Bacteriology Exam 2

Mycobacterium is aerobic or anaerobic?

aerobic

mycobacterium is spore-forming or non-spore forming?

non-spore forming

what is the shape of mycobacterium?

rod shaped

mycobacterium is _______ and therefore Ziehl-Neelsen positive

acid fast

mycobacteria is a _____, _______ pathogen

intracellular, opportunistic

some mycobacteria produce ______ pigment 

carotenoid 

what are the major diseases caused by mycobacteria?

• tuberculosis

• johne’s disease = paratuberculosis

• feline leprosy

• skin tuberculosis and bovine farcy

• granulomatous lesions

main hosts for M. lepraemurium

rats and mice

main hosts for M. avium spp. paratuberculosis

cattle, sheep, goats, and deer

disease caused by M. lepraemurium

rat and feline leprosy

eugonic means

enhanced growth

dysgonic means

inhibited growth

what mycobacteria requires a growth supplement of Mycobactin?

M. avium spp. paratuberculosis

effect of glycerol of m. tuberculosis

eugonic

effect of glycerol of M. bovis 

dysgonic 

effect of glycerol on M. avium complex

eugonic

what is the mycobacteria species that has enhanced growth with pyruvate while the others have no effect?

M. bovis

what mycobacterium causes tuberculosis in cattle?

M. bovis

in what cells does the mycobacterium survive in the lungs?

macrophages and dendritic cells

clinical signs of tuberculosis

• only evident in advanced disease

• loss of condition

• cough

• intermittent pyrexia

• marked induration of affected quarters

• supramammary lymph node enlargement 

• mastitis 

diagnosis of tuberculosis

• tuberculin test

• IFN-y assay

• ELISA detecting antibodies 

• lesion sample 

• isolation of M.bovis 

• tissue samples → PCR, histopathology, ZN staining

what bacteria can cause a false positive on tuberculin test?

M. phlei 

what may cause the tuberculin test to show a false negative?

• animals with advanced tuberculosis (IgG) 

• test at early stages of infection 

what are bacteria that may cross react with tuberculosis on the tuberculin test?

• M. avium 

• M. paratuberculosis 

• nocardia spp. 

what tuberculin test is most commonly used for routine testing because of its simplicity but is prone to false positive and very sensitive?

single intradermal 

what tuberculin test is used with avian TB or johne’s disease is prevalent that is more specific that the SID but more complex?

comparitive 

what tuberculin test is used in postpartum animals as well as those infected and has high efficiency but is very time consuming with a risk of anaphylaxis?

short thermal 

what tuberculin test is used in postpartum animals and in advanced cases that is very sensitive and accurate but requires 3 visits?

stormont 

why is avian tuberculosis mainly seen in older birds?

because the disease is chronic 

where can one find granulomas lesions in an animal infected with avian tuberculosis?

• liver

• spleen

• bone marrow

• intestine

feline leprosy is a _____ disease

cutaneous

who is most susceptible to johne’s disease?

calves BUT they wont show signs until at least 2 years of age because the disease is chronic

how is johne’s disease (paratuberculosis) transmitted?

oral ingestion of organisms shed in the feces of infected animals 

pathogenesis of paratuberculosis

ingested mycobacteria taken up by M cells → cross the epithelial layer → engulfed by macrophages in which they survive → interferes with maturation of phagosome-lysosome fusion → granuloma formation in lamina properia and submucosa of GIT → enteropathy led to loss of plasma proteins and malabsorption of nutrients and water 

clinical signs of animals infected with paratuberculosis 

• diarrhea, persistent and profesur 

• weight loss

• mucosa of terminal small intestine and large intestine thickened and folded 

• mesenteric and ileocecal lymph nodes are enlarged and edematous 

what are the different types of skin tests?

• johnin = m. avium var paratuberculosis 

• brucella abortus 

• mallin = Burkholderia mallei 

• histoplasmin = histoplasmosis 

• coccidioidin = coccidioidomycosis