The causal linkages between the use of antibiotics in animals and the spread of antibiotic resistance in humans involve complex ecological processes, including the development of resistance, within- and between-species spread, circulation amongst animal and human populations, and the behavioral and economic conditions that foster or inhibit this circulation and spread. This study will look at the ecology and evolution of the spread of antibiotic resistance in northern coastal Ecuador, where road-building and deforestation are leading to an influx of small-scale poultry farming in rural communities. The study area offers a unique opportunity to investigate the role of the environment in the evolution of antibiotic resistance at the household, village and landscape scales and will draw on our expertise in molecular and microbial ecology, epidemiology, mathematical modeling, and ethnography. Intensive antibiotic usage in animal husbandry is a major contributor to the growing problem of antibiotic resistance worldwide, posing threats to both animal and human health. Understanding the ecological processes involved in the emergence and spread of antibiotic resistance is crucial in designing effective intervention programs. The research team will include graduate students at the University of Michigan and the Universidad San Francisco de Quito (USFQ). There will be training and periodic health education workshops for community health workers, and the sharing of findings with health ministry employees at the local, provincial and national levels in Ecuador.