Location: Foodborne Toxin Detection and Prevention Research
Project Number: 2030-42000-054-007-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2023
End Date: Aug 31, 2024
Objective:
The objective of this project is to identify the risks wild bird communities pose to food safety on fresh produce farms by combining field-collected data in the Central Coast of California with a literature review of pre-existing foodborne pathogen prevalence data. To do this, we will complete the following four core objectives: 1. Identify which avian species are more likely to harbor fecal-borne zoonotic pathogens and quantify temporal patterns of pathogen occurrences. 2. Identify which landscapes (i.e. agricultural, urban, suburban, forest landscapes, etc.) are most likely to host avian species that test positive for fecal-borne zoonotic diseases. 3. Test previously collected fecal samples for zoonotic pathogens. Samples were collected from farms growing leafy greens, situated along a landscape gradient near and far from livestock grazing habitats. 4. Examine seasonal differences in avian community structure and abundance on the same farms across two harvest seasons and the planting season.
Approach:
1. We will complete a systematic literature review of fecal-borne zoonotic pathogens (including, but not limited to, Salmonella, E. coli, Campylobacter, Yersinia, Giardia, and Amoeba) from birds tested in both natural and clinical settings. From the literature search, we will collect information from each paper concerning: (a) where the study was completed, (b) the type of landscape the study was completed in, (c) which bird species was observed, and (d) the timing of the outbreaks.
2. After collecting meta-data from the literature review, we will use meta-analytic methods answer the following questions: 1) Does the environment in which a bird is located affect the likelihood of testing positive for fecal-borne zoonotic pathogens? 2) Which bird species are more (and less) likely to test positive zoonotic pathogens? 3) Are there spatiotemporal patterns in avian zoonotic pathogen prevalence? Data from the literature review will be supplemented with previous collated pathogen occurrence data (>11,000 pathogen tests reported in Smith et al. 2022), >600 samples collected by our group in California Central Coast produce farms, and >500 samples collected by collaborators at the University of Georgia in peach and pecan orchards throughout the Southeastern United States.
3. We will sequence avian fecal samples collected across two harvest seasons on California Central Coast leafy-green farms (spring and fall) and one planting season (winter) to identify from which bird species they originated. Following this, we will use PCR to test for the presence of Salmonella, E. coli, and Campylobacter. We will analyze which species are more likely to test positive for these pathogens, and if the prevalence of pathogens changes temporally across species.
4. Finally, we will analyze previously collected bird occurrence and abundance data from the same leafy-green farms as the fecal samples. We will analyze how bird community structure and abundance change across different seasons, including migration and the over-wintering season. We will combine the data from the literature review, the fecal sample tests, and bird community data on farms to create a risk assessment for different species to help farmers reduce the risk of transmission from wild birds.
