Occurrence and Distribution of Multi-Antibiotic Resistant Bacteria from the Great Kanawha River, West Virginia

During the spring and summer of 2004 subsurface mid-channel samples were collected from the Kanawha River and its five primary tributaries (New, Gauley, Elk, Coal and Pocatalico Rivers). The first two objectives of this study were to enumerate bacteria resistant to ciprofloxacin, erythromycin or tetracycline, and test them for multiple resistance to seven commonly used antibiotics. The third objective was to determine the Minimum Inhibitory Concentration (MIC) for seven antibiotics starting at concentrations 20 times the published working concentrations for Gram-negative bacteria. The final objective of this study was to determine if a novel Impact Scoring system incorporating a current water quality indicator, fecal coliforms, and new indicators, antibiotic resistant bacteria could be applied to the Kanawha River. All of the isolates (n = 60) were resistant to 3 or more of the 7 antibiotics tested. Ninety-five percent were resistant to 4 or more, 92% were resistant to 5 or more, 88% were resistant to 6 or more and 81% were resistant to all seven antibiotics. One-hundred percent exhibited resistance to tetracycline. Ninetyeight percent exhibited resistance to ampicillin and sulfamethizole. Ninety-five percent exhibited resistance to ciprofloxacin and 93% were resistant to erythromycin, streptomycin, and virginiamycin. Isolates in non-industrialized regions exhibited sensitivity to some of the antibiotics tested. Isolates collected in industrial regions exhibited resistance to all seven antibiotics. These findings suggest that multiple antibiotic resistance (MAR) may be associated with industrialization on the river