Transmission of Novel Bacterial Pathogens through Pigs Transported from Myanmar to Mizoram

Background: Illegal migration of pigs/piglets from Myanmar to Mizoram is a common practice to meet the local demands. The migrated animals are suspected as potential carrier of various microbial pathogens. The present study was conducted on isolation, identification and molecular characterization of major bacterial pathogens (Actinobacillus pleuropneumoniae, Bordetella bronchiseptica, Haemophilus parasuis, Mycoplasma hyopneumoniae and Pasteurella multocida) in pigs illegally migrated from Myanmar to Mizoram. Methods: A total of 209 rectal swabs and 209 nasal swabs were collected from apparently healthy migrated pigs during October 2018 to April, 2019. All the samples were processed for PCR based detection of target bacterial species followed by isolation and identification by bacteriological techniques. The bacterial species were further confirmed by BD Phoenix automated bacterial identification system and selected virulence genes of the bacterial species were determined by specific PCR assay. Result: By species specific PCR, 110 samples were found to be positive for selected bacterial species, of which 20 (9.57%), 1 (0.478%), 86 (41.15%), 2 (0.956%) and 1 (0.478%) were A. pleuropneumoniae, B. bronchiseptica, H. parasuis, M. hyopneumoniae and P. multocida, respectively. A total of 52 bacterial strains were isolated and identified, of which 11, 1, 39 and 1 were A. pleuropneumoniae, B. bronchiseptica, H. parasuis, M. hyopneumoniae and P. multocida, respectively. Virulence genes were detected in A. pleuropneumoniae and H. parasuis isolates. Based upon the published literatures, this is the first ever report of isolation and identification of pathogenic A. pleuropneumoniae and H. parasuis in pigs in India.