Mastering Microbiology Ch. 14 & 15

An infection that does NOT cause any signs of disease is a(n)_________

subclinical infection

Infections in which the pathogen is distributed throughout the body are referred to as generalized infections or_______

systemic infections

According to the animation, surgical infections account for what percentage of nosocomial infections? a. 20% b. 15% c. 8% d. 40% e. 11%

a. 20%

Which of the following would be considered a vector? a. A fly carrying disease from fecal matter to food b. Water containing bacteria from fecal matter c. Saliva that is transmitted between individuals during kissing d. Water droplets that come from a sneeze from an infected individual

a. A fly carrying disease from fecal matter to food

How might a patient who is not being treated with an antibiotic still be exposed to an antibiotic? a. Antibiotics can be used in aerosols, thereby entering the environment. b. Health care workers being treated with antibiotics may pass the antibiotic on to the patient. c. Visitors currently being treated with antibiotics can pass them on to the patient.

a. Antibiotics can be used in aerosols, thereby entering the environment.

All of the following bacteria release endotoxin EXCEPT a. Clostridium botulinum. b. Salmonella typhi. c. Haemophilus influenzae. d. Proteus vulgaris. e. Neisseria meningitidis.

a. Clostridium botulinum.

Which of the following would be the first sign of an infection that resulted in the release of endotoxin? a. Fever b. Pain c. Nausea d. Weakness

a. Fever

Which of the following features of Salmonella prevent it from being phagocytosed? a. Flagella b. Invasins c. Fimbriae

a. Flagella

Which of the following statements is true regarding hand washing? a. Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction. b. Hand washing should be done frequently by healthcare workers. c. Hand washing should be done frequently by patients. d. Hand washing should be done before and after patient interaction.

a. Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.

Which of the following statements about staphylococcal enterotoxin is FALSE? a. It is produced by Staphylococcus aureus growing in the host's intestines. b. It causes diarrhea. c. It is an exotoxin. d. It causes vomiting. e. It is a superantigen.

a. It is produced by Staphylococcus aureus growing in the host's intestines.

Where is the site of Shigella attachment in the host? a. M cells b. Intestinal epithelial cells c. Phagocytes d. Leukocytes

a. M cells

Meningitis and gonorrhea are caused by a. Neisseria species. b. measles virus. c. Pseudomonas species.

a. Neisseria species.

Koch's postulates established criteria for proving that a specific organism causes a specific disease. Which of the following is NOT one of the criteria given by Koch's postulates? a. The pathogen must be isolated from inoculated animals and must be different from the original organism. b. The same pathogen must be present in every case of the disease. c. The pathogen must be isolated from the diseased host and grown in pure culture. d. The pathogen isolated from a pure culture must cause the disease in a healthy lab animal.

a. The pathogen must be isolated from inoculated animals and must be different from the original organism.

Which of the following statements about the development of infectious diseases is correct? a. The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state). b. The prodromal period is characterized by very severe symptoms. c. During the incubation period, the infected individual exhibits obvious signs of sickness. d. The period of decline is the time when the infected individual's health rapidly deteriorates.

a. The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state).

How do fibrinolysins enhance a pathogen's virulence? a. They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin. b. They destroy the fibers that are found at the base of superficial tissues, allowing for deeper penetration by the pathogen. c. They destroy the molecules that hold cells together.

a. They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin.

Biofilms provide pathogens with an adhesion mechanism and aid in resistance to antimicrobial agents. a. True b. False

a. True

Both normal and transient flora can become opportunistic pathogens. a. True b. False

a. True

Cytopathic effects, such as inclusion bodies and syncytium formation, are the visible signs of viral infections. a. True b. False

a. True

Infections with some viruses may induce chromosomal changes that alter the growth properties of host cells. a. True b. False

a. True

Many pathogens use the same portal for entry and exit from the body. a. True b. False

a. True

When would endotoxins be released from a bacterial cell? a. When the cell dies b. When the cell moves toward a energy source c. When the cell attaches to a host cell in the human body d. During bacterial conjugation

a. When the cell dies

A nosocomial infection is a. acquired during the course of hospitalization. b. always caused by medical personnel. c. only a result of surgery. d. always caused by pathogenic bacteria. e. always present, but is inapparent at the time of hospitalization.

a. acquired during the course of hospitalization.

When aerosols containing pathogens spread disease from a distance of less than one meter, it is considered a. contact transmission. b. vector transmission. c. airborne transmission. d. waterborne transmission

a. contact transmission.

A patient acquires an infection by touching a contaminated door handle. Which mode of transmission best describes this scenario? a. indirect contact transmission b. droplet transmission c. direct contact transmission d. vehicle transmission

a. indirect contact transmission

A needlestick is an example of a. indirect contact transmission by fomite. b. direct biological transmission by vector. c. direct contact. d. vehicle transmission. e. droplet transmission.

a. indirect contact transmission by fomite.

A patient who has been hospitalized with uncontrolled muscle spasms has probably been infected with bacteria that secrete a(n) a. neurotoxin. b. membrane disrupting toxin. c. superantigen. d. enterotoxin.

a. neurotoxin.

Which of the following cytopathic effects is cytocidal? a. release of enzymes from lysosomes b. antigenic changes c. giant cells d. inclusion bodies e. transformation

a. release of enzymes from lysosomes

The health of the patient a. should be the primary concern of the healthcare worker. b. is secondary to the health of co-workers in healthcare settings. c. is secondary to the health of the healthcare worker.

a. should be the primary concern of the healthcare worker.

Which of the following is an example of direct damage due to bacterial infection? a. the invasion and lysis of intestinal cells by E. coli b. the excessive secretion of fluids in a Vibrio cholera infection c. the fever, nausea, and low blood pressure in a Salmonella infection d. the uncontrolled muscle contractions in Clostridium tetani infection e. the hemolysis of red blood cells in a staphylococcal infection

a. the invasion and lysis of intestinal cells by E. coli

Certain traits that allow pathogens to create infection and cause disease are termed a. virulence factors. b. collagenases. c. streptokinases. d. hyaluronidases.

a. virulence factors.

Which domain of the A-B toxin binds to cell surface receptors on the host cell? a. Both the A and B domains have the ability to bind to cell surface receptors. b. B domain c. A-B toxins do not bind to cell surfaces. d. A domain

b. B domain

How can capsules enable bacteria to evade the immune system? a. A capsule is a superantigen that distracts the immune system. b. Capsules block the complement biding sites on the surface of the pathogen. c. Capsules can bind up IgA, rendering it inactive.

b. Capsules block the complement biding sites on the surface of the pathogen.

In general, the LD50 for exotoxins is much greater than the LD50 for endotoxins. a. True b. False

b. False

Most symptoms of endotoxins can be treated with administration of anti-endotoxin antibodies. a. True b. False

b. False

Reservoirs of infections are always animate objects. a. True b. False

b. False

According to your Concept Map, which of the following organisms exhibits antigenic variation? a. S. pneumoniae b. N. gonorrheae c. Mycobacterium tuberculosis d. H. influenzae

b. N. gonorrheae

How can health care workers reduce the occurrence of nosocomial infections? a. Reduce the number of times they visit a patient b. Practice more stringent aseptic techniques c. Limit the number of visitors who can see the patient d. Administer all medications orally instead of through injections

b. Practice more stringent aseptic techniques

How are superantigens different from other types of exotoxins? a. Superantigens must be endocytosed into a target cell before becoming active. b. Superantigens cause an overstimulation of the host immune system. c. Superantigens comprise two functional domains. d. Superantigens only act against host neurons.

b. Superantigens cause an overstimulation of the host immune system.

How does a capsule help certain bacteria evade detection by the immune system? a. Capsules allow the bacteria to stick together, creating a larger mass that is too big for immune cells to engulf. b. The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign. c. The capsule makes the bacterium too sticky to be phagocytosed by the immune cells. d. Capsules have the ability to destroy antibodies secreted by the immune system.

b. The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.

Which is an example of vehicle disease transmission? a. Touching a telephone with cold viruses on its surface b. The presence of Listeria on undercooked chicken served for dinner c. The transmission of MRSA from skin to skin contact d. The bite of a mosquito containing malaria

b. The presence of Listeria on undercooked chicken served for dinner

How are immune cells able to detect foreign pathogens? a. They can compare the DNA sequences from the foreign cells to host DNA. b. They are able to detect structures on the surfaces of foreign cells that are not found in the host. c. They detect foreign, unfamiliar chemical substances released by the invading cells.

b. They are able to detect structures on the surfaces of foreign cells that are not found in the host.

How can surgeons help to limit nosocomial infections? a. They should prescribe as many antibiotics as possible. b. They should perform surgeries and invasive procedures only when absolutely necessary. c. They should prescribe immunosuppressive drugs to their patients. d. They should only operate on healthy individuals.

b. They should perform surgeries and invasive procedures only when absolutely necessary.

What is the role of epidemiology? a. To learn what diseases can be caused by respiratory pathogens. b. To learn how to treat and prevent various diseases. c. To learn which medicines are effective at killing pathogens. d. To learn which organisms cause disease.

b. To learn how to treat and prevent various diseases.

Which of the following microorganisms actually grows inside the macrophage? a. Leishmania b. Tuberculosis bacterium c. Shigella d. Streptococcus pneumoniae e. Legionella

b. Tuberculosis bacterium

The yeast Candida albicans does not normally cause disease because of a. other fungi. b. antagonistic bacteria. c. parasitic bacteria. d. commensal bacteria. e. symbiotic bacteria.

b. antagonistic bacteria.

the table shows the ID50 for Staphylococcus aureus in wounds with and without the administration of ampicillin before surgery. Based on the data, the administration of ampicillin before surgery a. replaces tetracycline. b. decreases the risk of staphylococcal infection. c. increases the risk of staphylococcal infection. d. has no effect on risk of infection. e. The answer cannot be determined based on the information provided.

b. decreases the risk of staphylococcal infection.

Bacteria such as E. coli and Salmonella produce invasins that bind host cells, thus causing the cells to a. release cytokines. b. engulf the bacteria. c. release TNF. d. destroy the bacteria. e. produce iron-binding proteins.

b. engulf the bacteria.

Which of the following contributes to the virulence of a pathogen? a. numbers of microorganisms that gain access to a host and evasion of host defenses b. numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production c. numbers of microorganisms that gain access to a host d. evasion of host defenses e. toxin production

b. numbers of microorganisms that gain access to a host, evasion of host defenses, and toxin production

Endotoxins in sterile injectable drugs could cause a. giant cell formation. b. septic shock symptoms. c. nerve damage. d. no damage, because they are sterile. e. infection.

b. septic shock symptoms.

If a patient notices a healthcare worker not following suggested precautions, a. they should immediately wash their hands. b. they should immediately bring it to the attention of the healthcare worker. c. they should leave the healthcare facility immediately.

b. they should immediately bring it to the attention of the healthcare worker.

Plague is transmitted through the bite of an infected flea. Which of the following best describes this mode of transmission? a. direct contact transmission b. vector transmission c. indirect contact transmission d. vehicle transmission

b. vector transmission

Which of the following would be considered a fomite? a. A fly b Contaminated water c. An infected toy d. A tick

c. An infected toy

The CDC is located in a. Los Angeles, CA. b. New York City, NY. c. Atlanta, GA. d. Washington, DC. e. Chicago, IL.

c. Atlanta, GA.

What type of nosocomial infection is likely to arise from intravenous catheterizations? a. Urinary tract b. Surgical c. Bacteremia d. Lower respiratory e. Cutaneous

c. Bacteremia

Which of the following is an example of the symbiotic relationship known as mutualism? a. a tapeworm in the gastrointestinal tract of a human b. saprophytic Mycobacterium of the ear c. E. coli within the large intestine d. Corynebacterium on the surface of the eye

c. E. coli within the large intestine

The brain tissue of the birds indicated the possibility of encephalitis. What is encephalitis, and why should this type of infection cause concern among health care professionals? a. Encephalitis is an inflammation of the meninges. It is a concern to health care professionals because of how quickly the infection will spread to the rest of the body. b. Encephalitis is an inflammation of the peripheral nervous system. It is a concern to health care professionals because of how quickly the infection will spread to the rest of the body. c. Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures. d. Encephalitis is an inflammation of the spinal cord. It is a concern to health care professionals because the infection will spread to the brain.

c. Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.

Where do Salmonella pathogens grow and replicate in the infected host? a. Inside Shigella cells b. Inside M cells c. Inside phagocytes d. Inside intestinal epithelial cells

c. Inside phagocytes

How does the protozoan Trypanosoma evade detection by the immune system? a. It produces a capsule which is composed of polysaccharides similar to those found in the host. b. It prevents phagosome-lysosome fusion. c. It can change the surface antigens frequently, preventing the immune system from tracking it. d. It can resist oxidation inside macrophages.

c. It can change the surface antigens frequently, preventing the immune system from tracking it.

Which of the following is the best mode of controlling the spread of West Nile infections? a. Kill all mosquitoes to prevent the transmission of West Nile virus. b. Kill all birds to prevent the amplification and transmission of West Nile virus. c. Limit exposure to mosquitoes to prevent the transmission of West Nile virus. d. Limit exposure to birds to prevent the transmission of West Nile virus.

c. Limit exposure to mosquitoes to prevent the transmission of West Nile virus.

What are leukocidins? a. Molecules that can degrade IgA b. Molecules that destroy the complement proteins c. Molecules that are capable of destroying phagocytes

c. Molecules that are capable of destroying phagocytes

Which of the following statements about adherence is true? a. Most bacteria can adhere to any cell in the host. b. The host cell receptors for bacterial adhesins are usually proteins. c. Most bacterial adhesins are glycoproteins or lipoproteins. d. Adhesins are always located on the bacterium's cell membrane.

c. Most bacterial adhesins are glycoproteins or lipoproteins.

What is the etiologic agent of typhoid? a. Shigella b. E. coli c. Salmonella

c. Salmonella

If mosquitoes are the mode of transmission for West Nile virus, why did the students in Bill's virology class focus on finding the virus in the dead birds rather than collecting mosquitoes to examine? a. The students tried to isolate and identify West Nile virus from birds because they are large animals. It would be difficult to isolate West Nile virus from mosquitoes because they are small. b. The students tried to isolate and identify West Nile virus from birds because they had access to dead birds that were known to be infected with West Nile virus. c. The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals. d. The students tried to isolate and identify West Nile virus from birds because it is faster to isolate the virus from a bird than to isolate it from a mosquito.

c. The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.

Why are invasive procedures likely to increase the risk of nosocomial infections? a. Invasive procedures require long term hospital stays, thereby increasing the number of visitors seen by the patient. b. Invasive procedures must use antibiotics. c. These procedures allow microbes from the skin to enter the bloodstream of the patient. d. These procedures are carried out by health care workers, who carry resistant microbes.

c. These procedures allow microbes from the skin to enter the bloodstream of the patient.

How do superantigens enable pathogens to hide from the immune system if they actually stimulate the immune system? a. They cause the immune system to turn on itself. b. They cause the immune system to destroy IgA antibodies. c. They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen. d. They cause fever, which destroys the complement proteins.

c. They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.

Which of the following does NOT contribute to the symptoms of a fungal disease? a. capsules b. metabolic products c. cell walls d. allergic response of the host e. toxins

c. cell walls

Which disease would be potentially propagated in an environment without functional plumbing and in which drinking water is contaminated with sewage? a. ringworm b. influenza c. cholera d. yellow fever

c. cholera

The most frequently used portal of entry for pathogens is the a. mucous membranes of the gastrointestinal tract. b. skin. c. mucous membranes of the respiratory tract. d. parenteral route. e. All of these portals are used equally.

c. mucous membranes of the respiratory tract.

Which of the following is a fungal zoonosis that can be transmitted by direct contact? a. Lyme disease b. West Nile encephalitis c. ringworm d. tapeworm

c. ringworm

Which of the following is classified as a latent disease? a. tuberculosis b. infectious mononucleosis c. shingles d. influenza

c. shingles

A person who attended a picnic early in the day develops a very high fever and is unresponsive by the evening. This person most likely has been exposed to a(n) a. membrane disrupting toxin. b. enterotoxin. c. superantigen. d. cytotoxin.

c. superantigen.

Which of the following is NOT a communicable disease? a. malaria b. tuberculosis c. tetanus d. typhoid fever e. AIDS

c. tetanus

Symptoms of protozoan and helminthic diseases are due to a. waste products excreted by the parasite. b. tissue damage due to growth of the parasite on the tissues. c. tissue damage due to growth of the parasite on the tissues, waste products excreted by the parasite, and products released from damaged tissues. d. products released from damaged tissues. e. tissue damage due to growth of the parasite on the tissues and waste products excreted by the parasite.

c. tissue damage due to growth of the parasite on the tissues, waste products excreted by the parasite, and products released from damaged tissues.

All of the following contribute to a pathogen's invasiveness EXCEPT a. coagulases. b. capsules. c. toxins. d. cell wall components. e. hyaluronidase.

c. toxins.

The rise in herd immunity amongst a population can be directly attributed to a. increased use of antibiotics. b. improved handwashing. c. vaccinations. d. antibiotic-resistant microorganisms. e. None of the answers is correct.

c. vaccinations.

A dog develops a diarrheal disease after drinking water from a creek during a hike with his owner. Which of the following best describes this method of disease transmission? a. contact transmission b. vector transmission c. vehicle transmission d. There is not enough information to determine the mode of transmission.

c. vehicle transmission

Epidemiology is defined as the study of a. how a disease is transmitted. b. where a disease occurs. c. where and when a disease occurs, and how it is transmitted. d. when a disease occurs.

c. where and when a disease occurs, and how it is transmitted.

Which of the following would be an example of disease transmission via indirect contact? a. Mr. Smith sneezes on an airplane, and the person sitting beside him catches his cold. b. A tick that is infected with Lyme disease bites a hiker, and the hiker gets Lyme disease. c. A restaurant worker has diarrhea caused by Norovirus. He fails to wash his hands adequately before preparing the salad, and his customers get sick. d. A student sneezes on her test booklet. The instructor grades it and catches her cold.

d. A student sneezes on her test booklet. The instructor grades it and catches her cold.

Which of the following is considered a major category of transmission of disease? a. Vector transmission b. Vehicle transmission c. Contact transmission d. Contact, vehicle, and vector transmission

d. Contact, vehicle, and vector transmission

Which of the following statements about lysogenic conversion is true? a. Lysogenic conversion is a result of the transfer of plasmids from one bacterium to another. b. Lysogenic bacteria are always less virulent than non-lysogenic bacteria because the viral infection weakens them. c. Endotoxin production by bacteria is frequently the result of a lysogenic infection. d. Exotoxin production by bacteria is frequently the result of a lysogenic infection.

d. Exotoxin production by bacteria is frequently the result of a lysogenic infection.

Which of the following statements about biological transmission is FALSE? a. The pathogen reproduces in the vector. b. The pathogen may require the vector as a host. c. The pathogen may enter the host in the vector's feces. d. Houseflies are an important vector. e. The pathogen may be injected by the bite of the vector.

d. Houseflies are an important vector.

Which of the following enzymes breaks down the "glue" that holds cells together? a. Fibrinolysin b. Streptokinase c. Collagenase d. Hyaluronidase

d. Hyaluronidase

Why is a release of endotoxin into the bloodstream potentially deadly? a. Endotoxin can quickly enter the brain from the bloodstream, causing brain damage. b. It causes necrosis of the liver. c. It results in dehydration of the patient. d. It can lower blood pressure and cause the patient to go into shock.

d. It can lower blood pressure and cause the patient to go into shock.

Endotoxins are also known as a. interleukin-1. b. cytokines. c. prostaglandins. d. Lipid A.

d. Lipid A.

Which of the following statements concerning pathology, infection, and disease is true? a. Microorganisms that make up the normal microbiota of an individual never cause disease. b. The term infection is synonymous with the term disease. c. The majority of microorganisms are pathogenic. d. Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.

d. Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.

Which of the following virulence factors would be found in Staphylococcus aureus? a. Collagenase b. Hyaluronidase c. Streptokinase d. Staphylokinase

d. Staphylokinase

What do hyaluronidase and kinase have in common? a. They both break down components of the extracellular matrix. b. They are both critical components of microbial capsules. c. They both directly prevent phagocytosis. d. They are both enzymes involved in evading host defense. e. All of the above are correct.

d. They are both enzymes involved in evading host defense.

How do Shigella cells move between host cells? a. They are secreted by phagocytes. b. They lyse the M cell, releasing thousands of new cells to infect other host cells. c. They are secreted directly into the epithelial cells from the M cells. d. They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another.

d. They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another.

Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease? a. West Nile virus causes an infection and death in birds such as crows and blue jays. b. West Nile virus causes a latent viral infection that can emerge later in life. c. West Nile virus was first isolated in Uganda in 1937 and has caused significant outbreaks every year since then. d. West Nile virus outbreaks have increased in number and affected areas since 1937.

d. West Nile virus outbreaks have increased in number and affected areas since 1937.

The fimbriae of Neisseria gonorrhea and enteropathogenic E. coli are examples of a. adhesins. b. ligands. c. receptors. d. adhesins and ligands. e. adhesins, ligands, and receptors.

d. adhesins and ligands.

Which of the following virulence factors could directly prevent phagocytosis and/or phagocytic degradation? a. M proteins b. capsules c. waxy lipids d. all of the above e. none of the above

d. all of the above

Which of the following diseases is NOT spread by droplet infection? a. measles b. tuberculosis c. diphtheria d. botulism e. the common cold

d. botulism

An exotoxin that has the ability to kill or damage host cells is referred to as a(n) a. enterotoxin. b. superantigen. c. A-B toxin. d. cytotoxin. e. neurotoxin.

d. cytotoxin.

Malaria is an infectious disease caused by infection with a protozoan. In certain tropical regions, malaria is constantly present. We would say that malaria is a(n) __________ disease in these regions. a. epidemic b. pandemic c. sporadic d. endemic

d. endemic

Koch observed Bacillus anthracis multiplying in the blood of cattle. What is the condition specifically called when pathogens multiply in the blood? a. systemic infection b. bacteremia c. focal infection d. septicemia e. local infection

d. septicemia

Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that a. bacteria that cause periodontal disease adhere to teeth. b. streptococci get bacterial infections. c. streptococci cause periodontal disease. d. streptococcal colonization is necessary for periodontal disease. e. bacteria that cause periodontal disease adhere to gums and teeth.

d. streptococcal colonization is necessary for periodontal disease.

Measles viruses are capable of inactivating host defenses by a. producing superantigens. b. destroying complement proteins. c. producing leukocidins. d. suppressing the immune system.

d. suppressing the immune system.

The ID50 is a. the dose that will kill some of the test population. b. the dose that will cause an infection in some of the test population. c. a measure of pathogenicity. d. the dose that will cause an infection in 50 percent of the test population. e. the dose that will kill 50 percent of the test population.

d. the dose that will cause an infection in 50 percent of the test population.

Which of the following is NOT a reservoir of infection? a. a sick animal b. a healthy person c. a hospital d. a sick person e. None of the answers is correct; all of these can be reservoirs of infection.

e. None of the answers is correct; all of these can be reservoirs of infection.

Which of the following pairs is mismatched? a. syphilis direct contact b. salmonellosis vehicle transmission c. influenza droplet infection d. malaria vector e. None of the pairs is mismatched.

e. None of the pairs is mismatched.

Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections? a. Inexpensive b. Reusable c. Washable d. Long e. Single-use

e. Single-use

Transient microbiota differ from normal microbiota in that transient microbiota a. cause diseases. b. are found in a certain location on the host. c. are always acquired by direct contact. d. never cause disease. e. are present for a relatively short time

e. are present for a relatively short time

The science that deals with when diseases occur and how they are transmitted is called a. morbidity and mortality. b. ecology. c. public health. d. communicable disease. e. epidemiology.

e. epidemiology.

Which one of the following does NOT contribute to the incidence of nosocomial infections? a. lack of insect control b. antibiotic resistance c. lack of handwashing d. lapse in aseptic techniques e. gram-negative cell walls

e. gram-negative cell walls

One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in a. body odor. b. normal microbiota returning immediately. c. fewer diseases. d. no bacterial growth because washing removes their food source. e. increased susceptibility to disease.

e. increased susceptibility to disease.

The major significance of Robert Koch's work is that a. microorganisms can be cultured. b. diseases can be transmitted from one animal to another. c. microorganisms are the result of disease. d. microorganisms are present in a diseased animal. e. microorganisms cause disease.

e. microorganisms cause disease.

A disease that is constantly present in a population is called a(n)_________

endemic disease

Microorganisms that typically colonize a host without causing disease are referred to as the ________

normal microbiota