β-Lactamase-Producing Multidrug-Resistant Bacterial Pathogens from Tracheal Aspirates of Intensive Care Unit Patients at National Institute of Neurological and Allied Sciences, Nepal

Abstract

The widespread use of tracheal intubation and mechanical ventilation to support the critically ill patients increases the risk of development of tracheobronchitis and bronchopneumonia. This cross-sectional study was conducted with an aim to isolate and identify bacterial pathogens from tracheal aspirates producing extended-spectrum β-lactamase (ESBL), AmpC β-lactamase, and metallo-β-lactamase (MBL) from August 2011 to April 2012 at National Institute of Neurological and Allied Sciences (NINAS), Kathmandu, Nepal. ESBL was detected by combined disk assay using cefotaxime and cefotaxime with clavulanate, AmpC β-lactamase by inhibitor-based method using cefoxitin and phenylboronic acid, and MBL by Imipenem-EDTA combined disk method. 167 bacterial strains were isolated from 187 samples and majority of them were Acinetobacter spp. followed by Klebsiella pneumoniae with 32.9% and 25.1%, respectively. 68.8% of isolates were multidrug resistant (MDR) and Acinetobacter spp. constituted 85.4%. ESBL, AmpC β-lactamase, and MBL were detected in 35 (25%), 51 (37.2%), and 11 (36.7%) isolates, respectively. Pseudomonas spp. (42.8%) were the predominant ESBL producer while Acinetobacter spp. were the major AmpC β-lactamase producer (43.1%) and MBL producer (54.5%).

Prevalence of carbapenem resistant bacterial strains isolated from different clinical samples: study from a tertiary care hospital in Kathmandu, Nepal

“…Quite high rates of AmpC β-lactamase (37.2%) and MBL (36.7%) production (among gram negative bacteria) in comparison to our study were reported by Khanal et al [24] but as in our study highest rate of MBL production was reported to be shown by Acinetobacter spp. [24]. The carbapenemase enzymes are both the chromosomal and plasmid encoded.…”

“…Similarly, Gupta et al reported the prevalence of carbapenem resistance among enterobacteriaceae to be varying from 17% to 22% [23]. Quite high rates of AmpC β-lactamase (37.2%) and MBL (36.7%) production (among gram negative bacteria) in comparison to our study were reported by Khanal et al [24] but as in our study highest rate of MBL production was reported to be shown by Acinetobacter spp. [24].…”

Ventilator Associated Tracheobronchitis: Incidence, Etiology, Predisposing Risk Factors and Drug Resistance

“…Pseudomonas aeruginosa was the predominant ESβL (36%) and MβL (44%) producer which were similar to the study conducted by Lee et al, (Lee et al, Table.5 Clinical spectrum of diseases of VAT Dey et al, (2007) where in E. coli and Klebsiella pneumoniae were predominate ESβL producers. An elevated level of drug resistance in Pseudomonas aeruginosa is because of the different mechanisms that include production of different types of -lactamases primarily ESβL, AmpC enzymes, and metallocarbapenemases, aminoglycoside-modifying enzymes, loss of porin proteins, and the presence of efflux pumps (Kumari et al, 2007).…”

First report on rapid screening of nanomaterial-based antimicrobial agents against β-lactamase resistance using pGLO plasmid transformed Escherichia coli HB 101 K-12

“…Effective tackling of antimicrobial resistance requires better diagnostic techniques and novel drugs (Khanal et al 2013). Traditionally, the discovery of new antimicrobial agents effective against resistant bacteria involves the use of pathogenic resistant strains isolated from clinical setting.…”