Abstract
The study was aimed to determine the phenotypic and genotypic antimicrobial resistance in the isolated bacteria from the influent (25), effluent (15) and surface, ground water (15) surrounding the pharmaceutical industries located in south India. Forty-eight isolates out of 55 samples were obtainedviz.Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter aerogenes, Corynebacterium sp., Acinetobacter sp., Aeromonas punctata, Ralstonia picketti, Staphylococcus aureus, Stenotrophomonas maltophillia, and Citrobacter freundii. The phenotypic profile of resistance through antibiotic susceptibility test was carried out against sixteen different antibiotics. Standard PCR technique was used for the detection of 12 genes encoding carbapenems, quinoline, aminoglycoside, β-lactam belonging blaOXA-58, blaOXA-22, qnrA, qnrB, aac(6)-Ib-cr, aac (3)-XI, mec A, qepA, aadB, blaVIM, blaOXA-48 and blaNDM. Pseudomonas aeruginosa (1: TN/I/2020) showed presence of 3 resistance genes. qnrB (489 bp) gene was present in a maximum of 7 isolates while blaVIM (196 bp) gene was present in 6 isolates. The resistant gene blaNDM (621 bp) was present in three different isolates; aac (X):6)-lb-cr (482 bp), qepA (495 bp), aadB (500 bp), blaOXA-58 (843 bp) resistant genes were present in two different isolates each among the bacterial isolates obtained in this study. In phenotypic resistance profiling by AST method, a maximum of 14 antibiotics were resistant among 16 tested. Similarly, in genotypic resistance profiling, among 12 resistant genes tested, a maximum of three resistant genes were noticed in Pseudomonas aeruginosa. There were positive and negative correlations observed between phenotypic and genotypic resistance among different antibiotics and their resistance genes indicating the variations in the resistant gene expression.