Naola Ferguson, DVM, associate professor at the University of Georgia, speaks to Poultry Health Today. Results from the same field study showed litter also contained the highest levels of the bacteria.

Environmental samples from farms naturally infected with MS were obtained to try and find an explanation for the increased incidence of MS in US poultry flocks during the last five years.

“We collected different samples of things that just naturally occur in the poultry house,” she said, to evaluate their potential in transmitting MS to other farms.

MS was also found in the dust and on feathers, but the most was found in litter. Broilers are on the litter all the time, and MS may be able to survive longer in moist litter, Ferguson noted.

Some strains of MS transmit very well and persist in the environment. These strains also tend to be resistant to antibiotics, she explained.

Ferguson does not believe MS survives in the litter for extended periods of time, but she recommends litter be treated when it’s removed to prevent the spread of MS to other flocks. Any type of cleaning to reduce the amount of MS in the litter will work: heat treatment, composting or letting it lie fallow.

Diagnostics for the future

Asked about the role of molecular diagnostics and Mycoplasma, Ferguson said she hopes more advanced diagnostic techniques such as genetic sequencing currently used in research eventually will be available in more diagnostic laboratories, but that could take another three to five years.

“The cost right now is still a little high, and it still is a specialised technique,” said Ferguson, who has been involved in the development of a sequence database for Mycoplasma gallisepticum. “[Sequencing is] not something that you can take a technician and train them to do it in a day,” she said, but added, “we’re hoping that we can get it to a point where, in terms of cost and turnover, it is something that several different labs are able to do.”

One issue with next-generation sequencing (NGS), she noted, is that clinicians aren’t sure how to analyse the huge amount of data generated.

With current polymerase chain reaction (PCR) testing, one disease is evident, so veterinarians know how to proceed. With NGS, the results can show 50 different bacteria or genera, which can make it difficult to pinpoint the real problem, Ferguson explained.