THE MYCOBACTERIUM Flashcards
The general characteristics of Mycobacteria
Slender, slightly curved or straight rod-shaped organisms
Non motile
Non spore forming
Non-encapsulated
Strictly aerobic; catalase +
Mycobacteria produces what type of granules
Much granules
Acid responsible for its acid-fast staining characteristics
Mycolic acid
Consequences of high lipid content
Staining requires a longer time or application of heat
and once stained, it resist decolorization with acid-alcohol
The 3 major groups of Mycobacteria
Mycobacterium tuberculosis complex
Non-tuberculous mycobacteria (NTM)
Mycobacterium leprae
Organisms under the Mycobacterium tuberculosis complex
M. tuberculosis
M. bovis
M. africanum
M. microti
M. canetti
It is primarily a pathogen of the respiratory tract (TB)
Mycobacterium tuberculosis
It is once called “consumption”
Mycobacterium tuberculosis
Mycobacterium tuberculosis has a gram _________ cell wall
positive
M. tuberculosis has tapered ends and may exhibit “_______”
cording
It causes tuberculosis and Pott’s disease
M. tuberculosis
M. tuberculosis causes
tuberculosis and Pott’s disease
It is TB of the bone and muscles
Pott’s disease
Mycobacterium tuberculosis grows usually within …
8 weeks or 2 months
The virulent strains of Mycobacterium tuberculosis that is necessary to cause disease
Cord factor
The 3 types of tuberculosis
Primary TB
Secondary TB
Disseminated TB
A type of TB results from the initial infection of MTB
Primary TB
A type of TB results from the re-establishment of active infection after a period of dormancy
Secondary TB
A type of TB results when the infection spreads throughout the body
Disseminated TB
A macrophage in the lungs
Alveolar macrophage
A type of test that detects a patient’s cell-mediated immune response to bacterial antigen
PPD (Purified Protein Derivative) Test
It measures a person’s immune reactivity to specific mycobacterial antigens
Interferon-Gamma Release Assays
A zoonotic mycobacterium organism
Mycobacterium bovis
A zoonotic mycobacterium organism
Mycobacterium bovis
Found primarily in cattle, dogs, cats, swine, parrots, and humans
Mycobacterium bovis
Has small, granular, rounded white colonies with irregular margins
Mycobacterium bovis
A mycobacterium organism that is slow grower, and non pigmented
Mycobacterium bovis
Primary agent of intestinal TB in man through ingestion of contaminated milk
Mycobacterium bovis
Mycobacterium bovis is a source of …
BCG (Bacille Calmette-Guerin) vaccine
Atypical Mycobacteria is also known as …
MOTT (Mycobacteria Other Than Tuberculosis) and NTM (Non-tubercle Bacillus)
It is an opportunistic pathogen in patients with liver disease, immunocompromised, percutaneous trauma
Atypical Mycobacteria
MOTT’s classification
Runyoun’s classification
Mycobacterium’s classification is based on
Photoreactivity (ability to produce pigment)
The 4 groups in Runyoun’s classification
GROUP1-Photochromogens
GROUP2-Scotochromogens
GROUP3-Nonphotochromogens
GROUP4-Rapid growers
It produces carotene pigment upon exposure to light
GROUP1-Photochromogens
It produces carotene pigment in light or dark
GROUP2-Scotochromogens
No pigment; these colonies are a buff color
GROUP3-Nonphotochromogens
Non-pathogenic group which grows with in less than 7 weeks
GROUP4-Rapid growers
Organisms under GROUP1-Photochromogens
M. kansasii
M. marinum
M. simiae
M. asiaticum
GROUP2-Scotochromogens
M. gordonae
M. scrofulaceum
M. flavescens
GROUP 3-Nonphotochromogens
M. avium
M. gastri
M. terrae
M. xenopi
M. ulcerans
GROUP 4-Rapid growers
M. fortiutum
M. smegmatis
M. phlei
It is also known as Yellow bacillus
Mycobacterium kansasii
Characteristics of Mycobacterium kansasii
Grows best at 37 degC
Growth is evident in 14-28 days
Tween 80 hydrolysis (positive) in 3 days
Nitrate reduction (positive)
Rapid Catalase Activity & Pyrazinamidase (negative)
Causes Chronic Pulmonary Disease
Characteristics of Mycobacterium marinum
Grows optimally at 30-32 degC
Growth at 24 degC and 32 degC occurs in 2 weeks
Grows poorly or fails to grow at 35-37 degC
Niacin Test (positive)
Tween 80 (positive)
Urease (positive)
Pyrazinamidase (positive)
Causes SWIMMING POOL GRANULOMA
Characteristics of Mycobacterium scrofulaceum
Causes CERVICAL LYMPHADENITIS
Produces smooth, buttery, yellow to orange colo. in 4-6 weeks
Pigment production evident in absence or presence of light
Heat stable catalase (positive)
Characteristics of Mycobacterium szulgai
Photochromogen at 25 degC
Schotochromogen at 35-37 degC
Nitrate Reduction (positive)
Tween 80 (slow positive)
Fails to grow on 5% NaCl
May cause pulmonary & cutaneous disease
Also known as Tap Water Bacillus
Mycobacterium gordonae
Characteristics of Mycobacterium gordonae
Usually non-pathogenic
Previously known as M.aquae
Grows in 7 days at 37 degC as yellow to orange colo.
Tween 80 (positive)
Heat stable catalase (positive)
Characteristics of Mycobacterium xenopi
Slow grower and produces small colonies
Optimal growth at 42 degC
On Cornmeal Agar produces branching colonies “Bird’s Nest”
Catalase (positive)
Arylsulfatase test (positive) in 2 weeks
Causes pulmonary infection in patients with pre-existing lung pathologies
It is a normal flora kind of mycobacterium
Mycobacterium flavescens
