Isolation, identification, characterization and antibiogram of Pasteurella multocida isolated from pigs in Mizoram with special reference to progressive atrophic rhinitis

Aim: Isolation and identification of Paturella multocida from pigs of Mizoram with or without clinical lesions of progressive atrophic rhinitis (PAR) followed by their detection, capsular typing and screening for toxA gene. Materials and Methods: Four hundred nasal swabs sampled from pigs were collected from 6 different districts of Mizoram. Swabs were processed for detection and isolataion of P. multocida by PCR and traditional bacteriological assays. Isolates were subjected for multiplex PCR for capsular typing, detection of toxA gene and characterization by RAPD-PCR. Isolates were also tested for antimicrobial sensitivity profile by disc-diffusion method. Results: A total of 21 swabs were found to be positive by P. multocida species specific PCR (PM-PCR) with an amplicon of 460 bp, of which P. multocida could be isolated from 15 swabs (3.75%). All the isolates were grouped under capsular type A (n=9) and D (n=6) by multiplex PCR. All the isolates were found to be negative for toxA gene by PCR, indicating the isolates as non-toxigenic. Isolates under similar capsular type provided a unique banding pattern by RAPD-PCR, whereas no discrimination was observed between serotypes. Conclusion: Although, no isolates exhibited toxA gene by PCR, isolataion of P. multocida of capsular type A and D may be an indication of their possible role in PAR in pigs of Mizoram.