In -Vitro Antibiotic Resistance and Heavy Metal Tolerance Patterns of Gram-Positive and Gram-Negative Bacteria Isolated From Effluent Treated Water of Delhi, India.

Abstract

Heavy metal contamination and antibiotic resistance is a global problem. Bacterial populations in metal polluted environment adapt to toxic concentration of heavy metals and become metal resistant. In the present study several samples were collected in gamma sterilized bottles for evaluating the heavy metal tolerance and antibiotic resistance pattern of isolated bacterial strains. Isolation and identification of bacterial strains were done by using IS guidelines. These bacterial strains were isolated from different effluent treatment plants located in community of Delhi. All the samples were analyzed for the presence of Gram-positive bacteria like S.aureus, and for Gram-negative bacteria like P.aeruginosa, E. coli. After isolation, biochemical and morphological methods were followed for the identification of strains. Primary screening methods were applied to isolate heavy metals resistant organisms. Further susceptibility patterns of these isolates were studied towards Several Antibiotics such as Amoxicillin, Ampicillin, Cloxacillin, Cephalosporin, Doxycycline, Gentamycin, Meropenem, Streptomycin and Tetracycline. All isolates were found to have 100% resistance against lead except P.aeruginosa (67%). Gram-positive bacteria i.e. S.aureus was found susceptible when checked against all selected antibiotic except Doxcyline where no zone of inhibition was observed. Organisms such as E.coli and P. aeruginosa showed variable resistance pattern These heavy metal resistant organisms could be a potential agent for bioremediation of heavy metals polluted environment.