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RUSVM Bacteriology Gram Positives > Mycobacterium > Flashcards

Flashcards in Mycobacterium Deck (52)
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1

Mycobacterium description

**Aerobic & Acid fast!** non spore-forming rods, No flagella or capsules, Gram positive but poor at staining

2

What does it mean to be acid fast?

Can bind phenol based dyes and resist discoloration

3

Mycobacterium Major diseases

*Tuberculosis* - Paratuberculosis - Granulomatous diseases

4

Mycobacterium Virulence factors

Lipids/glycolipids/peptidoglycolipids - Alkyl hydroperoxidase reductase - Sufolipids, phosphatidyl inosital mannoside, surface mycosides, waxes - Glycolipid Dimycolyl trehalose - Mycobactins & exochelins

5

Mycobacterium virulence factors that aid in intramacrophage survival & account for acid-fastness

Lipids, glycolipids, peptidoglycolipids

6

Mycobacterium virulence factors that are responsible for resistance

Alkyl hydroperoxidase reductase

7

Mycobacterium virulence factor - "cord factor"

Dimycolyl trehalose glycolipid

8

Mycobacterium virulence factor for iron acquisition

Mycobactins & Exochelins

9

Tuberculosis - 3 species responsible

*Reportable Disease*!!!! - M. tuberculosis, M. bovis, M. avium

10

Tuberculosis - Reservoir species of different Mycobacterium species

Humans (M. tuberculosis) - Cattle & wild mammals (M. bovis) - Birds (M. avium)

11

Tuberculosis- Transmission

Mainly inhalation & ingestion - Transplacental, transovarian - intrauterine also possible

12

Tuberculosis Pathogenesis

- Inhalation--> respiratory tract, adjacent lymph nodes & serous cavities - Hematogenous dissemination to liver & kidney - Rare udder infection (zoonotic!!) - Some transplacental to calves (liver & spleen lesions if not aborted)

13

Tuberculosis Disease patterns

Acute exudative process - Neutrophilic - Large infecting dose favored (inhalation) - High virulence - Predisposition of host - Loose tissue architecture (lungs) - Emaciation - Low grade fever - Enlarged lymph nodes - cough - diarrhea (tissue damage from cytokines, help spread organism)

14

What Tuberculosis signs arise after effective cell-mediated immune response?

Localized arrested pulmonary lesions

15

What Tuberculosis signs arise after ineffective cell-mediated immunie response?

Active pulmonary tuberculosis, generalized tuberculosis

16

Tuberculosis in ruminants - causative species

M. bovis!! sometimes avium/tuberculosis

17

Tuberculosis in ruminants- Disease pattern

Granulomatous lesions all over lungs, serous cavity surfaces! -

18

Tuberculosis in horses

M. avium - Rare - GI infection, pharynx & intestine, maybe lungs, spleen & serous membranes

19

Tuberculosis in pigs

M. bovis & avium - GI, Miliary lesions in liver & spleen

20

Tuberculosis species in Dogs & Cats

Mainly M. bovis

21

When I say Marie's Disease, you say...

Dog tuberculosis - M. bovis

22

Tuberculosis in dogs

Marie's Disease - Hypertrophic pulmonary osteoarthropathy

23

Tuberculosis in cats

Intestinal & abdominal localization, ulcerative skin lesions

24

Tuberculosis in birds

M. avium complex - Grows @ higher temp - Alimentary infection--> disseminate to liver & spleen. Transovarian infection to chicks rare

25

Tuberculosis in foals! and DDx for gram positive, aerobic bacteria causing pneumonia

Rare! DDx : Rhodococcus equi

26

Tuberculosis species in primates

M. bovis (mainly) M. tuberculosis, M avium & non-tuberculous mycobacteria in immunosuppressed

27

M. tuberculosis in primates

Airborne route, mostly respiratory tract infections

28

M. bovis in primates

Ingestion, unpasteurized milk!!

29

Case Study - Nasty picture of gross growth on vet surgeons finger

Verrucose lesion of cutaneous tuberculosis

30

Tuberculosis breed resistance

Zebu cattle (with hump) more resistant than other breeds.