Contamination with Salmonella can occur anywhere in the food chain; using Premi®Test Salmonella from DSM-Checkpoint, for serotyping can trace the source of the problem back to the hatchery, breeder flock, feed mill, grow-out farm or processing plant where the problem arose.
Over a sustained period of several years (1997 - 2006) an anti-Salmonella action programme in The Netherlands, in which serotyping has played a key role, has resulted in a less than 1% occurrence of both Salmonella enteritidis and S. typhimurium , and a fall in overall contamination from 35% to 6%.
The successful monitoring of breeder houses has owed much to the regular analysis and rapid serotyping of Salmonella positive samples. To avoid contamination of separate lots from other breeder houses, a special regime involving meticulous segregation (separation or canalization) has been introduced aiming to minimize cross-contamination. Similar strict monitoring measures were introduced in grow-out houses and on farms, while processing plants were subjected to strict canalization and cleaning regimes.
A similar regime is carried out at breeders and hatcheries with daily sampling of each new hatch. At grow-out houses, protective overshoes are sampled 10 days before stock is slaughtered. Finally, in the processing phase, 30 caecal or feather, skin and meat samples are taken at every house.
In the meantime, EU regulations and guidelines require a regular monitoring in the production chain for food of animal origin. In this regulation, serotyping is required for 5 strains mostly involved in illnesses related to Salmonella contamination. In the coming years more, and finally all, strains will be added to this list.
Monitoring for Salmonella and serotyping the positive samples will then be an integral part of the control for this aspect of food safety of products of animal origin.
There are 2000 Salmonella subtypes or serovars. Different Salmonella contaminations are often caused by different serovars. Classical serological methods require well trained and experienced staff and full serovar identification can take up to 2-3 weeks or more. But routine serovar identification is important for two main reasons: first, recent EU and national requirements demand more detailed serovar identification when positive salmonella contamination is found. Second, routine serovar identification enables each specific cause of salmonella contamination in the food chain to be pinpointed, thus reducing contamination by being able to take appropriate sanitary measures in that specific part of the production chain. As has been demonstrated in The Netherlands, excellent results have been achieved with this approach.
Premi®Test Salmonella - identifies a number of serovars in a single test
To meet the challenges presented by salmonella contamination and to meet the tighter governmental regulations, Premi®Test Salmonella is a Salmonella serotyping method that is extremely fast and identifies a large number of serovars in a single test enabling the source of contamination in the supply chain to be indicated faster and with greater precision.
For more information on Premi®Test contact Goeijen-de, Francoise or visit the DSM website