Classification of perA sequences and their correlation with autoaggregation in typical enteropathogenic Escherichia coli isolates collected in Japan and Thailand |
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| Authors: | Mariko Iida Noboru Okamura Mitsugu Yamazaki Jun Yatsuyanagi Takayuki Kurazono Rieko Suzuki Noriaki Hiruta Junko Isobe Kazuko Seto Kimiko Kawano Hiroshi Narimatsu Orn‐Anong Ratchtrachenchai Nobuhiko Okabe Kenitiro Ito |
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| Institution: | 1. Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo, Japan;2. Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan;3. Aichi Prefectural Institute of Public Health, Aichi, Japan;4. Akita Prefectural Institute of Public Health, Akita, Japan;5. Saitama Prefectural Institute of Public Health, Saitama, Japan;6. Kanagawa Prefectural Institute of Public Health, Kanagawa, Japan;7. Yokosuka City Institute of Public Health, Kanagawa, Japan;8. Toyama Prefectural Institute of Public Health, Toyama, Japan;9. Osaka Prefectural Institute of Public Health, Osaka, Japan;10. Miyazaki Prefectural Institute of Public Health, Miyazaki, Japan;11. Oita Prefectural Institute of Health and Environment, Oita, Japan;12. Department of Medical Sciences, National Institute of Health, Nonthaburi, Thailand |
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| Abstract: | Enteropathogenic Escherichia coli (EPEC) strains produce a bundle‐forming pilus (BFP) that mediates localized adherence (LA) to intestinal epithelial cells. The major structural subunit of the BFP is bundlin, which is encoded by the bfpA gene located on a large EAF plasmid. The perA gene has been shown to activate genes within the bfp operon. We analyzed perA gene polymorphism among typical (eae‐ and bfpA‐ positive) EPEC strains isolated from healthy and diarrheal persons in Japan (n= 27) and Thailand (n= 26) during the period 1995 to 2007 and compared this with virulence and phenotypic characteristics. Eight genotypes of perA were identified by heteroduplex mobility assay (HMA). The strains isolated in Thailand showed strong autoaggregation and had an intact perA, while most of those isolated in Japan showed weak or no autoaggregation, and had a truncated perA due to frameshift mutation. The degree of autoaggregation was well correlated with adherence to HEp‐2 cells, contact hemolysis and BFP expression. Our results showed that functional deficiency due to frameshift mutation and subsequent nonsense mutation in perA reduced BFP expression in typical EPEC strains isolated in Japan. |
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| Keywords: | bfpA bundle forming pilus enteropathogenic Escherichia coli perA |
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