Acid-fast Bacilli, Spirochetes, Parasitic Bacteria

Question 1

M. tuberculosis vs. M. canetti

Answer 1

M. tuberculosis: rough colonies

M. canetti: smooth colonies

Question 2

M. tuberculosis vs. M. bovis

Answer 2

M. tuberculosis: resistant to TCH

M. bovis: susceptible to TCH or T2H

Question 3

How long does mycobacteria take to grow?

Answer 3

2-60 days (pathogenic are slow growers)

Question 4

Mycobacteria characteristics

Answer 4

Aerobic

Non-spore forming (except M. marinum)

Intracellular pathogens

Nonmotile

Slow growing

Acid-fast cell wall

Question 5

Habitat of NTM

Answer 5

Environmental (water, soil)

Question 6

Mycobacterium tuberculosis complex species

Answer 6

M. tuberculosis
M. bovis
M. africanum
M. caprae
M. pinnipedii
M. microti
M. canetti

Question 7

Tests for M. tuberculosis

Answer 7

PPD (Purified Protein Derivative) - detects exposure or infection

Quantiferon test for latent TB - release interferon gamma if exposed to TB because T cells have memory

Question 8

M. bovis

Answer 8

Ingestion of infected cow milk

BCG vaccine

HIV patients more susceptible

Question 9

Mtb Diseases

Answer 9

Pott TB (bent spine)

Miliary TB

goes to various parts of the body

Can form granuloma

Question 10

Runyon classification of Nontuberculosis Mycobacteria

Answer 10

Group I: photochromogens (colonies pigmented in light - yellow orange colonies)
Group II: scotochromogens (colonies pigmented in light or dark)
Group III: nonphotochromagens (no pigment)
Group IV: rapid growers (non pigmented to yellow/buff colonies)

Question 11

Which is the only non cultivable organism?

Answer 11

Mycobacterium leprae

Question 12

Photochromogens species

Answer 12

KAMSIN

M. kansasii (nitrate +)
M. asiaticum
M. marinum
M. simiae
M. intermedium
M. novocastrense

Question 13

M. kansasii

Answer 13

Dark red crystal forms when exposed to light (beta carotene)

Wants to be tb

Lung disease

Question 14

M. marinum

Answer 14

Fish disease

Swimming pool granulomas, red blue nodules on hand

Spore forming

Question 15

M. simiae, M. asiaticum, M. marinum, vs M. kansasii

Answer 15

(table)
SQ catalase, tween, nitrate
SAMK (simiae, asia, marine, kansas)

+- -
++-
- - - (30*C)
+++

Question 16

Scotochromogens species and differentiating factors

Answer 16

M. szulgai - nitrate and tween (+)
M. scrofulaceum - urease +, tween (-)
M. gordonae - urease and nitrate (-), tween (+) - present in TAP WATER

Question 17

Nonphotochromogens

Answer 17

Produce no pigment in light or dark

M. avium complex
M. xenopi (grows at 42-45C)
M. ulcerans (grows at 30C)
M. haemophilum (requires hemin)