Detection and molecular characterisation of Mycoplasma spp. from respiratory tract infections in pigs

Achieving food security involves the maintenance of intensive production systems and large animal populations where infectious diseases are the most important challenge that need to be addressed. Respiratory infections in pigs are a formidable threat to swine farmers worldwide. It is multifactorial and is caused by the interplay between bacterial pathogens, viral agents and environmental factors. The present study aimed to identify mycoplasmal agents causing respiratory infections in pigs. A total of 43 samples, comprising of nasal swabs, and necropsy samples with pneumonic lesions were collected. The DNA extracted from the samples were subjected to Mycoplasma genus-specific, followed by species-specific PCR. Twenty five samples were positive for Mycoplasma spp., but further molecular detection performed through species-specific primers, revealed that 12 samples were positive for M. hyorhinis. None of the samples were positive for M. hyopneumoniae. The identity of the amplicons were confirmed by nucleic acid sequencing and BLAST analysis. The evolutionary relationship between the detected organisms was also studied by phylogenetic analysis. This study hints at the significance of M. hyorhinis in causing respiratory infections in swine and also suggests that M. hyopneumoniae may not be a significant health hazard for swine populations of north Kerala