Life Technologies has announced the launch of a new ELISA test for bluetongue virus (BTV) antibodies.
According to the company, studies have confirmed that the LSI VET Ruminant Bluetongue II-serum ELISA can detect antibodies to BTV in experimentally infected sheep after 6 days, and in cattle after 7-8 days - several days sooner than some other commercially available test kits, including the company's previous ELISA test which the new product has replaced.
Life Technologies asked the UK's Pirbright Institute, the European Union Reference Laboratory for BTV, to conduct a preliminary assessment of the new test. The new test was able to detect antibodies in all 24 BTV reference sera and BTV 26 held by Pirbright, and showed high sensitivity in a longitudinal study of experimentally infected animals.
The Pirbright study also demonstrated that the LSI VET Ruminant Bluetongue II-serum ELISA could detect BTV antibodies in cattle and sheep that had been vaccinated with an inactivated Bluetongue vaccine.
The new test was developed by Life Technologies Animal Health in its research laboratory near Lyon in France and will be available in EU countries via Life Technologies Animal Health distributors according to local regulatory requirements (see www.lifetechnologies.com/lsi-animal-health) for details.
A Europe-wide survey has found that speed and accuracy are the key features that farm animal veterinary surgeons and farmers want from diagnostic tests
More than 334 individuals from 8 countries were asked about their current usage and knowledge of diagnostics, and asked what they would like to see in the future. Greater accuracy was the number one need among veterinary surgeons, mentioned by 37%, followed by more speed (22%); cost savings (16%) and greater confidence in the results (8%) were other features that they would like to see improved.
The survey, which was commissioned by global biotechnology company Life Technologies, showed that most test results are currently available in one to three days, but still a significant proportion have to wait three to six days for results (39%) or even more than six days (20%). Only 10% currently get their results within 24 hours.
Although many of the vets were aware of modern molecular diagnostics tests such as PCR (polymerase chain reaction) which generally offer quicker results than culture testing, most did not know which were used most often. The vast majority of farmers were happy to leave the decision on type of diagnostics test to their veterinarian.
Frederic Bar, Sr. Marketing Manager EMEA at Life Technologies said: "The results show that veterinarians are looking for the speed and accuracy that modern molecular diagnostics, such as PCR, can provide, but this technology is still not being used as widely as it could be."
"One way in which veterinarians could get faster, more accurate-results would be to specify PCR when they submit samples to diagnostic laboratories.
"Diagnostics have really moved on in recent years and the modern tests can give very reliable results, often in just one day, so veterinarians and farmers can make herd health decisions more quickly."
The survey found that BVD, IBR and MAP tests were the most commonly used in cattle, while PRRS, Influenza A and Salmonella topped the list for swine. For sheep and goats, Salmonella, MAP and Chlamydia were the most frequently mentioned tests; for horses, EHV, equine infectious anaemia and Salmonella were most common. Avian influenza was by far the most commonly tested disease in poultry.
US-based Life Technologies has launched a new PCR-based test system which, according to the company, allows large numbers of pigs to be screened more quickly and cost-effectively for a range of common pathogens, such as PRRSV, SIV and PCV2.
The system uses samples of oral fluids which can be obtained by leaving a cotton rope in each pen for pigs to chew on. After 20 minutes or so, the rope can be retrieved and the saliva and gingival crevicular fluid squeezed into a sample bag and represents a pooled sample from the group.
Studies have demonstrated that oral fluid samples collected in this way can form the basis of a quick and cost-effective method for screening a range of common viral pathogens. The samples were tested using a commercially available sample preparation and real-time PCR test system which can isolate and identify viral nucleic acid in a matter of hours.
For PRRS, pooled samples of oral fluids were collected from groups of experimentally infected pigs using the rope technique, along with serum samples from each individual pig on the same days. Both serum samples and oral fluids were processed using the same Applied Biosystems preparation system and real- time PCR test, both of which were supplied by Life Technologies. The results showed that PRRSV nucleic acid was detectable in both serum and oral fluid samples from the day of infection through to 40 days after infection.
For PCV2, 24 pigs that were free of PRRSV and SIV were divided into 4 pens in separate rooms, and challenged with two different virus strains (PCV2a and PVC2b) at different times. One pen acted as a (non-challenged) control. Oral fluids were collected regularly up to 140 days after initial challenge and tested using real-time PCR. High titres of PCV2 were detected from day 12 to day 28 post infection and virus was detectable throughout the entire testing period (days 2 to 98).
For SIV, a total of 180 spiked oral fluid samples were tested using real-time PCR, and subtyping reagents were also used to identify haemagglutinin and neuraminidase subtypes. The results showed that SIV nucleic acid was detectable in oral fluid samples spiked with high, medium and low copy numbers of SIV, and all positive samples could be successfully sub-typed.
Christina Boss, European Professional Service Veterinarian for Life Technologies said: "Collecting samples in this way is far less invasive for the pigs and so avoids unnecessary stress. And because all of the pigs will chew on the rope, it provides a very broad sample from the group, which is the key to assessing overall herd health. In addition, if the pooled sample provides a positive result, then the animals in that pen can be tested individually to identify those that are infected.
"These results show that the simplicity of oral fluid sampling, combined with the speed and sensitivity of a PCR-based system, provides a practical and cost- effective way of monitoring large numbers of pigs for common virus pathogens.
"The use of a semi-automated, PCR-based diagnostic system means that nucleic acid purification can be achieved in just 25 minutes and results from the real-time PCR available in 90 minutes. The molecular test is very specific and reliable, so the veterinarian can initiate individual testing as quickly as possible and make confident recommendations to the producer."
According to Life Technologies, screening for PRRS using samples of oral fluids has been gaining popularity over recent years because large numbers of pigs can be tested without increased cost or labour. The new research is due to be presented as a poster at the ESPHM meeting in Bruges in April.