Lesson 7: Mycobacterium species

Question 1

General Description; MYCOBACTERIUM SPECIES

Answer 1

• ACID-FAST (ZN-positive) rods
• cell walls rich in complex lipids and waxes containing MYCOLIC ACIDS
• complex egg-enriched media required for growth of pathogenic species
• AEROBIC, NON-MOTILE, NON-SPORE-FORMING
• genus includes OBLIGATE PATHOGENS, OPPORTUNISTIC PATHOGENS and SAPROPHYTES
• pathogenic species grow slowly, colonies visible after several weeks
• some mycobacteria produce CAROTENOID PIGMENTS
• Resistant to chemical disinfectants and environmental influences but susceptible to heat treatment (PASTEURIZATION)
• multiply intracellularly and CAUSE CHRONIC, GRANULOMATOUS INFECTIONS
• major diseases include TUBERCULOSIS, JOHNE’S DISEASE and FELINE LEPROSY

Question 2

Major diseases of mycobacterium species

Answer 2

tuberculosis, johne’s disease, and feline leprosy

Question 3

economically important disease caused by M. bovis occurs worldwide

Answer 3

Tuberculosis in cattle

Question 4

can survive for several months in environment and is mainly transmitted by?

Answer 4

aerosol

Question 5

upon death of macrophages, ____________ are released and engulfed by surrounding viable phagocytes/macrophages to continue spreading the infection

Answer 5

Mycobacterial bacilli

Question 6

Test is done 30-50 days after infection using mycobacterial tuberculin called?

Answer 6

purified protein derivative (PPD)

Question 7

worldwide occurrence, caused by M. lepraemurium, the aetiologic agent of rat leprosy. Large numbers of ZN-positive bacilli are present in smears from the lesions

Answer 7

Feline leprosy

Question 8

a chronic, contagious, invariably fatal enteritis which can affect domestic and wild ruminants.

Answer 8

Paratuberculosis (Johne’s disease)

Question 9

The aetiologic agent, ________________, ______________ is an acid fast organism formerly referred to as ______________.

Answer 9

M. avium subsp. , paratuberculosis

Mycobacterium johnei