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