Question 1

Negative mycobacterial cultures are reported final, and the cultures are discarded after what period of time?

Accepted Answer

A) 7 days 
B) 2 weeks 
C) 4 weeks 
D) 8 weeks 
A) 7 days 
B) 2 weeks 
C) 4 weeks 
D) 8 weeks D

Question 2

On Gram stain, mycobacteria appear as

Accepted Answer

A) slender, well-stained gram-positive bacilli. 
B) poorly stained, beaded, gram-positive bacilli. 
C) gram-variable to gram-positive bacilli. 
D) partially invisible gram-negative bacilli. 
A) slender, well-stained gram-positive bacilli. 
B) poorly stained, beaded, gram-positive bacilli. 
C) gram-variable to gram-positive bacilli. 
D) partially invisible gram-negative bacilli. B

Question 3

Characteristics that are found in the bacteria called Mycobacterium are

Accepted Answer

A) a cell wall that contains N-glycolylmuramic acid and a very high lipid content. 
B) resists staining with commonly used basic aniline dyes. 
C) resist decolorization by acidified alcohol. 
D) slow growth as compared to most other human pathogenic bacteria. 
E) All of the above are correct. 
A) a cell wall that contains N-glycolylmuramic acid and a very high lipid content. 
B) resists staining with commonly used basic aniline dyes. 
C) resist decolorization by acidified alcohol. 
D) slow growth as compared to most other human pathogenic bacteria. 
E) All of the above are correct. E

Question 4

The 3-day test that is useful for identifying the rapid-growers M.fortuitum and M.chelonae and that measures the rate by which this enzyme breaks down phenolphthalein disulfate into phenolphthalein and other salts is

Accepted Answer

A) the niacin test. 
B) the phenolphthalein test. 
C) the arylsulfatase test. 
D) the Tween 80 test. 
A) the niacin test. 
B) the phenolphthalein test. 
C) the arylsulfatase test. 
D) the Tween 80 test.

Question 5

What quantity of CSF is considered sufficient for detection of tuberculous meningitis?

Accepted Answer

A) 10 mL 
B) 5 mL 
C) 1 mL 
D) 20 mL 
A) 10 mL 
B) 5 mL 
C) 1 mL 
D) 20 mL

Question 6

Large numbers of a poorly stained, beaded, gram-positive bacilli in a sputum specimen might be which bacterium?

Accepted Answer

A) Klebsiella pneumoniae 
B) Mycobacterium spp. 
C) Streptococcus pneumonia 
D) Actinomyces spp. 
A) Klebsiella pneumoniae 
B) Mycobacterium spp. 
C) Streptococcus pneumonia 
D) Actinomyces spp.

Question 7

The presence of what in CSF is thought to be diagnostic of tuberculous meningitis?

Accepted Answer

A) Mononuclear leukocytes and acid-fast bacilli 
B) Acid-fast bacilli 
C) Tuberculostearic acid 
D) Increased protein and decreased glucose 
E) All of the above are correct. 
A) Mononuclear leukocytes and acid-fast bacilli 
B) Acid-fast bacilli 
C) Tuberculostearic acid 
D) Increased protein and decreased glucose 
E) All of the above are correct.

Question 8

M.fortuitum, M.chelonae, and M.abscessus are

Accepted Answer

A) responsible for approximately 90% of clinical mycobacterial disease. 
B) able to grow on routine bacteriologic media. 
C) weakly gram-positive rods resembling diphtheroids on Gram stain. 
D) seen as visible colonies that appear on solid media in 7 days or less. 
E) All of the above are correct. 
A) responsible for approximately 90% of clinical mycobacterial disease. 
B) able to grow on routine bacteriologic media. 
C) weakly gram-positive rods resembling diphtheroids on Gram stain. 
D) seen as visible colonies that appear on solid media in 7 days or less. 
E) All of the above are correct.

Question 9

The system of classification based on growth rate and colonial pigmentation is called

Accepted Answer

A) Bergey's. 
B) scotochromogenic. 
C) Runyon. 
D) carotenoid. 
A) Bergey's. 
B) scotochromogenic. 
C) Runyon. 
D) carotenoid.

Question 10

The mycobacterial species that occur in humans and belong to the M.tuberculosis complex include

Accepted Answer

A) M.tuberculosis, nontuberculous mycobacteria, M.bovis, and M.africanum. 
B) M.tuberculosis, M.gordonae, M.bovis BCG, and M.africanum. 
C) M.tuberculosis, M.bovis, M.avium, and M.intracellulare. 
D) M.tuberculosis, M.bovis, M.bovis BCG, and M.africanum. 
A) M.tuberculosis, nontuberculous mycobacteria, M.bovis, and M.africanum. 
B) M.tuberculosis, M.gordonae, M.bovis BCG, and M.africanum. 
C) M.tuberculosis, M.bovis, M.avium, and M.intracellulare. 
D) M.tuberculosis, M.bovis, M.bovis BCG, and M.africanum.

Question 11

Photochromogens can be described as are referred to as

Accepted Answer

A) slow-growing nontuberculous mycobacteria whose colonies become pigmented when exposed to light. 
B) slow-growing nontuberculous mycobacteria whose colonies are pigmented when grown in the dark or the light. 
C) slow-growing nontuberculous mycobacteria whose colonies produce no pigment whether they are grown in the dark or the light. 
D) slow-growing tuberculous mycobacteria whose colonies become pigmented when exposed to light. 
A) slow-growing nontuberculous mycobacteria whose colonies become pigmented when exposed to light. 
B) slow-growing nontuberculous mycobacteria whose colonies are pigmented when grown in the dark or the light. 
C) slow-growing nontuberculous mycobacteria whose colonies produce no pigment whether they are grown in the dark or the light. 
D) slow-growing tuberculous mycobacteria whose colonies become pigmented when exposed to light.

Question 12

Slow-growing nontuberculous mycobacteria whose colonies are pigmented when grown in the dark or the light are referred to as

Accepted Answer

A) scotochromogens. 
B) photochromogens. 
C) nonphotochromogens. 
D) chromogenicums. 
A) scotochromogens. 
B) photochromogens. 
C) nonphotochromogens. 
D) chromogenicums.

Question 13

Optimal conditions for recovery of M.haemophilum from specimens include

Accepted Answer

A) inoculation to a chocolate agar plate. 
B) incubation at 25° to 33°C. 
C) placement of an X-factor disk on the media. 
D) 5% to 10% carbon dioxide and high humidity. 
E) All of the above are correct. 
A) inoculation to a chocolate agar plate. 
B) incubation at 25° to 33°C. 
C) placement of an X-factor disk on the media. 
D) 5% to 10% carbon dioxide and high humidity. 
E) All of the above are correct.

Question 14

A positive tuberculin skin test, or PPD test, is characterized by

Accepted Answer

A) erythema and induration. 
B) redness and rash. 
C) swelling and erythema. 
D) edema and rash. 
A) erythema and induration. 
B) redness and rash. 
C) swelling and erythema. 
D) edema and rash.

Question 15

The fluorochrome method of staining Mycobacterium

Accepted Answer

A) is less sensitive than the conventional carbolfuchsin stains. 
B) enables the smear to be initially examined at lower magnifications. 
C) results in a lower yield of positive smears. 
D) will substantially increase the amount of time needed for examining smears. 
E) All of the above are correct. 
A) is less sensitive than the conventional carbolfuchsin stains. 
B) enables the smear to be initially examined at lower magnifications. 
C) results in a lower yield of positive smears. 
D) will substantially increase the amount of time needed for examining smears. 
E) All of the above are correct.

Question 16

In identification of mycobacterial isolates, the niacin test involves

Accepted Answer

A) the accumulation of niacin in the medium in which the organism is growing. 
B) the metabolism of niacin to nicotinic acid by enzymatic action. 
C) testing the isolate for susceptibility to niacin. 
D) utilization of niacin in metabolic pathways to produce nicotinic acid. 
A) the accumulation of niacin in the medium in which the organism is growing. 
B) the metabolism of niacin to nicotinic acid by enzymatic action. 
C) testing the isolate for susceptibility to niacin. 
D) utilization of niacin in metabolic pathways to produce nicotinic acid.

Question 17

The tuberculin skin test, or PPD test, is based on

Accepted Answer

A) delayed hypersensitivity cell-mediated immunity to certain antigenic components of the organism. 
B) injection of M.tuberculosis under the skin and subsequent mild cutaneous infection. 
C) antigen-antibody reactions occurring at the injection site. 
D) All of the above are correct. 
A) delayed hypersensitivity cell-mediated immunity to certain antigenic components of the organism. 
B) injection of M.tuberculosis under the skin and subsequent mild cutaneous infection. 
C) antigen-antibody reactions occurring at the injection site. 
D) All of the above are correct.

Question 18

For reliable results, the niacin test should be

Accepted Answer

A) performed only from cultures on L-J that are at least 2 weeks old and show at least five colonies. 
B) performed only from cultures on L-J that are at least 3 weeks old and show at least 50 colonies. 
C) performed only from cultures on 7H11 agar that are at least 3 weeks old and show at least 50 colonies. 
D) performed only from cultures on 7H11 agar that are at least 2 weeks old and show at least five colonies. 
A) performed only from cultures on L-J that are at least 2 weeks old and show at least five colonies. 
B) performed only from cultures on L-J that are at least 3 weeks old and show at least 50 colonies. 
C) performed only from cultures on 7H11 agar that are at least 3 weeks old and show at least 50 colonies. 
D) performed only from cultures on 7H11 agar that are at least 2 weeks old and show at least five colonies.

Question 19

Slow-growing nontuberculous mycobacteria whose colonies become pigmented when exposed to light are referred to as

Accepted Answer

A) scotochromogens. 
B) photochromogens. 
C) nonphotochromogens. 
D) chromogenicums. 
A) scotochromogens. 
B) photochromogens. 
C) nonphotochromogens. 
D) chromogenicums.

Question 20

Slow-growing nontuberculous mycobacteria whose colonies produce no pigment whether they are grown in the dark or the light are referred to as

Accepted Answer

A) scotochromogens. 
B) photochromogens. 
C) nonphotochromogens. 
D) chromogenicums. 
A) scotochromogens. 
B) photochromogens. 
C) nonphotochromogens. 
D) chromogenicums.

Exam 42: Mycobacteria

Negative mycobacterial cultures are reported final, and the cultures are discarded after what period of time?

On Gram stain, mycobacteria appear as

Characteristics that are found in the bacteria called Mycobacterium are

The 3-day test that is useful for identifying the rapid-growers M.fortuitum and M.chelonae and that measures the rate by which this enzyme breaks down phenolphthalein disulfate into phenolphthalein and other salts is

What quantity of CSF is considered sufficient for detection of tuberculous meningitis?

Large numbers of a poorly stained, beaded, gram-positive bacilli in a sputum specimen might be which bacterium?

The presence of what in CSF is thought to be diagnostic of tuberculous meningitis?

M.fortuitum, M.chelonae, and M.abscessus are

The system of classification based on growth rate and colonial pigmentation is called

The mycobacterial species that occur in humans and belong to the M.tuberculosis complex include

Photochromogens can be described as are referred to as

Slow-growing nontuberculous mycobacteria whose colonies are pigmented when grown in the dark or the light are referred to as

Optimal conditions for recovery of M.haemophilum from specimens include

A positive tuberculin skin test, or PPD test, is characterized by

The fluorochrome method of staining Mycobacterium

In identification of mycobacterial isolates, the niacin test involves

The tuberculin skin test, or PPD test, is based on

For reliable results, the niacin test should be

Slow-growing nontuberculous mycobacteria whose colonies become pigmented when exposed to light are referred to as

Slow-growing nontuberculous mycobacteria whose colonies produce no pigment whether they are grown in the dark or the light are referred to as

Microbial Taxonomy

Bacterial Genetics Metabolism and Structure

Host-Microorganism Interactions

Laboratory Safety

Specimen Management

Role of Microscopy

Traditional Cultivation and Identification

Nucleic Acid-Based Analytic Methods for Microbial Identification and Characterization

Immunochemical Methods Used for Organism Detection

Serologic Diagnosis of Infectious Diseases

Principles of Antimicrobial Action Resistance

Laboratory Methods and Strategies for Antimicrobial Susceptibility Testing

Staphylococcus, Micrococcus, and Similar Organisms

Streptococcus, Enterococcus, and Similar Organisms

Bacillus and Similar Organisms

Listeria, Corynebacterium, and Similar Organisms

Erysipelothirix, Lactobacillus, and Similar Organisms

Nocardia, Streptomyces, Rhodococcus, Oerskovia, and Similar Organisms

Enterobacteriaceae

Acinetobacter, Stenotrophomonas, and Other Organisms

Pseudomonas, Burkholderia, and Similar Organisms

Achromobacter, Rhizobium, Ochrobactrum, and Similar Organisms

Chryseobacterium, Sphingobacterium, and Similar Organisms

Alcaligenes, Bordetella Nonpertussis, Comamonas, and Similar Organisms

Vibrio, Aeromonas, Plesiomonas Shigelloides, and Chromobacterium Violaceum

Sphingomonas Paucimobilis and Similar Organisms

Moraxella

Eikenella Corrodens and Similar Organisms

Pasteurella and Similar Organisms

Actinobacillus, Kingella, Cardiobacterium, Capnocytophaga, and Similar Organisms

Haemophilus

Bartonella and Afipia

Campylobacter, Arcobacter, and Helicobacter

Legionella

Brucella

Bordetella Pertussis and Bordetella Parapertussis

Francisella

Streptobacillus Moniliformis and Spirillum Minus

Neisseria and Moraxella Catarrhalis

Overview and General Considerations

Laboratory Considerations

Obligate Intracellular and Nonculturable Bacterial Agents

Cell Wall-Deficient Bacteria: Mycoplasma and Ureaplasma

The Spirochetes

Laboratory Methods for Diagnosis of Parasitic Infections

Laboratory Methods in Basic Mycology

Laboratory Methods in Basic Virology

Bloodstream Infections

Infections of the Lower Respiratory Tract

Upper Respiratory Tract Infections and Other Infections of the Oral Cavity and Neck

Meningitis and Other Infections of the Central Nervous Systems

Infections of the Eyes, Ears, and Sinuses

Infections of the Urinary Tract

Genital Tract Infections

Gastrointestinal Tract Infections

Skin, Soft Tissue, and Wound Infections

Normally Sterile Body Fluids, Bone and Bone Marrow, and Solid Tissues

Laboratory Physical Design, Management, and Organization

Quality in the Clinical Microbiology Laboratory