First report of Mycoplasma hyopneumoniae seroprevalence in farmed wild boars in China

Porcine enzootic pneumonia caused by Mycoplasma hyopneumoniae affects the global pig industry with significant economic losses. It is yet to know whether wild boars in China were infected with M. hyopneumoniae. The present study was conducted to examine the seroprevalence and to evaluate risk factors of M. hyopneumoniae infection in farmed wild boars in China. A total of 882 serum samples were collected from farmed wild boars in Jilin City, Siping City and Baishan City in Jilin Province, northeastern China from April 2015 to February 2016, and were examined by the double sandwich enzyme-linked immunosorbent assay (ELISA). Seventy-eight out of 882 (8.8%) serum samples were M. hyopneumoniae-seropositive. Among region groups, wild boars from Jilin city (11.7%, 33/281) had the highest seropositivity, followed by Siping city (11%, 29/263) and Baishan city (4.7%, 16/338), and the difference was statistically significant (P = 0.0031). The M. hyopneumoniae seroprevalence in the female wild boars (9.0%, 75/831) was higher than that in the male wild boars (5.9%, 3/51) (P = 0.4429). The results of this investigation showed that farmed wild boars were susceptible to M. hyopneumoniae. Logistic regression analysis showed that there is a significant correlation between the geographical area and M. hyopneumoniae infection, which may be related to the regional environment. This is the first report of M. hyopneumoniae seroprevalence in farmed wild boars in China, which provided baseline information for further studies and control of M. hyopneumoniae infection in wild boars in China.