Comparison of double disc synergy test and phenotypic confirmatory disc diffusion test for detection of ESBL production and their antimicrobial resistance pattern.

ABSTRACT

Extended spectrum beta- lactamases (ESBLs) continue to be a major problem in clinical setup worldwide. An attempt is made to detect ESBL production among Enterobacteriaceae members by phenotypic methods, which is easier to perform in all laboratories. A total of 138 multi-drug resistant strains from pyogenic infection were tested for ESBL production by Double disc synergy test (DDST) and Phenotypic confirmatory disc diffusion test (PCDDT). Of the 84 ESBL producer identified, PCDDT detects 71 (84.5%) whereas DDST detects 52 (61.9%) as ESBL producers. Continued detection of ESBL is essential for proper disease management. PCDDT is better and easy test for screening than DDST. Confirmation has to be done by molecular methods.