Emerging Trends of Beta-Lactamases in Western Nepal: A Growing Public Health Concern.

Background

Clinically challenging bacterial infections are caused by microorganisms producing extended-spectrum β-lactamases (ESBLs), AmpC β-lactamase (AmpC), and carbapenemases, which confer antibiotic resistance and may result in treatment failure. This study was aimed at determining the prevalence of ESBL, AmpC, and carbapenemase-producing clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

Methods

This study was a cross-sectional study. A total of 362 isolates of E. coli, K. pneumoniae, and P. aeruginosa from urine, blood, pus, sputum, swab, and endotracheal (ET) tube tips were obtained from patients attending Manipal Teaching Hospital, Pokhara, Nepal, during March 2022 to October 2022. Phenotypic confirmation of ESBL, AmpC, and carbapenemase was done by combined disk test and modified Hodge test.

Results

The prevalence of ESBL among isolates was found to be 58.3%. Confirmative tests showed 65.3% P. aeruginosa, 30.2% K. pneumoniae, and 17.7% E. coli were AmpC producers. Among the carbapenem-resistant isolates, 81.7% showed phenotypic evidence of carbapenemase production based on the modified Hodge test. Additionally, 9.9% and 5.2% of isolates demonstrated phenotypic characteristics suggestive of metallo-β-lactamase (MBL) and Klebsiella pneumoniae carbapenemase (KPC) activity, respectively.

Conclusion

The ESBL production was the predominant mechanism of resistance to β-lactam drugs, followed by AmpC and carbapenemase production. Routine identification and monitoring of these organisms, followed by detection of β-lactamase production, optimize the effective management and prevention of antimicrobial resistance.