Sequence and Evolutional Analysis of Escherichia coli O54 O-antigen Gene Cluster
大肠杆菌O54 O-抗原基因簇的破译及进化分析

The Escherichia coli O54 O antigen gene cluster was sequenced. It was found to contain genes responsible for the biosynthesis of nucleotide sugar dTDP rhamnose ( rmlBDA and rmlC ), genes encoding O unit flippase( wzx ) and O antigen polymerase( wzy ) and putative transferase. Unlike most of the cases in which rml genes are located together, rmlC was apart from other rml genes. Further analysis indicated that rmlC gene was recently introduced into the O antigen gene cluster of Escherichia coli O54 It was also found that E.coli O54 and Shigella bodyii 9 are closely related. By polymerase chain reaction for the 166 E.coli and 43 Shigella O serogroups, wzx and wzy as specific genes for E.coli O54 were identified This work provides the basis for a sensitive test for the rapid detection of E.coli O54