Open AccessO-antigen biosynthesis gene clusters of Escherichia albertii: their diversity and similarity to Escherichia coli gene clusters and the development of an O-genotyping method
Author(s) -
Tadasuke Ooka,
Kazuko Seto,
Yoshitoshi Ogura,
Keiji Nakamura,
Atsushi Iguchi,
Mikiko Honda,
Yoshiki Etoh,
Tetsuya Ikeda,
Wakana Sugitani,
Takayuki Konno,
Keiichi Kawano,
Naoko Imuta,
Kiyotaka Yoshiie,
Yukiko Hara-Kudo,
Koichi Murakami,
Tetsuya Hayashi,
Junichiro Nishi
Publication year - 2019
Publication title -
microbial genomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.476
H-Index - 28
ISSN - 2057-5858
DOI - 10.1099/mgen.0.000314
Subject(s) - biology , genotyping , genetics , escherichia coli , serotype , gene , phylogenetic tree , genotype , microbiology and biotechnology
Escherichia albertii is a recently recognized human enteropathogen that is closely related to Escherichia coli . In many Gram-negative bacteria, including E. coli , O-antigen variation has long been used for the serotyping of strains. In E. albertii , while eight O-serotypes unique to this species have been identified, some strains have been shown to exhibit genetic or serological similarity to known E. coli / Shigella O-serotypes. However, the diversity of O-serotypes and O-antigen biosynthesis gene clusters (O-AGCs) of E. albertii remains to be systematically investigated. Here, we analysed the O-AGCs of 65 E. albertii strains and identified 40 E. albertii O-genotypes (EAOgs) (named EAOg1-EAOg40). Analyses of the 40 EAOgs revealed that as many as 20 EAOgs exhibited significant genetic and serological similarity to the O-AGCs of known E. coli / Shigella O-serotypes, and provided evidence for the inter-species horizontal gene transfer of O-AGCs between E. albertii and E. coli . Based on the sequence variation in the wzx gene among the 40 EAOgs, we developed a multiplex PCR-based O-genotyping system for E. albertii (EAO-genotyping PCR) and verified its usefulness by genotyping 278 E. albertii strains from various sources. Although 225 (80.9 %) of the 278 strains could be genotyped, 51 were not assigned to any of the 40 EAOgs, indicating that further analyses are required to better understand the diversity of O-AGCs in E. albertii and improve the EAO-genotyping PCR method. A phylogenetic view of E. albertii strains sequenced so far is also presented with the distribution of the 40 EAOgs, which provided multiple examples for the intra-species horizontal transfer of O-AGCs in E. albertii .