title: Typical enteroaggregative Escherichia coli is the most prevalent pathotype among E. coli strains causing diarrhea in Mongolian children.
abstract: Diarrhea remains one of the main sources of morbidity and mortality in the world, and a large proportion is caused by diarrheagenic Escherichia coli. In Mongolia, the epidemiology of diarrheagenic E. coli has not been well studied. A total of 238 E. coli strains from children with sporadic diarrhea and 278 E. coli strains from healthy children were examined by PCR for 10 virulence genes: enteropathogenic E. coli (EPEC) eae, tir, and bfpA; enterotoxigenic E. coli (ETEC) lt and st; enteroinvasive E. coli (EIEC) ipaH; enterohemorragic E. coli stx1 and stx2; and enteroaggregative E. coli (EAEC) aggR and astA. EAEC strains without AggR were identified by the HEp-2 cell adherence test. The detection of EAEC, ETEC, EPEC, and EIEC was significantly associated with diarrhea. The incidence of EAEC (15.1%), defined by either a molecular or a phenotypic assay, was higher in the diarrheal group than any other category (0 to 6.0%). The incidence of AggR-positive EAEC in the diarrheal group was significantly higher than in the control group (8.0 versus 1.4%; P = 0.0004), while that of AggR-negative EAEC was not (7.1 versus 4.3%). Nineteen AggR-positive EAEC strains harbored other EAEC virulence genes-aggA, 2 (5.5%); aafA, 4 (11.1%); agg-3a, 5 (13.8%); aap, 8 (22.2%); aatA, 11 (30.5%); capU, 9 (25.0%); pet, 6 (16.6%); and set, 3 (8.3%)-and showed 15 genotypes. EAEC may be an important pathogen of sporadic diarrhea in Mongolian children. Genetic analysis showed the heterogeneity of EAEC but illustrated the importance of the AggR regulon (denoting typical EAEC) as a marker for virulent EAEC strains.
authors.affiliation: Department of Pediatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
authors.forename: Jav
authors.initials: J
authors.lastname: Sarantuya
authors.forename: Junichiro
authors.initials: J
authors.lastname: Nishi
authors.forename: Naoko
authors.initials: N
authors.lastname: Wakimoto
authors.forename: Shirchin
authors.initials: S
authors.lastname: Erdene
authors.forename: James P
authors.initials: JP
authors.lastname: Nataro
authors.forename: Jalaluddin
authors.initials: J
authors.lastname: Sheikh
authors.forename: Mayumi
authors.initials: M
authors.lastname: Iwashita
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Manago
authors.forename: Koichi
authors.initials: K
authors.lastname: Tokuda
authors.forename: Masao
authors.initials: M
authors.lastname: Yoshinaga
authors.forename: Koichiro
authors.initials: K
authors.lastname: Miyata
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Kawano
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000382:microbiology*; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015534:Trans-Activators / Q000235:genetics; D014774:Virulence
chemical_list: C088603:AggR protein, E coli; D029968:Escherichia coli Proteins; D015534:Trans-Activators