Incidence of Beta-Lactamase Enzymes among Klebsiella pneumonia Isolates Causing Urinary Tract Infections in Aliabad, North-East Iran

Abstract

Aims: In the past decade, drug resistance in Gram negative bacilli has become a serious problem. The production of extended spectrum beta-lactamase (ESBL), AmpC beta-lactamase, and metallo beta-lactamase (MBL) enzymes in Klebsiella pneumoniae strains is the mechanism of drug resistance among these commonly isolated Gram negative bacteria from clinical specimens. The aim of this study was to assess the frequency of β-lactamase enzymes, including extended spectrum β-lactamases (ESBLs), metallo-β-lactamases (MBLs), and AmpC beta-lactamases, in K. pneumonia strains isolated from urine samples referred to medical laboratories in Aliabad. Materials & Methods: A total of 780 urine samples were collected from patients suspected of having UTI from March to June 2017. In positive urine samples, K. pneumonia isolates were identified by biochemical tests. Antibiotic resistance pattern was determined by disk diffusion method, and phenotypic confirmatory test was performed for detecting ESBLs, MBLs, and AmpC BLs producers. Findings: Out of 378 positive samples for UTI, 97 K. pneumonia strains were isolated. Most of the isolates (more than 90%) were resistant to ampicillin and amoxicillin; however, imipenem and amikacin were effective antibiotics against the isolates. The frequency of ESBLs, MBLs, and AmpC BLs producers was determined as 33.3, 21.3, and 5.1%, respectively. Conclusions: In this study, 14 isolates were simultaneously positive for ESBL and AmpC BL production, and 2 isolates were co-producer of ESBL and MBL. This finding could have a great impact on the management and treatment of UTI cases. Therefore, detection of beta-lactamases is of great importance for controlling and reducing the spread of ESBL, AmpC BL, and MBL producing strains.