CTX-M-type Extended-Spectrum β-Lactamase Producing Enterobacteriaceae Isolated from Urine in a Tertiary Care Hospital, Kathmandu, Nepal
Background: Despite the global increase of CTX-M type extended-spectrum-β-lactamases (ESBLs) in recent years among Enterobacteriaceae isolates from urinary tract infections, little data is available from Nepal. Objective: This study was conducted to detect the genes encoding extended-spectrum β-lactamases among Enterobacteriaceae isolated from the urine samples in Nepal. Methods: A total of 148 Enterobacteriaceae isolates were collected in Annapurna Neurological Institute and Allied Sciences from urine samples from July 2016 to June 2017. ESBLs production was detected according to the Clinical and Laboratory Standards Institute (CLSI) recommended methods. PCR and sequencing were used for the detection of ESBL genes. Results: Overall 24.3% (36/148) of the study isolates were positive for ESBL production. E. coli was the predominant ESBL-producing organism (28.8%). ESBL-producing organisms showed a high rate of resistance to ceftazidime (58.4%), cefepime (91.7%), aztreonam (83.4%), and ciprofloxacin (80.6%). Also, 30.6% of ESBL-producing organisms were multi-drug resistant. All ESBL producers were CTX-M positive; other ESBL genes were not detected. The majority of the ESBL positive organisms produced CTX-M-15 (n= 31) and few organisms (n= 5) were CTX-M-27 producers. Conclusion: The present study shows that the predominant CTX-M type ESBL in our hospital setting is CTX-M-15.