Mycoplasma/ureaplasma And Mycobacterium

Front 1

General characteristics of Mycoplasma/Ureaplasma

Back 1

• highly fastidious
• smallest free living organisms
• no permanent cell wall (has sterols in plasma membrane instead)

Front 2

Mycoplasma pneumoniae

Back 2

cause of walking pneumonia

 School-age children and young adults are most susceptible
 Up to 50% in confined populations, such as in military settings,
college dorms, and prisons

Front 3

Mycobacteria - general characteristics

Back 3

• aerobic
• non-spore forming rods
• waxy cell that doesn't readily
• pick up stain
• resist decolorization with acid-alcohol decolorizing agents “acid-fast”

Front 4

Mycobacterial infections

Back 4

Most mycobacterial infections are spread through inhalation of contaminated
droplets.

Front 5

Three Classifications of Mycobacterium

Back 5

• Mycobacterium tuberculosis complex or MTB
• Atypical mycobacteria or nontuberculous mycobacteria (NTM)
• Mycobacterium leprae

Front 6

MTB group

Back 6

organisms that cause tuberculosis:

• M. tuberculosis
• M. bovis
• M. africanum
• M. ulcerans

Front 7

Tuberculosis

Back 7

• formation of spherical granulomatous lesions, called tubercles, and caseous (cheese-like) necrosis.

• pulmonary
• Person-to-person transmission via respiratory droplets

Front 8

Atypical mycobacteria (NTM)

Back 8

Can cause tuberculosis-like illness but no evidence of person to person
transmission

Front 9

Mycobacterium leprae

Back 9

Causes leprosy (Hansen’s disease)

Front 10

NTM classification

Back 10

• "Runyon Groups" - based on pigment production and rate of growth

Front 11

Photochromogens (Runyon group I)

Back 11

Slow-growing (2-6 weeks)
• Nonpigmented when grown in absence of light
• Produce yellow or orange pigment when exposed to light and reincubated (photoactivation)

Front 12

Scotochromogens (Runyon group II)

Back 12

• Slow growing species that produce yellow to orange pigment whether grown in light or dark
• Pigment produced deepens to orange or dark red with exposed to light

Front 13

Nonphotochromogens (Runyon group III)

Back 13

• Slow-growing organisms that may be lightly pigmented (buff, tan or pale yellow)

• Pigment does not intensify when exposed to light

Front 14

Rapid-growers (Runyon group IV)

Back 14

Organisms that form mature visible colonies within 7 days of incubation

Front 15

Photochromogens (Runyon group I)

organisms

Back 15

M. kansasii - 2nd to MAC in
causing NTM pulmonary infections;

M. marinum - Skin infections associated with
aquariums and pools

Front 16

Scotochromogens (Runyon group II)

organisms

Back 16

M. scrofulaceum - Common cause of
cervical lymphadenitis especially in children
in Africa

M. gordonae - Tap water bacillus, Nonpathogen, lab contaminant

M. szulgai - (photochromogen at
25C)

Front 17

Nonphotochromogens
(Runyon III)

organisms

Back 17

M. avium-inracellulare
complex (MAC or MAIC) - pulmonary disease resembles Tuberculosis, primarily infects swine and birds

M. xenopi
Pulmonary infections;
grows best at 42C

M. haemophilium
Subcutaneous lesions,
ulcers, and abscesses

M. ulcerans
Causative agent of
chronic
ulcerative skin disease;
Grows best at 32-33 C

Front 18

Rapid
Growers
(Runyon IV)

organisms

Back 18

M. fortuitum complex (M. chelonae
and M. fortuitum): Isolated from
soil and water; associated with various
wound infections

Front 19

AFB staining: Carbol Fuchsin-Based Stains

Back 19

Ziehl-Neelsen technique: Heat is used to drive the stain into the cell wall.

Kinyoun technique: Stain contains a detergent to drive the stain into the cell wall.

positive: red

negative: blue

Front 20

AFB staining: Fluorochrome based stain

Back 20

Rhodamine-auramine or auramine O: binds to mycolic acid

Mycobacteria appear yellow to orange

Front 21

Niacin accumulation (ID technique)

Back 21

Niacin accumulation: All mycobacteria produce niacin and most possess an enzyme to convert niacin to niacin ribonucleotide.

Only M. tuberculosis, M. simiae, and rare strains of M. bovis, M. marinum, and M. cheloni lack this enzyme

(yellow = positive for accumulation)