Identification of Antibiotic Resistance Genes from Microbes of Water Reservoirs

The development and spread of antibiotic resistance among bacteria is considered a universal threat to human, animal and environmental health. The effect of clinically relevant antibiotic resistance genes and antibiotic resistant bacteria that are released from anthropogenic sources, together with the excessive use of antibiotics in both human and veterinary settings, is currently considered to be a serious environmental problem. The environmental settings (e.g. water or soil) is important on the cycling of antibiotic resistance in nature. The antibiotic resistant genes carried by microbial communities can multiply in their hosts, pass on to other bacterial populations and is subject to further evolution. Therefore, environmental antibiotic resistant genes are an abundant reservoir of potentially transferable resistance for pathogens. In this study, 239 antibiotic resistances bacteria are isolated from water reservoir samples. Antibiotic resistance profiles were examined by employing heterotrophic plate counts (HPC) as a culturing method to obtain counts of bacteria resistant to 7 different classes of antibiotics. Many of the 239 isolates had resistance to ampicillin (β-lactam class), vancomycin (glycopeptide class), lincomycin (lincosamide class) and trimethoprim (dihydrofolate reductase inhibitor class). Furthermore, the antibiotic resistance genes are identified by screening from genomic library of multi antibiotic resistance bacteria. The most common types of antibiotic resistant genes were efflux pumps and genes conferring resistance to vancomycin, tetracycline, or β-lactam antibiotics used in veterinary and human healthcare. In conclusion, distinct antibiotic resistant bacteria phylotypes and a variety of antibiotic resistant genes are present in water reservoirs, suggesting that proper water treatment approaches should be applied for safe drinking water.