Antibiotics and antibiotic-resistant bacteria in the environment: sources and impacts

The increasing impact of the environment on the emergence and spread of antimicrobial resistance has been witnessed with the increased number of studies during the past decade. Therefore, the environment is increasingly being considered a key partner for its role in the global spread of antibiotic resistance among clinically important bacterial species. The use of antibiotics in agriculture, aquaculture, and veterinary settings as well as the waste from animal farms, wastewater from pharmaceutical companies, and hospitals are major sources of antibiotic residues and antibiotic resistance genes in the environment. The chapter focuses on the sources of antibiotics in the environment as well as key drivers and factors that contribute to the emergence of antibiotic resistance. Moreover, we outline the impact of antibiotic pollution in the environment on the resistance evolution among the natural microbial populations as well as in humans and animals.