ISOLATION AND CHARACTERIZATION OF MULTI-DRUG RESISTANT (MDR) AND EXTENSIVELY DRUG RESISTANT (XDR) BACTERIA FROM DIVERSE ENVIRONMENTAL NICHES

Antimicrobial resistance (AMR) emerged as a major challenge to public health and significantly impacting the global economy. Infections due to multi-drug resistant (MDR) bacteria are difficult to treat and cause financial burden on patients. Environment may serve as a genetic pool of several drug resistant genes and help bacteria to emerge as notorious superbugs. This study aimed to characterize MDR bacterial isolates from environmental samples and comparative analysis of MDR and multi-drug sensitive (MDS) strains for the expression of virulence factors. Twenty six (n=26) different environmental samples (water, soil, air and surface) were collected for the purpose. The antimicrobial susceptibility testing performed using 12 antibiotics belongs to six different antibiotic classes. The potential virulence factors were determined among MDR and MDS isolates. Thirty (n=30) bacterial isolates belong to 13 different genera (Staphylococcus spp., Enterococcus spp., Escherichia spp., Bacillus spp., Acinetobacter spp., Klebsiella spp., Pseudomonas spp., Shigella spp., Enterobacter spp., Citrobacter spp., Streptococcus spp., Streptobacillus spp. and Proteus spp.) were identified. All recovered isolates were susceptible to aminoglycosides. The most frequently (23.33%) isolated bacterium was Staphylococcus aureus. Overall, 63.33% (19/30) bacterial isolates were MDR, of which, 73.68% (14/19) were extensively drug resistant (XDR). Biofilm production observed in all the isolates as weak (53.34%) and moderate (46.66%). MDR plus XDR phenotype was observed among 42.85% (6/14) of the moderate biofilm producers. Statistically, no significant difference was observed between MDR and MDS isolates for the expression of virulence traits (p>0.05 for calculated χ² of 8.496). Incidence of MDR and XDR phenotype was higher among isolates recovered from water samples and was least among surface samples. Release of such notorious superbugs in the environment should not be overlooked and biomedical waste management (BMW) rules must be followed.