Comparision of Screening Methods for Detection of Extended Spectrum β-Lactamases

Extended spectrum beta lactamases are defined as beta lactamases capable of hydrolyzing oxyiminocephalosporins andare inhibited by beta lactamases. A total of 100 samples were screened from which 32 (32%) showed the positive result forE.coli, 25% for K.pneumoniae, 9.37% for Proteus vulgaris, 12.5% for Enterobacter aerogenes, and 18.75% for Citrobacter spp. The ESBL production was detected and the comparison were done between the different methods, the sensitivity of double discmethod for detection of ESBL production in E.coli was 67% with positive predictive value (PPV) 71% followed by idometric tube test with sensitivity 55% and PPV 57%. The present study showed the highest prevelence of E.coli among the urine samples causing various infections due to advent ESBL producers which posted great threat to the use of many classesof antibiotics particularly Cephalosporins and it was referred that the double disc synergy (DDS) method to the best and rapid method for ESBL detection.