PHENOTYPIC AND MOLECULAR CHARACTERIZATION OF EXTENDED SPECTRUM BETA LACTAMASE PRODUCING KLEBSIELLA PNEUMONIAE: ANTIBIOTIC SENSITIVITY PATTERNS AND DETECTION OF BlaCTX-M GENE IN CLINICAL ISOLATES FROM NORTHEAST INDIA

Background: Infections due to extended spectrum β-lactamase producing Enterobacteriaceae are on the rise globally. Theypose serious public health problems due to their resistance to large number of antibiotics. Therefore, the study presentsresults of phenotypic characterization of Extended Spectrum β-Lactamase (ESBL) producing Klebsiella pneumoniae isolatedfrom various clinical specimens as well as their molecular analysis. The aim of the study is to detect the prevalence of ESBLproduction in Klebsiella pneumoniae isolated from various clinical specimens. This study also detects the performance ofdouble disc synergy test to detect ESBL and molecular analysis of the beta-lactamase gene, blaCTX-M, in ESBL producingKlebsiella pneumoniae. Materials and Methods: A total of 171 isolates were recovered from various clinical specimensfrom a tertiary care hospital out of which 88 isolates were identified as Klebsiella pneumoniae, which were analyzed fortheir antibiotic susceptibility test by the modified Kirby–Bauer disc diffusion method. Using the double disc synergy test(DDST), ESBL production was detected in the isolates. Gene-specific primers were utilized in PCR analysis to determine thepresence of blaCTX-M. Results: Out of 88 clinical isolates, 12 (13.6%) of them were found ESBL producers. The majorsource of ESBL producers was respiratory tract samples. The highest resistance was observed in Ampicillin (68.2%)followed by Cefoxitin (65.5%), Cefotaxime (48.9%) and Ceftazidime (46.6%) while Fosfomycin (23.86%) showed the leastresistance. When five ESBL-positive isolates were selected for PCR analysis, blaCTX-M was found in four of them onmolecular analysis. Conclusion: In this study high level of drug resistance was observed among the clinical isolates ofKlebsiella pneumoniae. ESBL production was determined among the isolates, where blaCTX-M was identified to be theprimary cause, highlighting the need for routine molecular surveillance to guide treatment strategies.