Leknes, Norway-based feed producer STIM and its sister company ACD Pharma have identified bacteriophages capable of efficiently killing Moritella viscosa, a bacteria known to cause winter ulcers in farmed fish along the Norwegian coast.
Based off their findings, the companies expect to create a “a new biocontrol product ready for the market by the time the water starts getting colder again and the risk increases for new outbreaks,” according to a press release.
The new product will be their second created out of bacteriophage research. The companies established the first biocontrol product based on bacteriophages, a world first, in 2018. The product “targeted the bacteria causing yersiniosis in salmon and has been shown to be highly effective in removing Yersinia ruckeri from hatchery production water, biofilters, and wellboats,” STIM said.
STIM announced the moritella bacteriophage product this month at its annual fish health and aquaculture conference. With moritella outbreaks increasing, STIM said vaccines are becoming less effective and causing “a big problem for fish farmers all along the Norwegian coastline this winter.”
“The rising number of moritella outbreaks is linked to mutations in the bacteria, making the available vaccines less effective. It is also linked with the widespread use of mechanical sea-lice treatments on wellboats that may render the skin more vulnerable for infection from the bacteria. Wellboat sea-lice treatments [are] in fact within the range of application for the new product that is expected to hit the market in the autumn,” STIM said.
Wellboat transportation and sea-lice treatments, which are stressful for salmon, tend to promote the shedding of bacteria in greater amounts, thus increasing the likelihood of outbreak. Moritella viscosa attacks the skin of infected fish, causing sores and sepsis, according to thecompany.
“Adding our yersinia bacteriophages to the water removes Yersinia ruckeri from the equation, as the number of these bacteria quickly drop to undetectable amounts. Lab results with our moritella bacteriophages leads us to believe that the effect will be exactly the same for the new product,” STIM Research and Development Director Hans Petter Kleppen said.
Because Moritella viscosa thrives in colder temperatures, STIM said it is “working to have the new product available before the sea temperatures start to drop again.” The companies said they will focus on scaling production and conducting field and safety tests through the summer months.
The sister companies have been researching bacteriophages for the last 12 years in an effort to enhance the aquaculture’s toolbox, STIM CEO Jim Roger Nordly said.
“We knew that we needed new tools in our toolbox and bacteriophages are just that. Together with effective vaccines it will play a major part in reducing the need for antibiotics and thereby reducing the development of antibiotic resistance, which is one of our greatest global health threats,” Nordly said.
At the company's conference, STIM also presented the possibility of producing autogenic vaccines, which are short-term "emergency vaccines" based on isolates from single sites or locations.
“In collaboration with competent vaccine producers, we will be able to deliver these vaccines within three months from receiving the needed isolates. If we act fast, we can be in much better shape going into the next moritella season,” Nordly said.
Photo courtesy of STIM
