A genetic testing kit that identifies and quantifies multiple Salmonella serovars in the same reaction tube could help poultry companies pinpoint where specific serovars are entering the production chain, as well as evaluate live production and processing interventions.
The GenoPATHX system identifies and quantifies up to four Salmonella serovars simultaneously from poultry rinses, ground meat and environmental samples without traditional enrichment procedures, explained QuantiPath Vice President of Sales Elizabeth Krushinskie, DVM, PhD.
“GenoPATHX works directly on mixed samples, without culture, transfer or colony isolation. What is present at collection is what is detected and quantified,” stated Krushinskie.
One test reaction can yield up to eight results, including four serovar identifications and four quantification measurements. Producers can select specific serovar primers based on operational needs.
The testing approach differs from conventional polymerase chain reaction (PCR) methods that require enrichment and colony isolation. Traditional enrichment can allow certain serovars to overgrow others, potentially skewing results from the original sample, explained Krushinskie.
Additionally, selecting isolated colonies after enrichment may or may not accurately represent the sample, potentially introducing subjectivity into the results.
The system can function in-house or through third-party laboratories. According to Krushinskie, Quantipath plans to release additional test kits for Listeria, E. coli and Campylobacter.
How it works
A poultry rinse, ground meat or environmental sample is filtered and then concentrated by centrifugation to pellet the target Salmonella cells. These cells are lysed to release their deoxyribonucleic acid (DNA).
Serovar-specific primers are then used in a thermocycler to amplify small sections of the DNA. Up to four target serovars can be analyzed in a single reaction. Each probe carries a unique fluorophore color to allow for differentiation between serovars.
Results are calculated based on the amplification cycles required for each serovar-specific DNA fragment to reach threshold. A linear regression algorithm then reveals the total Salmonella concentration and independent target serovars per sample.