title: Prevalence and characterization of multidrug-resistant and extended-spectrum beta-lactamase-producing Escherichia coli from pediatric wards of a Malaysian hospital.
abstract: The emergence of Escherichia coli resistant to extended-spectrum cephalosporins (ESCs) is of concern as ESC is often used to treat infections by Gram-negative bacteria. One-hundred and ten E. coli strains isolated in 2009-2010 from children warded in a Malaysian tertiary hospital were analyzed for their antibiograms, carriage of extended-spectrum beta-lactamase (ESBL) and AmpC genes, possible inclusion of the beta-lactamase genes on an integron platform, and their genetic relatedness. All E. coli strains were sensitive to carbapenems. About 46% of strains were multidrug resistant (MDR; i.e., resistant to ≥3 antibiotic classes) and almost half (45%) were nonsusceptible to ESCs. Among the MDR strains, high resistance rates were observed for ampicillin (98%), tetracycline (75%), and trimethoprim/sulfamethoxazole (73%). Out of 110 strains, bla(TEM-1) (49.1%), bla(CTX-M) (11.8%), and bla(CMY-2) (6.4%) were detected. Twenty-one strains were ESBL producers. CTX-M-15 was the predominant CTX-M variant found and this is the first report of a CTX-M-27-producing E. coli strain from Malaysia. Majority (3.1%) of the strains harbored class 1 integron-encoded integrases with a predominance of aadA and dfr genes within the integron variable region. No gene cassette encoding ESBL genes was found and integrons were not significantly associated with ESBL or non-ESBL producers. Possible clonal expansion was observed for few CTX-M-15-positive strains but the O25-ST131 E. coli clone known to harbor CTX-M-15 was not detected while CMY-2-positive strains were genetically diverse.
authors.affiliation: Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Wing Sze
authors.initials: WS
authors.lastname: Ho
authors.forename: Ganeswrie
authors.initials: G
authors.lastname: Balan
authors.forename: Savithiri
authors.initials: S
authors.lastname: Puthucheary
authors.forename: Boon Hong
authors.initials: BH
authors.lastname: Kong
authors.forename: King Ting
authors.initials: KT
authors.lastname: Lim
authors.forename: Lai Kuan
authors.initials: LK
authors.lastname: Tan
authors.forename: Xiu Pei
authors.initials: XP
authors.lastname: Koh
authors.forename: Chew Chieng
authors.initials: CC
authors.lastname: Yeo
authors.forename: Kwai Lin
authors.initials: KL
authors.lastname: Thong
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D015780:Carbapenems / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D002675:Child, Preschool; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D007223:Infant; D019426:Integrases / Q000235:genetics*; D008296:Malaysia / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D015995:Prevalence; D062606:Tertiary Care Centers; D018440:beta-Lactam Resistance / Q000187:drug effects / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D002511:Cephalosporins; D019426:Integrases; C048795:AmpC beta-lactamases; D001618:beta-Lactamases