Question 1

What classifies an organism as a multidrug-resistant Mycobacterium tuberculosis?

Accepted Answer

A)  Resistance to at least isoniazid and rifampin 
B)  Resistance to isoniazid, rifampin, ethambutol, and streptomycin 
C)  Resistance to streptomycin and rifampin 
D)  Resistance to ciprofloxacin and imipenem 
A)  Resistance to at least isoniazid and rifampin 
B)  Resistance to isoniazid, rifampin, ethambutol, and streptomycin 
C)  Resistance to streptomycin and rifampin 
D)  Resistance to ciprofloxacin and imipenem A

Question 2

All of the following are traditional characteristics used to identify mycobacteria, except

Accepted Answer

A)  rate of growth. 
B)  colony morphology. 
C)  Gram stain results. 
D)  pigmentation. 
A)  rate of growth. 
B)  colony morphology. 
C)  Gram stain results. 
D)  pigmentation. C

Question 3

A sputum culture from a patient in Texas has buff colored colonies growing in approximately 4 weeks. After exposure to light, the colonies turn intense yellow. This isolate is most likely

Accepted Answer

A)  M. scrofulaceum. 
B)  M. kansasii. 
C)  M. fortuitum. 
D)  M. xenopi. 
A)  M. scrofulaceum. 
B)  M. kansasii. 
C)  M. fortuitum. 
D)  M. xenopi. B

Question 4

The most common nontuberculosis mycobacterium (NTM) infecting humans

Accepted Answer

A)  M. marinum. 
B)  M. ulcerans. 
C)  M. haemophilium. 
D)  M. avium-intracellulare complex. 
A)  M. marinum. 
B)  M. ulcerans. 
C)  M. haemophilium. 
D)  M. avium-intracellulare complex.

Question 5

A child presents to his physician with fever, a nonproductive cough, and shortness of breath. The physician orders a routine sputum culture and an acid-fast bacillus culture and smear. The smear shows red organisms arranged in ropes. What is the most probable cause of this child's fever and cough?

Accepted Answer

A)  Mycobacterium leprae 
B)  M. avium 
C)  M. intracellulare 
D)  M. tuberculosis 
A)  Mycobacterium leprae 
B)  M. avium 
C)  M. intracellulare 
D)  M. tuberculosis

Question 6

What media are recommended for routine culturing of specimens for the recovery of acid-fast bacilli?

Accepted Answer

A)  Löwenstein-Jensen (LJ) and liquid-based media 
B)  Middlebrook 7H10 and cooked meat broth 
C)  Sabouraud dextrose and LIM broth 
D)  Thiosulfate-citrate-bile salts-sucrose (TCBS) and thioglycollate broth 
A)  Löwenstein-Jensen (LJ) and liquid-based media 
B)  Middlebrook 7H10 and cooked meat broth 
C)  Sabouraud dextrose and LIM broth 
D)  Thiosulfate-citrate-bile salts-sucrose (TCBS) and thioglycollate broth

Question 7

A 35-year-old man travels on a multidestination vacation over a 2 month period, including lengthy stops in tropical Africa and Southeast Asia. Six weeks after returning come home to the United States, he develops a productive cough, fatigue, weight loss, low-grade fever, and night sweats. What disease should the physician consider as a result of his travel history?

Accepted Answer

A)  Streptococcal pneumonia 
B)  Primary atypical pneumonia 
C)  TB 
D)  Pneumonia caused by gram-negative rods 
A)  Streptococcal pneumonia 
B)  Primary atypical pneumonia 
C)  TB 
D)  Pneumonia caused by gram-negative rods

Question 8

What is the optimum culture incubation time for most mycobacteria associated with human disease?

Accepted Answer

A)  2 to 6 weeks 
B)  1 to 2 weeks 
C)  5 to 7 days 
D)  3 to 5 days 
A)  2 to 6 weeks 
B)  1 to 2 weeks 
C)  5 to 7 days 
D)  3 to 5 days

Question 9

All of the following are biochemical tests for the identification of Mycobacterium spp., except

Accepted Answer

A)  gelatin liquefaction. 
B)  hydrolysis of Tween 80. 
C)  iron uptake. 
D)  arylsulfatase. 
A)  gelatin liquefaction. 
B)  hydrolysis of Tween 80. 
C)  iron uptake. 
D)  arylsulfatase.

Question 10

All of these stains are commonly used to visualize mycobacteria on a smear, except

Accepted Answer

A)  Ziehl-Neelsen. 
B)  Kinyoun. 
C)  auramine. 
D)  acridine orange. 
A)  Ziehl-Neelsen. 
B)  Kinyoun. 
C)  auramine. 
D)  acridine orange.

Question 11

What constituent of LJ medium is added to suppress the growth of gram-positive bacteria?

Accepted Answer

A)  Carbolfuchsin 
B)  Malachite green 
C)  Gentian purple 
D)  Mercurochrome 
A)  Carbolfuchsin 
B)  Malachite green 
C)  Gentian purple 
D)  Mercurochrome

Question 12

If a person has had TB during his or her lifetime, how likely is it that the person will get the disease again?

Accepted Answer

A)  5% to 15% 
B)  20% to 25% 
C)  1% 
D)  50% 
A)  5% to 15% 
B)  20% to 25% 
C)  1% 
D)  50%

Question 13

What is the purpose of the digestion-decontamination processing of specimens submitted for mycobacterial culture?

Accepted Answer

A)  To release all bacteria in the sample 
B)  To make the specimen easier to plate 
C)  To allow chemical decontaminants to kill nonmycobacterial organisms 
D)  To liquefy the outer cell wall of the mycobacteria so that they will grow faster 
A)  To release all bacteria in the sample 
B)  To make the specimen easier to plate 
C)  To allow chemical decontaminants to kill nonmycobacterial organisms 
D)  To liquefy the outer cell wall of the mycobacteria so that they will grow faster

Question 14

What component of mycobacteria is used for identification in nucleic acid hybridization assays?

Accepted Answer

A)  DNA 
B)  Ribosomal RNA 
C)  Transfer RNA 
D)  Messenger RNA 
A)  DNA 
B)  Ribosomal RNA 
C)  Transfer RNA 
D)  Messenger RNA

Question 15

The Centers for Disease Control and Prevention (CDC) recommends all the following drugs for the treatment of Mycobacterium tuberculosis, except

Accepted Answer

A)  ethambutol. 
B)  isoniazid. 
C)  rifampin. 
D)  ciprofloxacin. 
A)  ethambutol. 
B)  isoniazid. 
C)  rifampin. 
D)  ciprofloxacin.

Question 16

What medium is recommended for the recovery of Mycobacterium haemophilum?

Accepted Answer

A)  Sheep blood agar (SB
A)  
B)  Chocolate 
C)  Polysaccharide egg antigen (PE
A)  
D)  LJ 
A)  Sheep blood agar (SB
A)  
B)  Chocolate 
C)  Polysaccharide egg antigen (PE
A)  
D)  LJ

Question 17

Middlebrook 7H10 and 7H11 media are enriched with all of the following, except

Accepted Answer

A)  oleic acid. 
B)  bovine albumin. 
C)  heme. 
D)  beef catalase. 
A)  oleic acid. 
B)  bovine albumin. 
C)  heme. 
D)  beef catalase.

Question 18

What are nonchromogens?

Accepted Answer

A)  Species that produce carotene pigment upon exposure to light 
B)  Species that produce pigment in the light or the dark 
C)  Species whose colonies remain buff colored after exposure to light 
D)  Species whose colonies fluoresce under ultraviolet light 
A)  Species that produce carotene pigment upon exposure to light 
B)  Species that produce pigment in the light or the dark 
C)  Species whose colonies remain buff colored after exposure to light 
D)  Species whose colonies fluoresce under ultraviolet light

Question 19

What is the single most important piece of equipment in a mycobacterial laboratory?

Accepted Answer

A)  Ultraviolet lights 
B)  Covered centrifuge 
C)  Biological safety cabinet 
D)  CO2 incubator 
A)  Ultraviolet lights 
B)  Covered centrifuge 
C)  Biological safety cabinet 
D)  CO2 incubator

Question 20

What are scotochromogens?

Accepted Answer

A)  Species that produce carotene pigment upon exposure to light 
B)  Species that produce pigment in the light or the dark 
C)  Species whose colonies remain buff colored after exposure to light 
D)  Species whose colonies fluoresce under ultraviolet light 
A)  Species that produce carotene pigment upon exposure to light 
B)  Species that produce pigment in the light or the dark 
C)  Species whose colonies remain buff colored after exposure to light 
D)  Species whose colonies fluoresce under ultraviolet light

Exam 26: Mycobacterium Tuberculosis and Nontuberculous Mycobacteria

What classifies an organism as a multidrug-resistant Mycobacterium tuberculosis?

All of the following are traditional characteristics used to identify mycobacteria, except

A sputum culture from a patient in Texas has buff colored colonies growing in approximately 4 weeks. After exposure to light, the colonies turn intense yellow. This isolate is most likely

The most common nontuberculosis mycobacterium (NTM) infecting humans

A child presents to his physician with fever, a nonproductive cough, and shortness of breath. The physician orders a routine sputum culture and an acid-fast bacillus culture and smear. The smear shows red organisms arranged in ropes. What is the most probable cause of this child's fever and cough?

What media are recommended for routine culturing of specimens for the recovery of acid-fast bacilli?

What is the optimum culture incubation time for most mycobacteria associated with human disease?

All of the following are biochemical tests for the identification of Mycobacterium spp., except

All of these stains are commonly used to visualize mycobacteria on a smear, except

What constituent of LJ medium is added to suppress the growth of gram-positive bacteria?

If a person has had TB during his or her lifetime, how likely is it that the person will get the disease again?

What is the purpose of the digestion-decontamination processing of specimens submitted for mycobacterial culture?

What component of mycobacteria is used for identification in nucleic acid hybridization assays?

The Centers for Disease Control and Prevention (CDC) recommends all the following drugs for the treatment of Mycobacterium tuberculosis, except

What medium is recommended for the recovery of Mycobacterium haemophilum?

Middlebrook 7H10 and 7H11 media are enriched with all of the following, except

What are nonchromogens?

What is the single most important piece of equipment in a mycobacterial laboratory?

What are scotochromogens?

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

Anaerobes of Clinical Importance

The Spirochetes

Chlamydia, Rickettsia, and Similar Organisms

Mycoplasma and Ureaplasma

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