disease transmission by an arthropod vector, such as a mosquito or tick
correct order
domain, kingdom, phylum, class, order, family, genus, species
Severe diarrhea accompanied by blood or mucus in the stool is called..
dysentery
Some microbes are very resistant to antimicrobial chemicals. Which of the following would be the easiest to kill?
e coli
The symptoms of schistosomiasis are due primarily to __________.
eggs deposited by adult worms in host tissue
One remarkable finding on a patient's laboratory workup is a marked eosinophilia. This might be suggestive of __________.
either a parasitic infection or an allergic (hypersensitivity) reaction
Members of the Kingdom Fungi are __________.
either unicellular or multicellular
Which type of microscope is needed to view a virus in the laboratory?
electron
a coenzyme assists an enzyme by accepting or donating matter. What does NAD+ transfer?
electrons
All of the following steps are involved in the aerobic electron transport chain. Which step happens last
electrons are transferred to O2
What is the best way to control West Nile encephalitis?
eliminate the vector
increased human exposure to new and unusual infectious agents in areas that are undegoing ecologic changes accounts for the
emergance of new infectuous disease
A rash on mucus membranes, such as the interior of the mouth, is called
enanthem
Malaria is an infectious disease caused by infection with a protozoan. In certain tropical regions, malaria is constantly present. We would say that malaria is a(n) __________ disease in these regions.
endemic
Inflammation of the sac around the heart is called...
endocarditis
Which structure is NOT found in cestodes?
endospores
Patients developed inflammation a few hours following eye surgery. Instruments and solutions were sterile, and the Limulus assay was positive. The patients' inflammation was due to
endotoxin
Which type of bacterial enzyme helps spread Streptococcus pyogenes by digesting blood clots?
fibrinolysin
What cell structures does Neisseria gonorrhoeae use to attach and enter host epithelial cells?
fimbriae
which of the following are NOT major targets for action of anitmicrobials
flegella
microscopy that identifies pathogens
flourescnese
Which of these methods can identify bacteria in a sample without culturing the bacteria?
flow cytometry and fluorescent in situ hybridization (FISH)
The general term for any nonliving object involved in the spread of infection is called a __________.
fomite
Some members of the genus Rhizobium are notable for their ability to __________.
form nodules in plant roots that allow nitrogen fixation
The frequency of influenza epidemics is associated with the __________
frequency of mutations in viral genes for envelope spikes
Why are fully human antibodies preferred over murine antibodies?
fully human antibodies do not cause unwanted immune responses
proteins DO NOT
function in genteic inheritence
A new soil microorganism has been described. On some growth media, it forms colonies of unicellular organisms, but under certain conditions it forms long, multicellular filaments and spores. The cells have nuclei, and their cell walls are composed of chitin. To which of the following groups does this new organism belong?
fungi
Meningitis can be caused by Cryptococcus neoformans. What type of pathogen is C. neoformans?
fungi
Tetracyclines are effective against all of the following EXCEPT __________.
fungi
Ringworm is caused by a/an __________.
fungus
You contaminate the kitchen counters with Salmonella enterica in chicken blood and expose it to a variety of treatments to study the survival of the bacteria on kitchen surfaces. The following DRT values were obtained: 2.0 minutes at 52°C; 3.7 minutes at pH 2.6; 13.3 minutes with 10 mM hydrogen peroxide; and > 35 days without treatment. Which treatment is most effective against S. enterica?
heat (52C)
which steps are common to gram stain and acid fast stain
heat fixation
Streptococci secrete virulence factors that destroy RBCs. These virulence factors are called
hemolysins
Which type of hepatitis kills more people than AIDS in the United States and is known as the "silent epidemic" since recognizable symptoms do not occur until about twenty years after initial infection?
hep c
An open cut on a dental hygienist's hand is exposed to blood from a patient's mouth. All of the following are potentially bloodborne pathogens to which she may have been exposed EXCEPT __________.
hepatitis A
Some gastrointestinal diseases are diagnosed using a culture, others by direct antigen detection methods, and still others by measuring a specific IgM titer. Which of the following diseases is detected by doing an IgM titer?
hepatitis A
Which of the following pairs is NOT a correct match?
hepatitis A; chronic form of hepatitis
A patient has an STI characterized by sporadically recurring, painful, fluid-filled blisters in the genital area. A Gram stain and bacterial culture indicate the presence of normal bacterial microbiota. What is the most likely etiologic agent?
herpes simplex (HSV)
one of the sites of allosteric regulation of the Krebs cycle is the conversion of pyruvic acid to acetyl CoA. Which of the following conditions would you expect to inhibit the converstion of pyruvic acid to acetyl CoA?
high ATP and high NADH
Which of the following contains an INCORRECT match?
hookworm, incomplete digestive system
The only known host of a pork tapeworm is a/an __________.
human
A 24-year-old woman in Minnesota complained of a flulike illness accompanied by a high fever and headache a week after being bitten by a tick. During examination of a blood smear, it was noted that some of her monocytes contained clumps of tiny bacteria (morulae). What is the most likely diagnosis?
human granulocytic anaplasmosis
What virus has a clear association with Burkett's lymphoma and causes almost all cases of infectious mononucleosis?
human herpevirus 4, EB virus
Measles can potentially be eradicated because __________.
humans are the only reservoir, and vaccination is effective
which of the following terms are mismatched
hyperthermophiles, 0C
A 10-month-old infant has become constipated and demonstrates muscular weakness by her inability to sit up or crawl. Her muscle tone is continuing to deteriorate, and she is beginning to have difficulty holding her head up. While questioning her mother to get more information, the doctor noted that the infant's cereal had been sweetened with honey for the last 10 days. What is a likely diagnosis?
infant botulism
Four days after playing in the wading pool at a neighborhood park, several 3- and 4-year-old children experienced abdominal cramping and watery diarrhea. Upon microscopically examining the children's stools with an acid-fast stain, doctors found red, cyst-like structures about 10 microns in diameter. What is the most likely diagnosis?
infection with Cryptosporidium spp.
Tularemia can be contracted by humans by all of the following methods EXCEPT __________.
infection with Epstein-Barr virus
Haemophilus influenzae can cause all of the following respiratory infections EXCEPT __________.
influenza
The small roundworm, Trichinella spiralis, causes the infection trichinellosis. What is the most common way that to become infected with this worm?
ingesting undercooked pork
Anthrax is caused by the endospore-forming bacteria,Bacillus anthracis. The most dangerous form of anthrax in humans is...
inhalational (pulmonary) anthrax
Which of the following mechanisms is antifungal?
inhibit ergosterol synthesis
The antimicrobial effects of AMPs include all of the following EXCEPT
inhibition of phagocytosis
Treatment for rabies exposure requires __________.
injections of antirabies vaccine and immune globulin
For Agrobacterium tumefaciens to be used to introduce foreign DNA into a plant cell, that DNA must first be __________.
inserted into the T-DNA region of the Ti plasmid of A. tumefaciens
Polyphosphate (volutin), carboxysomes, and magnetosomes are examples of
insulin bodies
H bonds are important in the formation of
interactions between complex molecules, such as nucleic acids and proteins
Enteric bacteria would most likely be found in which environment?
intestinal tract of an animal
Cell-mediated immunity in part protects against __________.
intracellular bacteria and viruses
Siderophores are bacterial proteins that compete with the host's
iron-transport proteins
Bacillary dysentery __________.
is caused by members of the Shigella genus
Innate immunity
is nonspecific and present at birth.
The chemical 5-bromouracil is a mutagen because it __________.
is similar to thymine in structure but not base-pairing ability
PVR ____
is useful as a step that may precede DNA fingerprinting or DNA sequencing
Which antimicrobial works by inhibiting the synthesis of mycolic acid?
isoniazid
which of the following is NOT true of gram negative outer membrane
it contains enzymes for energy synthesis
the plasma membrane is consdiered a barrier to the enviroment because
it controls the passage of molecules into the cell
How can lysogeny turn the normally harmless E. coli into a pathogen?
lysogency - delivery of genes by a virus It can undergo lysogenic conversion, change in the characteristics of the microbe due to a prophage (DNA of bacteriophage incorporated into bacterial chromosome); bacteria immune to infection by same phage and prophage can cause pathogenesis
Lichens __________.
made of a fungus and a photosynthetic partner
Which of the following is NOT a step in identification of bacteria by DNA probes?
making the probe double stranded
The lectin pathway for complement action is initiated by
mannose on the surface of microbes.
A commensal bacterium
may also be an opportunistic pathogen
Lesions of the oral cavity called Koplik's spots are a diagnostic indicator of which viral disease?
measels
All of the following are methods of avoiding host antibodies EXCEPT
membrane-disrupting toxins.
bacteria growing in and on the human body, including normal microbacteria as well as pathogens, are classified as
mesophilic and heterotrophic
Which of the following is NOT an example of microbial antagonism (also known as competitive exclusion)?
microbes producing vitamins and growth factors that can be utilized by the host
The ID50 for many pathogens is significantly smaller when testing with gnotobiotic animals compared to animals with normal microbiota. This is likely because of __________.
microbial antagonism
The major significance of Koch's work is that
microorganisms cause disease
which of the following is NOT a chemical requirement of all bacteria
molecular oxygen
properties true of bacteria and viruses
molecules of nucleic acids determine heredity
Palivizumab is used to treat respiratory syncytial virus disease. This antiviral drug is a(n)
monoclonal antibody.
In the human intestinal tract, E. coli produces vitamins beneficial to the host and can inhibit pathogen growth. In turn, the bacterium is supplied with nutrients and an environment for growth. This symbiotic relationship between E. coli and its host is an example of __________.
mutualism
When a disease develops it follows a certain sequence of steps. During the period of illness various disease symptoms can occur such as myalgia, pharyngitis, photophobia, and lymphadenopathy.What is the common term for each of the stated symptoms?
myalgia - muscle pain pharyngitis - sore throat lymphadenopathy - enlargement of the lymph nodes
A microbiologist cultures bacteria from throat swabs and sputum from a patient who he suspects has a certain atypical pneumonia. After the appropriate incubation time, very small "fried-egg"-looking colonies are observed growing on the media. What type of pneumonia does the patient most likely have?
mycoplasmal
Influenza viruses are classified according to their hemagglutin and __________ proteins.
neuraminidase
Which drug is NOT a nucleoside analog?
nevirapine
Following coronary artery bypass surgery, seven patients develop Rhodococcus bronchialis infections. Cultures of the operating rooms, Nurse A, and Nurse B are taken. R. bronchialis grows from the hand and nasal swabs of Nurse A. The patients' infections are an example of a/an __________.
nosocomial infection
Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a
nosocomial infection
Health care professionals who fail to use aseptic techniques can cause __________.
nosocomial infections
Healthcare-associated infections are traditionally known as...
nosocomial infections
Which of the following contributes to the virulence of a pathogen?
numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production
Which method cannot be used to culture viruses in a laboratory?
nutrient agar culture media
An ampicillin-sensitive culture of E. coli is transformed with a plasmid that contains the gene of interest plus an ampicillin-resistant gene. If it is then plated on an ampicillin-containing growth medium, __________.
only the bacteria with the plasmid will grow
A mother infected with gonorrhea has transmitted the disease to her infant as he passed through the birth canal. This infection in the infant is called __________.
ophthalmia neonatorum
niacin, when added to a medium, would be considered a
organic growth factor
Which of the following is used for treating influenza infections?
oseltamivir
NADH molecules formed during glycolysis and in the Krebs cycle are
oxidized when electrons are passed to the electron transport chain
Warts are generally caused by __________.
papillomavirus
If a patient has a deep tissue infection as the result of an animal bite on the arm, the portal of entry is described as the __________.
parenteral route
The mumps virus mainly targets which salivary glands?
parotid
Very few individuals will survive a rabies infection once rabies symptoms appear, so it is imperative to begin treatment immediately. One part of the treatment regime is to inject human rabies immune globulin harvested from people who are immunized against rabies. What type of immunity would be acquired by this method of treatment?
passive
A number of skin infections caused by MRSA (methicillin-resistant Staphylococcus aureus) were detected among members of the wrestling teams of several local high schools. Which of the following methods might demonstrate whether these infections are caused by the same bacterial strain?
phage typing
a eukaryotic cell can ingest a prokaryotic cell by
phagocytosis
A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes?
phagocytosis in the inflammatory response
microscopy that views internal structures
phase contrast
which organism is NOT correctly matched to its energy source
photoautotroph; CO2
which of the following is NOT functionally analogous pair
pili, centrioles
Enterobius vermicularisis commonly known as the...
pinworms
Which of these cell types is NOT involved in cell-mediated immunity?
plasma cells
Which of the following is an example of a cloning vector?
plasmid
What organic molecules are R-factors?
plasmids
A severe complication of bronchitis that involves the pulmonary alveoli is called...
pneumonia
Which disease is correctly matched with the common portal of entry?
poliomyelitis; mucous membranes of gastrointestinal tract
Recombinant DNA can be introduced into a host cell by any of the following methods EXCEPT __________.
polymerase chain reaction
Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed,
polypeptide B would not be able to enter the cells.
Which antifungal drug was recently introduced to treat systemic fungal infections?
posaconazole
the ___ charge of basic dye adheres to the ___ charge of bacterial surfaces
positive, negative
You are preparing a medium for growing fastidious bacteria and must add several heat-labile solutions of growth factors. Which of the following is an appropriate strategy for preparing and sterilizing this medium?
prepare and autoclave the medium before adding the growth factors
a clear oval in gram stain procedure in center of cell indicates
presence of endospores
When the antibiotic chloramphenicol binds to the 50S portion of the ribosome, the effect is to __________.
prevent the ribosome from moving along the mRNA strand
the __ structure of proteins is the unique sequence of amino acids linked together
primary
A _____________ infection is an acute infection that causes the initial illness while a ___________ infection is caused by an opportunistic pathogen after the initial infection has weakened the body's defenses.
primary infection, secondary infection
Kuru, spongiform bovine encephalitis, and Creutzfeldt-Jakob Disease are all caused by which type of pathogen?
prion
which of the folloing is LEAST likely to be damaged by exposure to gamma radiation
prions
which of the following infectious agents challenge the current sterilization strategies that have been accepted and in use for decades
prions
How might a virus pick up a human oncogene?
specialized transduction
Which of the following processes is involved in the production of diphtheria toxin by C. diphtheria or erythrogenic toxin by Streptococcus pyogenes?
specialized transduction
A new microorganism has been discovered that resides in the mouths of dogs. This microorganism lacks a nucleus, has a cell wall consisting of peptidoglycan and an outer membrane of lipopolysaccharide, is shaped like a corkscrew, and is motile by means of an axial filament. This organism is most likely related to __________.
spirochaetes
Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that
streptococcal colonization is necessary for periodontal disease.
Which group A streptococci is the most common cause of puerperal sepsis?
streptococcus pyogenes
Sporotrichosis is the most common type of __________.
subcutaneous mycoses
A vaccine against HIV proteins made by a genetically-engineered vaccinia virus that has infected a eukaryotic cell line is a(n)
subunit vaccine.
Purified protein from Bordetella pertussis is used in a(n)
subunit vaccine.
Which of the following antibiotics inhibits folic acid synthesis?
sulfanilamide
Symptoms of intense inflammation and shock occur in some gram-positive bacterial infections due to
superantigens
Which of the following is NOT associated with Candida albicans?
susceptibility to penicillin
Both transcription and DNA replication involve __________.
synthesis using a DNA template
Infections in which the pathogen is distributed throughout the body are referred to as generalized infections or __________.
systemic infections
all of the following are true of the plate count method EXCEPT that it
takes less than 12 hours to complete
What vector spreads the etiological agent of African Trypansomiasis?
teste fly
The symptoms of tetanus are caused by an extremely potent neurotoxin called
tetanoplasmin
Which of the following is NOT a communicable disease?
tetanus
Which of these diseases does not have a human reservoir?
tetanus
A migrant farmworker has been brought into the emergency room showing early symptoms of tetanus. He indicates that he had received a puncture wound in his hand a week before the onset of symptoms. When asked about vaccination or booster, he did not know whether he had ever been vaccinated. Which of the following should be administered to the patient as soon as possible?
tetanus immune globulin
Which of these conditions would NOT affect the ability of Streptococcus mutans to attach to teeth?
the absence of Actinomyces, a bacterium that can be part of dental plaque
what do all of these bacteria have in common
the bacteria are most likely growing in biofilms
The most important element in the pathogenicity of S. pneumoniae is __________.
the capsule
what will occur if a bacterial cell with a weakened or damaged cell wall is placed in pure water
the cell will swell and burst
Assume you are growing a bacterial culture in a glucose medium. Your lab partner adds more glucose in hopes of speeding up the experiment. The bacteria suddenly die. The best explanation for this result is that
the cells plasmolyzed
Members of the Adenoviridae cause __________.
the common cold
You are reviewing the following results of a disk- diffusion antibiotic susceptibility test on an isolate of Staphylococcus aureus: Antibiotic A: ZI (zone of inhibition) = 0 millimeters Antibiotic B: ZI = 23 millimeters Antibiotic C: ZI = 16 millimeters Antibiotic D: ZI = 19 millimeters
the correct answer cannot be determined
Botox has both therapeutic and cosmetic uses. What is Botox?
the deadly toxin of botulism
The ID50 is
the dose that will cause an infection in 50 percent of the test population.
the usefullness of antibiotics is hampered by
the emergance of antibiotic- resistant bacteria
The respiratory system is protected against harmful microbes by all of the following EXCEPT __________.
the lacrimal apparatus
Pasteurized milk in an unopened container spoils in the refrigerator. A sample reveals the presence of microorganisms. The most likely explanation is
the mircrobes that survived pasteurization were able to grow at 4C
Genetic technology has enabled screening for a variety of genetic conditions, and use of this technology is becoming more widely available. Which of the following is likely to become an important issue that will need to be addressed?
the need for legislation to protect the privacy of individuals' genetic information
The morbidity rate is best defined as __________.
the number of individuals, relative to the population, affected by a particular disease in a period of time
A differential cell count is used to determine each of the following EXCEPT
the number of red blood cells.
What causes the visible precipitation seen in a positive precipitin ring test?
the optimal ratio of antigen to antibody has been reached (the zone of equivalence)
Define diapedesis
the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation.
You observe large ( >10 micrometer) oval cells in a sputum sample from a patient. Your culture of the sample reveals fuzzy filamentous colonies. You conclude that __________.
the patient has an infection caused by a dimorphic fungus
Complement can be activated by all of the following EXCEPT __________.
the presence of host tissue
Which of the following is a xenotransplantation product?
the replacement of a human's heart valve with a pig's heart valve
In the lac operon of E. coli, __________.
the repressor protein binds to the operator in the absence of lactose
which of these is NOT a characteristic of the autclave
the requirement for long( hours) exposure times
For the amino acid aspartic acid (asp), __________.
the sequence of the DNA template would be CTG
Not true for both TEM and SEM
the speciman must be sectioned before viewing
Why is the Sabin oral polio vaccine more effective than the injected Salk vaccine?
the vaccine mimics an actual infection and induces excellent, and probably long life, immunanity
You are viewing a sputum smear that has been stained with an acid-fast stain. On this smear you see 5-micrometer-long red cells. You can conclude that
there are aicd fast bacteria in the specimen
An effective vaccine does NOT exist for the common cold, because __________.
there are likely over 200 agents that cause the common cold
Consider the polypeptide sequence encoded by the following DNA. TACAAAGAAATT If base number 6 is changed to G, how will this affect the polypeptide?
there will be no change
HIV selectively destroys CD4 cells and as a result, a person with AIDS is susceptible to life-threatening viral infections. Knowing this, you can conclude that __________.
these viruses have T-dependent antigens
All of the following statements are true of yeasts EXCEPT that __________.
they always cause disease
All of the following are part of the mechanism of action of alpha and beta interferons EXCEPT
they are effective for long periods.
Which statement is true of endotoxins?
they are released upon cell lysis
All of the following statements are true of the fungi EXCEPT that ________.
they are strict aerobes
Subunit vaccines tend to be safer than whole-cell vaccines because __________.
they cannot reproduce in the host
All of the following are true regarding NK cells EXCEPT
they destroy infected body cells by phagocytosis.
Symptoms of protozoan and helminthic diseases are due to
tissue damage due to growth of the parasite on the tissues, waste products excreted by the parasite, and products released from damaged tissues.
Western blotting is best used for which of the following?
to detect a specific protein in a mixture
the ames test is used ____
to determine if a chemical is mutagenic and possibly carcinogenic
In which of the following cases would the Limulus amebocyte lysate (LAL) assay be used?
to ensure that a sterilized medical device is free of endotoxin
Which of the following is NOT a purpose of genetic modification?
to remove antibiotic resistant plasmids from bacteria
Septic shock is most often caused by gram-negative bacteria due to a toxic substance in their cell wall that contains endotoxins that are released upon cell lysis. What is the toxic cell wall substance called? NOTE: The most common cause of sepsis is gram positive bacteria, whereas septic shock is mainly caused by gram negative bacteria.
toxic lipopolysaccharides
Nonpathogenic Vibrio cholerae can acquire the cholera toxin gene by
transduction
Your lab partner has mixed a dead tryptophan+ strain of Bacillus subtilis with a live tryptophan- strain and observes that her B. subtilis culture is now tryptophan+. The most likely explanation for this is __________.
transformation
_____ is a compound found in antimicrobial soaps that targets gramp positive bacteirs
triclosan