title: Co-existence of beta-lactamases in clinical isolates of Escherichia coli from Kathmandu, Nepal.
abstract: BACKGROUND
  The trend of extended-spectrum beta-lactamases producing Escherichia coli (ESBL-EC) is increasing in Nepal. Limited studies have been reported investigating ESBL types and carbapenemases in E. coli.
  
  
  METHODS
  A cross sectional study was conducted between June 2012 to January 2013 in Kathmandu Medical College and Teaching Hospital, Nepal. Non-repetitive clinical samples from out-patient department (OPD) and Intensive Care Units (ICU) were processed for bacteriological culture and identification of E. coli. Antibiotic susceptibility test, screening and phenotypic confirmation for ESBLs and carbapenemases and PCR (blaCTX-M, blaSHV and blaTEM-type ESBLs, blaVIM, blaIMP and blaNDM-1-type carbapenemases, and class 1 integron element integrase gene) were performed. Clones were resolved by PCR-Randomly Amplified Polymorphic DNA.
  
  
  RESULTS
  Out of 332 non-repetitive clinical specimens processed for culture and identification 160 (48.2%) were culture positive. Of which, 93 (58.1%) were E. coli. Of these, 24 (25.8%) were phenotypically confirmed as ESBL-EC and 3 (12.50%) of 24 ESBL-EC were carbapenemase producers. blaCTX-M-type ESBL was most common (23, 95.8%) followed by blaTEM (7, 29.2%) and blaSHV (3, 12.5%). blaVIM, blaIMP and blaNDM-1 were present in 3, 2 and 2 ESBL-EC, respectively. Class 1 integron element was present in 18 (75.0%) ESBL-EC. Nine isolates possessed more than one type of beta-lactamases. Interestingly, all carbapenemase producers were isolated form ICU and co-existence of blaCTX-M, blaSHV, blaTEM, blaIMP, blaVIM and blaNDM-1 beta-lactamases was documented in one ESBL-EC (EC104). All most all isolates had different RAPD patterns.
  
  
  CONCLUSIONS
  For the first time in Nepal, high prevalence of blaCTX-M-type ESBL and co-existence of ESBLs and carbapenemases has been described. Continuous monitoring and surveillance and proper infection control and prevention practices will limit the further spread of these super-bugs within this hospital and beyond.
authors.forename: Ram Hari
authors.initials: RH
authors.lastname: Pokhrel
authors.affiliation: Department of Microbiology, Kathmandu Medical College and Teaching Hospital, Kathmandu, Nepal. badri_bishal@yahoo.com.
authors.forename: Badri
authors.initials: B
authors.lastname: Thapa
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kafle
authors.forename: Pradeep Kumar
authors.initials: PK
authors.lastname: Shah
authors.forename: Chanwit
authors.initials: C
authors.lastname: Tribuddharat
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000302:isolation & purification; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000302:isolation & purification; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000302:isolation & purification*; D005838:Genotype; D006784:Hospitals, Teaching; D006801:Humans; D008826:Microbial Sensitivity Tests; D009390:Nepal / Q000453:epidemiology; D001618:beta-Lactamases / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D001618:beta-Lactamases; C063912:carbapenemase