Evaluation of Resistance in Intestinal Coli Forms Isolated from Industrial Wastewater, Domestic Wastewater and Various Parts of the Wastewater Treatment System of Arak City

Heavy metals such as cadmium، mercury، nickel and Oxyanions for example chromate and tellurite are toxic elements that entering into the environment in different ways and are harmful for biological systems، especially humans، animals and plants، so to remove it from the environment is essential. Microorganisms، especially bacteria have a very important role in the biological removal of heavy metals and are used in biotechnology. In this study، has been done the counting intestinal coli forms and heavy metals resistant strains isolated from industrial wastewater، domestic wastewater and various parts of the wastewater treatment system of Arak city. In this study 4 genus of bacteria intestinal including Klebsiella spp.، Escherichia coli، Citrobacter and Enterobacter were isolated from effluent samples above and were determined the minimum inhibitory concentration (MIC) against the concentration of various heavy metals such as cadmium chloride، nickel sulfate، mercuric chloride، potassium chromate and potassium tellurite using the agar dilution method، and were reported their resistance against some antibiotics by disk method. In this study، for first time، high MIC، 22mM (4032μg/ml) than cadmium، 20mM (3884μg/ml) than chromium، 20mM (6157 μg / ml) than telluride، 10mM (2628μg/ml) than nickel and 1mM (271. 5μg/ml) than mercury، were reported for Klebsiella spp. bacteria