26 Oct 2023
Ceva Animal Health says culture medium will help differentiate vaccine from different strains.
Vet Times
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Ceva Animal Health has announced launch of a culture medium to provide assurance on how well birds have been vaccinated as part of a standard laboratory method to differentiate its Cevac Salmovac vaccine strain from field strains of Salmonella enteritidis.
The company has been working with Biomerieux’s ASAP culture medium to help with the differentiation.
All laying flocks adhering to the British Lion Code of Practice must be vaccinated against Salmonella enteritidis and Salmonella typhimurium during the rearing period. Environmental sampling is carried out to monitor the flocks for Salmonella infection between 22 and 26 weeks, continuing every 15 weeks throughout the laying period.
Version 8 of the British Lion Code of Practice states approved Salmonella testing laboratories must undertake testing to differentiate between field and vaccine strains of Salmonella.
Cevac Salmovac contains a double attenuated (adenine-histidine auxotrophic) Salmonella enteritidis strain in live freeze-dried form, which stimulates active immunisation in chickens, reducing colonisation, persistence, and invasion of the intestinal tract and internal organs by field strains of Salmonella enteritidis and S typhimurium. It is administered via drinking water.
The Cevac Salmovac vaccine strain can occasionally be detected during routine sampling. When this occurs, an accredited laboratory can carry out the differentiation testing while also sending the samples to the official confirmatory laboratory for final identification.
The ASAP Salmonella differentiation test has 100% sensitivity and 100% specificity for differentiating the Cevac Salmovac vaccine strain from any Salmonella field strain; Ceva Salmovac grows dark blue/purple colonies on ASAP media, while all other Salmonella bacteria field strains grow pink/red colonies.
Pippa Abbey, poultry national veterinary services manager at Ceva Animal Health, said: “Several tests are available to differentiate Cevac Salmovac from Salmonella field strains; however, using ASAP as a second medium significantly improves and speeds up the differentiation process, ensuring that laboratories can quickly and efficiently detect the presence of the Cevac Salmovac strain.
“The ASAP media is also a useful tool for monitoring Cevac Salmovac drinking water vaccination and helps with vaccination auditing.”
For further information, telephone Ceva Animal Health on 01628 334056.
