Shiga toxin 2f-producing Escherichia albertii from a symptomatic human.

The previously identified Shiga toxin (Stx) 2f-producing Escherichia coli O115:HNM strain F08/101-31, isolated from a symptomatic human, was confirmed to be E. albertii in the present study by whole genome DNA-DNA hybridizations, by sequencing (cpn60, dnaJ, and 16S rRNA genes), and by multi-locus sequence typing. The F08/101-31 strain was originally identified as E. coli rather than the relatively new bacterial species E. albertii, which was first described in 2003, because it did not display any of the biochemical characteristics of E. albertii. This new classification will impact public health management strategies in Japan because the present study showed that some E. albertii strains, which are often misidentified as E. coli, produce Stx and likely cause diarrhea in humans. Therefore, further guidelines for the management and identification of Stx-producing E. albertii are required in Japan.