Microbiology

Chapter 20

Question 1

What virulence factor is common to all Gram negative bacilli?

A) Capsule

B) Exotoxin

C) Endotoxin

D) DNase

E) Hemolysin

Question 2

What component of lipopolysaccharide accounts for most of its adverse effects?

A) Endotoxin

B) Lipid A

C) Peptidoglycan

D) Polysaccharide

E) Lipoprotein

Question 3

What genus of organisms is important as decomposers and bioremediators?

A) Pseudomonas

B) Brucella

C) Francisella

D) Bordetella

E) Alcaligenes

Question 4

What condition is a result of a Pseudomonas aeruginosa infection in a compromised host?

A) Skin rashes

B) Urinary tract infections

C) External ear infections

D) Corneal ulcers

E) Pneumonia

Question 5

Brucellosis is spread to humans by human contact with all but which of the following?

A) Blood

B) Urine

C) Placentas

D) Cerebrospinal fluid

E) Raw milk

Question 6

What is the cardinal manifestation of human brucellosis?

A) Vomiting and diarrhea

B) A pseudomembrane in the throat

C) A fluctuating pattern of fever

D) Peeling of the skin on the palms and soles

E) A cough that lasts for months

Question 7

What is/are the chief reservoir(s) for Francisella tularensis?

A) Domestic animals

B) Ticks and biting flies

C) Humans and other large primates

D) Rabbits and rodents

E) Soil

Question 8

What is the reservoir for Bordetella pertussis?

A) Soil

B) Healthy human carriers

C) Water

D) Wild rodents

E) Arthropods

Question 9

Why has the number of reported cases of pertussis risen during the past 25 years?

A) The pertussis vaccine does not provide long-term protection.

B) The number of healthy carriers has risen.

C) More children (who account for the majority of cases) were born during this time period.

D) The organism mutated to a more virulent form.

E) Fewer parents have vaccinated their children against pertussis.

Question 10

How are Legionella species transmitted from their natural habitats to humans?

A) Aerosols

B) Dust

C) Contaminated food

D) Contaminated drinking water

E) By vectors

Question 11

What is the reservoir of Legionella species?

A) Healthy human carriers

B) Soil

C) The ameba Hartmanella

D) Water

E) Wild rodents

Question 12

Which is not a characteristic of the coliform group?

A) Non-glucose fermenting

B) Lactose fermenting

C) Oxidase negative

D) Gram negative rods

E) Non-sporeforming

Question 13

A positive indole test indicates cleavage of indole from what substrate?

A) Lactose

B) Glucose

C) Tyrosine

D) Tryptophan

E) Sucrose

Question 14

Why does urea medium turn pink during a positive reaction?

A) The organism ferments lactose to acidic end-products which then lower the pH of the medium

B) The organism can utilize citrate as a carbon source and releases carbon dioxide which then combines with water and sodium to produce sodium carbonate and raises the pH of the medium

C) The organism produces urease which accumulates and lowers the pH of the medium

D) The organism cannot grow in the presence of bile salts

E) The organism produces urease that cleaves urea into ammonium which then raises the pH of the medium

Question 15

What is the reservoir for Escherichia coli O157:H7?

A) Humans

B) Cattle

C) Soil

D) Wild rodents

E) Ameba

Question 16

Which pathogenic strain of Escherichia coli is typically responsible for most travel-related gastrointestinal diseases?

A) Enterotoxigenic

B) Enteroinvasive

C) Enteropathogenic

D) Enterohemorrhagic

E) Enteroaggregative

Question 17

What disease accounts for the majority of clinical disease associated with Enterobacter?

A) Nosocomial pneumonia

B) Meningitis

C) Bacteremia

D) Urinary tract infections

E) Septicemia

Question 18

Which genus of the enteric group is considered to be a primary pathogen?

A) Serratia

B) Shigella

C) Escherichia

D) Klebsiella

E) Proteus

Question 19

What is the reservoir for Salmonella typhi?

A) Wild rodents

B) Soil

C) Humans

D) Pigs

E) Fowl

Question 20

Why is antibiotic resistance among the salmonellas on the rise?

A) New strains of these organisms are emerging

B) The organisms are naturally resistant to most antibiotics

C) Most patients who contract salmonellosis fail to visit a physician

D) Viral infections cannot be treated with antibiotics

E) The practice of adding antibiotics to animal feeds

Question 21

Most food infections or other enteric illnesses are transmitted by all but which of the following?

A) Food

B) Fingers

C) Families

D) Feces

E) Flies

Question 22

Why can shigellosis be spread by direct person-to-person contact?

A) Because it is spread by the respiratory route

B) Because the organisms have so many virulence factors

C) Because people can become chronic carriers

D) Because the organisms' infectious dose is approximately 200 organisms

E) Because the organisms form endospores which are very resistant

Question 23

What are the endemic reservoirs of Yersinia pestis?

A) Fleas

B) Rats

C) Chipmunks

D) Humans

E) Mice and voles

Question 24

Which is incorrect about the plague?

A) It is caused by Yersinia pestis.

B) Less than 10 cases per year occur in the U.S.

C) Infection causes bubos in the groin.

D) Even with proper treatment, the plague is generally fatal.

E) It is an internationally quarantinable disease.

Question 25

What disease is caused by Haemophilus influenzae?

A) Acute bacterial meningitis

B) Flu

C) Shipping fever

D) Chancroid

E) Conjunctivitis