Open AccessStructural and genetic evidence for the close relationship between Escherichia coli O71 and Salmonella enterica O28 O‐antigens
Author(s) -
Hu Bo,
Perepelov Andrei V.,
Liu Bin,
Shevelev Sergei D.,
Guo Dan,
Senchenkova Sof'ya N.,
Shashkov Alexander S.,
Feng Lu,
Knirel Yuriy A.,
Wang Lei
Publication year - 2010
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2010.00676.x
Subject(s) - salmonella enterica , biology , escherichia coli , prophage , genetics , gene , antigen , enterobacteriaceae , salmonella , microbiology and biotechnology , homology (biology) , bacteria , bacteriophage
O‐antigen is the most variable cell wall constituent of Gram‐negative bacteria. Escherichia coli and Salmonella enterica are closely related species. In this work, we present structural and genetic evidence for the close relationship between O‐antigens of E. coli O71 and S. enterica O28. The E. coli O71 O‐antigen was found to consist of tetrasaccharide‐repeating units containing d ‐Gal p NAc, d ‐Gal p , l ‐Rha p , and d ‐Qui p 3NAc, with multiple O ‐acetyl lateral groups. It is very similar to the known structure of the S. enterica O28 O‐antigen, which has the same backbone units, but with a lateral Glc residue instead of O ‐acetyl groups. The O‐antigen gene clusters of E. coli O71 and S. enterica O28 were sequenced and found to contain the same genes with high‐level similarity. All of the genes expected for the synthesis of the common backbone structure of the two O‐antigens were identified based on homology. It is proposed that the two gene clusters had originated from the same ancestor, and diverged by acquiring prophage genes to carry out side‐chain modifications. This is a new pair of the closely related E. coli and S. enterica O‐serogroups. The serogroup‐specific genes of E. coli O71 and S. enterica O28 were also identified.