Mark Horstman joins a genetics lab on wheels on the hunt for Burkholderia pseudomallei.
Fires, floods, venomous stingers. Animals with lots of teeth. But there's something that hardly anyone knows anything about. It's ancient, it's practically invisible, it can kill you within 48 hours and it's living right here beneath my feet.
Meet Burkholderia pseudomallei. It's a native bacterium that lives in water and soil. But it doesn't stop there.
This bacteria is highly versatile. It manages to colonise pretty much everything.
And when that includes us, it causes a disease called 'Melioidosis'.
Think of us as accidental consequences and being caught in the crossfire.
People with chronic health problems, like diabetes, lung disease and heavy alcohol use, are most at risk.
They're definitely deadly for unfortunately still too many people.
Over the last two decades, Melioidosis has claimed 107 lives in the Northern Territory, nine in the last year alone.
If you're sensible, if you don't walk around in bare feet in muddy areas, you know, if you look after any cuts and scrapes and other things that you might get while you're in the Top End, then you're not going to get Melioidosis.
But recent wet seasons in the north have seen more infections than ever before.
If it happened to me, it could happen to you or... your friend, your wife, your husband, your neighbour.
To follow the Melioidosis trail, I've come to the wild north of tropical Australia.
From here, in the Kimberley, right across northern Australia, through Darwin, into Townsville, this is the front line for Melioidosis research in the world's tropics.
The first step in mapping the risk of Melioidosis - find out where the microbes live. As they drive across the Kimberley, microbiologists Tim Inglis and Adam Merritt sample soil at river crossings every 100 kilometres or so.
You like to draw big conclusions over a big area. We're trying to do that with an even more challenging task, which is a very small beastie you can't even see with the naked eye.
I'm put to work at the cutting edge of this research.
A new one for science, eh?
A new one for science - the first sample from this spot.
Might find the original Burkholderia. You never know. That's it. Oh, perfect! Got... nice, greeny, fine, clay, mud sort of consistency.
This is the natural habitat of Burkholderia pseudomallei. The bacteria aren't trying to invade us - we just end up colliding with them.
These are the sharks of the soil. They're out there, they're minding their own business, they're in a habitat that they're comfortable with, and then we go and stumble into it.
Studying how they coexist with other life forms, like living inside amoebae, provides clues to how they infect humans.
They can survive for a very long time in water, but we think they may be able to survive even longer in amoebae. There's a possibility that's where they may have learnt how to live inside cells, such as cells of the human body.
Tim and Adam have put a state-of-the-art genetics lab in the back of their car, to analyse the samples for microbial DNA while on the road.
These environmental pathogens are quite difficult to find, especially during the dry season. And we believe that the further you transport the samples, the more likely you are to get a false negative result. By getting the equipment into the field, we're getting closer to where those organisms are and hopefully we'll get a higher positive rate.
We'll return to see whether they do. On the other side of the border, the Darwin hospital is dealing with a surge in the number of Melioidosis cases.
There's been this big change. So, in summary, over the last three years, we've had 252 cases, which is way bigger than we would have expected from our previous figures.
The last season we had 30 patients in intensive care, and at the beginning of the 2000s, we would probably have eight or ten. So it has significantly increased. It waxes and wanes, depending on, usually, how big the wet season is.
It's taken Paul Griggs months to recover from the last wet season, when he was struck down by the simple act of mowing the lawn.
As you can see, rural block, a lot of grass. So there's a fair bit of mowing. I jabbed myself in the leg, which opened a wound. No, not a major issue, but given the amount of muck that had been thrown out from the mower, that's how the infection entered the body.
But not just gardeners are at risk. Helen Bateman believes she caught Melioidosis at her city apartment.
Beautiful, yes. We like it. Did this for the reason that we didn't have to garden on weekends. From the Melioidosis and being so sick, I've had other issues that have arisen - kidneys, liver, pancreas. So I'm now unfortunately on insulin on a daily basis. And, yeah, so it's a terrible disease.
So it's dramatically changed your life.
Helen's life was saved by a lengthy stay in intensive care.
We've had terrific outcomes in the last ten years, compared to the previous ten years, when most of the patients who came to intensive care with Melioidosis would die.
The treatment aims to kill the bacteria with antibiotics, stop blood poisoning and boost the patient's immune system.
Now we have a 25% mortality rate, down from 95% previously.
It's a dramatic decrease. We mostly see it in the lungs in intensive care, causing very serious pneumonia. But we also have to go hunting for where it's hiding, and it can be in the liver, the spleen, the kidneys... You can see all the black areas are actually areas of infection - abscesses within the liver. If you can see this really big area here - it's 7 centimetres - this big one here is what we're looking at draining.
There are three ways the bacteria enter the body. Through open wounds in the skin, in drinking water, or into the lungs when inhaled.
It's a very resistant and resilient little organism.
They also colonise plants, and Darwin is growing grassy highways that spread the bacteria directly into the city. Weeds like Mission and Tully grass spread quickly along drainage channels and into the bush, providing ideal habitat.
These roots all excrete nutrients, and these nutrients are just paradise for the bacteria - it's pretty much their food.
This is the dry season in Darwin, and it should be a tough time for soil bacteria to survive. But with the spread of introduced grasses like these, that keep the soil moister for longer, the Melioidosis bacteria can thrive in the parks and backyards all year round.
That means that the public is now potentially more exposed to this bacteria, even in the dry season. But so far, we haven't really seen this translated into cases. Luckily we haven't seen it happening yet.
For more than a decade, Mark Mayo has been keeping an eye out.
I'm part Indigenous, so half the cases of Melioidosis have been Indigenous people in the Northern Territory, so it sort of relates to me and I've had family members that've had it, as well.
His lab at the Menzies School for Health Research cultures bacteria from hundreds of soil, water and air samples. The aim is to pinpoint the Melioidosis hotspots and find explanations for the surge in infections. Unchlorinated bore water supplies are sampled on rural properties, to try and match bacteria with clinical cases.
What we found was that out of 55 of them, 18 were positive for the presence of the bacteria. Even though that's around 30% of the water we found positive, we don't see 30% of the people living in rural areas coming in.
We really don't understand the environmental aspects of this organism, we don't understand about its dispersal and we actually don't understand about its virulence.
Another key question is the extent to which the bacteria are carried by air and dispersed by high winds and heavy rain. One theory is that soil disturbed by construction activity whipped up in the cyclone season may partly explain Darwin's increase in Melioidosis cases. It rings true for Helen, who fell sick during a cyclone.
The rain was so heavy that it actually bubbled up through this downpipe.
Lob on my little veranda up here and knock me for six. Yeah.
There's enough capacity for airborne infection that the US lists this microbe as a potential biological weapon, along with anthrax or Ebola. Over in the Kimberley, Tim Inglis has found links between cyclone tracks and outbreaks of Melioidosis.
If, as a result of climate change, we see more of those severe weather events bringing soil and dust storms, and especially moist soil, in from the Northern Territory across Western Australia, we are going to see more cases of disease.
That means development in the north could have major implications for public health, with the expansion of suburbs, mining, and agriculture, such as the Ord irrigation scheme.
That irrigation scheme needs to be monitored and monitored very closely. Because if it's not managed carefully, we could end up with a number of health threats.
There are two global epicentres for Melioidosis - north Australia and south-east Asia, where the death rates in agricultural areas are much higher. The Melioidosis bacteria still call Australia home.
Over hundreds of millions of years, they evolved here, and moved to south-east Asia around the time of the last ice age. That's important for research, because it means that the ancient Australian strains are the ancestors to the rest of the world.
What we learn from the ancestral strains here, could be the key to saving lives elsewhere, by developing a simple diagnostic test, and perhaps a vaccine. At the end of the road in the Kimberley, the genetics lab on wheels confirms the presence of Burkholderia DNA, only 24 hours after sampling the soil.
Well, this is good - we've got two positives out of the four that we tested. That's a higher high rate than we normally expect.
Not only are there more spots on the Melioidosis map, they may have found a new strain of bacteria.
That suggests that we've got greater load of these organisms present locally, and this is a place worth looking at in much greater detail.
Linking microbiology in a creek bed to clinical research at a hospital bed is crucial for learning to live with the Melioidosis bug.
In the end, when the patient gets better and they come back and they say, 'Thank you very much,' that's what our job's all about, that's what makes it worthwhile.
I am a survivor of melioidosis, I don't know of anybody else that has survived it, I had it in 2009 late August.
This forum is now closed. Thank you very much to Prof Tim Inglis and Prof Bart Currie for being available tonight for several hours across three time zones. And thank you too to all the people involved in tonight's broadcast, and to everyone who has participated in the forum. Your thought-provoking feedback is very heartening. Please feel free to make further contributions here, but be aware Tim and Bart are no longer online to answer questions. Stay safe everyone!
I have been very ill the past week.
With High temperatures, chills, headaches which has been diagnosed as Bacterial pnuemonia. The pnuemonia was only seen via an Xray.
I was in the Kimberley region during August as far up as Kununurra.
I fell at one of the Gorges cutting my leg. It was basically untreated until I arrived back in Bunbury, when it started to become very nasty and took two lots of antibiotics to clear it up.
It is very reasonable for you to ask your doctors to test for melioidosis and tell them your travel history. If the docs and laboratory know to look for melioidosis in the culture tests they do at the start and before any treatment then if it is melioidosis it will almost always grow in the cultures to confirm the diagnosis. If the specific melioidosis tests werent done at the start but you are now better, they can still do a "melioidosis serology" test to look for recent exposure - the blood test would be sent to the Perth reference lab Id think.
Karen, Sorry to hear about your trials. You can ask your doctor to organise a blood test for melioidosis. Fortunately there have been no cases associated with soil or water exposure in Geikie or Winjana Gorges. The peak season for melioidosis risk is during the wet. When we travelled the Gibb in August many of the creeks were dry or very low. In Perth and further south this winter it has been a bad season for commoner causes of pneumonia.
I really enjoy watching the program.
very proud of you, thank you and I hope one day I become like you.
Let's see what the cause of that serious infection was. If indeed it was melioidosis we'll hear about it through public health. Environmental testing can be requested by mine safety officers and management. So far there has only been one outbreak of melioidosis in WA and that was almost 15 years ago. Most of our cases affect people with underlying chronic disease, as in the NT.
I do regular work in mangroves in Darwin harbour. Could Meliodosis occur in the saline muds in mangrove areas that are subject to tidal inundation?
I'm sure Bart will want to comment specifically on Darwin Harbour. The bacteria that cause melioidosis are generally intolerant of salt water.
Welcome to WA viewers. Prof Tim Inglis and Prof Bart Currie are here to answer your questions.
hi bart, as a former employee at RDH health library i must say it was a pleasure to see the breadth of material you requested access to for research information. how wide do you think the holistic umbrella should extend in research endeavours given the many breakthroughs that have occured via cross pollination of research? cheers fred.
As the time zones roll across our wide brown land, welcome to NT and SA who are joining us now. Check out the questions already asked, and the answers kindly provided by Prof Tim Inglis and Prof Bart Currie. Please feel free to contribute further!
My Dad had melioidosis [he died back in 1997]...not from Melioidosis though. He lived most of his life in a small town 20 miles south of Maryborough, only went as far north as Mackay a couple times. He said at the time it was extremely rare to have caught the disease so far south, going by what the Dr's told him. He was in the infectious disease ward in Brisbane for quite a long time before being let out. He never really shook it off. I remember he had massive sores 4-6" across just under his skin. Enough said, great to know there's people out there trying to work out how to beat this threat. Cheers.
I had never heard of this before, but can anyone tell me if it is similar/related in any way to Lyme disease? I noticed the treatment was antibiotics.
It is a completely different bacterium to that which causes Lyme disease.
I was in both Darwin and Townsville last year and around March this year I was hospitalised with a body temp of 41.9 and ill. Blood was taken and the hospital found a bug which they said you can only get in Asia or Africa, they called it melioidosis, they carried out chest xrays and a ct of the liver and found an abcess, I spent 8 days in ICU the abcess was drained and put on strong anti biotics since then I have numbness in my left hand finger tips to elbow and also the same in both feet toes to just below the knee. I am on 2 types of drugs Tramal SR 150mg and Cymbalta duloxetine HCI 60 mg 1 tablet each day of both drugs.With out these pills I can`t walk and have both pain and sharp pins and needles in both feet and hands.I can`t get an answer when it will get better.
I am a carer for someone who believes they have melioidosis. She has had many tests which have come back negative. She fully believes she has a chronic type of this disease. Is there acute melioidosis and chronic melioidosis. Her horse was put down a few months ago as its titer was 640 for this bacteria.
From our studies around 10% of all cases are "chronic" illness but these are almost all either a less severe pneumonia or skin lesions that havent healed. But when the doctors do the swabs, cultures for melioidosis they should grow the bacteria. Her GP can seek advice from an infectious diseases specialist if that hasnt happened as yet.
I live in Cairns. I am the mother of a 3 and 1 year who love to play in the garden and the dirt and mud. Am I placing them at an unacceptable risk?
Thats a good question that we get asked a lot in Darwin. Melioidosis is very rare in kids and especially in healthy children. So we advise parents to let kids be kids. But if a child has a severe chronic illness which affects their immune system then we give the same advice as to adults in risk groups about avoiding exposure to wet season mud and to severe weather/storms.
I'm currently doing a biology assignment about diseases. this topic is right along the lines of the assignment. I was wondering why the US decided to declare Melioidosis a possible bioweapon. what features make it suitable to become one?
Why did the US decide to count Melioidosis as a potential bioweapon?
I think it is because the bacteria have the ability to cause such severe disease, can cause infection from aerosol inhalation and are resistant to many commonly used antibiotics.
I guess a part of the reason is that it scored a lot of interest during the Cold War. In the US some Viet Nam veterans developed late onset infection, resulting in melioidosis being nicknamed the Viet Nam time bomb. Melioidosis remains an exotic infection in the US, but here it is endemic in our tropical north.
G'day Bart, you may recall that I contracted cutaneous melioidosis in approx 2005, as well as one of my passengers. His was internal. I think it was you who said that they were different strains. Can a geographical location be put on those in light of the work shown on the Catalyst program tonight? I'd be interested to know if I caught it in the NT or the Kimberley.
Great to hear from you. Can you maybe email me to discuss further. The 2 infections were indeed different strains and new technology of sequencing the whole genomes of bacteria is enabling a much more refined way to compare strains from different locations for geographical attribution. I imagine the great footage of the Kimberley in Mark's program is close to the wonderful experiences you have shown so many people over many years, including my mum!
I saw the very interesting program on Catalyst tonight concerning melioidosis. An old friend, a woman aged about 65 who has had breast and other cancer with consequent removal of lymph glands in her right arm, was scratched on an arm by a pine cone by a major river in coastal northern NSW some two weeks ago, and it became infected. She was hospitalised and airlifted to Brisbane where she has been in an induced coma for some time but is now coming out of it. The hospital is I believe trying to identify the infection. In the course of this she has suffered renal failure, heart stoppages and other problems in her internal organs. Amputation of the arm to stop the infection has been considered I believe. Could this be melioidosis?
Im sorry to hear about your friend's illness.
To date there have been no cases from NSW and the organism is not known to be present there.
But the Brisbane labs are good at growing the bacteria from patient samples in melioidosis cases.
Many thanks Bart. I guess it is a bit like cane toads in crocodile land, they are there until they are on your doorstep. I too share your faith in the Queensland hospital system and from what I have heard they are doing a wonderful job with my friend. Just a thought.
Good question, Ian. The melioidosis distribution map doesn't include NSW, but there have been occasional cases as far south as Towoomba in the East and Toodyay in the West. It is therefore more likely to be a less 'tropical' infection, but the potential range of causes is very wide - hence the difficulty for the doctors making the diagnosis.
Thank you for your investigation. I want to know if the same invasivness by this bacteria is found in companion animal or the animals are resistant to this bacteria.
Melioidosis has been reported in a wide range of animal species including livestock and native animals. But there is very little evidence that any of these pose a risk of transmitting the infection to humans. As we mentioned in the feature, this is usually an infection of environmental encounter.
Various animals are very susceptible to melioidosis. A big problem for goats and sheep in the tropical north. Australia's first cases were in sheep in Qld.
Dogs and cats can get melioidosis but it isnt common - only a handful of cases a year in the north despite all those pets.
Exotic animals in tropical zoos have also been affected, but animals native to the north seem prety much immune, which makes sense from an evolutionary perspective.
The story on melioidosis interested me as I was mudbaking by a river near Alice Springs/Uluru area some years ago, as well as gardening on a property in the desert. I have developed chronic fatigue syndrome in the past 10 years & testing via quantum feedback device, tells me I have chronic omeba, parasites, etc & my immune dystem is compromised, which is beginging to affect various main organs. regular blood tests show some indications od auto- immune disorder but all regular tests appear normal. Is it possible this bacteria, melioidosis, could be hiding & has spread from further north?
Thanks for the question, Janine. These are matters best dealt with by an infectious disease specialist clinic. So these comments are more general, and not specific to your case. We have not found any links between chronic fatigue syndrome and melioidosis despite the fascinating ability of the bacteria (Burkholderia pseudomallei) to lurk undetected inside a person's tissues for years or even decades. When these bacteria are dormant in human cells they do not appear to cause any features of disease.
This isnt the pattern of illness we see with melioidosis and although we have had rare cases from south of Tennant Creek it is extremely uncommon outside the tropical north.
I am in the final stages of a medical degree, and am just wondering in what circumstances (i.e locality, season) and what the common presentation(s) of Melioidosis are to carry forward with me in my career?
Great work on the story too!
The pdf references provided by Mark above these comments have lots of the info you want.
Plus - come and work at Royal Darwin Hospital, or one of the other hospitals in the tropical north - always keen to get enthusiastic docs.
Is Melioidosis prevalent in PNG? I lived for many years in Port Moresby and am married to a Papua New Guinean and I have not come across this before. Would the PNG health officials have the resources to diagnose this?
Some detailed work has been done on melioidosis in PNG by our colleague Jeff Warner and his group as James Cook Uni. It is certainly present there, and there is some evidence of at least one small hot spot.
Is there data about the incidence of melioidosis in PNG or patterns of illness compared with Australia?
Great to hear from you. The hot spot Tim referred to and that Jeff Warner has studied for over a decade is in Western Province. Very rare cases in Port Moresby and serology studies support it being rare in the Capital.
But I think it is present in your old work place in Gulf Province - and certainly it is a well know problem on the islands in the adjacent Torres Straits.
Why is Burkholderia pseudomallei endemic/confined to the NT and QLD? What prevents its spread elsewhere in Australia - temperature?
Is there any antibiotic or other drug which can be taken as a preventative or in case of a suspicion, e.g. malaria can be suppressed in advance by taking tetracycline.
Unfortunately there is little place for antibiotic prophylaxis apart from specific groups at very high risk, like clinical laboratory staff after exposure due to a laboratory spill. Good lab practice aims to prevent such events by careful handling procedures. Similarly, the mainstay of prevention is for people who are at high risk taking personal protective measures like wearing protective clothing during work outdoors in the wet season, prompt cleaning of minor skin trauma contaminated by dirt etc.
What does the bacteria like to eat?
Given that there is always a dynamic/symbiotic relationship between plant roots and bacteria and that some Burkholderia species are beneficial to plants; Is it likely that B. pseudomallei also serves dome purpose? If not would plant roots try to protect themselves from it?
What is your opinion of this research paper?
In vitro methanol leaf extracts of Tamarindus indica have shown anti-B. pseudomallei in India.
Has this been replicated here?
Good question. There are a group of near-neighbour species of bacteria that do not cause human infection and which have adapted to a niche close by plant roots. Some of these species help fix atmospheric Nitrogen. Others may just be commensals - eating at the same table. Recent genetic work shows that Burkholderia pseudomallei appears to have developed from these less virulent near-neighbour bacteria, and on the way have gained the ability to invade free-living cells - like amoebae.
There are several projects under way to look at the ability of synthetic compounds or naturally occurring substances to boost innate immunity against this group of intracellular bacterial pathogens like Francisella.
Burkholderia have a phenomenal appetite for a very wide range of bacterial foods. They store away energy in granules of polymers that keep them going when famine conditions occur.
Fascinating story. So very happy to see the great work you are continuing to do on melioidosis, Bart and Tim. The mobile lab is a fantastic idea and I hope it yields many more insights into this very important disease of Australia and Asia. Best wishes from Melbourne.
Good evening all. Welcome to a discussion about melioidosis. Standing by are Prof Tim Inglis (medical microbiologist at Uni of WA and PathWest) and Prof Bart Currie (Menzies School of Health Research, and Head of Infectious Diseases at Royal Darwin Hospital). I'm here to help too - as I made the story! - and moderate the forum.
Yes, providing the concentration is right. We've done much more detailed work on the use of bleach and sunlight. Both are effective, but some strains are a little more resistant than others. The big surprise was how sensitive B. pseudomallei was when we measured exposure to broad band UV in sunlight.
Hi my name is Kurt. I am 6 years old. I want to be a scientist when I grow up. I just watched the story about melioidosis with my dad and I would like to know why it grows in the dirt.
Good question, Kurt. It has adapted to survive in soil. These bacteria can live on a wide range of food substances present in the soil, especially around plant roots as Mirjam commented. But it is also very tough and can last for years in distilled water (with no food at all). A very tough little germ indeed.
Than you Professor Inglis. I would like to research bacteria from other planets. What what type of course would I need to do?
You're welcome. You will need to study astrobiology. NASA, CALTEC and the Jet Propulsion Lab in Pasadena, California have had a long running interest in microbial life on other planets. Closer to home, scientists are getting really interested in the microbes that can be found high in the earth's atmosphere. They are a bit easier to study that life on other planets. It would be really cool to take our lab without walls into outer space.
Maybe ask your parents to come to the Northern Territory as we get fantastic views of our universe in the Outback and we have terrific schools.
Hello, I just watched your programme and the problems associated with melioidosis now make a lot of sense as I have often believed I have difficulty pinpointing the source of a noise in an environment with heavy background noise. I am currently 26 years old and I have been told that as a child I had many problems with inner ear infections and I was never diagnosed with melioidosis. Currently I still feel I have difficulty listening in on group conversations or listening to speech in a noisy environment. Should I seek a proper diagnosis and are there any steps I can take to improve my hearing as an adult?
Is it in or going to get to the larger cities?
By larger, I take it you mean other than Darwin. Public health surveillance keeps an eye on melioidosis in all parts of northern Australia. In WA cases have been creeping slowly southwards with each cyclone season. But the small number of culture-positive cases notified is matched by people who contract the infection through work or recreation in the tropical north. Maybe this species is too sensitive to cold winter nights to overwinter in the southeast.
Thanks for the question, Mike. Genetic fingerprinting is now good enough to say that different patients have different strains of bacteria. Very occasionally there have been clusters of cases due to the same strain, but the majority and one-off fingerprints. That means that we can usually only pinpoint the place where exposure occurred if we happen to have an environmental sample from the location concerned. The picture is muddied further by the way cyclones and other storms appear to blow around the bacteria, quite possibly over long distances. In WA the location of likely B. pseudomallei exposure span a huge distance with little, if an, evidence of clustering. Sorry to be such a disappointment, but as Bart said, there's a lot we don't understand about why and how this species causes infection.