Molecular characterization and gene expression analysis of multidrug resistant bacterial strains from various clinical and non clinical sources

Abstract

newline newlineInfections play a major role in the healthcare system. The serendipitous discovery of penicillin opened a new gateway where physicians tried to cure all the diseases with this new molecule. Unknowingly exposing the pathogens to the lower concentration of antibiotics, organisms developed antibiotic resistance. Microorganisms develop resistance through mutations, which occur in the DNA of the cell during replication, or through horizontal gene transfer. There are three mechanisms of antibiotic resistance, namely, enzymatic degradation of the antibiotics, alteration of targeted bacterial proteins and changes in membrane permeability to antibiotics. The silent spread of colonizing multidrug resistant bacteria in healthcare setup is a major threat. The resistance pattern of multidrug resistant organisms limit the options available for antimicrobial therapy to the clinician and it results in increased morbidity, mortality rates and health care costs. The detection of the organisms at the earlier stage of infection could help patients get appropriate line of treatment. In the current study non-clinical samples (swabs and air sampling) from frequently touched sensitive surfaces in hospitals, wastewater samples from sewage treatment plants and hotels, and co-operative societies, and clinical samples (urine, stool, blood, sputum etc.) were collected from patients admitted to tertiary care hospitals, and their outpatient departments were enrolled for the screening process. The isolates showing resistance towards more than two groups of antibiotics were considered multidrug resistant and were screened for carbapenem resistance, subjected to molecular characterization and gene expression analysis to detect and quantify the resistance gene. Selected organisms showing high expression were subjected to whole genome sequencing to detect the mutations in resistance genes. Out of the isolated and identified 3113 clinical and 1311 non-clinical isolates, 651 isolates were found to be multidrug resistant. These isolates were subject