Molecular Characteristics of Cephalosporin Resistant Escherichia coli and Klebsiella pneumoniae Isolated from Children in a Tertiary Care Centre of Central Kerala, India

Aims: The study was aimed to determine the molecular characteristics of extendedspectrum beta-lactamases (ESBL) producing cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae isolated from children below ten years of age. Background: Geographically diverse variations in the prevalence of ESBL genes were reported. No data were available on the prevalence of ESBL genes in central Kerala, India, among children below 10 years of age. Methods: A cross-sectional study was performed to analyze ESBL genes in cephalosporin-resistant E. coli and K. pneumoniae strains isolated from samples received in the Microbiology laboratory of a tertiary care centre during the period between May 2021 and July 2022. The strains showed that ESBL + cephalosporin resistance was subjected to PCR-based genotyping for the genes such as bla (beta-lactamase) CTX-M-1, blaCTX-M-15, blaCTX-M-U, blaTEM, blaPER and SHV. Results: Among the total 228 samples analyzed, 136 (60%) had no growth. Ninety-two (40 %) samples showed growth of E. coli and K. pneumoniae. Among the isolates that showed growth, 39 (42%) were sensitive, and the remaining 53 (57%) were resistant to third-generation cephalosporins. Among the isolates showed resistance, 22 (42%) were ESBL positive and 31 (58%) were ESBL negative. Among the positive ESBL, nine E. coli strains (60%) were positive for CTX-M-15 and CTX-M-1. CTX-M-15 and CTX-M-U were present in six (85%) K. pneumoniae with ESBL +. Conclusion: E. coli and K. pneumoniae isolated from specimens of children below ten years of age showed 41-42% ESBL producers. Prevalent ESBL-producing genes in E. coli were CTX-M- 15 and CTX-M-1. CTX-M-15 and CTX-M-U were prevalent in ESBL-producing K. pneumoniae.