Heavy metal tolerance in association with plasmid mediated multiple antibiotic resistances among clinical bacterial isolates

Abstract

The heavy metal tolerance in association with plasmid mediated antibiotic resistance among bacteria has been reported around the globe. This communication conducted an experiment to explore the coexistence of antibiotic resistance and heavy metal tolerance in clinical bacteria and the involvement of R-plasmid in such phenomenon. By disc diffusion method, 6 clinical bacteria: Escherichia coli (n=3), Pseudomonas aeruginosa (n=2) and Proteus mirabilis (n=1), utilized in the study, displayed resistance to multiple antibiotics with MAR (multiple antibiotic resistance) indices 0.15-0.77; such bacterial isolates showed tolerance to Hg 2+ , Cd 2+ , Cr 6+ and Cu 2+ at 3-37.5 μg/ml, 75-800 μg/ml, 100-400 μg/ ml and 600-900 μg/ml, respectively. The SDS treatment induced the test bacteria to mislay their resistance property (following susceptibility test) with a parallel loss of single plasmid (following agarose gel electrophoretic analysis) contained in them. This study confi rms the antibiotic co-resistance with heavy metal tolerance among human pathogenic bacteria, and underlines the regular vigilance of bacterial R-plasmid in order to combat the multiple antibiotic resistances of such bacteria as well as the infection caused by them.

Principal component analysis exploring the association between antibiotic resistance and heavy metal tolerance of plasmid-bearing sewage wastewater bacteria of clinical relevance

“…[ 40 ] reported the functionality of polluted urban wetlands as a reservoir of MDR bacteria: P. putida group ( P. plecoglossicida and P. guariconensis ) carrying carbapenem resistance genes. Our earlier report demonstrated multidrug resistance among clinical bacterial isolates, with P. aeruginosa having 8-drug resistance (Am–Ce–Cm–Ct–Cx–Nx–Pc–PT and Am–Ce–Cp–Ct–Cx–Nx–Pc–PT) phenotypes and E. coli having 8–10-drug resistance (Am–Ce–Cm–Cp–Cx–Mp–Nx–Pc, Am–Ce–Cp–Ct–Cx–Mp–Nx–Pc–PT and Am–Ce–Cp–Ct–Cx–Mp–Nx–Pc–PT-Tc) phenotypes [ 8 ]. Multiple antibiotic resistance has also been reported among the potentially pathogenic bacteria isolated from riverine water as well as municipal sewage water [ 6, 7 ].…”