Jan. 1, 2020 - Dec. 31, 2021Funding Agency
Center for Produce SafetyAmount Awarded
Ynes Ortega, Ph.D.
University of Georgia
In the past six years, a large number of cyclosporiasis cases have been reported in the US. Historically Cyclospora outbreaks have been associated with ingestion of imported fresh produce. In 2018, more than 2,200 cyclosporiasis laboratory-confirmed cases were reported using Culture Independent Diagnostic Tools (CIDT). That same year, two large outbreaks were associated with fresh produce (romaine lettuce and shredded carrots) and vegetable trays (cauliflower, broccoli and carrots) implicating vegetables produced in the US. These outbreaks raise several questions about Cyclospora in the US. The prevalence and persistence of Cyclospora in the environment in the US (water and soil) is unknown. We propose to test river and canal water from Florida and California. We will also examine the prevalence of Cyclospora in fresh produce consumed in Florida. To perform these analyses, we will be first examining the specificity and sensitivity of three molecular detection methods using water and fresh produce. The significance of this project is that we will be able to determine if Cyclospora oocysts are present in river/irrigation waters in two states where agriculture is intensive and we will be able to recommend a suitable method to test for Cyclospora in agricultural settings.
Cyclospora cayetanensis infection can be acquired by ingestion of contaminated foods containing Cyclospora oocysts. Cyclospora outbreaks in the US have been often linked to produce imported from endemic locations. In 2018 one outbreak was associated with broccoli, cauliflower, carrots and dill dip trays, products that have been for the first time associated with Cyclospora. The second outbreak was associated with ingestion of salad mixes sold in McDonalds fast food restaurants. The salads were prepared by a Fresh Express plant in Illinois and the lettuce was grown in the US. These two events have raised several questions about Cyclospora in the US.
In this project we propose the determine the temporal and spatial distribution of Cyclospora in water and produce in two US states: Florida and California. For this, first we propose to compare three Cyclospora detection methods. The first one will be the BAM19b for produce and the BAM19a for irrigation water. These methods will be compared with those we use in our laboratory. Significant differences can be noted, from sample size, elution buffers and molecular detection targets for specific and sensitive detection of Cyclospora. The BAM method and method 2 target the 18S rRNA gene whereas method 3 targets the mitochondrial DNA. The most robust method will be used to perform the environmental surveys.
The significance of this study is to determine the best method for environmental testing for Cyclospora cayetanensis and to determine what is the distribution of C. cayetanensis in the US. These two objectives are critical to implement monitoring and intervention strategies not only in the US but also in endemic locations.