Immunological studies on pasteurella haemolytica in sheep

In the period from January-July 2001 respiratory manifestations appeared on 53 out of 239 sheep at Sakha station of reproduction Research center, causing death of 30 cases. Clinically history symptoms and necropsy findings were reported. Pasteurella haemolytica was incriminated as the causative agent of this problem. This organism was isolated from nasal swabs of clinically diseased sheep and from pharyngonasal swabs, lung tissue of six emergency slaughtered cases. The isolates were identified biochemically and serologically and using pathogenicity test. Two antigens leukotoxin and whole cell associated with Pasteurella haemolytica. SDS-PAGE of leukotoxin yield four protein bands ranged from 80 KDa to 98 Kda while whole cell antigen yielded 10 protein bands ranged between 22 to 85 KDa. Antigens associated with P. haemolytica whole cell and leukotoxin were identified for their immunogenic activity by neutralization test and ELISA. The neutralizing antibodies against leukotoxin in sheep were significantly higher than antibodies against the whole cell antigen. Also, antibodies titre to leukotoxin by ELISA were significantly higher than antibody titre to whole cell antigen, Pathological examination revealed that the sacrified sheep suffered from pneumonia with various lesions in lymph nodes, liver, kidney, heart and brain

Oedematous skin disease: a recurring infection in buffaloes

Eighteen Corynebacterium pseudotuberculosis were isolated from 30 specimens [9 biopsies from closed skin lesions and 21 exudate specimens from open lesions] collected from 27 buffalos with symptoms of skin infection. C. pseudotuberculosis was isolated in pure cultures from 6 out of 9 biopsies and in mixed cultures from 12 out of 21 exudate specimens. The majority of isolates were of biotype II [15 isolates], whereas only 3 isolates were of biotype I. The pattern of isolation of both biotypes I and II from biopsies and exudate specimens was similar. Both biotypes I and II differed in their course of pathogenicity in G. pigs. C. pseudotuberculosis was not isolated from blood suckling and biting flies [236 files] existed on the infected animals and in their premises. This might rule out the role of vectors in transmission of infection. In-vitro antibiotic sensitivity testing revealed that C. pseudotuberculosis isolates were most sensitive to penicillin 89%, amoxycillin 89%, erythromycin 83%, chloramphenicol 78% and ampicillin 78%. The histological examination of skin biopsies from the diseased buffalos showed inflammatory reaction due to the bacterial infection