title: Phylogenetic grouping and pathotypic comparison of urine and fecal Escherichia coli isolates from children with urinary tract infection.
abstract: The aim of this study was to investigate the phylogenetic background and to assess hlyD (involved in the secretion of haemolysin A) and intI1 (encoding a class 1 integrase) in Escherichia coli isolates derived from urinary and fecal specimens. A total of 200 E. coli isolates was collected from patients presenting with urinary tract infection (UTI) during September 2009 to September 2010 and screened for hlyD and intI1 genes by polymerase chain reaction (PCR). Phylogenetic analysis showed that E. coli is composed of four main phylogenetic groups (A, B1, B2 and D) and that uropathogenic E. coli (UPEC) isolates mainly belong to groups B2 (54%) and D (34%) whereas group A (44%) and D (26%) are predominant among commensal E. coli isolates. In this study, hlyD was present in 26% of UPEC and 2% of commensal E. coli isolates. However, hemolytic activity was detected for 42% of UPEC and 6% of commensal E. coli isolates (p < 0.05). intI1 gene was more frequently expressed in UPEC (24%) in comparison with commensal E. coli isolates (12%). Resistance to aztreonam, co-trimoxazole and cefpodoxime were frequently found among UPEC isolates whereas commensal E. coli isolates were commonly resistant to co-trimoxazole, nalidixic acid and cefotaxime. Concluding, a considerable difference between UPEC and commensal E. coli isolates was observed regarding their phylogenetic groups, presence of class 1 integron and hlyD gene, hemolysin activity and resistance pattern. The detection of class 1 integrons and hlyD gene was higher among UPEC compared with commensal E. coli isolates. These findings may contribute for a better understanding of the factors involved in the pathogenesis of UPEC.
authors.affiliation: Bacteriology Department Tarbiat Modarres University Tehran Iran Bacteriology Department, Tarbiat Modarres University, Tehran, Iran.
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Navidinia
authors.affiliation: Bacteriology Department Tarbiat Modarres University Tehran Iran Bacteriology Department, Tarbiat Modarres University, Tehran, Iran.
authors.forename: Shahin Najar
authors.initials: SN
authors.lastname: Peerayeh
authors.affiliation: Pediatric Infection Research Center Mofid Childrens' Hospital Shahid Beheshti University of Medical Sciences Tehran Iran Pediatric Infection Research Center, Mofid Childrens' Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Fallah
authors.affiliation: Bacteriology Department Tarbiat Modarres University Tehran Iran Bacteriology Department, Tarbiat Modarres University, Tehran, Iran.
authors.forename: Bita
authors.initials: B
authors.lastname: Bakhshi
authors.affiliation: Shahid Beheshti University of Medical Sciences Tehran Iran Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Raheleh Sadat
authors.initials: RS
authors.lastname: Sajadinia
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006460:Hemolysin Proteins / Q000235:genetics; D006801:Humans; D019426:Integrases / Q000235:genetics; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014552:Urinary Tract Infections / Q000382:microbiology*; D014556:Urine / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C065231:HlyD protein, E coli; D026901:Membrane Transport Proteins; D019426:Integrases; C115006:integron integrase IntI1
keywords: Escherichia coli; hlyD; intI1; phylogenetic typing groups; urinary tract infection (UTI)