AFB/Mycobacterium

____ stain = hot stain

____ stain = hot stain

Ziehl-Neilsen

____ stain = cold stain

Kinyoun

____ = fluorescent stain

auramine-rhodamine

T/F: any number of AFB seen on a smear is significant

T

____ media: 60% egg, malachite green

Lowenstein-Jensen

____ aids in dispersing colonies in liquid media

Tween 80

AFB: takes _-_ ____ for growth

3-6 weeks

T/F: can test urine for AFB

T

T/F: can refrigerate specimens for AFB testing overnight

T

Specimen decontamination: N-acetyl-L-cysteine (NALC) = ____ agent

mucolytic

Specimen decontamination: NaOH = ___

decontaminant

Stain and report AFB slides within ___ ___ of processing

24 hrs

Centrifuge decontaminated specimen for ___ min at ___ rpm before using sediment for making smears and inoculating media

20; 3000

Cauliflower colonies on LJ media => ___ ___

Mycobacterium tuberculosis

Mycobacterium avium complex: ____ colonies on LJ

non-pigmented

Rapid growers: M. _, M. _, and M. ____

fortuitum; chelonae; abscessus

Photochromogens: M. _, M. _, M. _, and M. _

kansasii; marinum; asiaticum; simiae

Scotochromogens: M. _, M. _, M. _, and M. _

scrofulaceum; gordonae; szulgai

Rough and buff colonies, serpentine cording on culture: M. ___ and M. ___

tuberculosis; bovis

Niacin accumulation => M. ___

tuberculosis

Nitrate reduction => M. _, M. _, and M. ___

tuberculosis; kansasii; fortuitum

Tween 80 hydrolysis < 5 days: M. ___ and M. ___

kansasii; marinum

Tween 80 hydrolysis > 5 days: M. ___ and M. ___

tuberculosis; bovis

Tween 80 hydrolysis 5-10 days: M. ___

gordonae

Tellurite: M. ___ and all ____

avium; rapid growers

Growth on MAC: M. ___ and M. ___

fortuitum; chelonae

M. chelonae: nitrate positive or negative?

negative

____chromogen: produces pigment in light

photo

____chromogen: produces pigment in dark and light

scoto

Rapid grower: growth in < ___ ___

7 days

M. ____: 32 degrees C optimum temp

ulcerans

M. ___: 30 degrees C optimum temp

marinum

Which is susceptible to TCH: M. tuberculosis or M. bovis?

bovis

Mycobacteria: gram-___ to gram-___ bacilli

positive; neutral

T/F: mycobacteria may appear beaded when stained

T

Read ZN and Kinyoun (carbolfuchsin) stains at ___X

100

ZN and Kinyoun (carbolfuchsin) stains: view > ___ fields before calling the slide negative.

300

Counter stain for ZN and Kinyoun (carbolfuchsin) stains = ___ ___

methylene blue

Fluorochrome stains: strong ___ light source with a ___ filter.

blue; FITC

Read Fluorochrome stains at ___ or ___X

25; 40

Some strains of M. ____ do not stain w/ fluorochrome dyes.

fortuitum

5% ___ ___: use for specimens known to be contaminated w/ Pseudomonas.

oxalic acid

Mycobactera: stimulated by ___ concentrations of fatty acids and inhibited by ___ concentrations

low; high

Mycobacteria media: carbon source = ___

glycerol

Malachite green function:

inhibition of growth of contaminants

Lowenstein-Jensen (LJ) is ___-based media.

egg

Which allows earlier detection of mycobacteria: clear agar-based media (e.g. 7H11) or egg media (LJ)?

agar

Protect 7H11 media from heat and light to prevent release of ____ (toxic to mycobacteria)

formaldehyde

_-_% CO2 is required for growth on 7H11 and stimulates growth on egg media (LJ)

5; 10

American Thoracic Society (ATS) media: egg or agar?

egg

Petragnani media: egg or agar?

egg

Gruft (LJ modification): ___ ___-based media.

selective egg

Middlebrook media: egg or agar?

agar

Mitchison's: ___ ___-based media

selective agar

Selective media: _, _, and ___

Gruft; Mitchison's; Mycobactosel

Mycobactosel: ___ ___-based media

selective egg

Curved strands of bacilli = ____

cording

Growth rate determined by which one: time of subculture time of detection from clinical sample?

subculture

Optimal growth temperature for M. xenopi = ___ degrees C

42

Photochromogens: produce ___ pigment when exposed to light.

carotene

Photochromogens: ___ ___ taking pictures of the ___ in ___

Asian; monkey; ocean; Kansas

M. tuberculosis, M. avium-intracellulare complex, M. bovis, M. haemophilum, M. ulcerans, M. chelonae, and M. fortuitum photoreactive class = ____

nonphotochromogens

M. szulgai, M. gordoae, M. scrofulceum photoreactive class = ____

scotochromogens

Photochromogens = Runyon group ___

1

Runyon Group 1 = ____

photochromogens

Scotochromogens = Runyon Group __

2

Runyon Group 2 = ____

scotochromogens

Nonchromogens = Runyon Group __

3

Runyon Group 3 = ____

nonchromogens

Rapid growers = Runyon Group __

4

Runyon Group 4 = ____

rapid growers

Rapid growers are usually pigmented or nonpigmented?

nonpigmented

Most common biochemical test for M. tuberculosis = ____

niacin

Niacin accumulation: positive = ____ color

yellow

Niacin accumulation: results are most consistent when performed on ___-based media.

egg

Negative niacin result => repeat in ___ ___ because young and/or few colonies may give false-negative.

several weeks

Nitrate reduction (to nitrite): positive = ___ color

red

Nitrate reduction test: no color change => add zinc => pink color => ____ result

negative

M. tuberculosis: heat-stable catalase ____

negative

Heat-stable catalase: positive after heating to ___ degrees C

68

Tween 80 hydrolysis: positive = ___ color

pink

Rapid growers (except M. chelonae) are iron uptake ___

positive

Which rapid grower is iron uptake negative? M. ____

chelonae

M. fortuitum. M. chelonae, and M. abscessus are ___-day arylsulfatase positive.

3

M. marinum, M. kansasii, and M. xenopi are ___-day arylsulfatase positive.

14

M. kansasii, M. marinum, and M. tuberculosis are pyrazinamidase ___

positive

M. bovis is pyrazinamidase ___

negative

T/F: can use pyrazinamidase to distinguish M. tuberculosis and M. bovis.

T

M. scrofulaceum = urease ___ M. gordonae = urease ___

positive; negative

TCH distinguishes M. ____ from M. ____

tuberculosis; bovis

Most ____ grow in the presence of 5% NaCl in egg-based media

rapid growers

Which has poorer growth on LJ, M. tuberculosis or M. bovis?

bovis

Orange crystals of beta carotene within colony centers => M. ____

kansasii

M. kansasii: type of disease caused: skin or pulmonary?

pulmonary

Which photochromogen is nitrate reduction positive? M. ___

kansasii

Which photochromogen is catalase negative? M. ___

marinum

Which photochromogen is Tween 80 hydrolysis negative? M. ___

simiae

Which photochromogen is niacin production positive? M. ____

simiae

M. scrofulaceum and M. gordonae are nitrate ___

negative

M. szulgai and M. flavescens are nitrate ___

positive