AFB/Mycobacterium

\____ 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