Mycobacterium Flashcards
(45 cards)
Mycobacterium: general
Gram (+), acid fast positve
discovered by Robert Koch
contain mycolic acid
Mycolic acids assists in
Acid fast staining
drug, chemical, environment resistance
immunomodulating activities
prevent phagocytic killing
Types of acid fast stain
Ziehl-Neelson
Kinyons
Auramine Rhodamine
The majority of mycobacterium are ___ pathogens
Opportunistic
Can ID mycobacterium by
growth patterns
Biochemical patterns
total cell fatty acid analysis
nucleic acid detection/PCR
Virulence factors
Mycolic acid containing cell wall lipids- surviving in macrophages, stimulate cytokine prod., immunomodulating effects
Cell protein antigens- do not play big role in disease
Exception to Cell protein antigen being pathogentic
M. ulcerans- mycolactone/macrolide toxins
Main reservoir of M. tuberculosis
Humans
Multi-drug resistant TB is resistant to at least
Isoniazid and rifampin
cause of zoonotic TB is
M. bovis
M. bovis: transmission
ingestion, inhalation, possibly by mucous membranes and broken skin
Main portal of entry is GIT
T or F
M. bovis has long survival term in environment
False
only survives a few weeks outside host
Other species with high prevalence of M. bovis
Cervids, badgers in UK, Feral brush tail possums in New zealand
M. bovis: clinical signs
Signs vary greatly, enlarged regional lymph nodes, Cachexia, pulmonary forms with chronic cough
TB in humans was known as
Consumption
M. bovis: pathogenesis
pyogranulomatous lesions in any organ
bacilli are phagocytosed by macrophages, casenous necrosis in center of lesion
casenous lesions of necrosis are surrounded by ___
multinucleated giant cells (Langhan’s cells)
Granulomas form as a result of ___ ____ immune response
Cell-mediated immune response- tubercle
Common later stage lesions are called
tuberculosis cavitary lesions
M. bovis: diagnostic tests
Tuberculin hypersensitivity skin lesions
Caudal fold tuberculin test
comparative cervical tuberculin skin test
interferon gamma release assay, necropsy, imaging, culture
M. Bovis: treatment
not practical or efficacious
anti-tubercular drugs
single drugs use is limited
Elements of bovine TB eradication programs
disease surveillance, pre and post moving test, cull positive animals, wildlife control
Mycobacterium leprae causes
Leprosy or Hansen’s disease
Only known reservoir for M. leprae is ___
nine-banded armadillo