Evaluation of Antibiotic-resistant Bacteria and Physicochemical Parameters in Groundwater, Impacted by Dairy Farms in Hatillo, Puerto Rico

摘要

The dairy industry produces many contaminants. This industry constantly uses a water resource in its processes, which carries these contaminants through the soil to groundwater supplies. Dairy cows excrete a significant fraction of antibiotics, posing a substantial risk that active or unchanged metabolites into the environment and leach to groundwater. The aim of this study is to determine if the dairy industry represents a source of bacterial contamination to groundwater, analyze the resistance to antibiotics in the identified bacteria and evaluate the risk to which nearby communities are exposed when they use them as drinking water. Samples were taken from three wells revealing antibiotic-resistant autochthonous bacteria. The physicochemical parameters were analyzed. Eight different types of bacteria were identified, Bacillus sp., Micrococcus sp., Acinetobacter baumannii, Enterobacter aerogenes, Enterobacter cloacae, E. coli, Pseudomonas aeruginosa, and Pseudomonas putida. Ammonium and nitrate in wells A and B exceeded limits, turbidity in wells A and C exceeded limits. However, the pH and temperature were within limits. Dairy farms can be a source of contamination to groundwater. Improvements in manure management are recommended using more profitable technologies in the transformation of waste from dairy industries. These contaminants can migrate through the soil and reach groundwater supplies, which can contribute to potential impact on public health and the environment.