Exploration of the basis of virulence attenuation and development of recombinant derivatives in a Mycoplasma synoviae live vaccine

Abstract

Mycoplasma synoviae is an important avian pathogen that is responsible for significant economic losses in the poultry industry worldwide. It is able to infect chickens, turkeys and other avian species, causing subclinical respiratory tract infections, synovitis, and egg abnormalities. A live attenuated temperature-sentitive (ts+) vaccine strain, MS-H, is widely used in many countries to prevent infection with M. synoviae. Due to its ts+ phenotype, MS-H does not grow at the core body temperature of birds, but colonises the upper respiratory tract and establishes a solid protection against wild-type M. synoviae. In rare cases, the ts+ MS-H strain may revert to a non-temperature-sensitive (ts−)..