What To Do When an Environmental Monitoring Program Falls Short of Solving the Listeria Problem [CASE STUDY]
Company X, a leading national supplier of prepared foods, was set with their environmental monitoring program. They had a well-established in-house routine testing plan that included, among other common actions, monitoring Listeria species throughout their process flow. Their plan and testing protocols were effective and efficient in collecting samples and evaluating for the organisms of concern. In fact, Company X had been observing recurring Listeria presumptive results throughout their facility and operations for 14 months. The problem was that they had been unable to eliminate the Listeria or trace it back to a source. Company X was testing for Listeria, but they wanted to understand it in their process. They turned to Eurofins and Rheonix.
CHALLENGE
Contextualize and eliminate the Listeria contamination that Company X was finding in their environment through in-house testing by answering:
- Is the Listeria we are seeing the same, persistent strain of Listeria or many unassociated strains?
- Is there a pattern to the Listeria recurrences that can help us to identify a root cause of the contamination?
APPROACH
Company X provided Eurofins Microbiology Laboratory in Mounds View, MN, with 88 presumptive Listeria samples that they had collected and stored over the span of approximately 14 months, as well as a floor plan from their facility. Eurofins analyzed the presumptive samples with the Rheonix Listeria PatternAlert™ assay and evaluated the results against the provided floor plan.
RESULTS
For each sample processed, the Rheonix Listeria PatternAlert™ assay assigned a company-specific ID, or “pattern,” based on the presence or absence of genomic sequences present in the Listeria. The detailed Eurofins analysis of Company X’s results identified a primary, consistent pattern for Listeria among the positive samples. Together with location data for each sample, the common Listeria pattern of concern could be placed throughout the main floor of the facility and within the equipment room. Finally, a trace of the process identified a mobile piece of equipment (cart) that traveled between and connected the seemingly disparate hot spots in the environment as the root cause of the recurring Listeria.
SOLUTION
Through detailed analysis of the locations of recurring Listeria, Company X was able to develop corrective actions to thoroughly clean the inside of the cart (harborage site) and eliminate it as a source of Listeria in the facility. In addition, Company X expanded upon and closed the gaps in their cleaning procedures for equipment as well as sanitation practices among the staff.
Following in-house screening, Company X now sends all positive Listeria enrichments to Eurofins Microbiology in Mounds View to be processed with Listeria PatternAlert™. New results are analyzed against the patterns in Company X’s Listeria PatternAlert™ database and using the PatternAlert analytical tools, Eurofins and Company X personnel can rapidly identify a recurrence of the initial pattern as well as visualize potential emerging issues.
Transitioning from reactive to proactive, Company X has strengthened their program by incorporating Rheonix Listeria PatternAlert™ testing through Eurofins as a routine step in their environmental monitoring.
Did this challenge sound all too familiar? Reach out today to learn more about how we can partner with your team and strengthen your program.
