Microbiology

Chapter 18

Question 1

What is the most serious pathogen within the genus Staphylococcus?

A) Staphylococcus epidermidis

B) Staphylococcus saprophyticus

C) Staphylococcus hominis

D) Staphylococcus aureus

E) Staphylococcus capitis

Question 2

Why is Staphylococcus aureus considered a troublesome hospital pathogen?

A) Because its optimum growth temperature is 37°C

B) Because it resists the effects of many disinfectants and antibiotics

C) Because it is a facultative anaerobe

D) Because it grows in large, round opaque colonies

E) Because it can digest proteins and lipids, and ferment a variety of sugars

Question 3

What is the most diagnostic species characteristic of Staphylococcus aureus?

A) The production of hyaluronidase

B) The production of penicillinase

C) The production of coagulase

D) The production of leukocidin

E) The production of α-toxin

Question 4

Which is not an effect of the Staphylococcus aureus alpha-toxin?

A) It acts upon the human gastrointestinal tract

B) It lyses red blood cells of various mammals

C) It causes leukocyte damage

D) It damages skeletal and heart muscle

E) It damages kidney tissues

Question 5

Staphylococcus aureus is most frequently isolated from what body site?

A) Gastrointestinal tract

B) Genitourinary tract

C) Vagina

D) Nostrils

E) Stomach

Question 6

What is the most common infection caused by Staphylococcus aureus?

A) Staphylococcal enterotoxicosis

B) Folliculitis

C) Toxic shock syndrome

D) Osteomyelitis

E) Staphylococcal Bacteremia

Question 7

Staphylococcal food intoxication is associated with eating all but which of the following foods?

A) Custards

B) Chicken salad

C) Ham and processed meats

D) Hamburger

E) Cream pastries

Question 8

What factor appears to support colonization and proliferation of both Staphylococcus aureus and the coagulase-negative staphylococci within patients?

A) An open wound

B) A preexisting condition

C) A foreign object

D) A primary infection

E) The use of antibiotics

Question 9

What is the key test that separates Staphylococcus aureus from other staphylococci?

A) Susceptibility to novobiocin

B) Catalase test

C) Growth on blood agar

D) Coagulase test

E) Urease test

Question 10

What is the key test that differentiates the staphylococci from the streptococci?

A) Catalase Test

B) Susceptibility to novobiocin

C) Growth on blood agar

D) Coagulase test

E) Urease test

Question 11

How are the streptococci differentiated from the staphylococci when viewed microscopically following the Gram stain procedure?

A) Staphylococci are Gram positive, while streptococci are Gram negative

B) Staphylococci are Gram positive and grow in grape-like clusters, while streptococci are also Gram positive, but grow in chains

C) Staphylococci are Gram positive cocci, while streptococci are Gram positive bacilli

D) Staphylococci are Gram negative bacilli, while streptococci are Gram negative cocci

E) They cannot be differentiated microscopically

Question 12

What is the most serious streptococcal pathogen of humans?

A) Streptococcus agalactiae

B) Streptococcus mutans

C) Streptococcus pyogenes

D) Enterococcus faecalis

E) Streptococcus sanguis

Question 13

Why do toxic shock syndrome and necrotizing fasciitis cause such severe pathology to host tissues?

A) The streptococcal toxins act as superantigens

B) The organisms have been infected by a temperate bacteriophage

C) The organisms possess M protein

D) The organisms produce streptokinase and hyaluronidase

E) The organisms are extremely resistant to antimicrobial drugs

Question 14

Primary infections caused by Streptococcus pyogenes are due to the organisms invading what two body sites?

A) Nose and vagina

B) Skin and eyes

C) Eyes and gastrointestinal tract

D) Mouth and urethra

E) Skin and throat

Question 15

What species of the streptococci can be transferred to an infant during delivery?

A) Streptococcus pyogenes

B) Enterococcus faecalis

C) Enterococcus faecium

D) Streptococcus bovis

E) Streptococcus agalactiae

Question 16

What test allows for the differentiation of Group A streptococci from other beta-hemolytic streptococci?

A) CAMP test

B) Hippurate hydrolysis

C) Esculin hydrolysis

D) Bacitracin sensitivity

E) Growth in 6.5% salt

Question 17

What is the major virulence factor of Streptococcus pneumoniae?

A) M protein

B) Pyogenic exotoxins

C) Capsule

D) DNase

E) Hyaluronidase

Question 18

What organism is responsible for the majority of cases of otitis media in children?

A) Streptococcus pneumoniae

B) Staphylococcus aureus

C) Streptococcus pyogenes

D) Streptococcus mutans

E) Staphylococcus epidermidis

Question 19

Virulence factors of Neisseria gonorrhoeae include all except which of the following?

A) Pili that promote attachment

B) Surface molecules that promote attachment

C) IgA protease

D) Hemolysis

E) Pili that slow phagocytosis

Question 20

Most cases of gonorrhea occur within what age range?

A) 14-18 years

B) 18-24 years

C) 24-26 years

D) 26-30 years

E) 30-35 years

Question 21

How do Neisseria gonorrhoeae appear when stained with the Gram stain and viewed microscopically?

A) Gram positive cocci in grape-like clusters

B) Gram negative rods

C) Gram positive diplococci

D) Gram negative cocci in grape-like clusters

E) Gram negative diplococci

Question 22

Meningitis associated with Neisseria meningitidis usually occurs as what type of disease?

A) Endemic

B) Epidemic

C) Pandemic

D) Isolated

E) Common-source

Question 23

What is the reservoir of Neisseria meningitidis?

A) Soil

B) Saltwater

C) Human carriers

D) Domesticated animals

E) Reptiles

Question 24

How is Neisseria meningitidis spread?

A) Through respiratory secretions or droplets

B) Through contaminated fomites

C) Through consumption of contaminated food or water

D) By insect vectors

E) Through sexual contact