PATHOLOGICAL AND MOLECULAR BASED STUDY OF PNEUMONIC PASTEURELLOSIS IN CATTLE AND BUFFALO (Bubalus bubalis)

In present study the clinico-pathological findings were recorded in naturally infected cattle and buffaloes due to Pasteurella multocida during an outbreak at different livestock herds. There was no significant difference in mortality among various groups of buffaloes (P>0.78) and cattle (P>0.49). The infected animals showed clinical signs of moderate to acute anorexia, salivation, fever, depression, dysponea, submandibular edema, mucopurulent nasal discharge and respiratory grunts. Few of infected animals died due to septicemia. The necropsy of dead animals was performed and visceral organs lungs, kidneys, heart and lymph nodes were observed for gross and histopathological lesions. The tissue samples from these organs were fixed in formalin for pathological changes. Necropsy of dead animals revealed severe pneumonia, consolidation of lungs and intense pleural adhesions. Serosanguinous fluid was accumulated in pericardium and peritoneal cavities. Histopathologically affected lungs exhibited severe congestion, mononuclear cell infiltration, thick interlobular septae punctuated with macrophages, plasma cells and peri-vascular cuffing. Liver, kidneys and lymph nodes had degenerative changes in histological sections. The specificity of P. multocida was determined by colony characteristics on MacConkey's agar and morphological features with Gram's iodine. The PCR product size approximately 511bp from lung tissues confirmed a total of 82% (19/23) bacterial isolates from dead animals.