Robel Patwary, Marjia Sultana, Marium Khaleque, Zahurul Haque M and Sahana Parveen
The purpose of this current study was molecular typing of extended-spectrum β-lactamases (ESBLs) encoded by ESBLs genes of 56 Escherichia coli isolated from environment lake water (n=15), food samples (n=20) and from clinical specimens (n=21). The prevalence of CTX-M type ESBL-producing Escherichia coli was 76.5% (39 of 51 Escherichia coli) in contrast 5 Escherichia coli were found as non ESBL by molecular method. Most prevalent ESBLs type was ESBL Ditype containing both blaCTX-M and blaTEM genes (43.13%, 22/51 ESBL Escherichia coli), in addition blaVEB found negative. 1 ESBL Escherichia coli from Environment lake water and 2 ESBL Escherichia coli from clinical sample harbored blaSHV gene as ESBL Tritype (contained TEM, CTX-M and SHV type ESBL) rather ESBL Monotype (only SHV type ESBL) or ESBL Ditype (SHV type and CTX-M or TEM type ESBL). Prevalence of Plasmidic AmpC was more in ESBL Escherichia coli isolated from Food (45.5%, 5/11 ESBL Escherichia coli) than Environment lake water and clinical specimens. Plasmidic AmpC were DHA type, CMY-2 was found negative. blaOXA ESBLs gene as (ESBLM-D) ESBL miscellaneous D-type was confirmed in 6 ESBL Escherichia coli lacking carbepenemase activity, 2 from Environment lake water and 4 from clinical samples, indeed blaNDM was not found. Chromosomal mediated constitutive cefoxitin resistant ESBL Escherichia coli (n=15) and also plasmidic AmpC harboring ESBL Escherichia coli (n=9) showed resistance to Cefoxitin (Amoxy-cephalosphorin) confirmed by AmpC disk test. 100% resistance encountered against Ampcillin, Cloxacillin and Erythromycin and most sensitive to imipenam except 3 clinical ESBL Escherichia coli. Almost all Escherichia coli showed resistance against cephalosporin group antibiotics more precisely against third generation cephalosporin group antibiotics (e.g. Ceftazidime and Ceftrioxone). Furthermore, ESBL genotyping revealed that Escherichia coli strains producing multiple β-lactamases and co-resistance may be a common phenomenon in Bangladesh.
