Characterization of CTX-M-15-Klebsiella pneumoniae from inpatients and outpatients of a teaching hospital.

Background  The presence of Extended-spectrum β-lactamase (ESBL) positive bacteria in hospital setting is an aggravating influential factor for hospitalized patients, and its consequences may be hazardous. Therefore, there is a need for rapid detection methods for newly emerging drug-resistant bacteria. This study was aimed at the molecular characterization of ESBL-positive  Klebsiella pneumoniae isolates recovered from clinical samples.   Methods  A total of 513  K. pneumoniae  isolates were obtained from various clinical samples during June 2019 to May 2020. The collected isolates were investigated for antimicrobial susceptibility (antibiogram), and PCR and DNA sequencing were performed to analyse the ESBL genes.   Results  Among the 513 isolates, as many as 359 (69.9%) were ESBL producers and 87.5% were multi-drug resistant, while none had resistance to imipenem. PCR scored 3% blaTEM, 3% blaSHV, and 60% blaCTX-M-15 genes for the tested isolates.   Conclusion  The study showed that CTX-M-15 was the major prevalent ESBL type among the isolates. Additionally, all the isolates were susceptible to carbapenems. Screening and detection of ESBL tests are necessary among all isolates from the enterobacteriaceae family in routine microbiology laboratory to prevent associated nosocomial infections. A larger study is essential to understand molecular epidemiology of ESBL producing organisms to minimize morbidities due to these multidrug resistant organisms.