title: The characterization and antibiotic resistance profiles of clinical Escherichia coli O25b-B2-ST131 isolates in Kuwait.
abstract: BACKGROUND
  Escherichia coli O25b-B2-ST131 are considered virulent extra-intestinal pathogens causing serious clinical complications such as urinary tract infection and bacteraemia. Our main objectives in this study were to characterise the multi-drug resistant (MDR) isolates of this lineage in Kuwait, and to demonstrate whether reduced susceptibility is spread clonally.
  
  
  RESULTS
  A subset of 83 (10%) non-duplicate and non-selective E. coli O25b-B2-ST131 out of 832 MDR E. coli was identified and collected. Minimum inhibitory concentrations of the isolates were determined and pulsed-field gel electrophoresis was used for typing.The majority (95.2%) of the 83 E. coli O25b-B2-ST131 harboured at least one bla gene with blaCTX-M-15 being the most prevalent. blaCTX-M-2 was present in one isolate. Also one isolate harboured blaCTX-M-56, qnrB1 and blaCMY-2 genes and carried IncF1 plasmids of about 97 kb and160 kb. qnrB and qnrS were found in 8 other blaCTX-M-15 containing isolates. The blaNDM, blaIMP, blaVIM and qnrA were not detected, however, the blaOXA-48 was present in two (2.4%).
  
  
  CONCLUSIONS
  The majority of isolates harbouring qnr genes demonstrated relatedness (≥85%) by PFGE. However, the diversity in PFGE profiles for the other MDR isolates reflected the changes in population genetics of E. coli O25b-B2-ST131. We identified for the first time the appearance of blaCTX-M-2 in the Middle East and blaCTX-M-56 outside the Latin American countries. The isolate harbouring blaCTX-M-56 also contained qnrB1 and blaCMY-2 genes and carried IncF1 plasmids. The appearance of a highly virulent E. coli O25b-ST131 that is resistant to penicillins, most cephalosproins, β-lactamase inhibitors as well as fluoroquinolones is a cause for concern.
authors.forename: Ali A
authors.initials: AA
authors.lastname: Dashti
authors.affiliation: Department of Medical Laboratory Sciences, Faculty of Allied Health Sciences, Kuwait University, Sulaibekhat, Sulaibekhat, 90805, Kuwait. leila@hsc.edu.kw.
authors.forename: Leila
authors.initials: L
authors.lastname: Vali
authors.forename: Sherief
authors.initials: S
authors.lastname: El-Shazly
authors.forename: Mehrez M
authors.initials: MM
authors.lastname: Jadaon
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology*; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007730:Kuwait; D008297:Male; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D010957:Plasmids / Q000032:analysis; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases