Scientists discover 'amazing' new fungus species connected to livestock facial eczema
Pithomyces chartarum, whcih looks identical to its newly discovered toxic relative.
Photo:
Landcare Research / supplied
New Zealand scientists studying a complex fungal disease that affects sheep have made a scientific breakthrough.
Facial eczema is a disease caused by a toxin produced by a fungus. The fungus grows in humid conditions and hurts sheep livers, making them very sensitive to ultraviolet light and reducing productivity.
The disease is estimated to cost farmers and the economy $332 million a year.
But
new research
has revealed there are two species of this fungi in New Zealand pasture, not just one as previously thought.
Scientists have named the new fungus species Pseudopithomyces toxicarius - identified as the primary producer of sporidesmin, the toxin produced by spores of the fungus. The new species is in addition to the better-understood non-toxic Pseudopithomyces chartarum.
The study's lead author Dr Bevan Weir, senior scientist at Manaaki Whenua Landcare Research, said the teams extensively studied the organisms, genomes and toxins found in New Zealand pasture and abroad.
"It was amazing when we got the first DNA sequencing data and there was just this incredibly clear split showing that there was definitely these two species on pasture," Weir said.
"It was a fantastic experience figuring out that we've kind of cracked it, and that in the past there have been reports of non-toxic strains or less toxic ones, and now we know the reason why."
He said the discovery followed years of hard work and dedication by research institutes, the agriculture industry and farmers.
AgResearch, Manaaki Whenua, Beef and Lamb and the Livestock Improvement Corporation were involved in the study, led by Beef and Lamb.
The seven-year project to eliminate the impacts of facial eczema in livestock was valued at $20.75m, and the government assigned $8.3m to it in March last year.
Weir said identifying the primary cause of facial eczema was a "critical step forward" in reducing its impact.
"The complicated thing is that although these species are really genetically distinct and have very different genes, under the microscope they are completely identical. So you can't tell them apart at all, even under our really good research microscopes.
"And this is a problem for assessing facial eczema risk, because at the moment the main method of assessing risk is doing spore counts, and it's still a good method, but some of those spores that the vets and farmers are counting under the microscope will be from the non-toxic species."
Weir said the ongoing sheep poo collection work will help them identify where the toxic and non-toxic species were found around New Zealand - but there were generally very little toxic examples found in the South Island, and more in the North Island.
AgResearch lead author Christine Voisey said the teams were grateful to the farmers that supported the study by providing samples that were vital to this research.
"Working on this project has been one of the most rewarding experiences of my career," she said.
"There is still much to learn about the biology of Pseudopithomyces, but this research brings us closer to developing tools that will help mitigate the impacts of facial eczema on New Zealand's farmers."
Beef and Lamb general manager of farming excellence Dan Brier said the research gave the sector a clearer foundation for developing more accurate diagnostic tools and effective management practices.
Sign up for Ngā Pitopito Kōrero, a daily newsletter
curated by our editors and delivered straight to your inbox every weekday.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
RNZ News
38 minutes ago
- RNZ News
The McMigraine hack: does it really work?
For people living with migraine disease it can be a debilitating condition that is invisible to others. In New Zealand, 753,000 people live with migraine, affecting three times as many women than men. Dr Fiona Imlach has lived with migraine for many years, and frustrated by the lack of migraine specific care, she co-founded Migraine Foundation Aotearoa New Zealand in 2022. Dr Imlach joins Jim to discuss migraine disease, its causes, and what can help. Photo: 123RF
RNZ News
2 hours ago
- RNZ News
The McMigraine meal hack: Does it actually work?
A 'migraine brain' is sensitive to sensory input. Photo: Quin Tauetau / RNZ Epidemiologist Dr Fiona Imlach has lived with migraines for many years. Now, as co-founder of Migraine Foundation Aotearoa New Zealand, she has also spent many years researching them. Imlach told Sunday Morning's Jim Mora a TikTok video suggesting a 'McMigraine Meal' - a bottle of Coke and a side of salty fries - as a treatment might not be totally far-fetched. "TikTok's not really the font of all wisdom but there is some element in this in terms of the cola, has caffeine in it, and we know that caffeine can be quite an effective migraine treatment." However, she said medication with caffeine in it could be a problem if over-used. An alternative was to limit caffeine intake to one or two cups of coffee per day and take it at the same time each day because the migraine brain "likes routine". A sugar hit could also help Imlach said, because there was a theory that a migraine attack was triggered by nerves in the brain being depleted of glucose. On the salty fries, Imlach said food cravings were much stronger during the prodrome phase causing people to think the food they ate triggered the attack when actually it was already underway. Salt was not known to help treat an attack, she said. A TikTok video claims a McDonald's coke and fries can help a migraine. Photo: AFP Imlach told Mora there was a lot of mystery surrounding migraines. In the past migraines had been treated as a vascular disease and thought of as an allergic disease with certain triggers, but Imlach said it was very much recognised as a neurological disease. She said migraine was a genetically-determined condition and some people inherited a pre-disposition through one of their parents. A person who suffered migraines was thought to have a "sensitive" brain, or a hyperactivity toward sensory input, and it did not react the way it normally would, she said. "That triggers all these other things you get with a migraine attack. Often people think about headache pain but also things like being sensitive to light and sound." Those symptoms, along with nausea, fatigue and mood disturbances were a brain disturbance caused by the sensitivities, and could be painful and unpleasant, she said. Migraine was a disease of the brain which was present all the time but symptoms were only triggered during an attack. When the attack was over, the migraine tendency didn't go away. Imlach said a classic migraine started with sufferers "feeling a bit rotten" in the "premonitory" stage, which preceded the attack. This was a stage people hadn't recognised very well in the past. For Imlach, she suffered cognitive difficulties during this phase - being unable to speak properly. The premonitory or prodrome phase could last up to two days according to brain scans of some patients. "So you're going about your life, you haven't got a headache, you think you're fine but actually your migraine attack has started." These early symptoms included difficulty concentrating, fatigue, and mild head pain and that could be a warning sign. A full blown attack involved other symptoms including a visual aura. "I used to get spots in my vision, which I couldn't see, or I'd get flashing lights. "And then you move on to the headache phase and that can last for a few hours to a few days. "Quite a severe pain. Usually on one side of the head - for me it was on one side of the head - sometimes it would move to the other side of the head for a while." Neck pain, nausea and vomiting were also common for Imlach who said while light sensitivity was common for many, she was highly sensitive to sound during an attack. "Even someone speaking to me can feel really painful and echo in my head and also I get sensitive to smells so smells can be really unpleasant. "Even someone's deodorant can make me want to vomit." Migraine prevalence was two to three times higher in women than men. "The hormone is probably the most common trigger. So women who have migraines will have a hormonal triggering element to that." This became obvious around puberty, while after menopause migraines could improve. There were two types of treatment for migraine - acute and prevention. The best available treatments for an attack was migraine-specific medication called triptans, as well as over-the-counter medicines. For frequent and severe attacks, Imlach said a preventative treatment should be considered to "calm the brain down". "Traditionally all we've had is treatments that have been repurposed from other conditions. "So we've had anti-depressants which people have taken and sometimes found it helps their migraine attacks." Others found to help were beta blockers and anti-hypertension medicines as well as botox, none of which were specifically developed to prevent migraines. In the past nine years new micro-medications had been developed specifically to treat one of the neurotransmitters in the brain involved in the pain part of the migraine attack, Imlach said. "Those have been a revolution in treatment and they don't have the same side-effects - they're much more tolerated - because they've been developed with migraine in mind." Unfortunately, they were not funded, she said. "We have three available in New Zealand at the moment but they are quite expensive and they're on Pharmac's waiting list so they've been approved for funding but they're just waiting to see whether Pharmac can actually get the budget to fund them." Imlach said frequent migraine sufferers had to be careful about taking too many migraine-specific triptans and over-the-counter medicines such as non-steroidal drugs. "If you start taking too many of those you can actually make the headache worse and you can actually develop a headache." That spoke to the migraine brain's sensitivity, she said. Sign up for Ngā Pitopito Kōrero , a daily newsletter curated by our editors and delivered straight to your inbox every weekday.
RNZ News
3 hours ago
- RNZ News
Alligator that swallowed jandal at Auckland Zoo gets all clear
Dixie the American alligator from Auckland Zoo during the procedure to put a camera put down her throat after she swallowed a jandal. Photo: Auckland Zoo An Auckland Zoo alligator which ate a jandal left behind in its enclosure had to undergo an hospital procedure to make sure the man-made object had passed. American alligator Dixie was seen swallowing the jandal in her habitat, Auckland Zoo said in a post on Facebook. "Although after this she continued eating well, our vet team wanted to ensure this was not going to be a longer-term health issue for her," the social media post on Sunday said. "Alligators can consume foreign objects because they're 'sit and wait' hunters. "If something moves near them, they will often automatically snap and eat it. This means that in the wild, alligators can die from ingesting man-made objects." The zoo's vets were joined by Dr Tommy Fluen, an external specialist experienced with endoscopy - where a thin flexible tube is passed into a patient's body. Once Dixie was safely anaesthetised, Fluen was able to look inside her stomach using a small camera attached to the scope. "Every inch of Dixie's stomach was examined, and thankfully a jandal was not found - however we did find a lot of half-digested meat and vegetation. "This means it is very likely the jandal was expelled previously." While the endoscopy was taking place, the zoo's vet team took the opportunity to check Dixie's eyes and body condition, which were "in great shape". "It would be amazing if Dixie never came across a man-made object in her habitat," the Auckland Zoo post said. "Hopefully, our visitors can help us with that preventative healthcare by going home with everything that they brought to the zoo." Head of veterinary services James Chatterton said for many people a trip to the zoo was the time they developed an interest in animals and started to care. "And that's the first step on providing a better future for wild animals everywhere," he said. Sign up for Ngā Pitopito Kōrero , a daily newsletter curated by our editors and delivered straight to your inbox every weekday.
