title: Detection of cytolethal distending toxin and other virulence characteristics of enteropathogenic Escherichia coli isolates from diarrheal patients in Republic of Korea.
abstract: Cytolethal distending toxins (CDTs) represent an emerging family of newly described bacterial products that are produced by a number of pathogens. The genes encoding these toxins have been identified as a cluster of three adjacent genes, cdtA, cdtB, and cdtC, plus 5 cdt genetic variants, designated as cdt-I, cdt-II, cdt-III, cdt-IV, and cdt- V, have been identified to date. In this study, a general multiplex PCR system designed to detect Escherichia coli cdts was applied to investigate the presence of cdt genes among isolates. As a result, among 366 E. coli strains, 2.7% were found to carry the cdtB gene. In addition, the use of type-specific primers revealed the presence of cdt-I, cdtIV, and cdt-V types of the cdt gene, yet no cdt-II or cdt- III strains. The presence of other virulence genes (stx1, stx2, eae, bfp, espA, espB, and espD) was also investigated using a PCR assay. Among the 10 cdtB gene-positive strains, 8 were identified as CDT-producing typical enteropathogenic E. coli (EPEC) strains (eae(+), bfp(+)), whereas 2 were identified as CDT-producing atypical EPEC strains (eae(+), bfp(-)). When comparing the cytotoxic activity of the CDT-producing typical and atypical EPEC strains, the CDT-producing atypical EPEC strains appeared to be less toxic than the CDT-producing typical EPEC strains.
authors.affiliation: Division of Enteric Bacterial Infections, Center for Infectious Diseases, National Institute of Health, Seoul 122-701, Korea.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Jong-Chul
authors.initials: JC
authors.lastname: Kim
authors.forename: Yun-Ae
authors.initials: YA
authors.lastname: Choo
authors.forename: Hyun-Chul
authors.initials: HC
authors.lastname: Jang
authors.forename: Yeon-Hwa
authors.initials: YH
authors.lastname: Choi
authors.forename: Jae-Keun
authors.initials: JK
authors.lastname: Chung
authors.forename: Seung-Hak
authors.initials: SH
authors.lastname: Cho
authors.forename: Mi-Seon
authors.initials: MS
authors.lastname: Park
authors.forename: Bok-Kwon
authors.initials: BK
authors.lastname: Lee
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology*; D054308:Enteropathogenic Escherichia coli / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000503:physiopathology; D010861:Fimbriae, Bacterial / Q000235:genetics; D006801:Humans; D007723:Korea; D005810:Multigene Family; D016133:Polymerase Chain Reaction; D012703:Serotyping; D014774:Virulence; D037521:Virulence Factors / Q000032:analysis / Q000235:genetics
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D037521:Virulence Factors; C067044:cytolethal distending toxin