Purpose: To document the prevalence of Salmonella, E. coli O157, and non-O157 shiga toxin-producing E. coli in small mixed crop/livestock farms in Arizona that sell their products, including milk, meat, eggs, and/or produce at farmers’ markets and other local venues.
Methods: We collected 503 samples from 17 farms from spring 2015 to summer 2016. We aseptically collected water, soil, leafy greens, tomatoes, domestic and livestock animal feces, and various types of compost, and tested them using traditional culture and end point PCR.
Results: All of the samples that tested positive for foodborne pathogens were collected during spring and summer, and came from farms that grew leafy greens and tomatoes, housed animals, and made their own compost. Two compost samples tested positive for E. coli O157. Non-O157 STEC and Salmonella were present in all sample types, with more animal feces harboring non-O157 STEC, and more leafy greens and soil harboring Salmonella.
Significance: We conducted the first pathogen survey in the southwest growing region of small biodiverse farms that integrate produce and livestock production, particularly those involved in the direct farm to fork pathway. Our results will contribute to the development of Best Management Practices for small mixed crop/livestock farmers in this unique farming region.