Mycoplasma hyorhinis is one of four important mycoplasma species considered pathogenic to swine. It is prevalent in pig farms worldwide, and it mainly inhabits the mucosa of the upper respiratory tract and tonsils. It can induce severe systemic infection leading to pleuritis, peritonitis, pericarditis, arthritis, eustachitis, and other ailments. Systemic spreading of M. hyorhinis from the site of infection to the rest of the body is assumed to be critical for disease progression, but the associated mechanism remains unclear.

Glycolytic enzymes are important moonlighting proteins and virulence-related factors in various bacteria. In this study, M. hyorhinis enolase, a glycolytic critical enzyme, was revealed as a multifunctional protein on the bacterial surface. It participates in cytoadhesion, and also functions as a receptor for two important host molecules (plasminogen and fibronectin). C-terminal lysines of enolase play important roles in these interactions. The findings suggest that enolase plays an indispensable role in infection and systemic invasion in M. hyorhinis.

Jia Wang of Institute of Veterinary Medicine, JAAS completed functional study of M. hyorhinis enolase and prepared the manuscript. Qiyan Xiong supervised and guided this work.

DOI：10.1186/s13567-022-01041-0