DOI: 10.4103/jascp.jascp_28_25 ISSN: 2772-364X
Determination of Colistin Resistance and its Association with Mcr-1 Gene in Carbapenem Resistant Klebsiella pneumoniae
Pranshu Pandey, Anupam Das, Vikramjeet Singh, Manodeep Sen, Jaya Garg, Jyotsna Agarwal
Objective:
The study aimed to phenotypically and genotypically characterize colistin resistance in carbapenem-resistant
Klebsiella pneumoniae.
Materials and Methods:
Isolates of
K. pneumoniae
obtained in 1 year period from various clinical samples were assessed for Carbapenem resistance using Kirby–Bauer disk diffusion method, and those found resistant were further analyzed for Colistin susceptibility using Broth microdilution method and interpreted as per European Committee on Antimicrobial susceptibility testing guidelines. The colistin-resistant isolates were subjected to molecular detection of
mcr-1
gene using gel-based polymerase chain reaction.
Statistical Analysis:
Odds ratios and 95% confidence intervals were calculated using appropriate statistical software.
P
values were calculated using the comparison of proportions, with a significant value being <0.05.
Results:
The study was conducted on 243 isolates of
K. pneumoniae
obtained from urine (41.6%), respiratory samples (25.9%), pus (16.4%), blood (10.3%), and sterile body fluids (5.8%). Out of these, around 35% were carbapenem-resistant. The carbapenem-resistant
K. pneumoniae
were isolated more from respiratory samples (44.4%) and least in urine (29.7%). Almost 55% of carbapenem-resistant
K. pneumoniae
were resistant to colistin, with almost 37% having a minimum inhibitory concentration of 8 μg/mL. Both the resistant isolates were maximally obtained from intensive care unit samples. None of the colistin-resistant isolates were found to harbor
mcr-1
gene.
Conclusions:
The colistin resistance remains under-detected due to a lack of proper infrastructure, especially in developing countries, and its ever-increasing resistance requires an evidence-based administration of the drug, especially to patients harboring known multidrug-resistant pathogens such as
K. pneumoniae
.