title: Prevalence and characteristics of cytolethal distending toxin-producing Escherichia coli from children with diarrhea in Japan.
abstract: In the present study, we examined the prevalence and characteristics of CTEC among diarrheal children in Japan during a year-long surveillance study. A PCR-RFLP assay for the detection and differentiation of five types of E. coli cdtB gene (types I through V) was developed, and 362 stool specimens collected from patients reporting to pediatric departments in two hospitals were analyzed. Of the 35 samples (9.7%) that were positive for the cdtB gene, 21 were positive for cdt-I, three for cdt-II, four for cdt-III, three for cdt-IV and four samples were positive for cdt-V, as determined by different molecular techniques. The recovery of CTEC having cdt alleles was a little less, which included 19 with cdt-I, one cdt-II, three cdt-III, three cdt-IV and four with cdt-V. Among 30 CTEC strains isolated, the majority of them (43%) belonged to serogroup 02. The other virulence genes such as astA, cnfl, eaeA, cnf2 and bfpA genes were detected in 14 (47%), 11 (37%), four (13%), three (10%) and one (3.3%) strains of CTEC, respectively. However, the other common virulence-associated genes specific for DEC were not detected in these strains. Interestingly, an untypable cdt gene was detected by PCR-RFLP in Providencia alcalifaciens. Our data indicate that CTEC may be associated with diarrheal children in Japan and most of them do not belong to a conventional enteropathogenic pathovar and thus differ from strains isolated in developing countries.
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hinenoya
authors.forename: Akira
authors.initials: A
authors.lastname: Naigita
authors.forename: Keiko
authors.initials: K
authors.lastname: Ninomiya
authors.forename: Masahiro
authors.initials: M
authors.lastname: Asakura
authors.forename: Kensuke
authors.initials: K
authors.lastname: Shima
authors.forename: Kazuko
authors.initials: K
authors.lastname: Seto
authors.forename: Teizo
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: T
authors.initials: T
authors.lastname: Ramamurthy
authors.forename: Shah M
authors.initials: SM
authors.lastname: Faruque
authors.forename: Shinji
authors.initials: S
authors.lastname: Yamasaki
mesh_terms: D000293:Adolescent; D001427:Bacterial Toxins / Q000096:biosynthesis*; D015373:Bacterial Typing Techniques / Q000379:methods; D002648:Child; D002675:Child, Preschool; D016172:DNA Fingerprinting / Q000379:methods; D004269:DNA, Bacterial / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology*; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology*; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D011532:Providencia / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D037521:Virulence Factors; C067044:cytolethal distending toxin