Final Lecture Exam - Micro

Emergence of infectious diseases can be caused by a variety of factors. Which factor listed below is related to human behavior? A. Mutations in microbes B. Earthquakes C. lack of vaccination D. Floods

C

Given the following LD50 values for Bacillus anthraces, through which portal of entry is it easiest to get anthrax? A. Inhalation; 20,000 endospores B. Ingestion; 1 million endospores C. Cutaneous; 50 endospores D. All of the listed choices are equally easy portals of entry

C

During the __________, a person recovers from a disease and the body returns to its pre-disease state. A. period of incubation B. period of convalescence C. period of illness D. period of decline

B

Capsules play a role in all of the following EXCEPT ___. A. Bacillus anthracis B. Klebsiella pneumoniae C. Mycobacterium tuberculosis D. Yersinia pestis E. Haemophilus influenzae

C

Ehrlichiosis is transmitted by ticks. This is an example of __________. A. vehicle transmission B. airborne transmission C. vector transmission D. indirect contact transmission

C

Saxitoxin is produced by ________. A. helminths B. protozoa C. fungi D. bacteria E. dinoflagellates

E

A disease that is constantly present in a population is called a(n) ___. A. endemic disease B. reportable disease C. epidemic disease D. communicable disease

A

Health care professionals who fail to use aseptic techniques can cause ___. A. nosocomial infections B. zoonoses C. predisposing factors D. herd immunity E. pathogens

A

Hepatitis B virus is only transmitted by a finger-stick device enters the host via which portal of entry? A. parenteral B. skin C. adherence D. mucous membrane

A

Infections in which the pathogen is distributed throughout the body are referred to as generalized infections or ___. A. systemic infections B. focal infections C. local infections D. emerging infections E. zoonoses

A

The morbidity rate is best defined as __________. A. the number of individuals, relative to the population, affected by a particular disease in a period of time B. the percentage of infectious diseases that are nationally notifiable C. the immunization rate for notifiable diseases that can be prevented through vaccination programs D. the decrease in death rate following effective vaccination

A

The protection from infection received when individuals susceptible to a particular disease live in a population where many individuals are immune is referred to as ___. A. herd immunity B. vaccination C. disease prevention D. latent immunity

A

The scum that builds up on shower doors, the formation of dental plaque on teeth, and the algae growth on the walls of swimming pools are all examples of _______. A. biofilms B. glycocalyces C. fimbriae D. capsules

A

What is the difference between normal and transient microbiota? A. Normal microbiota are permanently present B. Normal microbiota are opportunistic pathogens C. Normal microbiota cause disease D. Normal microbiota are on the human body

A

What is the general term for observable changes in cells that occur as a result of viral infection? A. Cytopathic effects B. Transformation bodies C. Syncytium D. Inclusion bodies

A

Which of the following body sites typically does NOT have normal microbiota? A. Kidney B. Nasopharynx C. Skin D. Vagina

A

Which of the following cell wall components do/does NOT contribute to virulence? A. All of the listed choices contribute to virulence B. M protein C. fimbriae D. Opa E. mycolic acids

A

Which of the following is NOT a notifiable infectious disease? A. Pneumonia B. Pertussis C. Salmonellosis D. Botulism

A

Which of the following is NOT considered an EID? A. These are all considered EIDs B. Avian influenza C. West Nile Encephalitis D. Chikungunya E. Methicillin-resistant Staphylococcus aureus

A

Which of the following is an accurate statement about A-B toxins? A. They are proteins B. They are a type of endotoxin C. The A component binds to a receptor on the host cell D. The A and B components must remain attached in order to exert their effects on the cell

A

Which of the following is the third stage of a disease? A. Period of illness B. Prodromal period C. Incubation period D. Period of Decline E. Period of convalescence

A

Which of the following organisms is NOT discharged through the respiratory tract? A. Poliovirus B. Bordetella pertussis C. Measles virus D. Histoplasma capsulatum

A

Which of these effects is most likely to occur if a pathogen enters the body by a portal of entry other than the preferred one? A. A milder disease will result B. A more severe disease will result. C. A different disease of the same severity will result Pathogens D. cannot enter by alternate routes.

A

Which of these events leads to all of the others in a pyrogenic (fever) response? A. Endotoxin is released from the cell wall of gram-negative bacteria B. Il-1 is released by macrophages C. Il-1 travels via the blood to the hypothalamus D. The hypothalamus releases prostaglandins E. The body's thermostat is set to a higher level, and fever occurs

A

Which of these statements about toxoids is INCORRECT? A. Gram-negative septic shock is commonly prevented by toxoids B. Toxoids stimulate the body to produce antitoxins without causing disease C. Diphtheria and tetanus can be prevented by toxoid vaccinations D. Exotoxins can be altered by heat or chemicals to form toxoids

A

Which of these substances does NOT protect a bacterium from phagocytosis? A. Siderophore B. Capsule C. Leukocidin E. M protein

A

Which one of these is NOT an example of pathogen entry via the parenteral route? A. infection of a hair follicle B. Entry through a break in the skin caused by a cut C. Injection of the pathogen via a contaminated needle D. Injection via the bite of an infected insect

A

Which type of nosocomial infection is the most common? A. surgical site infections B. gastrointestinal infections C. bloodstream infections D. urinary tract infections

A

All members of the seven families for whom Mary Mallon prepared meals developed typhoid fever. Mary did not get sick. This is an example of __________. A. a nosocomial infection B. a carrier C. sporadic disease D. an opportunistic infection

B

An example of descriptive epidemiology is __________. A. Florence Nightingale's studies of disease transmission in soldiers and civilians during the Crimean War B. John Snow's study of the London cholera outbreak from 1848 to 1849 C. a study comparing disease rates in vaccinated and unvaccinated individuals D. the first report of a disease occurrence E. a comparison of drug effectiveness in two groups of patients

B

Consider the following five infectious diseases: Ebola hemorrhagic fever avain influenza SARS West Nile encephalitis mad cow disease What do these diseases have in common? A. they are all transmitted by arthropod vectors B. they are all emerging infectious diseases C. they are all caused by viruses D. they all exhibit airborne transmission

B

Florence Nightingale compared disease rates and other statistics for soldiers versus civilian populations. This is an example of ___. A. case reporting B. analytical epidemiology C. controlled experimentation D. descriptive epidemiology

B

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? A. Normal microbiota provide supplemental nutrition to the host B. Normal microbiota stimulate the development of the immune system C. Normal microbiota are parasitic D. Normal microbiota are incapable of causing disease E. Normal microbiota always result in opportunistic infections.

B

In order to understand the full scope of a disease, we take its occurrence into account. The ___ of a disease is the number of people in a population who develop a disease at a specified time. A. incidence B. prevalence C. sporadic infection D. endemic infection

B

Koch's postulates are a set of guidelines to follow if you want to ___. A. determine how a disease is transmitted B. prove that a specific infectious disease is caused by a specific microorganism C. cure a disease D. identify the reservoir for a disease

B

Some organisms are capable of orchestrating alterations that are collectively termed antigenic variation. This allows an organism to ____. A. enter the host's body through more than one portal of entry B. evade the host's immune system C. drastically decrease its ID50 D. rapidly move through the host's tissues

B

Toxins that stimulate proliferation of T cells non-specifically and provoke intense immune responses are called _________. A. exotoxins B. superantigens C. endotoxins D. A-B toxins

B

Which of the following are possible locations for bacterial adhesins? A. Fimbriae B. All of the listed choices are possible locations for bacterial adhesions C. Flagella D. Pili

B

Which of the following diseases CANNOT be prevented by toxoids? A. Diphtheria B. Gram-negative septic shock C. Botulism D. Tetanus

B

Which of the following is NOT an example of microbial antagonism (also known as competitive exclusion)? A. Microbes producing acidic compounds that limit the growth of many bacteria B. Microbes producing vitamins and growth factors that can be utilized by the host C. Microbes competing with other microbes for nutrients D. Microbes producing compounds inhibitory to other microbes E. Microbes utilizing oxygen necessary for the growth of other microbes

B

Which of the following is part of a plan established by the CDC, NIH, and WHO to address and prioritize issues relating to EIDs? A. Detect infectious pathogens, the diseases they cause, and factors that influence their emergence B. These are all part of the plan related to EIDs. C. Expand basic and applied research on ecological and environmental factors that influence EIDs D. Enhance the communication of public health information and the prompt implementation of prevention strategies regarding EIDs E. Establish plans to monitor and control EIDs worldwide

B

Which of the following organisms does NOT enter through the gastrointestinal tract? A. Hepatitis A virus B. Rubella virus C. Trichinella spiralis D. Vibrio cholera

B

Which of the following pathogens does NOT belong with the others? A. Hantavirus B. Measles virus C. Brucella D. Yersinia pestis

B

Which of the following statements is NOT true of A-B exotoxins? A. They consist of two polypeptide components B. They are produced only by gram-negative bacteria C. The A portion of the toxin is the active component D. The B portion of the toxin binds to surface receptors on host cells E. Many exotoxins are A-B toxins

B

Which of these is a cell wall component that contributes to invasiveness? A. endotoxin B. M protein C. hemolysin D. coagulase

B

Which of these organisms does NOT produce an enterotoxin? A. Staphylococcus aureus B. Clostridium botulinum C. Vibrio cholerae D. Shigella spp.

B

Which of these statements is NOT true for bacterial capsules? A. Capsules related to virulence are produced by the causative agents of anthrax and bubonic plague B. Immune system antibodies are not produced against a capsule C. Pathogenic and nonpathogenic bacteria can produce capsules D. The importance of the capsule to virulence for Streptococcus pneumoniae can be determined because there are strains both with and without the capsule E. For Streptococcus pneumoniae, the encapsulated strain is more virulent

B

Which of these substances are most important in the establishment of biofilms? A. Siderophores B. Adhesins C. Invasins D. Exotoxins E. Hemolysis

B

___ are molecules on bacterial cell surfaces that enable them to adhere to the surface of host cells. A. Coagulases B. Adhesins C. Invasins D. Siderophores

B

Alfalfa sprouts were responsible for transmitting Salmonella to 32 people in four states. This is an example of __________. A. contact transmission B. droplet transmission C. vehicle transmission D. indirect contact transmission

C

An infection that does NOT cause any signs of disease is a(n) ___. A. endemic infection B. secondary infection C. subclinical infection D. sporadic infection

C

Based on the following LD50 values, which microbe is the most virulent? Assume each bacterium enters through the appropriate portal of entry. Cryptosporidium; 50 cells E. col O157; 1000 cells Shigella; 10 cells Vibrio cholera; 10^8 cells

C

John Snow analyzed information about cholera victims, including where the victims lived and where they got water. This is an example of __________. A. analytical epidemiology B. case reporting C. descriptive epidemiology D. controlled experimentation

C

P. aeruginosa and other gram-negative bacteria tend to be difficult to control with antibiotics because of their __________, which carry genes that determine resistance to antibiotics. A. genomes B. F factors C. R factors D. DNA

C

The presence of bacteria in the bloodstream is referred to as ___. A. cytokine storm B. symbiosis C. bacteremia D. edema E. bacterial dimorphism

C

The release of endotoxins as bacteria are destroyed by phagocytes causes the phagocytes to release tumor necrosis factor (TNF) the life-threatening loss of blood pressure occuring due to the action of TNF is called __________. A. toxoids B. exotoxic shock C. endotoxic shock D. toxic shock syndrome

C

Which of the following best defines the term pathology? Etiology The invasion and colonization of a host by a microorganism The structural and functional changes in an individual that are brought about by disease Pathogenesis

C

Which of the following events does NOT occur in diseases transmitted by vectors? A. In biological transmission, a vector transmits pathogens by defecating while taking a blood meal B. In biological transmission, pathogens multiply in the vector, which can transmit the pathogens by injecting saliva directly into the host C. In biological transmission, the vector multiplies in the human host D. In mechanical transmission, insects contact feces containing pathogenic bacteria and transfer it to food E. In biological transmission, vectors can spread pathogens by vomiting

C

Which of the following is NOT a predisposing factor of disease? A. Lifestyle B. Occupation C. All of the listed choices can be predisposing factors of disease D. Gender E. Climate

C

Which of the following virulence factors is specifically involved in helping an organism to physically spread throughout the body? A. hemolysin B. siderophores C. hyaluronidase D. endotoxins

C

Which one of these bacterial proteins can take iron from human lactoferrin? A. Protease B. Kinase C. Siderophore D. Hyaluronidase

C

Which one of these substances would NOT be produced at the same time as coagulase? A. Fimbriae B. Hemolysin C. Fibrinolysin D. Capsules

C

Which statement is true of endotoxins? A. They are produced by gram-positive bacteria B. They increase blood pressure C. They are released upon cell lysis D. They are disease specific E. They are proteins

C

Which would be the most UNLIKELY location to find adhesion molecules on a newly discovered bacterium? A. Glycocalyx B. Fimbriae C. Ribosomes D. Cell Wall E. Capsule

C

You conduct a Limulus amebocyte lysate (LAL) assay on a sample of fluid that should be sterile. The result is positive. What does this indicate? A. the fluid is not sterile B. gram-negative bacteria is growing C. endotoxin is present D. gram-positive bacteria are growing in the sample

C

___ are toxins modified to retain their ability to induce antibody formation but lose their toxicity. A. Exotoxins B. Superantigens C. Toxoids D. Endotoxins

C

___ pathogens are those that do NOT cause disease in their normal habitat but may do so in a different environment. A. Nosocomial B. Resident C. Opportunistic D. Transient

C

The LD50 of Vibrio cholerae is 10^8 cells through the oral route. If the bacterial cells are ingested with bicarbonate, the LD50 drops to 10^4. Which of these explanations is the most likely? A. Stomach acid increases the virulence of Vibrio cholerae B. Sodium bicarbonate decreases the virulence of Vibrio cholerae C. Sodium bicarbonate inactivates Vibrio cholerae D. Stomach acid decreases the virulence of Vibrio cholera E. Vibrio cholera makes toxins only in the presence of stomach acid

D

The fungus Coccidioides immitis is found in the soil. Humans contract coccidioidomycosis by inhaling fungal spores. Which of these terms applies to the role of soil in transmission of coccidioidomycosis? A. Soil is the vector B. Soil is the predisposing factor C. Soil is the carrier D. Soil is the reservoir

D

The pathogenicity of which of the following is NOT the result of lysogeny? A. Clostridium botulinum B. Corynebacterium diphtheriae C. Vibrio cholerae D. Clostridium tetani E. Streptococcus pyogenes

D

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 __________. A. epidemic infection B. emerging infectious disease C. endemic infection D. nosocomial infection E. vector-borne infection

D

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 ___. A. skin B. connective tissue C. gastrointestinal route D. parenteral route E. respiratory route

D

In a healthy human, resident microorganisms would be found in all of the following areas EXCEPT the ___. A. nasal passages B. lower urethra C. tooth and gum surfaces D. bloodstream E. conjunctiva

D

In some cases, viral infections may __________. A. cause cells to produce invasive enzymes such as hyaluronidase and collagenase B. cause cells to produce endotoxin C. cause cells to form capsules D. cause cells to lose contact inhibition

D

Microorganisms that typically colonize a host without causing disease are referred to as the _____. A. transient microbes B. pathogens C. opportunistic pathogens D. normal microbiota

D

On October 29, Barbara participated in a study group for her microbiology class. On November 1, Barbara had a "scratchy throat" when she swallowed. On November 2, Barbara had a headache, runny nose, and watery eyes. She was fully recovered on November 7. During which time was Barbara in the prodromal period? A. October 30 B. November 2 C. November 5 D. November 1

D

The ID50 for cutaneous anthrax due to Bacillus anthraces is 10 to 50 endospores, while the ID50 for inhalation anthrax is 10,000 to 20,000 endospores. This means that ____. A. inhalation anthrax is easier to acquire than cutaneous anthrax B. both cutaneous and inhalation anthrax can be easily acquired C. neither cutaneous or inhalation anthrax can be easily acquired D. cutaneous anthrax is easier to acquire than inhalation anthrax E. not enough information is available to answer this question

D

The symptoms of protozoan diseases are usually due to ________. A. endotoxins B. capsules C. exotoxins D. metabolic waste products

D

Two patients developed endophthalmitis (infection of the internal layers of the eye) within 24 hours of corneal transplant surgery. Streptococcus pneumoniae was isolated from conjunctival swabs of the affected eyes of both patients and from the supply of packing that was used to cover the eyes after surgery. This is an example of __________. A. contact transmission B. airborne transmission C. vehicle transmission D. a nosocomial infection

D

Which disease is correctly matched with the common portal of entry? A. Chlamydia; skin B. Measles; parenteral route C. Influenza; mucous membranes of genitourinary tract D. Poliomyelitis; mucous membranes of gastrointestinal tract E. Hookworm; mucous membranes of genitourinary tract

D

Which of the following is NOT necessary to satisfy Koch's postulates? A. The organism must be present in every case of the disease B. The organism must be grown in pure culture outside the diseased host C. The organism must cause the disease when introduced from pure culture into a healthy host D. The organism must cause disease through toxin production E. The organism must be re-isolated from the experimentally infected diseased animal and shown to be identical to the original isolate

D

Which of the following toxins is NOT produced by a bacterium as a result of lysogenic conversion? A. Diphtheria toxin B. Botulinum neurotoxin C. Staphylococcal enterotoxin D. Endotoxin

D

Which of these diseases does not have a human reservoir? A. HIV B. Gonorrhea C. Diphtheria D. Tetanus E. Candida albicans

D

Which of these diseases is NOT communicable? A. HIV B. Influenza C. Streptococcal sore throat D. Botulism

D

Which of these eukaryotic molecules/structures can be responsible for movement of bacteria within host cells? A. Flagella B. Cilia C. Invasins D. Actin molecules E. Pseudopods

D

Which of these events is an example of contact transmission? A. Several people become infected with Listeria after consuming contaminated ice cream B. Tuberculosis is spread from one person to another after traveling through the air for several meters C. Vacationers develop shigellosis, caused by the intestinal pathogen Shigella app. after drinking contaminated water D. A person drinking from a cup used by another individual E. A person develops plague from a flea bite

D

Which of these statements is true regarding portals of exit? A. The urinary tract is the most common portal of exit B. Polioviruses most often use the respiratory portal of exit C. The portal of exit for tuberculosis is the skin D. In most cases, a microbe uses the same portal for both entry and exit

D

Which one of these pairs is NOT correctly matched? A. leukocidin; lyses WBC membranes B. collagenase; breaks down connective tissue C. IgA protease; digest antibodies D. coagulase; lyses fibrin clots E. siderophore; traps iron

D

Which types of organisms produce the toxin responsible for paralytic shellfish poisoning? A. Protozoans B. Bacteria C. Helminths D. Algae

D

An infection transmitted by a handkerchief or tissue is transmitted by __________. A. direct contact B. common vehicle transmission C. droplet transmission D. a vector E. indirect contact

E

An infection transmitted by a hypodermic needle is transmitted by ________. A. direct contact B. common vehicle transmission C. droplet transmission D. a vector E. indirect contact

E

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 ___. A. commensalism B. parasitism C. antagonism D. opportunism E. mutualism

E

The occurrence of streptococcal bronchopneumonia in an individual recovering from influenza is an example of a ___. A. chronic infection B. latent infection C. subacute infection D. sporadic infection E. secondary infection

E

What cell structures does Neisseria gonorrhoeae use to attach and enter host epithelial cells? A. M proteins B. Cell wall waxes C. Flagella D. Capsules E. Fimbriae

E

Which of the following diseases does NOT share a commonality with the others? A. Hantavirus B. Brucella C. Yersinia pestis D. Rabies E. All of the listed choices share a commonality

E

Which of these conditions would NOT affect the ability of Streptococcus mutans to attach to teeth? The inability to form dextran The lack of a glycocalyx The lack of the enzyme glucosyltransferase The lack of sucrose E. The absence of Actinomyces, a bacterium that can be part of dental plaque

E

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? A. Prodromal period B. Period of illness C. Period of decline D. Period of convalescence E. Incubation period

E

Which of these viral cytopathic effects is most likely to be associated with the development of cancer? A. cell fusion B. stimulation of interferon production C. inclusion bodies D. cell death E. loss of contact inhibition

E

Which statement is NOT true of endotoxins? A. They can lyse amebocytes found in crab hemolymph B. Endotoxins are produced by Neisseria meningitidis and E. coli C. They are more heat-resistant than exotoxins are D. They can induce chills, fever, aches, clotting, shock, and miscarriage E. They are eliminated from the body as a result of antitoxin production

E

Women who have a healthy population of Lactobacillus spp. as part of the normal vagina microbiota are less likely to get yeast infections. Which of the following terms is used to explain this observation? A. Commensalism B. Parasitism C. Mutualism D. Synergism E. Competitive exclusion

E