Mesomycoplasma hyopneumoniae 168-L Genome sequencing. Mesomycoplasma hyopneumoniae 168-L

M. hyopneumoniae strain 168-L is the avirulent strain and is derived from the virulent parent strain 168. M. hyopneumoniae strain 168 was originally isolated from the no. 168 Er-hua-nian pig (a Chinese local breed very sensitive to M. hyopneumoniae) with typical clinical and pathogenic characteristics of mycoplasmal pneumonia of swine (MPS) in 1974. This field strain was gradually attenuated by more over 300 continuous passages through KM2 cell-free medium (amodified Friis medium). The 380th passage was named strain 168-L. Currently, M. hyopneumoniae strain 168-L has been extensively used as vaccine to against M. hyopneumoniae in China.