Isolation, characterization, antibiogram and pathology of Pasteurella multocida isolated from pigs

Aim: Isolation, characterization and antibiogram of Pasteurella multocida from diseased pigs of district Durg of Chhattisgarh, and to study pathological changes caused by swine pasteurellosis. Materials and Methods: An outbreak of swine pasteurellosis was suspected in pigs of Ruwabandha (Bhilai), Anjora, Somni, Tedesara, Tirgajhola villages of Durg district in Chhattisgarh, India during August and September of 2011. Nasal Swabs and blood samples from ailing pigs and heart blood and impression smears from morbid pigs were processed for detection and isolation of P. multocida by bacteriological methods. Detailed necropsy was conducted and gross and histopathological lesions were recorded. The test Isolates were subjected to antimicrobial sensitivity profile by disc-diffusion method. Results: The blood smears from heart blood and tissue impression smears revealed teaming of bipolar organisms indicating the presence of Pasteurella spp. The isolates obtained were subjected to Gram's staining for checking the purity and bipolar morphology and characterized biochemically. Gross lesions included severe acute pneumonia and haemorrhages in lungs, petechial haemorrhages on serous membranes and other visceral organs. On histopathological examination, lungs showed typical fibrinous bronchopneumonia, multifocal suppuration. All the isolates of P. multocida were 100% sensitive to Amoxicillin, Gentamicin, Enrofloxacin and showed 100% resistance to Ceftizoxim and Cloxacillin. Conclusion: Gross and microscopic lesions in dead animals are of great diagnostic value and are of characteristic of P. multocida infection. Cultural, morphological and biochemical characters are useful to rule out the causative agent as P. multocida. Antibiotic sensitivity pattern of the isolates should routinely be carried out for knowing the antibiotic resistance trends in an endemic area. Keywords: Chhattisgarh, Pasteurella multocida, pathology, pneumonic pasteurellosis, swine pasteurellosis.