RT Journal Article SR Electronic(1) A1 Ooka, Tadasuke A1 Seto, Kazuko A1 Ogura, Yoshitoshi A1 Nakamura, Keiji A1 Iguchi, Atsushi A1 Gotoh, Yasuhiro A1 Honda, Mikiko A1 Etoh, Yoshiki A1 Ikeda, Tetsuya A1 Sugitani, Wakana A1 Konno, Takayuki A1 Kawano, Kimiko A1 Imuta, Naoko A1 Yoshiie, Kiyotaka A1 Hara-Kudo, Yukiko A1 Murakami, Koichi A1 Hayashi, Tetsuya A1 Nishi, JunichiroYR 2019 T1 O-antigen biosynthesis gene clusters of Escherichia albertii: their diversity and similarity to Escherichia coli gene clusters and the development of an O-genotyping method JF Microbial Genomics, VO 5 IS 11 OP SP e000314 DO https://doi.org/10.1099/mgen.0.000314 PB Microbiology Society, SN 2057-5858, AB 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 ., UL https://www.microbiologyresearch.org/content/journal/mgen/10.1099/mgen.0.000314