Antibiotics and Antibiotic Resistance in Agriculture and Urban Environments.

Understanding the soil bacterial resistome is essential to understanding the evolution and development of antibiotic resistance, and its spread between species and biomes in the environment. Many studies have shown that antibiotic resistance has developed over time from resistance to single classes of antibiotics to multi-drug resistance and extreme drug resistance. The mechanisms of action of antibiotics and antibiotic resistance mechanisms have been studied almost exclusively in pathogenic bacteria. It is only in recent years that antibiotic resistance research has focused on the environment from which the antibiotics were initially extracted such as soil microorganisms and the soil ecosystem. Here we present the natural antibiotic resistome and understanding the ecology and evolution of antibiotic resistance in the non-clinical environment in order to identify reservoirs of both known and novel antibiotic resistance mechanisms. We will present data on antibiotic resistance in generic E. coli and Enterococcus sp from a mixed urban watershed with about 1.4 million peoples and 300,000 cattle in a 75 km² area. The study showed strong evidence that suggests that multiple antimicrobial resistant E. coli isolates and Enterocuccus sp were more frequent in the sediment with inputs from urban runoff. Therefore, the occurrence of more resistant E. coli isolates originating from urban runoff sources than agricultural sources in this watershed is crucial for water quality management strategies and public health awareness.