corynebacterium Flashcards
What’s the common characters of Coryneforms «diphtheriods» with C. d?
Morphology
occurs as normal flora on skin and mucus mem.
some are opurtinistics
Mention aerobic and nonaorobic non spore forming gram+ bacilli
aerobic: coryne
listeria
E. rhusiopathiea
non: Actinomycetes
Nocardia
Mention species of corynebacterium.
1_C. diph
2_C. psedotuberclosis: cause ulcerative lymphangitis, abscess, chronic purlenet infections in sheep. goat. horse. man
3_C. xerosis: non. pathogenic, in mucos mam. and conjunctival sac,skin in man
4_C. renal: non. pathogenic for man, cause cystitis, pyelonephritis in cattle.
Mention the biotypes of C. di.
gravis
mitis
belfanti
intermedius lipophyl
What’s habitat of C. d
Nasopharynx, skin lesions of humen carriers resorvoir
what’s the morphology of C. d
gram + bacilli, catalase+ club shape pleomorphic rods with swallowen end Chinese letter arrangment beaded, metachromatic granules
How dose volute granules stain?
methylene blue
Alberts stain
Neissers stain
ponders stain
When can we see numerous clear metachromatic granules?
when culture in pn rich media, loeffler media, dorset egg media.
mention the culture characters of C. d according to:
O2
T
media
aerobic , facultative anaerobes
can grow at 37 c
1_blood agar, B-hymolysis in gravis, mitis
2_loeffler serum. gray small granular colonies
3_blood tullerite medium: selective differntial medium, colonies gray «gravis» to black «mi»
4_other selective media:
CTBA cystein tull.. blo. agar
CAN.. colistin nalidixic agar
How can you defferentiate between different bootypes?
colony morphology on BTm
biochemical reaction
what suger dose C. d ferment?
produce cystinase or pyrizinamidase?
glucose, maltose with acid production
Gravis ferment starch, glycogen, produce hemolysis on rabbit red cell
mitis produce hemolysis on rabbit, ox red cells
cystinase
what’s thw factors influncing toxin production?
why?
lysogenic prophage
amount by extracellular conc. of iron:
high conc. activate d. toxin repressor which binds to toxin gene operator and prevent toxin production.
Mention the characters of diph. toxin
1_heat labile
2_highly toxic
3_highly antigenic
4_can be convert to toxoid
why only one exotoxin can inactivate EF2 in cell?
1_the turn over of EF is slow
2_only one molecule per ribosome is present in a cell.
Mention the mode of transmission for each type of diphe
1_Tonsillar by airborne droplets
2_conjunctival or skin by contact
3_cutenous appears as a papule then chronic non healing ulcer coverd by grayish mem.
what’s the clinical findings in diphe?
Generlized due to toximia
local due to multiplication of organism
1_sore throat, mild fever, ill health gross swelling of tonsills and pharynx 2_enlarged cervical nodes «bull neck» 3_grayish mem. covering tonsills and may extend to pos. pharyngeal wall and larynx 4_laryngeal obstructin and suffocation.
5_Nerve involvement may lead to paralysis of muscles of soft palate and pharynx leading to difficulties in swallowing and speach.
6_peripheral neuritis «paralysis of limbs»
7_myocarditis (arythimias, circualtory failure, death)
Mention the tests for toxogeicitiy detection.
1_Eliks test 2_pcr 3_ELISA 4_immunochromographic 5_Tissue culture cytotoxic assay 6_historical test
How can we diadnose diph?
1_clinically 2_microscopic exam«direct smear». of throat swab 3_culture 4_PCR 5_toxogenicity tests
Describe the cutanous diph pathogenesis.
a puncture of wound or cut can induce the organism to the subcutaneous tissue, leading to chronic non healing ulcer with a grey mem.
rarly exotoxin production leads to degeneration and death of tissue
How can you treat diph.?
1_ antitoxin at once, 20000/100000 unites intramasculary or intravenously.
2_Antibiotics: pencillin erythromycin in adequate doses
3_prophylaxis
how ti prepare diphi. toxoid?
filtrate of broth culture of a toxogenic strain is treated with 0.3 formalin to remove toxocity and retain antigenecity.
the fluid purified, standaralized, and adsorbed onto Aluminium hydroxide or Al phosphate as adjuvant
