ABSTRACT
Groundwater is one of the major drinking and public water supply sources around the globe. Due to the overuse and misuse of antibiotics in human beings as well as in veterinary animals, widespread occurrence and prevalence of antibiotic residues (AB), antibiotic-resistant bacteria (ARB), and antibiotic resistance genes (ARG) in the surface water and groundwater environments is frequently reported. Antimicrobial resistance (AMR) dissemination in groundwater is primarily due to the application of reclaimed wastewater for agricultural and recreational purposes as well as land application of animal manure. Groundwater environments containing AMR components could pose a serious public health risk due to increase in the frequency of human exposure to resistant pathogens. Resistant pathogens causing ARB infections are estimated to cause 10 million deaths by 2050, overtaking the mortality rates of non-ARB infections. AMR components in groundwater could also pose environmental risks, viz, accumulation, persistence, and toxicity. It is important to identify all possible sources and understand the fate/transport of AMR components in groundwater, in order to mitigate the AMR spread in groundwater environment. This chapter presents occurrence of AB, ARB, and ARG reported in groundwater. Major sources of AMR components in groundwater such as untreated wastewater, reclaimed wastewater, sludge, animal wastes, surface water, landfill, sewer systems, and septic systems are summarized. Fate of antibiotics, viz., sorption, leaching, and degradation/transformation mechanisms, fate of ARB and ARG are discussed in detail. Insights and future perspectives are also discussed.
