Jun 28, 2023

Automated test developed for detecting diarrheal pathogens in berries

A test that speeds detection of a human diarrheal disease than causes illnesses and outbreaks in fresh produce including berries, leafy greens and herbs has been developed.

Since 2018, more than 8,000 cases of cyclosporiasis (C. cayetanensis), which causes abdominal upset, have been identified in the U.S.

While historically associated with imported fresh food or international travel, cases of cyclosporiasis have been observed in the U.S. since the 1990s. During the 2018 cyclosporiasis outbreak investigations, investigators discovered produce grown in the U.S. could also be at risk for Cyclospora contamination, according to a news release. Illnesses and outbreaks caused by cayetanensis are associated with the consumption of fresh produce such as herbs, berries, and leafy greens.

Rheonix Inc., which manufactures microfluidic workstations and assays or laboratory investigative procedures for molecular testing, collaborated with the U.S. Food and Drug Administration’s Center for Food Safety and Applied Nutrition in developing a test for the detection of C. cayetanensis in food and environmental samples.

The fully automated method enables detection of low levels of cayetanensis, saving approximately four hours of hands-on time per 24-sample run compared with the existing workflow.

The FDA-Rheonix Research Collaboration began in February to rapidly develop, test and validate a fully automated screening assay that can detect low levels of cayetanensis in fresh produce, soil and surface agricultural water. The goal of the collaboration is to provide a validated automated method to rapidly and accurately identify contaminated samples. This is designed to advance the FDA’s ability to screen food and environmental samples for traceback and for risk assessment of agricultural practices and regions, according to the release.

The development was conducted in collaboration with scientists at the Office of Applied Research and Safety Assessment (OARSA) within the FDA’s Center for Food Safety and Applied Nutrition (CFSAN).

Rheonix is an Ithica, New York, manufacturer of automated molecular diagnostics and microfluidic workstations. Rheonix’s testing products include the Listeria PatternAlert Assay, a rapid method for Listeria strain typing. Clinical assays include the Rheonix COVID-19 MDx Assay for use under FDA emergency use authorization.