Detection of extended spectrum-beta lactamase enzymes producing E. coli that isolated from urine

Abstract

    The production of extended-spectrum- β lactamases (ESBLs) is an important mechanism for resistance to the third-generation cephalosporins. ESBLs represent a major group of lactamases enzymes that mostly produced by gram-negative bacteria, so the detection of these enzymes are very important for optimal patients care. The present study was done to detect extended spectrum beta lactamase producing E. coli among urinary tract infected patients. A total of 223 urine  samples were examined for presence of E. coli and those producing ESBL enzymes. Urine samples were cultured for aerobic bacteria and antimicrobial susceptibility testing carried out by using Kirby-Baur agar diffusion method. Coli were tested for ESBLs on Mueller-Hinton agar by both modified double disk ( MDDT ) and phenotypic confirmatory test. E. coli was the most common bacteria isolated from urine 104 ( 44.2 ).78 E. coli isolated from urine are tested for ESBL production and it was found that 30 ( 38.4 ) were MDDT positive and 27 phenotypic confirmatory test positive. Three strain E. coli were MDDT positive but negative by phenotypic confirmatory. Antibiotic susceptibility test showed that  E. coli isolated were totally resist ( 100% ) to ampicillin, moxicillin,and trimethoprim but maximum susceptible to imipenem  ( 100% ) and variable resistant to another antibiotics. The ESBLs producing E. coli are highly resist to different types of antibiotics , especially third generation cephalosporins.