10 Takeaways From The Center For Produce Safety’s Research Symposium

 

The seventh annual Center for Produce Safety’s Research Symposium, held this summer in Seattle, WA, offered 10 key learning points for growers and others in the industry.

1. Learn from illness outbreaks and recalls to avoid repeating similar mistakes. For example, the 2014 listeriosis outbreak dramatically impacted the U.S. apple industry. The outbreak was traced back to a small California apple producer, and the session highlighted the need for education and training to apple producers and also focused on equipment and facility sanitation.
2. Generic E. coli has limitations as an indicator for irrigation water quality. Three options are available for measuring the microbial quality of irrigation water. Generic E. coli is often used as an indicator for irrigation water testing. It is relatively inexpensive and a number of test procedures are available.
3. Alternative microbial water quality indicators and indexing organisms are on the horizon. The importance of understanding the physical and chemical parameters of irrigation waters regionally when looking for indicator organisms was a focal point of discussion.
4. Sample irrigation water sources correctly. In recent years a number of questions have been raised about how to sample various irrigation water sources when testing microbial quality. At this year’s Symposium, a researcher concluded that it was appropriate to sample irrigation canals anywhere that provided safe access.
5. Irrigation water sources can be treated with disinfectants, but if a grower finds an irrigation water source that is out of compliance, it would be desirable to be able to treat the water to mitigate the problem. At the 2016 Symposium, one researcher reported that short treatments with common disinfectants like sodium hypochlorite, chlorine dioxide, or proxy acetic acid may not be sufficient to eliminate human pathogens from irrigation water.
6. Validation and verification – know the difference. These terms have certainly become a focal point in industry food safety discussions as a result of the Food Safety Modernization Act and the preventive controls rule. Basically, validation means that an operator knows their preventive control works and verification means that your preventive control has been implemented correctly.
7. The search for surrogates continues. Surrogate microorganisms represent an essential tool for conducting validation studies. A surrogate is simply a microorganism that can be used to test preventive controls like wash water disinfection or those that might reduce the survivability of pathogens in the production environment. Facility operators and growers cannot use human pathogens in process facilities for fear of cross contamination so they need a surrogate that closely mimics or exceeds the survivability of the authentic pathogen without the public health consequences.
8. Bacterial detection is not really the problem, separating the pathogen from the other bacteria is the key. This quote came from Dr. Sam Nugen, University of Massachusetts, when he discussed his research on using bacteriophage to specifically bind pathogens and permit their extraction from other non-target organisms from complex food matrices. He uses a 90-minute digestion of the plant tissues followed by phage-based magnetic separation to separate the pathogen so that in can be measured.
9. Balancing the risk of animal intrusion and conservation is benefiting from emerging data acquisition technologies and understanding of the impact of the environment on pathogen growth and persistence. USDA reported on alternative strategies to preventing animals from entering production fields, understanding the types of animals that might enter a field, the duration of their visits, and their activity while in the field by using field-implanted cameras to record animal movements.
10. Understanding the genetics and gene expression in production environments will drive the next level of understanding in produce food safety. A theme that surfaced across a number of presentations was the importance of not only the genetic make-up of a pathogen but also physiological state of the pathogen reflective of gene expression.