Characterisation of Plasmids in Multidrug Resistant Uropathogenic Gram-negative Bacterial Isolates

Abstract

Introduction: Urinary Tract Infections (UTI) are one of the commonest conditions for which people seek medical care with an estimated 150 million episodes per annum worldwide. An unprecedented upsurge in the rate of development of antimicrobial resistance has reduced the therapeutic options leading to increased morbidity, prolonged hospital stays, development of complications. Majority of these infections are attributable to Gram negative bacteria which have now acquired resistance to almost all classes of antibiotics. Aim: To analyse the plasmid-mediated drug resistance and characterise the major plasmid families that are in circulation. Materials and Methods: A cross-sectional study comprising of a total of 95 non consecutive multidrug-resistant gram-negative bacterial isolates were subjected to Plasmid based replicon typing from January 2017 to June 2018. The 18 major replicons were divided in five multiplex and three uniplex Polymerase Chain Reaction (PCR) formats and the samples were subjected for plasmid characterisation and further sequencing of the plasmid Deoxyribonucleic Acid (DNA). The data obtained was analysed by Microsoft Excel software. Results: Escherichia coli, accounted for maximum n=51 (53.7%), Klebsiella pneumoniae n=19 (20%), Citrobacter sp n=11 (11.6%), miscellaneous gram negative n=14 (14.7%) The isolates exhibited a high degree of resistance to almost all tested antibiotics, sparing a few like Fosfomycin, Chloramphenicol, Imipenem, Amikacin. A total of 154 different plasmid families were detected from the 95 isolates. FIB replicon (24%), FIA (21%), F, W (20%), FIC, B/O (14%), Y (12%), I1 replicon (10.5%) were the major plasmid families detected in the present study. Conclusion: Many isolates exhibited the presence of more than one Incompatibility (Inc.) group plasmids, conferring multidrug resistance to the isolates. The study highlights the need for further research to study the association between plasmid families and their respective antibiotic resistance profiles for a given geographical niche and the need to devise further methods to target these epidemic plasmids.