Detection of blaNDM−1,mcr-1 and MexB in multidrug resistant Pseudomonas aeruginosa isolated from clinical specimens in a tertiary care hospital of Nepal

Abstract

Introduction Pseudomonas aeruginosa is an opportunistic pathogen, which causes healthcare-associated infections in immunosuppressed patients. They exhibit resistance to multiple classes of antibiotics via various mechanisms such as the over-expression of efflux pumps, decreased production of the outer membrane protein (D2 porin), over-expression of the chromosomally encoded AmpC cephalosporinase, modification of drugs, and mutation(s) at the target site of the drug. The bacteria also develop antibiotic resistance through the acquisition of resistance genes carried on mobile genetic elements. Limited data on phenotypic as well as genotypic characterization of MDR P. aeruginosa in Nepal infers the needs for this study. This study was carried out to determine the prevalence rate of metallo-β-lactamase (MBL-producer) as well as colistin resistant multidrug resistant (MDR) P. aeruginosa in Nepal and also to detect MBL, colistin resistance, and efflux pump encoding genes i.e. blaNDM−1, mcr-1 and MexB respectively in MDR P. aeruginosa isolated from clinical samples. Methods/methodology A total of 36 clinical isolates of P. aeruginosa were collected. All bacterial isolates were phenotypically screened for antibiotic susceptibility using Kirby Bauer Disc Diffusion method. All the multidrug resistant P. aeruginosa were phenotypically screened for MBL producer by Imipenem-EDTA combined disc diffusion test (CDDT). Similarly, MIC value for colistin was also determined by broth microdilution method. Genes encoding carbapenemase (blaNDM−1), colistin resistant (mcr-1) and efflux pump activity (MexB) were assayed by PCR. Results Among 36 P. aeruginosa, 50% were found to be MDR among which 66.7% were found to be MBL producer and 11.2% were found to be colistin resistant. Among MDR P. aeruginosa, 16.7%, 11.2% and 94.4% were found to be harbouring blaNDM−1, mcr-1 and MexB genes respectively. Conclusion In our study, carbapenemase production (encoded by blaNDM−1), colistin resistant enzyme production (encoded by mcr-1), and expression of efflux pump (encoded by MexB) are found to be one of the major causes of antibiotic resistance in P. aeruginosa. Therefore, periodic phenotypic as well as genotypic study in Nepal on P. aeruginosa would provide the scenario of resistance pattern or mechanisms in P. aeruginosa. Furthermore, new policies or rules can be implemented in order to control the P. aeruginosa infections.

Molecular Analysis of Carbapenem and Aminoglycoside Resistance Genes in Carbapenem-Resistant Pseudomonas aeruginosa Clinical Strains: A Challenge for Tertiary Care Hospitals

“…Previous reports from Pakistan detected bla NDM-1 , bla IMP , bla VIM , bla OXA-48 carbapenemases in CRPA [21,71,72,85,93,94]. These findings are supported by various global reports [14,73,90,[95][96][97][98][99][100][101]. On the other hand, the detection of bla KPC among CRPA was reported infrequently in Pakistan [94]; however, an increasing trend in the global dissemination of bla KPC -harboring P. aeruginosa has been observed [22,28,[102][103][104][105][106][107][108].…”

Genomic and Proteomic Analysis of Pseudomonas aeruginosa Isolated from Industrial Wastewater to Assess Its Resistance to Antibiotics

“…Current studies have shown that mexAB-oprM and mexXY-oprA efflux operons play an important role in antibiotic resistance in Pseudomonas aeruginosa isolates from Tabriz, Iran [33]. Pseudomonas aeruginosa was isolated from clinical specimens from a tertiary care hospital in Nepal, and MexB was detected in the multi-drug-resistant Pseudomonas aeruginosa [34]. Recent studies have shown that Pseudomonas aeruginosa isolates were multidrug-resistant with a high level of efflux pump expression of the MexA gene [35].…”