Microbiology - CH 13
an individual who shelters a pathogen for a long period of time after recovery (example: Typhoid Mary)
chronic carrier
Generally speaking, organisms with higher infectious doses have
lower
The internal cavity of any structure is generally referred to as the ____________. Examples could include: the chamber inside of the small intestine or inside the endoplasmic reticulum
lumen
To successfully use the _________________ tract as a portal of entry, a pathogen must be able to withstand enzymatic attack, abrupt changes in pH, and highly acidic conditions.
gastrointestinal
Axenic strains of mammals and birds developed in the laboratory are ______.
germ free
Coliform bacteria are described as
gram-negative, lactose fermenting, and facultative anaerobes
A disease that is transferred from person to person by sexual or intimate contact is
sexually transmitted infection
If an infectious agent is ___________ during a latent infection, then the disease can be transmitted to others.
shed or released
Fomites, food, and air serve as indirect transmission routes of pathogens.
true
a biological agent that is capable of causing infection and disease in healthy persons with normal immune defenses.
true or primary pathogen
A(n) ______ disease occurs when microbes cooperate in breaking down a tissue or one microbe creates an environment that enables another microbe to invade.
polymicrobial
A pathogen is considered unsuccessful if it does not have a specific
portal of exit
A pathogen is considered unsuccessful if it does not have a specific ________.
portal of exit
The portal of entry for the largest number of pathogens is the ______.
respiratory tract
Most of the microbes that live in soil or water are classified
saprobic
an infection that occurs as a complication of a pre-existing one
secondary
The general term for an inanimate material (solid object, liquid, or air) that serves as a transmission agent for pathogens
vehicle
Reservoirs of pathogens include
All of the choices are correct. water, soil, animals, humans
Which of the following is NOT a systemic effect of endotoxin release?
Increased blood pressure
Which is a NOT a sign of inflammation?
Pain
The exoenzyme that digests the collagen fibers in connective tissue
Collagenase
True or false: A disease that is transmitted by sexual or intimate contact is referred to as a nosocomial disease.
False
Which of the following are a potential threat of blood-borne disease?
Used needle Used razor
the presence of small numbers of viruses in circulating blood
Viremia
LPS is found in which type of bacterial cells?
Gram-negative
Which of the following is NOT an example of a common vehicle?
Personal items
Which of the following are the most common members of the normal flora of the mouth?
Streptococcus sanguis Streptococcus salivarius Streptococcus mitis
characterized by a rapid onset and short duration.
acute
Because of various mechanisms used by a host to expel microbes, a microbe must be able to ______ to cause disease.
adhere to host tissues
In most cases, pathogens leave the host through all of these EXCEPT
adhesion
Virulence factors fall into three categories
antiphagocytic effects, exoenzymes, and toxins.
All infectious diseases
are caused by microorganisms or their products.
The majority of vectors are
arthropods
It is common for infections to produce no noticeable symptoms. Infections of this nature are
asymptomatic
a healthy individual who is infected but shows no symptoms
asymptomatic carrier
a person with an inapparent infection who shows no symptoms of being infected yet is able to pass the disease agent on to others.
asymptomatic carrier
When a medical examiner cannot detect any signs of disease, however, the pathogen is actually present
asymptomatic infection
Researchers studying the importance of normal resident microbiota have developed laboratory strains of mammals and birds that are germ-free, also called
axenic
A(n) ______ vector actively participates in the life cycle of the pathogen
biological
Dengue fever is transmitted by the bite of a mosquito that has been infected with the virus after it has bitten a person who has dengue fever. In this scenario, the portal of exit would be the __________.
blood
Some type of contact must occur between the skin or mucous membranes of an infected person and an infectee in order for ______________ transimission to occur
direct
Agents that cannot survive outside of the host for long periods of time must be transmitted by
direct, contact
any deviation from the normal healthy state, as when the effects of microbial infection damage or disrupt tissues or organs.
disease
Streptokinase and staphylokinase
dissolve fibrin clots.
The types of transmission that involve air as a vehicle are
droplet nuclei aerosols
The human body typically begins to be colonized by its normal flora
during and immediately after birth.
Reservoirs are always humans or other animals.
false
The infectious dose of a pathogen is directly related to its portal of entry.
false
The virulence factors of a pathogen are established by how strong or weak a patient's body defenses are at the time of infection.
false
True or false: Microbes usually enter through smooth, unbroken skin.
false
Select all the terms that also describe normal resident microbiota.
indigenous microflora normal flora commensals
Transmission of infectious agents from host to host with the involvement of an intermediate inanimate material
indirect transmission
To cause actual damage to a host, a microbe must ______.
induce an injurious immune response produce toxins that destroy tissue
Pathogenic microorganisms penetrate the host defenses, enter the tissues, and multiply.
infection
The condition in which pathogens enter, establish, and multiply in the human host is
infection
The invasion and multiplication of a pathogen in the human host is referred to as
infection
The pathologic state involving the disruption and destruction of tissues by microbes is referred to as a(n)
infectious
defined as a wound, injury, or some other pathologic change in the tissue
lesion
Categorize each infectious agent by low, moderate or high infectious dose (ID).
low Measles, Shigella, Norovirus moderate Plague, Gonorrhea High Salmonella, Cholera
Swelling of one or more lymph nodes
lymphadenitis
A person harboring a persistent infectious agent ________ shed the agent during the latent stage.
may or may not
Not necessary to the life cycle of an infectious agent and merely transport it without being infected.
mechanical carrier
An animal that transports an infectious agent but is not infected by
mechanical vector
Any biological agent that causes disease is called
pathogen
Please read the following scenario: "Molly developed gastroenteritis after eating raw cookie dough. Upon culture of her stool, the causative agent was shown to be Salmonella typhimurium. Presumably the Salmonella was in the uncooked eggs in the raw cookie dough." What is the reservoir for the infection in this case?
the chickens from which the eggs came
Spread of a toxin from the site of infection through the blood is ________.
toxemia
A specific chemical product of microbes, plants, and some animals that has a poisonous effect on other organisms is a(n) ________.
toxin
a product of an organism that is poisonous to other organisms.
toxin
An individual who has been infected and are apparently healthy but continue to spread infection
asymptomatic
An infection that produces no noticeable symptoms
asymptomatic
The presence of small numbers of bacteria in the blood is referred to as __________.
bacteremia
The presence of viable, but not necessarily multiplying, bacteria in circulating blood
bacteremia
The microbial groups that make up the normal flora of the skin consist primarily of
bacteria and yeast
A __________ forms when microbial cells bind to each other and to host cells creating complex relationships.
biofilm
An animal that not only transports an infectious agent from one host to another but plays a role in the life cycle of the pathogen
biological vector
Animals that participate in the life cycles of pathogens and transmit pathogens from host to host are
biological vectors.
Please choose the answer that best fills in the blanks of this sentence in the correct order. A mosquito which transmits malaria by injecting infected saliva into the blood of its victim is an example of a __________ vector, whereas a fly which transmits trachoma on its feet as it moves from one infected individual to the eye area of a noninfected individual is an example of a __________ vector.
biological; mechanical
The first comprehensive (large scale) exposure of an infant to normal biota occurs during passage through the
birth
Helminths gain access to unbroken skin through burrowing, while other organisms are transmitted through insect or animal
bites
Which are ways infectious agents can gain access to unbroken skin?
bites of insects and animals digestive enzymes
When bacteria are grown on ____________agar plates, the production of hemolysins results in the appearance of clear zones in the agar surrounding the bacterial colonies
blood
an individual recovering from a disease who continues to shed the pathogen during recuperation
convalescent carrier
The time period when a patient is recovering from an infection as the immune response clears the infectious agent
convalescent period
The time period where a patient is recovering from an infection.
convalescent period
decline of symptoms and return to a state of health
convalescent period
The most effective means of exit from the human body for respiratory pathogens are
coughing, sneezing
Leukopenia is the __________ in the level of white blood cells in a patient.
decrease
Increased peristalsis of the bowel results in ______.
diarrhea
Any deviation or change from a state of health is known
disease
Many resident microbiota have the potential to cause _____________ if the microorganisms spread beyond their natural microhabitat within the body or if the host's immune system is compromised.
disease, infection
dried residues of mucus and saliva sprayed while sneezing and coughing that can contain a bacterium and remain airborne for a long time.
droplet nuclei
The dried residues of fine droplets from mucus or saliva that harbor and transmit pathogens are
droplet nuclei.
Starting in 2013, an outbreak caused by a filovirus called____________virus quickly became an epidemic.
ebola
The accumulation of excess fluid in cells, tissues, or serous cavities
edema
The accumulation of excess fluids in afflicted tissues and serous cavities
edema
A patient becomes sick with strep throat and is given antibiotics. However, after feeling better a few days later, the patient stops taking the antibiotic. A week later the patient becomes sick with strep throat again and testing finds it is due to the same strain which is now resistant to the antibiotic. This is an example of a/an __________ infection.
endogenous
Evidence that viruses can be normal residents of the human body comes from the Human Genome Project showing that 8-10% of DNA in human cells consists of sequences from endogenous
endogenous retroviruses
A bacterial toxin that is not ordinarily released but instead is an integral part of gram-negative cell walls is called a(n) ______.
endotoxin
The lipopolysaccharide of the outer membrane of gram-negative cell walls is a(an) __________.
endotoxin
a bacterial toxin that is part of the gram-negative cell wall and is usually released only when the bacteria has been damaged or destroyed.
endotoxin
Match each toxin type with its effect on the human host.
endotoxins have systemic effects such as fever, inflammation, diarrhea, and shock exotoxins have effects on a specific cell type
A person that collects and analyzes data regarding disease in a population
epidemiologist
The study of the frequency and distribution of disease and other health-related factors in human populations
epidemiology
The study of the frequency and distribution of disease and other health-related factors in human populations is called ______.
epidemiology
True or false: Droplets are suspensions of fine dust or moisture in the air that contain live pathogens.
false
The ________ route of indirect transmission in which a fecal carrier of disease contaminates food or drink during food handling, passing it on to those who consume it.
fecal-oral
A(n) ______ infection occurs when a microbe breaks loose from a localized infection and spreads to another tissue.
focal
When an infectious agent breaks loose from a localized infection and is carried by the circulation to another tissue, ____________ occurs.
focal
Gastrointestinal pathogens enter via______________. _____________, and other ingested substances.
food, drink
Some diseases can be vertically transmitted. This is understood to mean the disease is transmitted
from parent to offspring via milk, ovum, sperm, or placenta.
Pathogens that enter through the ______ tract must be able to withstand both enzymatic attack and abrupt changes in pH.
gastrointestinal
Skatole is one of the chemicals that ______.
gives feces a foul odor
Experiments where specific microbes are added back to germ-free animals are called __________ studies.
gnotobiotic
Lesions where inflammatory cells and microbes have been walled-off in the tissues are
granulomas , abscesses
Which types of lesions are characterized as walled-off collections of inflammatory cells and microbes found in the tissues?
granulomas , abscesses
Some microbes can produce an enzyme called ____________ which can induce the lysis of red blood cells.
hemolysin
Tissue damage is often indirectly caused by an excessive or inappropriate __________response to microbes.
host
period of time from initial contact with pathogen to appearance of very first symptoms
incubation period
The time from when pathogen first enters the body and begins to multiply, until symptoms first appear is the
incubation period.
The majority of microbial diseases are the result of ______.
indirect damage due to the host's excessive or inappropriate response
Infectious agents that are transmitted from host to host with the involvement of an intermediate inanimate material
indirectly transmitted
STORCH is an acronym that represents the most common
infections of the fetus and neonate.
Any damage or toxicity to the body caused by a pathogen is known as ________ disease.
infectious
Disruption of a tissue or organ caused by microbes or their products.
infectious disease
A nonspecific response to tissue damage that protects the host from further damage
inflammation
Local edema, swollen lymph nodes, fever, soreness, and abscesses are indications of
inflammation.
The gastrointestinal tract is the portal of entry for pathogens contained in ______ substances.
ingested
A toxinosis caused by the ingestion of toxins
intoxication
Botulism is the ingestion of a toxin in food and is an example of a/an __________.
intoxication
Ingestion of a bacterial toxin causes a toxinosis known as ________.
intoxication
the time during a clinical infection when the infectious agent multiplies at high levels and obvious signs/symptoms are present.
invasion period
The exoenzyme that digests the main protein component in skin and hair
keratinase
The only areas of the gastrointestinal tract that harbor numerous permanent resident microbes are the
large intestine oral cavity rectum
The body site with resident flora that produces beneficial body products, including vitamin K and several other vitamins is the
large intestine.
When a virus persists inside the host in an inactive state, this is specifically
latency
a state of inactive infection.
latency
A wound, injury, or other noticeable sign of infection or disease
lesion
Species of Streptococcus and Staphylococcus produce ____________, substances that are toxic to white blood cells, including phagocytes.
leukocidins
A(n) ______ infection occurs when a microbe enters a specific tissue, infects it, and remains confined there.
localized
An infection that remains confined to the initial infection site
localized
Microbe enters the body and remains confined to a specific tissue
localized infection
A person who mechanically transfers a pathogen without ever being infected by
mechanical carrier
Listeria and Shigella are able to utilize actin filaments for _______ inside an invaded cell.
motility
Extracellular enzymes utilized by microbes to dissolve host's defense barriers and promote the spread to deeper tissues are ________.
mucinase
The exoenzyme that digests the mucous coating on mucous membranes is
mucinase
Microbes are easily transferred between the sinuses, ears, and upper respiratory tract because they are interconnected by a continuous
mucous membrane lining
The death and disintegration of cells and tissues is referred to as ______.
necrosis
LPS is found in the outer membrane of Gram
negative cells
An infectious disease that does not arrive through transmission of an infectious agent from host to host
noncommunicable
an infectious disease that does not arise from host to host transmission.
noncommunicable disease
A child contracts tetanus after injuring their foot on a piece of glass contaminated with Clostridium tetani. While the condition is severe for the child, it is fortunate that there is no risk of them spreading tetanus to anyone else. This is because tetanus is a(an)
noncommunicable infectious disease
Please choose the answer that best fills in the blanks of this sentence in the correct order. A/An __________ infectious disease, such as a urinary tract infection, is not transmitted from person to person, whereas an infectious disease which is transmitted from one person to another, such as influenza, is referred to as a/an __________ infectious disease.
noncommunicable; communicable
The portal of exit is ______ the same as the portal of entry for a pathogen.
often
Pathogens that do not usually cause disease unless the host's immune system is weakened or compromised in some way are known as _________ pathogens.
opportunistic
Which would require that the host have a compromised immune system to cause an infection?
opportunistic pathogen
The ________, __________, ____________are the only areas of the GI tract that harbor permanent resident microbes. All of the other sections of the GI tract only harbor transient microbes.
oral intestine rectum
While the uterine environment was previously thought to be sterile, recent studies have shown that healthy placentas and amniotic sacs harbor bacteria similar to those found in the
oral cavity
A person with feces on their hands handles food and transmits it to another person who ingests the contaminated food
oral-fecal route
The relationship between a pathogen and its host is best described as ______.
parasitic
A(n) ______ carrier is not infected, but is contaminated with the infectious agent and spreads it to other hosts.
passive
an individual who picks up a pathogen while handling patients or contaminated supplies and spreads it to other individuals (frequently involved in nosocomial disease transmission
passive carrier
Any biological agent that causes disease is called a(n) ______.
pathogen
The incubation period is characterized by ______.
pathogen multiplication
Please choose the answers that best fill in the blanks of this sentence in order. The ability of a microbe to cause disease is called __________, whereas __________ refers to the degree to which a microbe can cause disease, or the relative capacity of a pathogen to invade and harm host tissues.
pathogenicity; virulence
Infection occurs when
pathogens enter and multiply in body tissues.
Microorganism is multiplying rapidly and causing fever and specific disease symptoms
period of invasion
The time period during a clinical infection when the infectious agent multiplies at high levels and exhibits its greatest toxicity
period of invasion
The time period during a clinical infection when the infectious agent multiplies at high levels and exhibits its greatest toxicity is known as the ______.
period of invasion
The stage of an infectious disease when specific signs and symptoms are seen and the pathogen is at peak activity is called the
period of invasion.
A category of white blood cells called ____________are most likely to be the first defense encountered upon entering the host by a microbe that is not part of the normal biota.
phagocytes
White blood cells capable of engulfing other cells and particles are generally referred to as ______.
phagocytes
The route a pathogen uses to get into the human host is called
portal of entry
The specific avenue through which pathogens depart the body
portal of exit
In many cases, normal biota can benefit the human host by ______.
preventing the overgrowth of potentially harmful biota
Resident microbiota can benefit the human host by _____________the overgrowth of __________microorganisms
preventing, harmful
In a sequence of infections, the first infection that predisposes the patient to further infection
primary
the initial infection in a previously healthy individual, which can later be complicated by an additional infection caused by a different microbe.
primary infection
A microbe or mixture of microbes known as ___________ are used to balance the normal flora and prevent infection.
probiotic
The ______ is the short period of mild symptoms occurring at the end of the incubation period.
prodromal stage
The short period of mild symptoms that follows the incubation period of an infection
prodromal stage
The initial, brief period of early, general symptoms such as fatigue and muscle aches is the
prodromal stage.
Exotoxins are
proteins
Rabid animals typically salivate excessively in the late stages of the disease. This excess salivation
provides a portal of exit for the virus.
The Human Immunodeficiency Virus attaches to host white blood cells by means of specialized __________.
receptors
In reference to diseases, the natural host or primary habitat of a pathogen
reservoir
The primary habitat in the natural world from which a pathogen originates is its __________.
reservoir
The primary, natural habitat of a pathogen where it persists is called the
reservoir
the primary habitat in the natural world from which a pathogen comes
reservoir
The stable microbes that inhabit the skin and exposed mucous membranes on a permanent or long-term basis, and generally do not cause disease are referred to as ______ biota.
resident Also called normal or indigenous biota
Microorganisms that survive the body's defenses and become permanently established in or on the body
resident microbes
Microbes that become permanently established on the human body are known
residents
The largest number of pathogens enter the body through the
respiratory tract
Most of the microbes that live in the water and soil are ____________meaning they live off of decomposing matter.
saprobes, saprobic
A Staphylococcus aureus infection that develops when the bacterium invades chickenpox lesions is an example of a(n) __________ infection.
secondary Correct
a subsequent infection with a different microbe that may occur following an initial infection
secondary infection
an additional infection, with a different microbe, that follows an initial infection.
secondary infection
A systemic infection associated with microorganisms multiplying in circulating blood
septicemia
Some diseases leave ______ in the form of long-term or permanent damage to tissues or organs after the course of the infection.
sequelae
A condition where an infection remains localized at the portal of entry but toxins produced by the pathogens are carried by the blood to the target tissue
toxemia
For diptheria and some staphylococcal diseases, the infection remains localized at the portal of entry but toxins from the pathogens travel to the target tissue through the bloodstream, in a condition known as ______.
toxemia
Tetanus is a disease caused by an infection at the site of a wound that has dramatic effects on the contraction of muscle tissue. This is an example of a(n):
toxemia
The genetically-controlled characteristic that gives an organism the ability to produce toxins is referred to as ______.
toxigenicity
Diseases that are caused by toxins produced by other organisms
toxinoses
Microbes that occupy the human body for only short periods
transients
Biological agents that can cause disease in healthy people with normal immune defenses are known as ________ pathogens.
true
A microbe such as Ebola virus that sickens most everyone that is infected would be characterized as a/an
true pathogen.
The ______of a particular microbe is determined by its ability to establish itself in the host and cause damage.
virulence
Any characteristic or structure of a pathogen that allows it to establish itself in a host or cause damage to the host is referred to as a(n) ______.
virulence factor
a property of a microbe that improves their invasiveness or ability to evade host defenses in order to cause disease.
virulence factor
Adhesive pili, exotoxins, and capsules are all microbial factors that help them establish infection. These are examples of
virulence factors.
Skin lesions and their exudates can serve as portals of exit for
warts fungal infections boils herpes simplex smallpox syphilis
An infectious disease that normally occurs in animals but humans can acquire through direct or indirect contact with infected animals
zoonosis
an infection indigenous to animals that can, on occasion, be transmitted to humans
zoonosis
A pathogen can directly damage its host by secreting
A pathogen can directly damage its host by secreting or toxins
Which component of an A-B toxin causes the most damage to a cell?
Active component (A)
Neonatal research has shown that breast milk contains oligosaccharides that cannot be digested by the infant, but can be digested by some species of Bifido bacterium (infantis). What does this discovery suggest?
Breast milk helps establish the normal microbiota of an infant's digestive system.
Which types of carriers have had or will have the disease but do not at the time of transmission?
Convalescent carriers Incubation carriers
Which are examples of normal flora of the skin?
Corynebacterium Staphylococcus Propionibacterium
Respiratory pathogens can exit the body most effectively by which of the following means?
Coughing Sneezing
In what ways do exotoxins usually affect host cells?
Damaging the cell membrane Causing lysis of cell Disrupting intracellular function
Mechanical vectors transmit the infectious agent by
Food Contaminated vehicle Direct contact
The three types of carriers that are infectious during the period before or after they have been infected with the disease
Incubation convalescent
What will happen If the inoculum is less than the infectious dose?
Infection and disease will not occur.
Which of the following statements regarding contact transmission is true?
Infectious agents that cannot survive for long periods outside of the host must be transmitted by contact transmission
What is the minimum number of microbes that must enter the body to cause infection?
Infectious dose
a nonspecific response to tissue injury or infection that protects the host from further damage.
Inflammation
Which body sites usually do NOT have a resident microbial population?
Inner ear canal Muscles
Which of the following is not a common site of entry through the skin?
Intact skin
Which general area of the body does NOT support resident biota?
Internal body fluids
Which body fluid is NOT involved in the transmission of sexually transmitted diseases?
Interstitial fluid
Which of the following microbes can be engulfed by phagocytes but are able to survive further destruction?
Legionella pneumophila Mycobacterium tuberculosis
An abnormally large number of white blood cells in the blood
Leukocytosis
an increase in the number of circulating white blood cells
Leukocytosis
an increase in the number of circulating white blood cells.
Leukocytosis
a decrease in the number of circulating white blood cells
Leukopenia
Which of the following is the substance referred to as endotoxin?
Lipopolysaccharide
Which of the following terms is used to describe the inside chamber of a structure (e.g., inside the small intestine or inside the endoplasmic reticulum)?
Lumen
Please choose the statement that best describes the benefits of microbial antagonism to the human host.
Microbial antagonism occurs when members of the normal microbiota prevent pathogens from colonizing and becoming established in the body.
the primary means of exit for pathogens that infect the upper and lower respiratory tracts.
Mucus Sputum nasal drainage other moist secretions
Non-pathogenic microorganisms are constantly being inhaled or ingested. Which of the following is the reason why these microorganisms do not cause disease?
NOT They have not evolved strategies to evade host defenses. Not They lack attachment factors and are readily expelled by the host.
defined as the death and disintegration of cells and tissues.
Necrosis
At the time of birth, what event provides a comprehensive exposure to microbial life?
Passage through the birth canal
Which anatomical areas are involved in the entrance of urogenital pathogens?
Penis Urethra Cervix Vagina
an acronym for the unified cluster of common fetal and neonatal infections that medical personnel must monitor.
STORCH
Which microbes produce a capsule or slime to physically prevent phagocytosis?
Salmonella typhi Streptococcus pneumoniae Cryptococcus neoformans
Which of the following are generally more precise?
Signs
Which genus is the most common resident flora of mouth surfaces?
Streptococcus
Which of the following pathogens compose the acronym for STORCH?
Syphilis Rubella Toxoplasmosis Cytomegalovirus
the collective total of genetic material from all the normal resident microbiota that can live in or on the body.
The Human microbiome
Explain why a microbe must be able to firmly adhere to the host tissues to cause disease.
The body has numerous mechanisms for flushing microbes from the tissues, such as coughing.
Bacterial kinases dissolve fibrin clots.
True
True or false: An infection that produces no noticeable symptoms even though the microbe is active in the host tissue is referred to as asymptomatic.
True
Which of the following diseases are caused by agents that exit through the skin?
Warts Herpes simplex Smallpox Boils Syphilis
An infection characterized by rapid onset with severe but short-lived effects
acute infection
more severe infection, rapid onset
acute infection
Mechanical vectors do NOT transmit infectious agents by ______.
aerosol formation
Please select characteristics exhibited by endotoxins, but not exhibited by exotoxins.
-composed of lipopolysaccharide -released by gram-negative bacteria -heat-stable -fever-inducing
Enterotoxins are
-proteins -virulence factors -toxins that target the intestines -exotoxins
Please select characteristics exhibited by exotoxins, but not exhibited by endotoxins.
-require very small doses to cause toxic effects -secreted from a living cell -have very specific targets
______ can be characterized as any deviation from the healthy state.
Disease
Exoenzymes play which of the following main roles in the disease process?
Dissolve the host defensive barriers Inflict damage on tissue
Please identify the four most significant interactions between humans and the microbes that live in and on our bodies.
-Microbes can protect and stabilize body surfaces on which they establish themselves as normal residents. -Microbes promote the development and maturation of host immune defenses. -Microbes may invade and grow in normally sterile body sites. -Microbes cause disease by damaging tissues and organs.
Please select the conclusions of studies comparing the health of germ-free animals to the health of animals with a normal complement of microbiota.
-Normal microbiota are a source of some vitamins. -Normal microbiota contribute to dental caries and periodontal disease. -The presence of normal microbiota can prevent some pathogens from becoming well-established. -Normal microbiota contribute to the development and maturation of the immune system.
The four stages of infection from beginning to end are
1) incubation period2) prodromal stage3) period of invasion4) convalescent period
Please order the following steps a microorganism takes in establishing an infection.
1. Microbes enter the host through a portal of entry. 2. Microbes adhere to receptors on host. 3. Microbes invade and make a pathway into cells. 4. Microbes multiply, grow, and spread. 5. Microbes attack specific tissues, establishing infection and disease.
Which of the following is an example of vertical transmission?
A mother transmitting syphilis to her fetus
a disease that is acquired while being treated in a hospital
A nosocomial disease
Which of the following are examples of systemic infections, or those that spread to several sites and tissue fluids, usually in the bloodstream?
AIDS, typhoid fever
Which are NOT examples of direct transmission?
Aerosol formation Droplet nuclei Contaminated vehicles
Biological vectors transmit the infectious agent by
Aerosol formation Touching the host Biting the host
Which of the following sources is not a usual source of food contamination?
Aerosols
suspensions of fine dust or moisture in the air that contain live pathogens, whereas droplets are dried microscopic residues ejected from the mouth and nose.
Aerosols
Which types of transmission involve air as the vehicle?
Aerosols Droplet nuclei
Resident microbiota are found in/on the
All of the choices are correct. -Nasal passages Skin mouth large intestine
the type of organism that is most often a vector for disease transmission.
Arthropods
Which step is NOT directly required to cause actual damage to the host?
Avoid the host immune defenses
the presence of small numbers of viable, but not necessarily multiplying, bacteria in circulating blood.
Bacteremia
the presence of viable, but not necessarily multiplying, bacteria in circulating blood.
Bacteremia
Which of the following intestinal microbes is not a member of the coliform group?
Bifidobacterium
Pathogens enter the skin through which means?
Bites of other organisms Breaks in the skin Digestive enzymes creating passage
The human body usually supports resident biota in which of the following areas?
Body fluids in exposed body cavities Tissues with contact to outside
Which of the following is NOT a portal of entry?
Circulatory system
What appears when bacteria growing on blood agar produce hemolysins?
Clear zones in agar
An exoenzyme that causes the clotting of blood or plasma
Coagulase
Which of the following exoenzymes is responsible for clotting the blood or plasma?
Coagulase
Which of the following exoenzymes is responsible for breaking down the fibers in connective tissue?
Collagenase
Blood is considered a portal of exit despite not having a direct route to the outside of the host. Which of the following is not an example of a blood transmission?
Contracting a hemolysin-positive Staphylococcus aureus infection in an abscess
the result of increased peristalsis in the bowel providing a more rapid exit for a pathogen.
Diarrhea
Which of the following is NOT a means by which pathogens enter the skin?
Diffusion across the stratum corneum
Which of the following is NOT a typical effect of exotoxins on target cells?
Digesting the principle fibers of connective tissue
Which are examples of direct transmission?
Droplet contact Sexual intercourse
Which factor does NOT make the human body a favorable environment for many different microbes?
Dryness
An infection characterized by high fever and severe gastrointestinal symptoms followed by rapid death, first observed in 2013, was caused by the
Ebola virus.
Which are SIGNS of inflammation?
Edema Lymphadenitis Abscesses
Which of the following which are considered coliforms?
Escherichia coli Citrobacter Enterobacter
All of the following genera are considered resident microbiota of skin sites, except
Escherichia.
a geometric object that has both a magnitude (or length) and direction
Euclidean vector
Which type of toxins have effects on a specific cell type?
Exotoxin
In zoonotic infections, the first human host usually serves as an index case for a large epidemic.
False
True or false: The portal of exit is always the same as the portal of entry for a pathogen.
False
Which of the following is not an important host factor that contributes to the success of a pathogen?
Family history of neurological disorders
Endotoxin causes a variety of systemic effects, including ______.
Fever Inflammation Hemorrhage Diarrhea Fatal shock condition
A person with which occupation is most at risk for a zoonotic disease?
Forest ranger
The main portals of entry include ______.
Gastrointestinal tract Respiratory tract Skin Urogenital tract
Which of the following characteristics describes coliform bacteria?
Gram-negative Facultative anaerobe Lactose fermenting.
Which of the following are flora of the respiratory tract?
Haemophilus Streptococcus species Neisseria species Staphylococcus aureus
________ are a type of bacterial exotoxin that disrupt the cell membrane of red blood cells.
Hemolysins
Which of the following is a term used to describe the "type" of transmission of a pathogen from one person to another, not including those transmitted from mother to fetus?
Horizontal
the direct or indirect transmission of a pathogen through a population
Horizontal
An effort to analyze the genomes of microbial residents that identified 10,000 different species populating the body is called the
Human Microbiome Project.
Which of the following statements regarding zoonosis is true?
Human are usually dead-end hosts in zoonotic infections.
occasionally detected through routine screening, although they are usually very difficult to discover and control, leading to the spread of pathogens. Listen to the complete question
Human carriers
Which of the following exoenzymes is responsible for digesting the "cement" that holds host cells together?
Hyaluronidase
Which of the following is NOT a main role for exoenzymes in the disease process?
Increase the amount of systemic inflammation
Which two factors determine the virulence of a particular pathogen?
Its ability to establish itself in the host Its ability to cause damage to the host tissues
The component of the gram-negative outer membrane called endotoxin
LPS
Which of the following are considered to be signs of blood infection?
Microbes in blood Leukopenia Leukocytosis
Which of the following indicates a relationship in which resident microorganisms prevent the overgrowth of intruder microorganisms when competing for survival in a common environment?
Microbial antagonism
the situation in which microorganisms compete for survival in a common environment and where resident microorganisms take actions that inhibit or destroy intruder microorganisms.
Microbial antagonism
What factors make the human body a favorable environment for a wide range of microbes?
Moisture Source of nourishment Temperature Surface area
Which of the following exoenzymes is responsible for breaking down the protective coating on mucous membranes?
Mucinase
If the infectious dose (ID) for gonorrhea is 1,000 cells and the ID for tuberculosis is 10 cells, which organism is more virulent?
Mycobacterium tuberculosis
Marion is going to the hospital for a triple bypass operation. She will have general anesthesia, an intravenous catheter, surgical wounds, and a urinary catheter. Which healthcare-associated infection is she at greatest risk for contracting?
NOT Urinary tract
Where is lipopolysaccharide (LPS) located in bacterial cells?
Outer membrane
Which is not the terminology used for resident flora?
Pathogenic flora
a broad concept that describes an organism's potential to cause infection or disease.
Pathogenicity
When a microbe that is not part of the normal biota enters the body, it is likely to first encounter which type of host defense?
Phagocytes
white blood cells that are capable of engulfing pathogens and cellular debris.
Phagocytes
beneficial, nonpathogenic microbes that can be ingested to re-establish normal microbiota
Probiotics
Which of the following steps is NOT required for a microbe to establish itself in a host?
Produce toxins or induce a damaging host response
If the inoculum is much larger than the infectious dose, what may occur?
Rapid onset of disease
Which portal of entry is the most commonly used by pathogens?
Respiratory
When is an infant first exposed to normal biota beyond the early resident microbiota present in uterine tissues?
Rupturing of the fetal membranes (water breaking)
Which "term - definition" pair is mismatched?
Secondary infection - Infection spreads to several tissue sites
A pathogen can directly damage its host by
Secretion of toxins Secretion of exoenzymes
Which body fluids are involved in the transmission of sexually transmitted diseases?
Semen Vaginal discharge
the presence of multiplying microbes in circulating blood
Septicemia
forms of long-term or permanent damage to tissue or organs resulting from a disease
Sequelae
forms of long-term or permanent damage to tissue or organs resulting from a disease.
Sequelae
One of the chemicals that gives feces their foul odor
Skatole
In most cases, pathogens leave the host via the portal of exit through:
Sloughing Excretion Secretion Discharge
Food is usually contaminated by which of the following sources?
Soil Handler Mechanical vector
Which are considered typical residents of the urethra?
Staphylococcus Nonhemolytic streptococci Corynebacterium
A client who is 22 weeks pregnant asks the nurse about infections that may lead to miscarriage or birth defects. The nurse answers that all of the following except ___________ are of particular concern for pregnant women.
Staphylococcus aureus
Of the following, the two that are most likely examples of endogenous infections are ______ and ______.
Staphylococcus infection of a hair follicle a Micrococcus infection resulting from a cut to the skin
Organisms from the genus _________are the most common residents of the mouth
Streptococcus
Experiments have been done to determine the infective dose of a specific pathogen in animals with normal microbiota and gnotobiotic animals. Predict how the infective dose for gnotobiotic animals is expected to compare to the infective dose of animals with normal microbiota.
The infective dose would be lower for the gnotobiotic animals.
What usually determines the composition of the initial intestinal population that colonizes the newborn?
The method of feeding
Why must some pathogens spread from their initial site of entry?
Their target tissue is a distance from entry portal
Why are microbes easily transferred between the sinuses, ears, and upper respiratory tract?
They are all connected by a continuous mucous membrane lining.
Which of the following is NOT considered to be a sign of blood infection?
Thrombopenia
a decrease in the number of platelets in the blood
Thrombopenia
a type of toxinosis in which a toxin is spread by the blood from the site of infection.
Toxemia
defined as the ability of an organism to produce toxins.
Toxigenicity
diseases caused by toxins produced by other organisms
Toxinoses
An epidemiologist is responsible for which of the following tasks?
Tracking the number of cases of a particular disease in a population Determining the causative agent of a disease Determining the distribution of disease cases in a population Identifying the source of an infectious agent Determining the mode of transmission for an agent
Which term is NOT used to refer to the normal microbes that inhabit the human body and usually do not cause disease?
Transient biota
Bottle or breastfeeding determines the initial composition of the intestinal microbiota.
True
Lactobacillus is a common bacterial resident of the female vagina.
True
True or false: A disease is considered communicable when the infectious agent can be transmitted from infected host to new host and establish infection in that host.
True
True or false: A microbe may be active in host tissue, even if no overt symptoms of infection manifest themselves.
True
True or false: A portal of entry is the route a pathogen uses to get into the human host.
True
True or false: A substance formed by some pathogens that impairs and sometimes lyses leukocytes is known as a leukocidin.
True
True or false: An infection indigenous to animals but naturally transmissible to humans is called a zoonosis.
True
True or false: People who are sick due to a pathogen in their blood stream can typically transmit the infection to others by blood exposure.
True
True or false: Subclinical implies that a medical examiner cannot see any signs of disease.
True
Transplacental infection occurs when microbes from the mother enter fetal circulation through which blood vessel?
Umbilical vein
Which locations are well-established sites harboring resident microbiota?
Upper respiratory tract Various parts of gastrointestinal tract External ear canal External genitals
Which anatomical area is NOT involved in the entry of urogenital pathogens?
Ureter
Of the sites listed below, which is most likely to be free of any normal microbiota?
Uterus
Which of the following is the term used to describe the transmission of a pathogen from the mother, across the placenta, to the baby?
Vertical transmission
the transmission of a pathogen from mother to offspring in utero.
Vertical transmission
Pathogenicity is
a broad concept that describes an organism's ability to cause disease
Even a weakly pathogenic species can become more virulent with
a large inoculum
Salmonella and E. coli are able to disrupt the ________ ________ of a cell in order to gain access to the cell interior.
actin cytoskeleton
An A-B toxin is composed of
active and binding
An A-B toxin is composed of a(n) _____________component and a(n) __________ component
active, binding
The process by which microbes gain a more stable foothold at the portal of entry through interaction of their molecules with host cell receptors is called ______.
adhesion
the process by which microbes gain a more stable foothold at the portal of entry through interaction of their molecules with host cell receptors.
adhesion
Which are categories of virulence factors?
antiphagocytic effects exoenzymes toxins
All of the following are communicable diseases, except
botulism
Since 8-10% of the DNA in human cells consists of sequences from endogenous retroviruses, this demonstrates that viruses
can be normal residents of the human body.
Please select the factors below that contribute to a microorganism's invasiveness.
capsule leukocidins hyaluronidase fibrinolysin
A ______ is an individual who inconspicuously shelters a pathogen and can spread it to others without knowing.
carrier
An individual who inconspicuously shelters a pathogen and spreads it to others without notice is a __________.
carrier
an individual who inconspicuously shelters a pathogen and can spread it to others without any notice.
carrier
Please choose the best definition of virulence factors.
characteristics of a microorganism that enable it to establish infection and cause disease
characterized as an infection that progresses and persists over a long period of time.
chronic
An infection that persists over a long duration
chronic infection
an infection that progresses and persists over a longer period of time; symptoms often less severe
chronic infection
Presence of organisms living in or on the body, but not causing any pathology
colonization
a single material that serves as the course of infection for many individuals, such as a contaminated water source
common vehicle, source
A disease is considered ____________when the infectious agent can be transmitted from infected host to new host.
communicable, contagious, transmissible
If an agent is transferred from an infected person to another person without an intermediate object, substance or space, it is said to be
contact
A disease that is highly communicable, especially through direct contact
contagious
very communicable, mainly through direct contact
contagious disease
Which of the following is NOT a method by which biological vectors transmit infectious agents:
contaminating food
The ______ is the time period where a patient is recovering from an infection.
convalescent period
The placenta is a(n) ________ barrier against most microorganisms in the maternal circulation
effective
An infectious agent that already exists on or in the human body is referred to as a(n) ______ agent.
endogenous
the study of the frequency and distribution of disease and other health-related factors in defined human populations.
epidemiology
The ________ layer of the skin is continually sloughed off and replaced.
epidermis
an extracellular enzyme that may be involved in hydrolysis of nutrient macromolecules or damage to host tissues.
exoenzyme
Microbial hyaluronidase, coagulase, and streptokinase are examples of
exoenzymes
An infectious agent that originates from outside of the body is called ______.
exogenous
An infectious agent that originates from outside the body, such as from the environment or another organism
exogenous
A toxin (usually a protein) that is secreted and acts upon a specific cellular target
exotoxin
A toxin that is secreted and acts upon a specific cellular target
exotoxin
The human immune system develops germ-free in the placenta, prior to any introduction to a microbe.
false
An inanimate object that harbors and transmits a pathogen is a
fomite
Any inanimate object that can serve as a vehicle for the spread of disease when contacted by an infected individual
fomite
an inanimate object that harbors and transmits pathogens
fomite
Prior to birth, tissues such as the placenta and the amniotic sac
host a small collection of bacteria similar to those found in the oral cavity.
An enzyme that digests hyaluronic acid, which is the "glue" that holds host cells together
hyaluronidase
Hosts with compromised ________ systems can easily be infected by resident biota.
immune
The time period from the initial contact with an infectious agent to the appearance of the first symptoms is known as the ______.
incubation period
Which of the following exoenzymes is responsible for breaking down the protein in the outermost skin cells?
keratinase
Please select the body sites that remain free of normal microbiota.
kidneys brain uterus bones
Bacterial enzymes called __________ dissolve fibrin clots.
kinases
Please select the patterns of direct (contact) transmission of infectious disease.
kissing, touching mother to fetus (vertical) vector droplet
A lower-than-normal white blood cell count
leukopenia
The infectious dose is the
minimum number
A(n) ______ infection occurs when several infectious agents establish themselves simultaneously at the infection site.
mixed
When several different pathogens interact simultaneously at the infection site
mixed infection
The rupture of the fetal membranes first exposes the fetus to _____ from the mother.
normal microbiota
The normal bacterial inhabitants of the human body can be referred to as:
normal microbiota commensals indigenous microflora normal flora resident microbiota
Long term microbial inhabitants of the skin and exposed mucosa, that participate in mutual or commensal association without generally causing disease in the host, are called
normal resident microbiota
The Human Microbiome Project uses metagenomic technology to analyze the genomes of
normal resident microbiota
The human microbiome is the collective total of all DNA sequences from the ______.
normal resident microbiota
The first microbes to colonize the upper respiratory tract are
oral streptococci
Ordinarily, the ______________ is an effective barrier against microbes in maternal circulation to the developing fetus.
placenta
Diseases caused by more than one infectious agent at the same time
polymicrobial disease
appearance of first early, nonspecific symptoms
prodromal stage
Any abnormality uncovered upon physical examination or diagnosis that indicates the presence of disease
sign
The objective, measurable evidence of disease evaluated by an observer is termed
sign
any objective evidence of a disease that can be observed or measured by an observer.
sign
A____________ is an objective assessment of disease, as opposed to a(n) ______________ which is the subjective assessment perceived by the patient.
sign, symptom
The outer layer of the _____________ and scalp is constantly being shed to the environment.
skin, epidermis
Some microbes secrete a ___________ or ____________that makes it physically difficult for a phagocyte to engulf them.
slime capsule
Microbes with ______ infectious doses are usually more virulent.
small
Infection will not proceed if the inoculum is ______ than the infectious dose.
smaller
The symptoms of inflammation include
soreness pain
The specific organism or object from which an infection is directly acquired
source
the individual or object from which an infection is actually acquired
source
Pathogens that infect the upper and lower respiratory tract exit via:
sputum nasal drainage moist secretions mucus
Some microbes have adapted to ___________ inside phagocytes after ingestion.
survive
Any subjective evidence of disease that is sensed by the patient
symptom
subjective evidence of infection and disease as perceived by the patient
symptom
The collection of signs and symptoms that when seen together indicate a particular disease
syndrome
a set of signs and symptoms that define a particular disease
syndrome
A(n) ______ infection invades many compartments and organs via the bloodstream.
systemic
Infection invades many compartments and organs via the bloodstream.
systemic infection
an infection that has spread to multiple body sites and tissue fluids; no longer restricted to one body site
systemic infection
Many infectious agents do not remain localized because their _______________________ is distant from their portal of entry.
target tissue
Which of the following is NOT an example of a communicable disease?
tetanus
All of the following would be examples of health problems studied by epidemiologists, except __________.
the development of an infectious disease in an immunocompromised patient
Which of the following is NOT an example of a portal of entry for microorganisms?
the meninges
All of the following are correct about mechanical vectors, except
the vector is important to the life cycle of the infectious agent.
Healthcare-associated infections involve all the following, except
they are only transmitted by medical personnel.
diseases caused by toxins produced by other organisms.
toxinoses
Microbes that do not colonize the human host, but instead are lost rapidly are referred
transient
The ______ tract is the portal of entry for pathogens that are transmitted through sexual contact.
urogenital
The portal of entry for pathogens that are transmitted through sexual contact is the
urogenital tract
To establish itself in a host, a microbe must ______.
utilize a portal of entry be able to adhere to host tissue survive immune system defenses
A live animal that transmits an infectious agent from one host to another
vector
An animal that transmits infectious agents from one host to another
vector
An animal, such as an arthropod, that transmits a pathogen from one host to another is a
vector.
The syphilis spirochete can cross the placenta and infect the fetus through the umbilical
vein
Tests reveal the presence of small numbers of viruses in a sample of blood taken from a patient
viremia
Any characteristic or structure of the microbe that contributes to the infection or disease state
virulence factor
any characteristic or structure of the microbe that contributes to the infection or disease state.
virulence factor
