Clinical Significance of Escherichia albertii

Tadasuke Ooka, Kazuko Seto, Kimiko Kawano, Hideki Kobayashi, Yoshiki Etoh, Sachiko Ichihara, Akiko Kaneko, Junko Isobe, Keiji Yamaguchi, Kazumi Horikawa, Tânia A.T. Gomes, Annick Linden, Marjorie Bardiau, Jacques G. Mainil, Lothar Beutin, Yoshitoshi Ogura, and Tetsuya Hayashi

Author affiliations: University of Miyazaki, Miyazaki, Japan (T. Ooka, Y. Ogura, T. Hayashi); Osaka Prefectural Institute of Public Health, Osaka, Japan (K. Seto); Miyazaki Prefectural Institute for Public Health and Environment, Miyazaki (K. Kawano); National Institute of Animal Health, Ibaraki, Japan (H. Kobayashi); Fukuoka Institute of Health and Environmental Sciences, Fukuoka, Japan (Y. Etoh, S. Ichihara, K. Horikawa); Yamagata Prefectural Institute of Public Health, Yamagata, Japan (A. Kaneko); Toyama Institute of Health, Toyama, Japan (J. Isobe); Hokkaido Institute of Public Health, Hokkaido, Japan (K. Yamaguchi); Universidade Federal de São Paulo, São Paulo, Brazil (T.A.T. Gomes); University of Liège, Liège, Belgium (A. Linden, M. Bardiau, J.G. Mainil); Federal Institute for Risk Assessment, Berlin, Germany (L. Beutin)

Abstract

Discriminating Escherichia albertii from other Enterobacteriaceae is difficult. Systematic analyses showed that E. albertii represents a substantial portion of strains currently identified as eae-positive Escherichia coli and includes Shiga toxin 2f–producing strains. Because E. albertii possesses the eae gene, many strains might have been misidentified as enterohemorrhagic or enteropathogenic E. coli.

Attaching and effacing pathogens possess a locus of enterocyte effacement (LEE)–encoded type III secretion system. They form attaching and effacing lesions on intestinal epithelial cell surfaces by the combined actions of intimin, an eae gene–encoded outer membrane protein, and type III secretion system effectors. Attaching and effacing pathogens include enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC, respectively) and Citrobacter rodentium (1,2). Escherichia albertii have recently been added to this group (3–5). However, the clinical significance of E. albertii has yet to be fully elucidated, partly because it is difficult to discriminate E. albertii from other Enterobacteriaceae spp. by using routine bacterial identification systems based on biochemical properties (6–9). A large number of E. albertii strains might have been misidentified as EPEC or EHEC because they possess the eae gene.