title: Phylogenetic Distribution of Virulence Genes Among ESBL-producing Uropathogenic Escherichia coli Isolated from Long-term Hospitalized Patients.
abstract: OBJECTIVE
  The present study was aimed to investigate the antibiotic resistance, virulence potential and phylogenetic grouping of ESBL-producing uropathogenic Escherichia coli (EP-UPEC) isolated from long-term hospitalized patients.
  
  
  METHODS
  EP-UPEC isolates from September 2013 to June 2014 at a tertiary care hospital of China were screened for ESBL-production by the double disk diffusion test. Isolates with ESBL-phenotype were further characterized by antibiotic resistance testing, PCR of different ESBL and virulence genes, and phylogenetic grouping.
  
  
  RESULTS
  One hundred and twenty EP-UPEC were isolated from long-term hospitalized patients. All EP-UPEC isolates were resistant to Ampicillin, Cefazolin, Cefuroxime, Cefotaxime, Cefoperazone and Ceftriaxone, and the majority of EP-UPEC isolates were resistant to Piperacillin (82.5%), Ciprofloxacin (81.2%), Trimethoprim-Sulfamethoxazole (72.5%). The isolates showed the highest sensitivity against Imipenem (98.4%), Piperacillin/tazobactam (96.7%), Cefoperazone/sulbactam (91.7%), Amikacin (90.8%) and Cefepime (75.8%). Nine different ESBL genotype patterns were observed and CTX-M type was the most prevalent ESBL genotype (42.5%, 51/120). Majority of EP-UPEC isolates possess more than one ESBL genes. EP-UPEC isolates belonged mainly to phylogenetic group B2(36.7%) and D(35.0%). The prevalence of traT, ompT, iss, PAI, afa, fimH and papC were 75.8%, 63.3%, 63.3%, 60.8%, 40.8%, 19.2% and 6.7%, respectively. The number of virulence genes (VGs) detected was significantly higher in group B2 than in group A (ANOVA, p<0.001), group B1(ANOVA, p= 0.012) and D (ANOVA, p<0.001).
  
  
  CONCLUSIONS
  EP-UPEC strains showed multidrug resistance and co-resistance to other non β-lactam antibiotics. CTX-M was the most prevalent ESBL genotype and majority of EP-UPEC strains more than one ESBL genes. EP-UPEC strains belonged mainly to phylogenetic group B2 and D, and most of the virulence genes were more prevalent in group B2.
authors.affiliation: Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China .
authors.forename: Ruike
authors.initials: R
authors.lastname: Zhao
authors.affiliation: Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China .
authors.forename: Jinfang
authors.initials: J
authors.lastname: Shi
authors.affiliation: Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China .
authors.forename: Yimin
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China .
authors.forename: Yanmeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China .
authors.forename: Qingzhen
authors.initials: Q
authors.lastname: Han
authors.affiliation: Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China .
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China .
authors.forename: Guohao
authors.initials: G
authors.lastname: Gu
authors.affiliation: Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China .
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
keywords: ESBL; Phylogenetic groups; Resistance; UPEC; Virulence