Tolerance pattern against the heavy metals and pesticides in Escherichia coli isolated from water samples.

Abstract

In this study water samples were investigated for the presence of heavy metals and pesticide resistance in Escherichia coli (E. coli) collected from district Jhal Magsi. Identification of E. coli was carried out via Polymerase Chain Reaction (PCR) assays. Heavy metals and pesticide resistance were conducted by the Kirby-Bauer disk diffusion method. E. coli was confirmed by using uidA (623 bp) and usp (515 bp) genes primer. A relatively high resistance rate was observed for Cd and DDT (2, 4 D) with 100% at the concentration of 1600 µl/mL. Samples showed the resistance pattern for Cr with 55% and sensitivity was 45% at 800 µl/mL. Resistance and sensitive percentage of Pb, Co were observed 61, 63, and 39, 37% at 400 µl/mL. Cyanazine resistance and the sensitive percentage were 51 and 49% at 800 µg/mL. For Chlorpyrifos and Carbofuran, 54 and 65% resistance and sensitivity 46 and 35% were measured at a lower range of 400 µl/mL. Excessive use of heavy metals and pesticide pollution in standing water near agriculture fields contributed to accelerating the abundance of multi-pollutant-resistant E. coli in water that could be useful in the bioremediation of pesticides and heavy metals.