Question 1

Examples of the mycobacterial species that occur in humans and belong to the Mycobacterium 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. D

Question 2

For reliable results,the niacin test should be performed only from cultures that are at least:

Accepted Answer

A) 2 weeks old and show at least five colonies on Löwenstein-Jensen medium. 
B) 3 weeks old and show at least 50 colonies on Löwenstein-Jensen medium. 
C) 3 weeks old and show at least 50 colonies on Middlebrook 7H11 agar. 
D) 2 weeks old and show at least five colonies on Middlebrook 7H11 agar. 
A) 2 weeks old and show at least five colonies on Löwenstein-Jensen medium. 
B) 3 weeks old and show at least 50 colonies on Löwenstein-Jensen medium. 
C) 3 weeks old and show at least 50 colonies on Middlebrook 7H11 agar. 
D) 2 weeks old and show at least five colonies on Middlebrook 7H11 agar. B

Question 3

Fluorescent staining is more sensitive than conventional carbolfuchsin stains.What counterstain is used during the procedure?

Accepted Answer

A) Methylene blue 
B) Crystal violet 
C) Potassium permanganate 
D) Auramine-rhodamine 
A) Methylene blue 
B) Crystal violet 
C) Potassium permanganate 
D) Auramine-rhodamine C

Question 4

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

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

Question 5

One drawback associated with the fluorochrome stain method for detecting Mycobacterium is that:

Accepted Answer

A) it is less sensitive than the conventional carbolfuchsin stains. 
B) it requires the smear to be initially examined at lower magnifications. 
C) many rapid-growers may not appear fluorescent with these reagents. 
D) it increases the amount of time needed for examining smears. 
A) it is less sensitive than the conventional carbolfuchsin stains. 
B) it requires the smear to be initially examined at lower magnifications. 
C) many rapid-growers may not appear fluorescent with these reagents. 
D) it increases the amount of time needed for examining smears.

Question 6

A fisherman who cut himself on a fishing hook later develops a cutaneous disease at the inoculation site.The exudate is aspirated and set up on a routine AFB medium for culture.It is incubated at 37°C,but no growth is observed after 8 weeks;however,a slide of the exudate was AFB-positive.Which one of the following statements explains these findings?

Accepted Answer

A) The infection is most likely the result of a viral infection. 
B) The organism should have been incubated at 30°C. 
C) The organism should have been incubated at 42°C. 
D) The infection is most likely fungal in nature. 
A) The infection is most likely the result of a viral infection. 
B) The organism should have been incubated at 30°C. 
C) The organism should have been incubated at 42°C. 
D) The infection is most likely fungal in nature.

Question 7

The specimens of choice for detecting urinary tract mycobacterial disease are:

Accepted Answer

A) single clean-catch midstream urine samples. 
B) 24-hour timed urine samples. 
C) three daily clean-catch midstream urine samples. 
D) biopsies of the suspected site. 
A) single clean-catch midstream urine samples. 
B) 24-hour timed urine samples. 
C) three daily clean-catch midstream urine samples. 
D) biopsies of the suspected site.

Question 8

The specimen of choice for detecting tuberculous pulmonary mycobacterial disease is:

Accepted Answer

A) spontaneously produced sputum. 
B) gastric lavage. 
C) transtracheal aspiration. 
D) bronchoscopy. 
A) spontaneously produced sputum. 
B) gastric lavage. 
C) transtracheal aspiration. 
D) bronchoscopy.

Question 9

What quantity of cerebrospinal fluid (CSF)is considered sufficient for the detection of tuberculous meningitis?

Accepted Answer

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

Question 10

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 11

Mycobacterium fortuitum,Mycobacterium chelonae,and Mycobacterium abscessus are:

Accepted Answer

A) responsible for approximately 90% of clinical mycobacterial disease. 
B) unable to grow on routine bacteriologic media. 
C) gram-negative rods resembling Escherichia coli on Gram stain. 
D) slow growers requiring a minimum of 14 days to grow. 
A) responsible for approximately 90% of clinical mycobacterial disease. 
B) unable to grow on routine bacteriologic media. 
C) gram-negative rods resembling Escherichia coli on Gram stain. 
D) slow growers requiring a minimum of 14 days to grow.

Question 12

The term complex as used in the Mycobacterium tuberculosis complex:

Accepted Answer

A) means that the identification of the organism is complex and is only performed in large reference laboratories. 
B) is used to describe two or more species whose distinction is complicated and of little or no medical importance. 
C) refers to a set of organisms that are genetically indistinguishable but are phenotypically different. 
D) refers to different subtypes of the bacteria M.tuberculosis. 
A) means that the identification of the organism is complex and is only performed in large reference laboratories. 
B) is used to describe two or more species whose distinction is complicated and of little or no medical importance. 
C) refers to a set of organisms that are genetically indistinguishable but are phenotypically different. 
D) refers to different subtypes of the bacteria M.tuberculosis.

Question 13

In the identification of mycobacterial isolates,the Tween 80 test involves:

Accepted Answer

A) an enzyme that is able to produce Tween 80 from certain ingredients found in the medium. 
B) a lipase that is able to hydrolyze polyoxyethylene sorbitan monooleate into oleic acid and polyoxyethylated sorbitol. 
C) the metabolism of niacin to nicotinic acid by enzymatic action. 
D) testing the isolate for susceptibility to Tween 80. 
A) an enzyme that is able to produce Tween 80 from certain ingredients found in the medium. 
B) a lipase that is able to hydrolyze polyoxyethylene sorbitan monooleate into oleic acid and polyoxyethylated sorbitol. 
C) the metabolism of niacin to nicotinic acid by enzymatic action. 
D) testing the isolate for susceptibility to Tween 80.

Question 14

The tuberculin skin test,or the purified protein derivative (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) humoral-mediated immune response. 
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) humoral-mediated immune response.

Question 15

Slow-growing NTM 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 16

The specimen of choice for detecting mycobacterium in a skin lesion or wound is a:

Accepted Answer

A) swab placed in Amie's transport medium or Stuart's medium. 
B) needle aspiration. 
C) skin scraping. 
D) swab placed in anaerobic conditions. 
A) swab placed in Amie's transport medium or Stuart's medium. 
B) needle aspiration. 
C) skin scraping. 
D) swab placed in anaerobic conditions.

Question 17

The primary reservoir of the Mycobacterium responsible for leprosy is:

Accepted Answer

A) infected humans. 
B) infected animals. 
C) contaminated food. 
D) contaminated objects. 
A) infected humans. 
B) infected animals. 
C) contaminated food. 
D) contaminated objects.

Question 18

When culturing for Mycobacterium,rapid-growers usually produce colonies within how many days after subculture?

Accepted Answer

A) At least 7 days 
B) Longer than 7 days 
C) 3 to 4 days 
D) 2 to 3 days 
A) At least 7 days 
B) Longer than 7 days 
C) 3 to 4 days 
D) 2 to 3 days

Question 19

The stain that requires heating the slide for better penetration of stain into the mycobacterial cell wall is known as the:

Accepted Answer

A) Kinyoun's. 
B) Ziehl-Neelsen. 
C) fluorochrome. 
D) carbolfuchsin. 
A) Kinyoun's. 
B) Ziehl-Neelsen. 
C) fluorochrome. 
D) carbolfuchsin.

Question 20

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) increases the amount of time needed for examining smears. 
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) increases the amount of time needed for examining smears.

Exam 41: Mycobacteria

Examples of the mycobacterial species that occur in humans and belong to the Mycobacterium tuberculosis complex include:

For reliable results,the niacin test should be performed only from cultures that are at least:

Fluorescent staining is more sensitive than conventional carbolfuchsin stains.What counterstain is used during the procedure?

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

One drawback associated with the fluorochrome stain method for detecting Mycobacterium is that:

The specimens of choice for detecting urinary tract mycobacterial disease are:

The specimen of choice for detecting tuberculous pulmonary mycobacterial disease is:

What quantity of cerebrospinal fluid (CSF)is considered sufficient for the detection of tuberculous meningitis?

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

Mycobacterium fortuitum,Mycobacterium chelonae,and Mycobacterium abscessus are:

The term complex as used in the Mycobacterium tuberculosis complex:

In the identification of mycobacterial isolates,the Tween 80 test involves:

The tuberculin skin test,or the purified protein derivative (PPD)test,is based on:

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

The specimen of choice for detecting mycobacterium in a skin lesion or wound is a:

The primary reservoir of the Mycobacterium responsible for leprosy is:

When culturing for Mycobacterium,rapid-growers usually produce colonies within how many days after subculture?

The stain that requires heating the slide for better penetration of stain into the mycobacterial cell wall is known as the:

The fluorochrome method of staining Mycobacterium:

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

Overview of Immunochemical Methods Used for Organism Detection

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

Erysipelothrix, 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 Non-culturable Bacterial Agents

Cell Walldeficient Bacteria: Mycoplasma and Ureaplasma

The Spirochetes

Overview of the Methods and Strategies in Parasitology

Intestinal Protozoa

Blood and Tissue Protozoa

Protozoa From Other Body Sites

Intestinal Nematodes

Tissue Nematodes

Blood Nematodes

Intestinal Cestodes

Tissue Cestodes

Intestinal Trematodes

Liver and Lung Trematodes

Blood Trematodes

Overview of Fungal Identification Methods and Strategies

Hyaline Molds, Zygomycetes, Dermatophytes, and Opportunistic and Systemic Mycoses

Dematiaceious Molds

Opportunistic Atypical Fungus: Pjirovecii

The Yeasts