Question 1

All of the following staphylococci are coagulase-positive except:

Accepted Answer

A) Staphylococcus aureus. 
B) S.saprophyticus. 
C) S.intermedius. 
D) S.delphini. 
A) Staphylococcus aureus. 
B) S.saprophyticus. 
C) S.intermedius. 
D) S.delphini. B

Question 2

How do staphylococci spread so easily when infecting the skin?

Accepted Answer

A) They produce hyaluronidase, which hydrolyzes hyaluronic acid present in the intracellular ground substance that makes up connective tissue. 
B) They produce lipase, which melts the fat under the skin, making it easier to spread. 
C) The hemolysins kill the white and red blood cells; then the protease liquefies the skin protein, allowing easy penetration for the bacteria. 
D) All of the above. 
A) They produce hyaluronidase, which hydrolyzes hyaluronic acid present in the intracellular ground substance that makes up connective tissue. 
B) They produce lipase, which melts the fat under the skin, making it easier to spread. 
C) The hemolysins kill the white and red blood cells; then the protease liquefies the skin protein, allowing easy penetration for the bacteria. 
D) All of the above. A

Question 3

Staphylococci resist the action of inflammatory cells by the production of toxins and enzymes, thereby establishing:

Accepted Answer

A) a focal lesion. 
B) an infection. 
C) toxic shock syndrome. 
D) scalded skin syndrome. 
A) a focal lesion. 
B) an infection. 
C) toxic shock syndrome. 
D) scalded skin syndrome. A

Question 4

What is the mechanism by which toxic shock syndrome toxin-1 (TSST-1) causes toxic shock syndrome (TSS)?

Accepted Answer

A) The bacteria release the toxin into the blood and it goes to the hypothalamus to produce an extremely high fever. 
B) The bacteria release the toxin into the gastrointestinal system where phagocytes engulf the bacteria, leaving a pseudomembrane that irritates the colon. 
C) The toxin is a superantigen that stimulates T-cell proliferation with production of large amounts of cytokines. 
D) All of the above. 
A) The bacteria release the toxin into the blood and it goes to the hypothalamus to produce an extremely high fever. 
B) The bacteria release the toxin into the gastrointestinal system where phagocytes engulf the bacteria, leaving a pseudomembrane that irritates the colon. 
C) The toxin is a superantigen that stimulates T-cell proliferation with production of large amounts of cytokines. 
D) All of the above.

Question 5

Staphylococcus aureus food poisoning is most commonly caused by which two enterotoxins?

Accepted Answer

A) A and D 
B) A and B 
C) B and C 
D) B and D 
A) A and D 
B) A and B 
C) B and C 
D) B and D

Question 6

What are the staphylococcal products that cause diarrhea and vomiting in humans?

Accepted Answer

A) Enterotoxins 
B) Endotoxins 
C) Cytolytic toxins 
D) Cellular components, such as protein A 
A) Enterotoxins 
B) Endotoxins 
C) Cytolytic toxins 
D) Cellular components, such as protein A

Question 7

What are the effects of the Panton-Valentine toxin produced by Staphylococcus aureus?

Accepted Answer

A) It acts on sphingomyelin in the plasma membrane of red blood cells. 
B) It kills polymorphonuclear leukocytes. 
C) It kills macrophages. 
D) It lyses red blood cells, damages platelets and macrophages, and can cause severe tissue damage. 
A) It acts on sphingomyelin in the plasma membrane of red blood cells. 
B) It kills polymorphonuclear leukocytes. 
C) It kills macrophages. 
D) It lyses red blood cells, damages platelets and macrophages, and can cause severe tissue damage.

Question 8

How is Staphylococcus saprophyticus presumptively identified?

Accepted Answer

A) Latex agglutination test for clumping factor 
B) Rabbit plasma test for coagulase 
C) Novobiocin susceptibility 
D) All of the above 
A) Latex agglutination test for clumping factor 
B) Rabbit plasma test for coagulase 
C) Novobiocin susceptibility 
D) All of the above

Question 9

What is the function of protein A in the cell wall of Staphylococcus aureus?

Accepted Answer

A) To keep the structural integrity of the cell wall and keep out antibiotics 
B) To bind the IgG and prevent phagocytosis 
C) To bind the IgM and inactivate natural killer cells 
D) To block the activation of the complement cascade 
A) To keep the structural integrity of the cell wall and keep out antibiotics 
B) To bind the IgG and prevent phagocytosis 
C) To bind the IgM and inactivate natural killer cells 
D) To block the activation of the complement cascade

Question 10

A young man goes to his physician complaining of large, raised, suppurative abscesses on his neck.The man denies having a fever or the chills.What is the name of the lesions on his neck, and what organism causes this type of lesions?

Accepted Answer

A) Staphylococcus epidermidis and boils 
B) S.aureus and furuncles 
C) S.saprophyticus and carbuncles 
D) S.sciuri and folliculitis 
A) Staphylococcus epidermidis and boils 
B) S.aureus and furuncles 
C) S.saprophyticus and carbuncles 
D) S.sciuri and folliculitis

Question 11

What is a rare but potentially fatal multisystem disease characterized by high fever, hypotension, and shock, and it is associated with highly absorbent tampons?

Accepted Answer

A) Toxic epidermal necrolysis 
B) Scalded skin syndrome 
C) Bullous impetigo 
D) Toxic shock syndrome 
A) Toxic epidermal necrolysis 
B) Scalded skin syndrome 
C) Bullous impetigo 
D) Toxic shock syndrome

Question 12

All of the following enzymes are produced by staphylococci except:

Accepted Answer

A) lipase. 
B) hyaluronidase. 
C) amylase. 
D) protease. 
A) lipase. 
B) hyaluronidase. 
C) amylase. 
D) protease.

Question 13

What infection occurs secondary to influenza A virus, has a high mortality rate, and occurs among the infants and immunocompromised patients?

Accepted Answer

A) Gangrene 
B) Staphylococcal pneumoniae 
C) Staphylococcal meningitis 
D) Staphylococcal peritonitis 
A) Gangrene 
B) Staphylococcal pneumoniae 
C) Staphylococcal meningitis 
D) Staphylococcal peritonitis

Question 14

Which staphylococcus produces wide zones of beta hemolysis on 5% sheep blood agar?

Accepted Answer

A) Staphylococcus epidermidis 
B) S.aureus 
C) S.intermedius 
D) S.saprophyticus 
A) Staphylococcus epidermidis 
B) S.aureus 
C) S.intermedius 
D) S.saprophyticus

Question 15

A young, healthy woman was rushed to the hospital with a high fever, hypotension, and shock.She had not been feeling well that day, but her condition progressively worsened throughout the day.She was feeling fine until a couple days after she started menstruating.What condition could this woman be exhibiting?

Accepted Answer

A) Scalded skin syndrome 
B) Toxic epidermal necrolysis 
C) Toxic shock syndrome 
D) Food poisoning 
A) Scalded skin syndrome 
B) Toxic epidermal necrolysis 
C) Toxic shock syndrome 
D) Food poisoning

Question 16

What tests are used to detect clumping factor that differentiates Staphylococcus aureus from other staphylococcal species?

Accepted Answer

A) Novobiocin and hemolysin A 
B) Coagulase and latex agglutination 
C) Complement fixation and coagulase 
D) Latex agglutination and enzyme immunoassay (EI
A)  
A) Novobiocin and hemolysin A 
B) Coagulase and latex agglutination 
C) Complement fixation and coagulase 
D) Latex agglutination and enzyme immunoassay (EI
A)

Question 17

Infections caused by Staphylococcus aureus are suppurative, meaning:

Accepted Answer

A) these infections ooze lymph fluid. 
B) the infection is filled with pus and necrotic tissues. 
C) the acute inflammatory response gorges the area with red blood cells. 
D) the toxins activate the coagulation system, which isolates the infection. 
A) these infections ooze lymph fluid. 
B) the infection is filled with pus and necrotic tissues. 
C) the acute inflammatory response gorges the area with red blood cells. 
D) the toxins activate the coagulation system, which isolates the infection.

Question 18

Staphylococcal enterotoxin B is linked to:

Accepted Answer

A) carbuncles. 
B) staphylococcal pseudomembranous enterocolitis. 
C) food poisoning. 
D) toxic shock syndrome. 
A) carbuncles. 
B) staphylococcal pseudomembranous enterocolitis. 
C) food poisoning. 
D) toxic shock syndrome.

Question 19

All of the following virulence factors are associated with Staphylococcus aureus except:

Accepted Answer

A) enterotoxins. 
B) cytolytic toxins. 
C) cellular components such as protein A. 
D) endotoxins. 
A) enterotoxins. 
B) cytolytic toxins. 
C) cellular components such as protein A. 
D) endotoxins.

Question 20

Colony characteristics for Staphylococcus aureus on blood agar after 18 to 24 hours incubation at 35° C include all the following except:

Accepted Answer

A) swarming. 
B) smooth. 
C) white. 
D) round. 
A) swarming. 
B) smooth. 
C) white. 
D) round.

Exam 14: Staphylococci

All of the following staphylococci are coagulase-positive except:

How do staphylococci spread so easily when infecting the skin?

Staphylococci resist the action of inflammatory cells by the production of toxins and enzymes, thereby establishing:

What is the mechanism by which toxic shock syndrome toxin-1 (TSST-1) causes toxic shock syndrome (TSS)?

Staphylococcus aureus food poisoning is most commonly caused by which two enterotoxins?

What are the staphylococcal products that cause diarrhea and vomiting in humans?

What are the effects of the Panton-Valentine toxin produced by Staphylococcus aureus?

How is Staphylococcus saprophyticus presumptively identified?

What is the function of protein A in the cell wall of Staphylococcus aureus?

A young man goes to his physician complaining of large, raised, suppurative abscesses on his neck.The man denies having a fever or the chills.What is the name of the lesions on his neck, and what organism causes this type of lesions?

What is a rare but potentially fatal multisystem disease characterized by high fever, hypotension, and shock, and it is associated with highly absorbent tampons?

All of the following enzymes are produced by staphylococci except:

What infection occurs secondary to influenza A virus, has a high mortality rate, and occurs among the infants and immunocompromised patients?

Which staphylococcus produces wide zones of beta hemolysis on 5% sheep blood agar?

What tests are used to detect clumping factor that differentiates Staphylococcus aureus from other staphylococcal species?

Infections caused by Staphylococcus aureus are suppurative, meaning:

Staphylococcal enterotoxin B is linked to:

All of the following virulence factors are associated with Staphylococcus aureus except:

Colony characteristics for Staphylococcus aureus on blood agar after 18 to 24 hours incubation at 35° C include all the following except:

Bacterial Cell Structure, Physiology, Metabolism, and Genetics

Host-Parasite Interaction

The Laboratory Role in Infection Control

Control of Microorganisms

Performance Improvement in the Microbiology Laboratory

Specimen Collection and Processing

Microscopic Examination of Materials From Infected Sites

Use of Colony Morphology for the Presumptive Identification of Microorganisms

Biochemical Identification of Gram-Negative Bacteria

Immunodiagnosis of Infectious Diseases

Applications of Molecular Diagnostics

Antimicrobial Agent Mechanisms of Action and Resistance

Antimicrobial Susceptibility Testing

Streptococcus, Enterococcus, and Other Catalase-Negative, Gram-Positive Cocci

Aerobic Gram-Positive Bacilli

Neisseria Species and Moraxella Catarrhalis

Haemophilus and Other Fastidious Gram-Negative Bacilli

Enterobacteriaceae

Vibrio, Aeromonas, Plesiomonas, and Campylobacter Species

Nonfermenting and Miscellaneous Gram-Negative Bacilli

Anaerobes of Clinical Importance

The Spirochetes

Chlamydia, Rickettsia and Similar Organisms

Mycoplasma and Ureaplasma

Mycobacterium Tuberculosis and Nontuberculous Mycobacteria

Medically Significant Fungi

Diagnostic Parasitology

Clinical Virology

Agents of Bioterror and Forensic Microbiology

Biofilms: Architects of Disease

Upper and Lower Respiratory Tract Infections

Skin and Soft Tissue Infections

Gastrointestinal Infections and Food Poisoning

Infections of the Central Nervous System

Bacteremia and Sepsis

Urinary Tract Infections

Genital Infections and Sexually Transmitted Diseases

Infections in Special Populations

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