Phenotypic Cofirmatory Disc Diffusion Test (PCDDT), Double Disc Synergy Test (DDST), E-Test Os Diagnostic Tool for Detection of Extended Spectrum Beta Lactamase (ESΒL) Producing Uropathogens

Abstract

Background: The aim of this study was to probe the best diagnostic tool for the detection of Extended Spectrum β-lactamase (ESβL) producing uropathogen and their antimicrobial susceptibility profile to treat the infections properly. Methods: Clinical samples of urine were cultured on Cysteine Lactose Electrolyte Deficient (CLED) Agar medium. Antimicrobial sensitivity tests were carried out by Kirby-Bauer disc diffusion method. Phenotypic methods were used for further confirmation of β- lactamase production by phenotypic confirmatory disc diffusion test (PCDDT), double disc synergy test (DDST) and by E-test for ESBL production. Aswab on Mueller-Hinton (MH) agar plates was used for further studies and the Optical Density (O.D.) of the cultures was set to 0.1 (at 530nm). Results: Sample size N= 200 was selected from patients suffering from UTI. Out of the 200 samples, n=141 samples yielded Aerobic Gram Negative Bacteria (AGNB). The commonest organism isolated was E.coli n=108, best antimicrobial result of 95% was shown by imipenem. Among the AGNB isolates, 20 organisms (12.98%) were ESBL producers. E.coli showed highest ESBL production of 85%. The most effective antimicrobial in ESBL producers was Imipenem (84%) Augmentin was least sensitive (05%). Conclusion: ESBL production is a common phenomenon in UTI patients and screening by DDST for these enzymes is a good epidemiological tool to assess the overall situation in a certain setup.It was also seen that Imipenem (Carbapenem) is the drug of choice.