Classification of perA sequences and their correlation with autoaggregation in typical enteropathogenic Escherichia coli isolates collected in Japan and Thailand.
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.
Iida
Mariko
M
Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo, Japan. miida.mi@tmd.ac.jp
Okamura
Noboru
N
Yamazaki
Mitsugu
M
Yatsuyanagi
Jun
J
Kurazono
Takayuki
T
Suzuki
Rieko
R
Hiruta
Noriaki
N
Isobe
Junko
J
Seto
Kazuko
K
Kawano
Kimiko
K
Narimatsu
Hiroshi
H
Ratchtrachenchai
Orn-Anong
OA
Okabe
Nobuhiko
N
Ito
Kenitiro
K
D000595:Amino Acid Sequence; D001422:Bacterial Adhesion; D002460:Cell Line; D003967:Diarrhea / Q000382:microbiology; D054308:Enteropathogenic Escherichia coli / Q000145:classification* / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity; D004847:Epithelial Cells / Q000382:microbiology; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D036781:Fimbriae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006461:Hemolysis; D020180:Heteroduplex Analysis; D006801:Humans; D007564:Japan; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013785:Thailand; D014774:Virulence
C104901:BfpA protein, E coli; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C120886:bfpT protein, E coli; D036781:Fimbriae Proteins