Question 1

What is an anaerobe?

Accepted Answer

A)  An organism that can live with very little oxygen 
B)  An organism that does not require oxygen to live 
C)  An organism that requires some oxygen but moderate concentrations of CO2 to live 
D)  An organism that requires small amounts of oxygen and carbon dioxide to live 
A)  An organism that can live with very little oxygen 
B)  An organism that does not require oxygen to live 
C)  An organism that requires some oxygen but moderate concentrations of CO2 to live 
D)  An organism that requires small amounts of oxygen and carbon dioxide to live

Question 2

What evidence indicates the presence of anaerobes in cultures?

Accepted Answer

A)  A foul odor upon opening an anaerobic jar or bag 
B)  Growth on the anaerobic plates, but not on the sheep blood agar (SB
A)  plates incubated in the CO2 incubator 
C)  Colonies on kanamycin-vancomycin laked-blood agar (KVLB
A)  that fluoresce brick-red under ultraviolet light 
D)  All of the above 
A)  A foul odor upon opening an anaerobic jar or bag 
B)  Growth on the anaerobic plates, but not on the sheep blood agar (SB
A)  plates incubated in the CO2 incubator 
C)  Colonies on kanamycin-vancomycin laked-blood agar (KVLB
A)  that fluoresce brick-red under ultraviolet light 
D)  All of the above

Question 3

All of the following organisms are found on the skin under normal conditions, except

Accepted Answer

A)  Propionibacterium. 
B)  Peptostreptococcus. 
C)  Streptococcus. 
D)  Clostridium. 
A)  Propionibacterium. 
B)  Peptostreptococcus. 
C)  Streptococcus. 
D)  Clostridium.

Question 4

Anaerobes outnumber aerobes in all of the following locations, except

Accepted Answer

A)  skin. 
B)  oral cavity. 
C)  gastrointestinal (GI) tract. 
D)  genitourinary tract. 
A)  skin. 
B)  oral cavity. 
C)  gastrointestinal (GI) tract. 
D)  genitourinary tract.

Question 5

The four major groups of anaerobic gram-negative bacilli include all the following, except

Accepted Answer

A)  Bacteroides fragilis. 
B)  Porphyromonas. 
C)  Prevotella. 
D)  Mobiluncus. 
A)  Bacteroides fragilis. 
B)  Porphyromonas. 
C)  Prevotella. 
D)  Mobiluncus.

Question 6

An Older adult patient in a nursing home is recovering from bacterial pneumonia. The patient has been on a lengthy regiment of antimicrobial agents. Subsequently, the patient is diagnosed with pseudomembranous colitis. What organism is the most likely cause?

Accepted Answer

A)  Clostridium difficile 
B)  C. tetani 
C)  C. perfringens 
D)  C. botulinum 
A)  Clostridium difficile 
B)  C. tetani 
C)  C. perfringens 
D)  C. botulinum

Question 7

All the following are categories of bacterial growth requirements for oxygen and carbon dioxide, except

Accepted Answer

A)  ambient air (95% O2 and 5% CO2). 
B)  microaerophilic (5% O2). 
C)  anaerobic (0% O2). 
D)  capnophilic (about 15% O2 and 5% to 10% CO2). 
A)  ambient air (95% O2 and 5% CO2). 
B)  microaerophilic (5% O2). 
C)  anaerobic (0% O2). 
D)  capnophilic (about 15% O2 and 5% to 10% CO2).

Question 8

After 24-hour incubation, an SBA from a vaginal culture reveals heavy growth of $\alpha$-hemolytic, pinpoint, rough colonies. A catalase test is performed, and it is negative. What organism should you suspect?

Accepted Answer

A)  Lactobacillus 
B)  Diphtheroids 
C)  Listeria 
D)  Arcanobacterium 
A)  Lactobacillus 
B)  Diphtheroids 
C)  Listeria 
D)  Arcanobacterium

Question 9

An anaerobic culture reveals colonies with a double zone of hemolysis on SBA plate. There was no growth on plates incubated aerobically. The Gram stain of that organism was a boxcar-shaped, gram-positive bacillus. What organism is this?

Accepted Answer

A)  Clostridium perfringens 
B)  C. difficile 
C)  C. ramosum 
D)  C. clostridioiforme 
A)  Clostridium perfringens 
B)  C. difficile 
C)  C. ramosum 
D)  C. clostridioiforme

Question 10

Bacterial vaginosis is a synergistic infectious process involving all the following bacteria, except

Accepted Answer

A)  Eubacterium. 
B)  Bacteroides. 
C)  Gardnerella. 
D)  Peptostreptococcus. 
A)  Eubacterium. 
B)  Bacteroides. 
C)  Gardnerella. 
D)  Peptostreptococcus.

Question 11

What are two important factors that must be taken into consideration when transporting specimens for anaerobic culture?

Accepted Answer

A)  Making sure there is enough specimen in a tightly closed container 
B)  Minimum exposure to oxygen and preventing drying out 
C)  Minimum exposure to oxygen and making sure the specimen is transported in a tightly closed screw-cap container 
D)  Drying out and proper nutrition 
A)  Making sure there is enough specimen in a tightly closed container 
B)  Minimum exposure to oxygen and preventing drying out 
C)  Minimum exposure to oxygen and making sure the specimen is transported in a tightly closed screw-cap container 
D)  Drying out and proper nutrition

Question 12

Which of the following is considered a better specimen for anaerobic culture than a swab?

Accepted Answer

A)  Aspirate 
B)  Washing 
C)  Scraping 
D)  Lavage 
A)  Aspirate 
B)  Washing 
C)  Scraping 
D)  Lavage

Question 13

What disease does Clostridium tetani cause?

Accepted Answer

A)  Botulism 
B)  Tetanus 
C)  Food poisoning 
D)  Myonecrosis 
A)  Botulism 
B)  Tetanus 
C)  Food poisoning 
D)  Myonecrosis

Question 14

Which of the following is characteristic of members of the genus Clostridium?

Accepted Answer

A)  Catalase positive 
B)  Spore-forming anaerobic bacilli 
C)  Spore-forming anaerobic cocci 
D)  Facultative anaerobes 
A)  Catalase positive 
B)  Spore-forming anaerobic bacilli 
C)  Spore-forming anaerobic cocci 
D)  Facultative anaerobes

Question 15

How are suspected colonies of anaerobes processed?

Accepted Answer

A)  Gram stain morphology and reaction is observed. 
B)  An aerotolerance test is set up. 
C)  A pure culture/subculture plate is inoculated and appropriate disks are added. 
D)  All of the above. 
A)  Gram stain morphology and reaction is observed. 
B)  An aerotolerance test is set up. 
C)  A pure culture/subculture plate is inoculated and appropriate disks are added. 
D)  All of the above.

Question 16

Which of the following bacteria is most likely the cause of tooth abscesses?

Accepted Answer

A)  Bacteroides fragilis 
B)  Porphyromonas asaccharolytica 
C)  P. gingivalis 
D)  Mobiluncus 
A)  Bacteroides fragilis 
B)  Porphyromonas asaccharolytica 
C)  P. gingivalis 
D)  Mobiluncus

Question 17

How does Clostridium difficile produce pseudomembranous colitis and antibiotic-associated diarrhea?

Accepted Answer

A)  Endotoxin 
B)  Hyaluronidase 
C)  Toxin A and toxin B (exotoxins) 
D)  Protease 
A)  Endotoxin 
B)  Hyaluronidase 
C)  Toxin A and toxin B (exotoxins) 
D)  Protease

Exam 22: Anaerobes of Clinical Importance

What is an anaerobe?

What evidence indicates the presence of anaerobes in cultures?

All of the following organisms are found on the skin under normal conditions, except

Anaerobes outnumber aerobes in all of the following locations, except

The four major groups of anaerobic gram-negative bacilli include all the following, except

An Older adult patient in a nursing home is recovering from bacterial pneumonia. The patient has been on a lengthy regiment of antimicrobial agents. Subsequently, the patient is diagnosed with pseudomembranous colitis. What organism is the most likely cause?

All the following are categories of bacterial growth requirements for oxygen and carbon dioxide, except

After 24-hour incubation, an SBA from a vaginal culture reveals heavy growth of α\alphaα -hemolytic, pinpoint, rough colonies. A catalase test is performed, and it is negative. What organism should you suspect?

An anaerobic culture reveals colonies with a double zone of hemolysis on SBA plate. There was no growth on plates incubated aerobically. The Gram stain of that organism was a boxcar-shaped, gram-positive bacillus. What organism is this?

Bacterial vaginosis is a synergistic infectious process involving all the following bacteria, except

What are two important factors that must be taken into consideration when transporting specimens for anaerobic culture?

Which of the following is considered a better specimen for anaerobic culture than a swab?

What disease does Clostridium tetani cause?

Which of the following is characteristic of members of the genus Clostridium?

How are suspected colonies of anaerobes processed?

Which of the following bacteria is most likely the cause of tooth abscesses?

How does Clostridium difficile produce pseudomembranous colitis and antibiotic-associated diarrhea?

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

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

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

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

After 24-hour incubation, an SBA from a vaginal culture reveals heavy growth of $\alpha$ -hemolytic, pinpoint, rough colonies. A catalase test is performed, and it is negative. What organism should you suspect?