title: Antibiotic-resistant ST38, ST131 and ST405 strains are the leading uropathogenic Escherichia coli clones in Riyadh, Saudi Arabia.
abstract: OBJECTIVE
  We investigated the molecular epidemiology of uropathogenic Escherichia coli (UPEC) from a tertiary care hospital in Riyadh, Saudi Arabia, revealing, for the first time, the population structure of UPEC in the region.
  
  
  METHODS
  A total of 202 UPEC isolates were recovered from hospital and community patients with urinary tract infection in December 2012 and January 2013. Strains were characterized by MLST, antibiotic susceptibility determination and virulence gene detection.
  
  
  RESULTS
  The most common lineages were ST131 (17.3%), ST73 (11.4%), ST38 (7.4%), ST69 (7.4%), ST10 (6.4%), ST127 (5.9%), ST95 (5.4%), ST12 (3.5%), ST998 (3.5%) and ST405 (3%). ST131 and ST405 isolates were significantly associated with high levels of antibiotic resistance (60% of ST131 carried CTX-M-14 or CTX-M-15 and 66.7% of ST405 isolates carried CTX-M-15). ST131, CTX-M-15-positive isolates were predominantly of the fimH30/clade C group, resistant to fluoroquinolones; members of this sub-group were more likely to carry a high number of genes encoding selected virulence determinants. The relatively high proportion of ST38 was notable and four of these isolates harboured aggR.
  
  
  CONCLUSIONS
  Our findings highlight the presence of MDR, CTX-M-positive ST38, ST131 and ST405 UPEC in Saudi Arabia. The high proportion of isolates with CTX-M is a particular concern. We suggest that ST38 UPEC warrant further study.
authors.affiliation: School of Medicine, University of Manchester, Manchester, UK King Abdullah International Medical Research Center, Riyadh, Saudi Arabia King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia majed.alghoribi-2@postgrad.manchester.ac.uk.
authors.forename: Majed F
authors.initials: MF
authors.lastname: Alghoribi
authors.affiliation: Faculty of Medicine, University of Tripoli, Tripoli, Libya.
authors.forename: Tarek M
authors.initials: TM
authors.lastname: Gibreel
authors.affiliation: Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK.
authors.forename: Garry
authors.initials: G
authors.lastname: Farnham
authors.affiliation: King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia Microbiology, Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City, Riyadh, Saudi Arabia.
authors.forename: Sameera M
authors.initials: SM
authors.lastname: Al Johani
authors.affiliation: King Abdullah International Medical Research Center, Riyadh, Saudi Arabia King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia Infection Prevention and Control Department, King Abdulaziz Medical City, Riyadh, Saudi Arabia.
authors.forename: Hanan H
authors.initials: HH
authors.lastname: Balkhy
authors.affiliation: Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK.
authors.forename: Mathew
authors.initials: M
authors.lastname: Upton
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D015995:Prevalence; D012529:Saudi Arabia / Q000453:epidemiology; D014552:Urinary Tract Infections / Q000453:epidemiology / Q000382:microbiology; D056689:Uropathogenic Escherichia coli / Q000145:classification* / Q000187:drug effects* / Q000235:genetics; D014774:Virulence / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents