[The outer membrane protein (OMP) patterns of Escherichia coli isolates of predominant O serogroups originated from chichens in different regions in China].

The purpose of this study is to determine the outer membrane protein (OMP) patterns of avian Escherichia coli isolates with predominant serogroups originated from 18 provinces, autonomous regions and municipal cities in China. Total of 204 isolates belonging to O18, O78, O2, O88, O11 and O26 serogroups respectively, were tested. The outer membrane proteins of these isolates were isolated with the improved N-lauroylsarcosine method and analyzed by SDS-PAGE. 4 different OMP patterns were identified with these isolates of predominant serogroups. 3 different OMP patterns with 56 isolates of O18, 4 with 54 isolates of O78, 2 with 28 isolates O2, 1 with 26 isolates of O88, 3 with 22 isolates of O11 and 1 with 18 isolates of O26 respectively, were found. Isolates with OMP pattern 1 were discovered in 6 different serogroups, and OMP-3 pattern was also shared by O18, O78 and O11 serogroups isolates. These results indicated that the OMP patterns of avian pathogenic Escherichia coli isolates of O18, O78, O2, O11 serogroups which were isolated from different regions in China were heterogeneous, and all of O88 and O26 serogroups isolates just belonged to OMP pattern 1. Moreover, the OMP pattern 1 was presented in isolates of six different predominant O serogroups.