Saving koalas: Gene study promises solution to deadly sex disease

By Matt McGrathEnvironment correspondent

2 July 2018

Australia's most famous tree hugger has been ravaged by sexually transmitted disease, attacks from dogs, being hit by cars and habitat loss.

Chlamydia has spread fast in koalas, causing infertility and blindness.

But scientists say decoding the genome should lead to an effective vaccine for the STD.

In fact, researchers say they've been amazed by the information that's been hidden in the marsupial's DNA.

While they didn't find a gene for cuteness, they've worked out how koalas can survive solely on a diet of eucalyptus - which poisons most other creatures that consume it.

Genes that are switched on in the koala's "cast-iron livers" appear to be responsible for the ability to detoxify the leaves.

Read more 

Treating koalas for chlamydia alters gut microbes, may upset eucalyptus leaf diet

Date:  March 26, 2018

Source:  University of California - Davis

Koalas are one of Australia's iconic animals, but they have been hard hit by an epidemic of Chlamydia infections contributing to a steep decline in numbers. Sick koalas brought to wildlife hospitals may be treated with antibiotics to clear up the chlamydia, but the antibiotics themselves can have severe side effects in the animals.

Read on  

Cars and chlamydia killing Queensland koalas

Date: February 21, 2017
Source: University of Queensland

Being hit by cars and chlamydia were the top causes of a dramatic rise in south-east Queensland koala deaths over the past two decades, according to a new University of Queensland-led study.

UQ School of Veterinary Science's Associate Professor Rachel Allavena and Dr Joerg Henning worked with the Queensland Government's Moggill Koala Hospital to analyse data about koala disease and death from 1997 to 2013.

"It's important data collected over the span of the koala population crash," Dr Allavena said.

"Populations throughout 'Koala Coast' declined by about 80 per cent over this period, so this iconic and famous species is in real trouble in our area."

The senior researchers and PhD student Viviana Gonzalez-Astudillo, determined that at least a quarter of the koalas hit by cars were otherwise in good health, meaning it was healthy, breeding animals that were killed.

About half of the population that died over the study period was affected by more than one disease or health problem, including trauma.

Chlamydia was particularly devastating for koalas, because of the potential to render females infertile and cause bladder and eye problems, making predator avoidance and food foraging harder.

Animal attacks, particularly from dogs, and wasting away from starvation, disease and poor teeth were other prominent causes of koala deaths.

continued 

Koala chlamydia vaccine trial raises hope Koala waiting to be vaccinated in Maroochydore, Queensland, Australia. 29 Oct 2014 Chlamydia causes blindness and infertility in koalas, and can be fatal Continue reading the main story Related Stories Threat to an Australian icon Koalas 'could face extinction' Australian scientists say they have successfully tested a vaccine aimed at protecting wild koalas from chlamydia. The disease has ravaged the native marsupial, which is under increasing threat. Microbiologists in Queensland now hope to protect some of the remaining population after successfully trialling a vaccine developed over five years. Koala numbers have plummeted in recent years and there are believed to be as few as 43,000 left in the wild. In some areas, numbers have dropped by as much as 80% in the past 10 years. The strain of chlamydia that affects koalas can lead to blindness, infertility and death among the animals. In the trial, microbiologists from the University of the Sunshine Coast in Queensland gave 30 koalas the vaccine while 30 others were left unvaccinated. All 60 were then fitted with radio collars so they could be monitored in their natural habitat at Moreton Bay, north of Brisbane. Of the 30 vaccinated, some were already infected with chlamydia, some were healthy and some were showing symptoms of the disease such as eye infections and reproductive tract infections. Researchers said that seven out of eight koalas suffering from eye infections who received the vaccine showed an improvement. But in the unvaccinated group, four of six koalas with eye infections saw their conditions worsen. Koala map The researchers also found that koalas infected with the chlamydia strain did not go on to develop the full-blown disease after they were vaccinated. "It's all very promising and it's not just that it's doing the right thing from an immune response point of view, but it's actually protecting a significant number of them out in the wild climbing around trees," Professor Peter Timms told AFP news agency. The Australian government has classified the koala as a vulnerable species as its numbers plummeted due to habitat loss, disease and other factors. Prof Timms said chlamydia was one of the "tipping points" contributing to the decline of the animal and it was crucial to stop its spread. "The vaccine would actually make a difference," he said. Researchers intend to continue the trial in areas where koalas are most at risk. More on This Story Related Stories Threat to an Australian icon 25 APRIL 2013, MAGAZINE Koalas 'could face extinction' 10 NOVEMBER 2009, ASIA-PACIFIC From other news sites Japan Times Scientists hope vaccine can save koala population ravaged by chlamydia 4 hrs ago TheStar.com.my Marsupial STD cure? Koala chlamydia gets a vaccine 11 hrs ago Mail Online UK Koalas CURED of chlamydia after Australian scientists carry out successful vaccine trial 24 hrs ago Bangkok Post Hopes raised after 'success' of koala chlamydia vaccine trial 29 hrs ago ABC Online Chlamydia 'breakthrough' in fight to protect koalas 35 hrs ago About these results Share this page ShareFacebookTwitter EmailPrint More Australia storiesRSS A gloved hand on keyboardData retention bill introduced Data about phone and computer use will be kept by telecommunications companies for two years if a bill introduced to the Australian parliament is passed. No impact study for wetlands dumping Peris emails 'part of family dispute' Top Stories

Australian scientists say they have successfully tested a vaccine aimed at protecting wild koalas from chlamydia.

The disease has ravaged the native marsupial, which is under increasing threat.

Microbiologists in Queensland now hope to protect some of the remaining population after successfully trialling a vaccine developed over five years.

Koala numbers have plummeted in recent years and there are believed to be as few as 43,000 left in the wild.

In some areas, numbers have dropped by as much as 80% in the past 10 years.

The strain of chlamydia that affects koalas can lead to blindness, infertility and death among the animals.

In the trial, microbiologists from the University of the Sunshine Coast in Queensland gave 30 koalas the vaccine while 30 others were left unvaccinated.

Continued ...