myco Flashcards
this group of mycobacterium is Slow grower species-require number of weeks to produce observable colonies
tuberculosis group
species under the tuberculosis group of myco
m. tuberculosis, microti, africanum
the moree rapidly growing species of myco which is -atypical,anonymous,or nontubercular mycobacteria
runyons group
how many days will the runyon group produce colonies
3-21 days
mycobacteria included in mycobacterium complex
m. avium and intracellulare
the environmental and free living myco bacteria were placed in runyon in what year
1959
categories of runyon group were based on
rate of growth, colony morphology, pigment production
-producing pigmented (yellow colonies) only after exposure to light;slow growing;requires 7
days or more for visible colony
photochromogenic froup 1
producing yellow or orange pigment in the absence of light, slow growin
- scotochromogenic
-producing no or slight pigment with exposure to light; slow growing
nonphotochromogenic
grow rapidly with visible growth in less than 7 day
variable pigmentation
-inhibit phagosome-lysosome fusion within macrophage
sulfolipids
virulence factor of mycobacterium
mycosides
glycolipids
mycolic acid
sulfolipids
enhanced survival of phagocytosed mycobacteria; act to
scavenge and detoxify the toxigenic oxygen radicals that are produced by the macrophage oxidative burst
glycolipids
toxic, contribute to granulomatous response;
glycolipids
control of cellular permeability
mycosides
associated with cord factor that inactivates mitochondrial membranes within phagocyte and also inhibit
chemotaxis;
mycosides
also associated with wax D and various proteins that induce delayed –type hypersensitivit
mycosides
excreted in respiratory discharges, feces, milk, urine and semen
myco bovis
pathogenesis of m. bovis
Infection via respiratory and intestinal tracts→local multiplication extracellular and intracellular due to resistance to
phagocytic killings→infected host cell and bacteria reach local lymph nodes→thoracic duct→general
dissemination→macrophage activation kills some bacteria→macrophage aggregation contribute to tubercle formation
which may be encompass by fibrous layer→ lymphatic spread is retarded but continuous extension occurs via erosion of
bronchi, blood vessels or viscera to new area
specimen from live animal in myco
aspirates from cavities, lymph nodes, biopsies, tracheobronchial lavages and the
centrifuged deposit from 50 ml milk from suspected mastitis case
specimens of myco from dead animals
fresh and fixed samples of lesions or a selection of lymph nodes from a tuberculin reactor
with no visible lesions
can also be stained with fluorescent dye and viewed under UV microscop
myco
zn pos, slender, often beaded roots
m. bovis
Media for the mycobacterium
egg-based lowenstein-jensen and stonebrinks
isolation m. bovis
Selective decontamination to reduce fast-growing mycobacteria
Digestion or liquefaction of mucus
Centrifugation of samples to concentrate number of bacteria before smear preparation and culture
acts as prophylaxis in zoos and animal parks (myco)
isoniazid
vaccine for prevention of infestation of m. bovis
bgc (bacilli-calmette guerin
Treatment, Prevention and control: myco
isoniazid
bgs
early detection
Tuberculin Tests commonly used:
tuberculin-purified protein derivative
most widely used tuberculin test
intradermal
inoculation sites of intradermal in tuberculin testing
caudal folds, vulvar lips, side of neck
: intradermal inoculation of regular and avian tuberculin at two different sites in the neck. Read at
72 hours by measuring swelling
comparative cervical
mostly used in primates; dilution of regular ‘bovine’ tuberculin is inoculated intradermally into the upper eyelid
opthalmis
Pathogenesis and Pathogenicity Mycobacterium avium subsp. paratuberculosi
ingestion of feces, contaminated food and water
ingested bacteria is taken up by macrophage to the intestinal lymph node
immune mediated granulomatous reaction on the submucosa with accumulation of large numbers of macropgahe and lymphocytes
slough off submucosa
chronic enteritis and diarrhea
emaciation and death
m. avium specimen to be collected from live animals
a small pinch biopsy from rectum or rectal scraping, biopsy from the mesenteric lymph nodes, fecal
samples
m. avium specimen to be collected from dead animals
fresh and fixed samples of a section of the ileocecal valve, mesenteric lymph nodes
in direct microscopy of m. avium, Smears of fecal and ileocecal valve mucosa stained with ZN reveals ___ which indicates intracellular growth
arge numbers of short, red staining
rods in clumps,
m avium intravenous johnin test positive reaction
a rise in temp to 1.5 C or more
serology testing for avium
Complement Fixation test for screening, Immunodiffusion, ELISA
avium subsp. paratuberculosis has been isolated from tissues of several human patients with
crohn’s disease
growth rate of m. tuberculosis and m. bovis
3-8 weeks
growth rate of m. avium
2-6 weeks
growth rate of m. avium subsp. paratuberculosis
ver slow upto 16 weeks
optimal incubation of myco
37
atmospheric requirement of myco
aerobic
colonial features of m. tuberculosis
rough, buff, difficult to break apart
colonial features of m. bovis
cream colored, raised with central rougness, break apart easily
colonial features of m. avium
sticky off white, break off easily
colonial features of m. avium subsp paratuberculosis
small, hemisherical, some pigmented
essential growth supplemet of m. avium subsp paratuberculosis
mycobactin
effect of added sodium pyruvate in myco
no effect except in bovis which is enhanced growth
effect of added glycerol in myco
tuberculosis and avium- eugonic
bovis- dysgonic
Formation of single or multiple granulomas or nodules of the skin 1-3 cm in diameter
mycobacterium lepraemurium
Painless and move freely. May ulcerate
and discharge a slight, serosanguineus exudate. It is though that cats acquire infection via rat bites.
mycobacterium lepraemurium
causes food poisoning to humans
bacillus cersus
causes sporadic abortion in cattle and sheep
bacillus licheniformis
chromosomally coded virulence factors of bacillus anthracis
1.Extracellular proteases
2.Siderophores
3.Anthrolysin O
4.Manganes Ion ATP binding cassette
5. Phospholipase C
pathogenicity of anthrax
Uptake of the spores by the host from the environment→ germination within the host and multiplication of the vegetative
form to large numbers→ bacteremia and toxemia→ death→ shedding of bacilli in the environment→sporulation.
Diseased animals due to anthrax may suffer from:
> sudden, unexpected death
mild anorexia or reduced milk production in case of cattle
steep rise in temperature
exudation of tarry blood from body orifices, failure of blood to clot, incomplete rigor mortis, splenomegaly in cattle from
orifices at death
how to kill spores of b. anthracis
autoclaving 121C/15 minutes amd dry heat 1500/60min. (not by boiling for under 10min)
what type of disinfectants is useful for anthrax
aldehydes, oxidizing and chlorinating disinfectants, beta propiolactone, ethylene oxide
what specie is highly resistant to anthrax
birds followedf by pigs and carnivores, then horses and humas
most susceptible to anthrax
cattle, sheep goat
sample specimen for anthrax
blood from ear or tal veins, edematous fluid, peritoneal fluid
specimen for culture of anthracid
blood or homogenous spleen
edematous swelling that is hot and painful later becomes old and painless
malognat carbuncle
respiratory infections smong workers working with hides, woll and hair contaminated with spores
woolsorter’s disease
bacilli is susceptible to
penicillin, streptomycin, tetracycline, fluoroquinolones, and erythromycin
what specie of bacili is motile, resistant to penicillin, hemolytic,
cereus
