[ODP21] 5. 病原性-a. 接着因子・定着因子

[ODP-100] 定型接着因子不明な分散接着性大腸菌の全ゲノム解析

山崎 康祐¹，谷本 佳彦^1,2，陳 彦霖¹，西川 禎一³，中台（鹿毛） 枝里子¹，和田 崇之¹ (¹大阪市立大・生活科学・環境健康科学，²神戸市健康科学研究所，³帝塚山学院・人間科学)

The afa/dr gene family has been a typical adhesin of diffusely adherent Escherichia coli (DAEC). Recently, we have isolated several DAEC strains without the adhesin (i.e., non-afa/dr DAEC) from diarrheal patients. In this study, we report the genome analysis of these strains in order to clarify their adhesins.
Among 924 bacterial strains isolated from patients with sporadic diarrhea, 19 strains were found to adhere to HEp-2 cells in the presence of mannose. Short reads obtained from each strain by MiSeq (Illumina) were assembled, and then auto-annotated by DFAST. Seven of the 19 strains were excluded from the subsequent analysis as those were other species than E. coli. The operons encoding the chaperone-usher adhesins (CUs) were comprehensively detected by the annotations and Local BLAST search.
As results, 136 operons were determined as CUs in all 12 strains. The phylogenetic classification proposed by Nuccio-Baumler using the amino acid sequences of the ushers revealed that, in addition to the ubiquitous classes, CUs belonging to the γ3 and κ classes, which are frequently reported in human clinical isolates, were found in some strains. Especially, γ3 is a class to which the afa/dr gene family also belongs, indicating the possibility that novel factors related to dispersed adhesion to human cells may have been detected.