title: Rapid emergence of ESBL producers in E. coli causing urinary and wound infections in Pakistan.
abstract: OBJECTIVE
  Production of extended spectrum beta -lactamases (ESBLs) by clinical isolates of pathogenic E. coli is a very serious therapeutic threat. This study was aimed to investigate the prevalence of ESBLs and associated drug resistance in E. coli isolates from urine and pus, and to report the drift from 2005 to 2009-10.
  
  
  METHODS
  Among 173 E. coli isolates, 82 were phenotypically detected as ESBL producers by standard cefotaxime / clavulanic acid and ceftazidime / clavulanic acid disc diffusion tests. Antimicrobial resistance of all ESBL producers was assessed by disc diffusion method. Presence of CTX-M, TEM, SHV and OXA groups was investigated by PCR.
  
  
  RESULTS
  The prevalence of ESBL producing E. coli increased significantly from 33.7% in 2005 to 60.0% in 2009-10 (urine: 31.8% to 62.9%; pus: 41.1% to 55.5%). Resistance to cefotaxime, ceftazidime, ciprofloxacin, gentamicin, nalidixic acid, ticarcillin-clavulanic acid, and trimethoprim-sulfamethoxazole was above 85% in both sets of isolates. Imipenem and Fosfomycin resistance was non-existent in 2005 but ranged from 3-15% in 2009-10. Remarkable increase from 9.5% to 64.7% in urinary tract isolates and from 0 to 55% in pus isolates was observed in colistin sulphate resistance. The dissemination of genes encoding ESBLs was: CTX-M 3.5%; TEM 10.7%; both CTX-M and TEM 3.5% in 2005, and CTX-M 42.5%; TEM 48.1%; both CTX-M and TEM 29.6% in 2009-10.
  
  
  CONCLUSIONS
  Our results showed very rapid emergence of multidrug resistant ESBL producing E. coli in Pakistan posing a very serious threat in the treatment of nosocomial and community acquired infections.
authors.affiliation: Muhammad Asif Habeeb, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O.Box 577, Jhang Road, Faisalabad, Pakistan, An affiliated Institute of Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad, Pakistan.
authors.forename: Muhammad Asif
authors.initials: MA
authors.lastname: Habeeb
authors.affiliation: Yasra Sarwar, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O.Box 577, Jhang Road, Faisalabad, Pakistan, An affiliated Institute of Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad, Pakistan.
authors.forename: Yasra
authors.initials: Y
authors.lastname: Sarwar
authors.affiliation: Aamir Ali, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O.Box 577, Jhang Road, Faisalabad, Pakistan, An affiliated Institute of Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad, Pakistan.
authors.forename: Aamir
authors.initials: A
authors.lastname: Ali
authors.affiliation: Muhammad Salman, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O.Box 577, Jhang Road, Faisalabad, Pakistan, An affiliated Institute of Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Salman
authors.affiliation: Abdul Haque, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O.Box 577, Jhang Road, Faisalabad, Pakistan, An affiliated Institute of Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad, Pakistan.
authors.forename: Abdul
authors.initials: A
authors.lastname: Haque
keywords: Drug resistance; ESBL production; Genotypic characterization; Pathogenic E. coli