Question 1

What is the cellular structure that Streptococcus pyogenes relies primarily on for its virulence?

Accepted Answer

A)  Peptidoglycan 
B)  Lipopolysaccharide 
C)  S antigens 
D)  M proteins 
A)  Peptidoglycan 
B)  Lipopolysaccharide 
C)  S antigens 
D)  M proteins

Question 2

Streptokinase is an enzyme produced by Group A streptococci that

Accepted Answer

A)  breaks down staphylococci. 
B)  breaks down connective tissue. 
C)  produces a maculopapular rash in rheumatic fever. 
D)  lyses fibrin clots. 
A)  breaks down staphylococci. 
B)  breaks down connective tissue. 
C)  produces a maculopapular rash in rheumatic fever. 
D)  lyses fibrin clots.

Question 3

Which of the following is the drug of choice for treating most streptococcal infections?

Accepted Answer

A)  Erythromycin 
B)  Cephalothin 
C)  Penicillin 
D)  Gentamicin 
A)  Erythromycin 
B)  Cephalothin 
C)  Penicillin 
D)  Gentamicin

Question 4

The major virulence factor for Streptococcus pneumoniae is

Accepted Answer

A)  hemolysin. 
B)  protease. 
C)  hyaluronidase. 
D)  capsular polysaccharide. 
A)  hemolysin. 
B)  protease. 
C)  hyaluronidase. 
D)  capsular polysaccharide.

Question 5

Skin infections or pyoderma caused by Group A streptococci result in all the following syndromes, except

Accepted Answer

A)  impetigo. 
B)  bullous impetigo. 
C)  cellulitis. 
D)  erysipelas. 
A)  impetigo. 
B)  bullous impetigo. 
C)  cellulitis. 
D)  erysipelas.

Question 6

Where are the viridans streptococci constituents of the normal microbiota?

Accepted Answer

A)  Upper respiratory tract 
B)  Female genital tract 
C)  Gastrointestinal tract 
D)  All of the above 
A)  Upper respiratory tract 
B)  Female genital tract 
C)  Gastrointestinal tract 
D)  All of the above

Question 7

What is the drug of choice to treat Group A streptococci when the patient cannot tolerate penicillin?

Accepted Answer

A)  Penicillin 
B)  Erythromycin 
C)  Gentamicin 
D)  Cefoxitin 
A)  Penicillin 
B)  Erythromycin 
C)  Gentamicin 
D)  Cefoxitin

Question 8

Streptococcus pneumoniae causes all the following infections, except

Accepted Answer

A)  pharyngitis. 
B)  pneumonia. 
C)  bacteremia. 
D)  meningitis. 
A)  pharyngitis. 
B)  pneumonia. 
C)  bacteremia. 
D)  meningitis.

Question 9

A microbiologist is reading a sputum culture on the bench. There is growth on the SBA and chocolate (CHOC) plates, but no growth on the MacConkey (MAC) plate. The colonies growing on the SBA have produced a wide, deep, clear zone of $\beta$-hemolysis around and under the colonies. What organism could this be?

Accepted Answer

A)  Escherichia coli 
B)  Staphylococcus aureus 
C)  Streptococcus pyogenes 
D)  Streptococcus pneumoniae 
A)  Escherichia coli 
B)  Staphylococcus aureus 
C)  Streptococcus pyogenes 
D)  Streptococcus pneumoniae

Question 10

A microbiologist is reading a sputum culture on the bench. There is growth on the BAP and CHOC plates, but no growth on the MAC plate. The colonies growing on the BAP have discolored the media to a green color around and under the colonies. What organism could this be?

Accepted Answer

A)  Escherichia coli 
B)  Staphylococcus aureus 
C)  Haemophilus influenzae 
D)  Streptococcus pneumoniae 
A)  Escherichia coli 
B)  Staphylococcus aureus 
C)  Haemophilus influenzae 
D)  Streptococcus pneumoniae

Question 11

Why do Streptococcus pneumoniae colonies on SBA sometimes appear like a coin-raised edges and a depressed center?

Accepted Answer

A)  The older growth at the center is smaller due to lack of nutrients. 
B)  The newer growths on the outside of the colony undergo the Quellung reaction. 
C)  The older growth at the center is killed due to autolysis. 
D)  The newer growth has a thicker capsule, therefore it appears raised. 
A)  The older growth at the center is smaller due to lack of nutrients. 
B)  The newer growths on the outside of the colony undergo the Quellung reaction. 
C)  The older growth at the center is killed due to autolysis. 
D)  The newer growth has a thicker capsule, therefore it appears raised.

Question 12

What disease is produced by Group A streptococci that are characterized by a rapidly progressing inflammation and necrosis of the skin, subcutaneous fat, and fascia?

Accepted Answer

A)  Erysipelas 
B)  Scarlet fever 
C)  Necrotizing fasciitis 
D)  Streptococcal toxic shock syndrome 
A)  Erysipelas 
B)  Scarlet fever 
C)  Necrotizing fasciitis 
D)  Streptococcal toxic shock syndrome

Question 13

All of the following are virulence factors associated with Group A Streptococcus, except

Accepted Answer

A)  enterotoxins. 
B)  hemolysins. 
C)  toxins. 
D)  enzymes. 
A)  enterotoxins. 
B)  hemolysins. 
C)  toxins. 
D)  enzymes.

Question 14

Which of the following tests can be used to presumptively identify Streptococcus pyogenes?

Accepted Answer

A)  Optochin 
B)  Bacitracin 
C)  Nitrate 
D)  Citrate 
A)  Optochin 
B)  Bacitracin 
C)  Nitrate 
D)  Citrate

Question 15

What test can be used to differentiate Streptococcus agalactiae from other $\beta$-hemolytic streptococci?

Accepted Answer

A)  Bacitracin 
B)  Hippurate hydrolysis 
C)  Pyrrolidonyl-a-naphthylamide (PYR) 
D)  Optochin 
A)  Bacitracin 
B)  Hippurate hydrolysis 
C)  Pyrrolidonyl-a-naphthylamide (PYR) 
D)  Optochin

Question 16

A young girl goes to her physician's office with a fever, headache, and a sore throat. The mother states the girl has a fever of 38.8° C (102° F). What test should the physician order?

Accepted Answer

A)  Throat culture 
B)  Antistreptolysin O 
C)  Optochin 
D)  Gram stain 
A)  Throat culture 
B)  Antistreptolysin O 
C)  Optochin 
D)  Gram stain

Question 17

What is one of the most common diseases caused by streptococci?

Accepted Answer

A)  Pharyngitis 
B)  Rheumatic fever 
C)  Acute glomerulonephritis 
D)  Scarlet fever 
A)  Pharyngitis 
B)  Rheumatic fever 
C)  Acute glomerulonephritis 
D)  Scarlet fever

Question 18

Two serious complications of an infection with Group A streptococci are

Accepted Answer

A)  toxic shock syndrome and scarlet fever. 
B)  gangrene and rheumatic fever. 
C)  acute glomerulonephritis and necrotizing fasciitis. 
D)  acute glomerulonephritis and rheumatic fever. 
A)  toxic shock syndrome and scarlet fever. 
B)  gangrene and rheumatic fever. 
C)  acute glomerulonephritis and necrotizing fasciitis. 
D)  acute glomerulonephritis and rheumatic fever.

Question 19

What causes the red spreading rash in scarlet fever?

Accepted Answer

A)  Hyaluronidase 
B)  Streptolysin O 
C)  Streptococcal pyrogenic exotoxins 
D)  Streptolysin S 
A)  Hyaluronidase 
B)  Streptolysin O 
C)  Streptococcal pyrogenic exotoxins 
D)  Streptolysin S

Question 20

Which of following is found in the cell wall made of streptococci and enterococci?

Accepted Answer

A)  Lipopolysaccharide and carbohydrates 
B)  Protein A and phospholipids 
C)  Cholesterol and teichoic acid 
D)  Teichoic acid and peptidoglycan 
A)  Lipopolysaccharide and carbohydrates 
B)  Protein A and phospholipids 
C)  Cholesterol and teichoic acid 
D)  Teichoic acid and peptidoglycan

Exam 15: Streptococcus, Enterococcus, and Other Catalase-Negative, Gram-Positive Cocci

What is the cellular structure that Streptococcus pyogenes relies primarily on for its virulence?

Streptokinase is an enzyme produced by Group A streptococci that

Which of the following is the drug of choice for treating most streptococcal infections?

The major virulence factor for Streptococcus pneumoniae is

Skin infections or pyoderma caused by Group A streptococci result in all the following syndromes, except

Where are the viridans streptococci constituents of the normal microbiota?

What is the drug of choice to treat Group A streptococci when the patient cannot tolerate penicillin?

Streptococcus pneumoniae causes all the following infections, except

A microbiologist is reading a sputum culture on the bench. There is growth on the BAP and CHOC plates, but no growth on the MAC plate. The colonies growing on the BAP have discolored the media to a green color around and under the colonies. What organism could this be?

Why do Streptococcus pneumoniae colonies on SBA sometimes appear like a coin-raised edges and a depressed center?

What disease is produced by Group A streptococci that are characterized by a rapidly progressing inflammation and necrosis of the skin, subcutaneous fat, and fascia?

All of the following are virulence factors associated with Group A Streptococcus, except

Which of the following tests can be used to presumptively identify Streptococcus pyogenes?

What test can be used to differentiate Streptococcus agalactiae from other β\betaβ -hemolytic streptococci?

A young girl goes to her physician's office with a fever, headache, and a sore throat. The mother states the girl has a fever of 38.8° C (102° F). What test should the physician order?

What is one of the most common diseases caused by streptococci?

Two serious complications of an infection with Group A streptococci are

What causes the red spreading rash in scarlet fever?

Which of following is found in the cell wall made of streptococci and enterococci?

Bacterial Cell Structure, Physiology, Metabolism, and Genetics

Hostparasite 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 Mechanisms

Antimicrobial Susceptibility Testing

Staphylococci

Aerobic Gram-Positive Bacilli

Neisseria Species and Moraxella Catarrhalis

Haemophilus, Hacek, Legionella, and Other Fastidious Gram-Negative Bacilli

Enterobacteriaceae

Vibrio, Aeromonas, 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 Infections

Infections in Special Populations

Zoonotic Diseases

Ocular Infections

Filters

What test can be used to differentiate Streptococcus agalactiae from other $\beta$ -hemolytic streptococci?