Understanding the local molecular epidemiology of mycoplasma hyopneumoniae from pig herds in Northern-Thailand

Abstract

© 2020, Chiang Mai University - Faculty of Veterinary Medicine. All rights reserved. Mycoplasma hyopneumoniae, a causative agent of Enzootic pneumonia (EP), is one of the most important issues contributing to economic losses in swine industry. A study of their genetics can further an understanding of its epidemiology assisted in developing the control strategy. Multilocus sequence typing (MLST) is widely accepted as a tool for this type of determination. In this study, 15 local strains of M. hyopneumoniae were isolated from consolidated lungs of slaughtered pigs in Chiang Mai and Lamphun provinces between 2018 and 2019 and genotyped by MLST. The variations of three housekeeping genes, adk, rpoB and tpiA were explored to query the specific sequence types (STs). Eleven STs were determined. Nine (ST135–ST143) were assigned as newly detected STs. The remaining two were ST117 and ST106. Of those strains recently detected, only one identified as ST106 was similar to others previously found by locals; ten STs recently investigated had not previously been found. New strains were carried by newly acquired pigs, and a high rate of overall mutation was emerged in a short period of time. The hygienic quarantine and disease detection, especially in pigs introduced to the region, should be taught and implemented in field practices.