Caseous lymphadenitis is a chronic infectious disease caused by Corynebacterium pseudotuberculosis. 1450 sheep from 5 flocks examined to determine prevelance, clinical finding, age and sex susciptability and molecular diagnosis of Corynebacterium pseudotuberculosis. 24 sheep characterized clinically by emaciation, unthriftness and enlargement of parotid, retropharyngeal, sub mandibular, pre scapular and inguinal lymph node given greenish pus. Parotid, retropharyngeal, and sub mandibular lymph node consider the most common lymph node affected (21 case), followed by pre scapular lymph node (2 case), followed by inguinal lymph node (one case). No of infected sheep with of C. pseudotuberculosis was 24 cases (1.65%) (C.pseudotuberculosis alone (10 cases), C.pseudotuberculosis with strept pyogens (4 cases) and C.pseudotuberculosis with Staphylococcus aureus (10 cases). The infection rates of C. pseudotuberculosis were zero percent in one month age till 12th month while 1.80% (4 animals), 1.18% (3 animals) 4.54% (8 animals), 9.1% (9 animals), in age group 1-2 years old (200 animals), 2-3 years old (198 animals), 3-4 years old (150 animals) and 4-5 years old (170 animals), respectively. The infection rates of caseous lymphadenitis were more prevalent in femals 2.24% (22 animals) than males 0.42% (2 animals). PCR on pld gene explain difference between culture and pus. Samples from 1 to 9 positive on culture PCR while sample number 10 negative while sample number 1,2,4,6,9,10 were positive on pus PCR and sample number 3,5,7,8 were negative. These results may due to presence of necrotic tissue and debris. We concluded that molecular diagnosis (PCR) in cultured samples has proved to be more efficient, reproducible and faster than PCR on pus to overcome the obstacles of pus and necrotic tissue.
Key words: Key words: Corynebacterium pseudotuberculosis, lymph node, PCR, sheep
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