الفهرس 
Cover Page Title in EnglishOnly 14 pages are availabe for public view
 |  | from | 32 |  |  |
| | | from | 32 | | |
Abstract
Nitrate negative strain of Corynebacterium pseudotuberculosis infecting the lymph nodes in the region of the point of entry while, nitrate positive strain infects horses and combination of the twos strains infects cattle. Both strains produce an exotoxin, similar to phospholipase D, which appears leukotoxic and damages endothelial cells. This is what promotes the spread from the initial penetration site to the regional lymph nodes and visceral organs. A total of 170 pus swabs were collected from different animal species (60 samples from multiple abscesses in sheep, 50 samples from lung abscess in young calf from abattoir and 60 samples from vaginal pyogenic discharge from cattle) for isolation and identification of Corynebacterium species, characterization the susceptibility profile this bacteria to antimicrobials, study the efficiency of the organism to make biofilm formation and detection of virulence gene (sigma gene) by PCR. Eighteen (30%) Corynebacterium pseudotuberculosis isolates were recovered from 60 samples of multiple abscesses, 6 isolates from 50 samples of lung abscess from young calf in abattoir in a percentage (12 %) and finally out 10 isolates from 60 samples of vaginal pyogenic discharge from cattle in a percentage (16.7%). The Corynebacterium isolates were 34, biochemical identification tests revealed that 24 isolates were positive for catalase, urease and ferment glucose, while all isolates (34) were negative for nitrate reduction, gelatin liquefaction and give β- Haemolysis on sheep blood agar. There are 12 isolates of Corynebacterium species has no ability to form biofilm (35.3%), 5 isolates has ability to form weak biofilm (14.7%), 13 isolates has ability to form moderate biofilm formation (38.2%), finally there are 4 isolates has ability to form strong biofilm formation (11.8%). Thirty-four isolates of Corynebacterium species isolated from different samples were tested for their sensitivity to 10 antimicrobial agents. The isolates were highly sensitive to Vancomycin and Streptomycin, moderately sensitive to Gentamicin, Erythromycin, Tetracycline, and Chloramphenicol but were resistant to Cephotaxime, Penicillin, Rifampicin and Amoxycillin-Clavulenic acid. Results revealed that there are 2 isolates (one from sheep and other from cattle) have virulent gene (sigma factor) with 490 bp, while 9 isolates have no virulent genes (sigma factor) of C. pseudotuberculosis.