Publication: Prevalence of Colistin-resistant Gram-negative Isolates Carrying the mcr-1 Gene among Patients Visiting a Tertiary Care Center
Date
2020
Journal Title
Journal ISSN
Volume Title
Publisher
Nepal Medical Association
Abstract
Abstract:
Introduction: Gram-negative isolates harboring mobilized colistin resistance (mcr-1) gene are a great threat to human health. They have been reported worldwide among various bacterial isolates. This work aimed to study the prevalence of colistin resistance among Gram-negative bacteria and the incidence of mcr-1 gene among these isolates.
Methods: A descriptive cross-sectional study was done at a tertiary care center from June 2016 to February 2017. An ethical approval was taken from review board of the Nepal Health Research Council (Reg. no: 274/2016). Convenience sampling was used. The data was collected and analyzed using Microsoft Excel 2010 and Statistical Package for Social Sciences (SPSS) Version 16 . Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data.
Results: Among 485 gram-negative isolates, only 13 (2.68%) (1.26-6.62 at 95% Confidence Interval) isolates were colistin-resistant and mcr-1 was present in two isolates. Predominant colistin-resistant isolates were E. coli 6 (4.1%), Enterobacter spp 2 (2.81%), and Acinetobacter spp 2 (2.81%). A high level of colistin-resistance was noted in 4 (30.7%) isolates as indicated by the very high value of colistin MIC (>256 µg/ml). ICU was the major site of isolation of colistin-resistant and mcr-1 positive pathogens. The majority of colistin-resistant isolates were highly drug-resistant and were sensitive only to polymyxin B. Antibiotics like imipenem, amikacin, gentamicin, aztreonam, ciprofloxacin, and piperacillin-tazobactam were effective for few of these isolates.
Conclusions: Though the prevalence of mcr-1 gene was low among colistin-resistant gram-negative isolates, the resistant pattern was quite alarming as these isolates were highly drug-resistant.
Description
Ashmita Paudel
Department of Microbiology, Regional College of Health Science and Technology, Pokhara, Nepal
Surya Prasad Devkota
Department of Microbiology, Pokhara Bigyan Tatha Prabidhi Campus, Pokhara, Nepal
Anima Shrestha
Department of Microbiology, Saint Xavier’s College, Maitighar, Kathmandu, Nepal
Anil Kumar Shah
Annapurna Research center, Maitighar, Kathmandu, Nepal.
Keywords
colistin-resistant, gram-negative isolates, mcr-1 gene, Nepal