bacteria

Rachel Mann

A new test will help protect Australia’s apple and pear  industry from a devastating bacterial disease affecting other countries, says a Victorian scientist.

Rachel Mann, of La Trobe University, has identified unique signatures in the DNA of fire blight-causing bacteria that can be targeted with a test, ensuring the accurate detection of the biosecurity hazard and the protection of the fruit industry’s economic viability.

“Maintaining Australia’s status as ‘fire blight free’ is not only important for protecting our industry from the disease, but also for retaining market access for Australian fruit into other countries,” says Rachel, who conducted the work at the Centre for AgriBioscience in a joint venture between La Trobe University and the Department of Environment and Primary Industries.

Fire blight is found in New Zealand, North America and Europe, but is not present in Australia.

“Fire blight causes the leaves, shoots and limbs of apple and pear trees to permanently shrivel and blacken. It can eventually kill whole trees and destroy orchards,” Rachel says.

By comparing the genomes of numerous fire blight-causing bacteria, Rachel identified unique signatures only found in the DNA of the fire blight bacteria, which could then be targeted for accurate diagnostic testing. Her work is set to have an international impact.

“Working with collaborators in the United States and Switzerland, we want our new tests to be accepted as the international standard for fire blight,” Rachel says.

“Additionally, as part of a new Plant Biosecurity CRC project, the methods used to develop improved tests for fire blight are now being used to improve tests for other microbes important to Australia’s biosecurity,” she says.

Victoria State Finalist: Rachel Mann, Department of Primary Industries Victoria /La Trobe University

 

 

Lucie Rankin

The discovery of a gene’s essential role in generating rare intestinal immune cells may hold hope for those with celiac disease or irritable bowel syndrome, say Melbourne scientists.

Lucille Rankin and a team at the Walter and Eliza Hall Institute discovered that the gene, T-bet, is important for the production of innate lymphoid cells, (ILCs) and is stimulated by the proteins from leafy greens, raising questions about the effect of food on our genes and immune system.

“Discovery of the T-bet molecule that make these immune cells paves the way for understanding how we might manipulate these cells and repair the communication breakdown that occurs in diseases such as IBS,” says Lucille, who did the research as part of her PhD.

ILCs help to promote good bacteria and the healing of small abrasions on the intestinal wall. Leafy green vegetables previously have been shown to have an important role in the production of ILCs. Lucille and her team discovered that the T-best molecule may be a possible pathway for this action.

The intestine makes up 70 per cent of our immune system and it is home to trillions of good bacteria that keep us healthy.  Immune cells in the intestine must be clever enough to tell the difference between good, health-promoting bacteria, harmless food particles and nasty disease-causing bacteria, which it must destroy.

When the communication system in the intestine breaks down, immune cells get confused and can begin to attack good bacteria and the intestinal lining, which results in irritable bowel syndrome (IBS) and colitis.  However, we still don’t know exactly how this happens and what causes such debilitating ailments.

Victoria State Finalist: Lucie Rankin, Walter and Eliza Hall Institute

Madleen Busse

At a time when antibiotic resistance is high, a promising new class of antibiotics has been developed to fight the bacteria that causes gastrointestinal ulcers and cancers.

Madleen Busse and a team of Monash University researchers have designed novel bismuth compounds that are more powerful than the drugs used to treat Helicobacter pylori (H. pylori), raising the possibility of faster and safer treatment for patients.

“We are one step closer to having a novel powerful antibiotic against H. pylori,” says Madleen Busse, who conducted the research as part of her PhD at Monash University.

“These compounds are 250 times more effective against H. pylori compared to the commercially available bismuth drugs,” she says.

Madleen, together with one of her supervisor’s collaborators, Professor Richard Ferrero of the Monash Institute of Medical Research, found that bismuth sulfonate compounds killed H pylori in vitro.  Her Monash University supervisor, Professor Phil Andrews, and his research team are now looking to conduct phase pre-clinical trials.

“All the research teams are very excited to see the research proceeding onto the next level to test the most promising antibiotics developed in the laboratory,” Madleen says.

H pylori has become increasingly resistant to antibiotics over the past 15 years, with patients having to undertake multiple therapies and higher doses of medication.  These triple and quadruple therapies often involve colloidal bismuth subcitrate.

Victoria State Finalist: Madleen Busse, Monash University

Krishna Venkidusamy

Bacteria prove fuel for thought as an Adelaide researcher reveals their ability to clean up petroleum waste and produce electricity.

Krishna Venkidusamy, of The University of South Australia, has developed microbial fuel cells that use bacteria to break down diesel and produce power, opening up the possibility of a green solution to Australia’s petroleum pollution problem.

“The technology employs the world’s tiniest inhabitants, bacteria, which can eat the petroleum waste and produce electrons. During this process, we can generate an electrical current,” says Krishna, who is doing the research as part of her PhD.

“The process is suitable for almost any type of organic waste material, from contaminated soil to the by-products of many industries,” she says.

A pilot study is set to demonstrate the economical removal of these pollutants from the environment while generating electricity. “More research will find the best candidate microbes, reduce costs for materials, and increase the technology for commercial scales,” Krishna says.

The approach also has potential in areas with limited access to electricity or where polluted sites are difficult to treat.

“The use of these microbial systems to clean up polluted sites has been known for decades, but only recent technological advances have made it possible to harness the electricity during the clean-up process,” Krishna says. “On a commercial scale, this technology will help produce a cleaner and safer environment and provide green energy at the same time.”

Nationwide there are over 100,000 sites contaminated with petroleum products such as petrol and diesel. Petroleum hydrocarbons, their primary constituents, pose risks to human health when inhaled, ingested or exposed to skin.

SA State Finalist: Krishna Venkidusamy, CRC for Contamination Assessment and Remediation of the Environment

 

New genus of bugs discovered at WA alumina refinery

Previously unknown species of naturally-occurring bacteria have the potential to save the alumina and aluminium industries millions of dollars while helping to reduce their impact on the environment, microbiologist Naomi McSweeney has found in a collaborative project between Alcoa of Australia, CSIRO and the University of Western Australia. [click to continue…]

A biotechnologist from the South Australian Research and Development Institute has taken using “everything but the pig’s squeal” to new lengths. Through clever recycling of pig waste, Andrew Ward has been able to produce feed for aquaculture, water for irrigation, and methane for energy. His ‘waste food chain’ can be applied to breweries, wineries and any system producing organic waste. [click to continue…]

p8070118‘Fool’s gold’ has tricked many amateur gold miners, but Queensland researchers have discovered it can reveal much about the early evolution of life on Earth.

Three billion years ago the Earth couldn’t support life as we know it – the atmosphere was deadly to oxygen-breathing plants and animals.
But two and half billion years ago life changed the Earth’s atmosphere creating the oxygen-rich air we rely on today. [click to continue…]

Little ripples, big swirl

16 August 2007

in 2007

How mini-earthquakes and tornados could one day be saving lives

Monash University engineer Leslie Yeo is using tiny earthquakes and tornados to assist the detection of biohazards and germ warfare. He and collaborator James Friend at the Micro/Nanophysics Research Laboratory hope to integrate their technology into an inexpensive, credit-card-sized sensor within five to ten years.

[click to continue…]

Warfare between bacteria could provide an environmentally friendly solution to biofouling, according to Dhana Rao and her colleagues at the University of NSW.

[click to continue…]

Billion year old bacteria in NT rocks and bugs from outer space

Researchers from the CSIRO, Sydney University and Colorado State University have developed a means of detecting signs of ancient microbes which may have lived on Earth or come from outer space.

The group already has picked up signs of bacteria more than a billion years old inside rocks from the Northern Territory.

The technique centres around analysing tiny oil droplets-sealed inside rocks as they formed-for traces of chemical compounds known only to be produced by particular types of organisms. The results provide unequivocal evidence of their presence.

“Oil forms from decayed organisms, and therefore contains fatty tracers or biomarkers for the organism from which they came-like the footprint of a dinosaur, but at a molecular level,” says Herbert Volk from CSIRO Petroleum, a member of the research team.

“It’s important that we understand these early organisms, as they were the building blocks for the evolution of the more complex life forms which play an important part in today’s ecosystems.”

The team has managed to extract such biomarkers from oil droplets sealed in Precambrian rocks from the Northern Territory for more than a billion years.

The chemical analysis of the oil indicates that it is derived from single-celled cyanobacteria, the aquatic and photosynthetic bacteria responsible for increasing oxygen levels in the atmosphere. There is also evidence of the presence of more complex strains of life.

“Microscopic evidence of fossilised microbes is very rare in rocks of this age, and if present are often fiercely debated,” Volk says. “Biomarkers have been extracted from rocks of similar age before, but these were not from oil droplets sealed in crystals, so they may have been contaminated by more recent life forms. The new results are free of such doubt.

“And should oil inclusions be found in extraterrestrial rocks such as meteorites or Martian rocks, the molecular signature would be perfectly protected from traces of terrestrial life that could otherwise compromise the information.”

Herbert is one of 13 Fresh Scientists presenting their research to the public for the first time thanks to Fresh Science, a national program hosted by the State Library of Victoria. One of the Fresh Scientists will win a trip to the UK courtesy of the British Council to present his or her work to the Royal Institution.

To view larger image, click on image:  
Remote arid landscape near the drill site in the Roper Superbasin in the Northern Territory, near the Gulf of Carpentaria.
Photo: Dr David Rawlings
The Roper Superbasin is one of the oldest basins known to contain petroleum which is where the researchers look for life.
 This is a thin slice of rock viewed through a microscope with UV light. The oil inclusions are seen fluorescing in bright blue. What the researchers look for are biomarkers of life. Some of the chemical structures they look for are hopanes, derived mainly from hopanols which are fatty alcohols in the cell walls of bacteria.
This is the chemical structure of a hopane molecule.
Herbert Volk (right) and colleague Simon George (left), analysing the oil droplets using a mass spectrometer.

Yoghurt won’t stop thrush

31 August 2004

in 2004

Probiotics not always the right approach

Millions of women around the world have probably used yoghurt as a folk remedy to prevent thrush while taking antibiotics. A Melbourne GP and PhD student has proven that Lactobacillus acidophilus, a key bacterium in yoghurt, was not effective in the prevention of thrush (‘vulvovaginitis’) after antibiotics.

Her findings were published today in the eminent British Medical Journal (BMJ). “It’s a reminder that all medicines, even natural ones need to be tested,” says Dr Marie Pirotta.

235 Melbourne women took probiotic (containing lactobacillus bacteria) or placebo
preparations orally or vaginally until four days after completion of their antibiotic course. They recorded any symptoms and provided vaginal swabs for analysis. The results were so clear cut that the trial was cut short on ethical grounds.

Dr Pirotta was surprised by her results, given that the folk remedy was so popular with women, including her own patients. “But at least now women can be better informed and can choose to use effective treatments instead,” she said. “Currently, there are no recommended medicines to prevent thrush, so women should discuss their options with their health care providers.”

Around 50% of women will suffer a bout of thrush after antibiotics at least once in their lifetime. Although thrush usually does not kill people, it does have a big impact on women’s physical and emotional wellbeing, as well as on their relationships. In 1995 the costs associated with diagnosing and treating thrush in the United States were $US1.8 billion (1).

The clinical trial was instigated after Dr Pirotta’s earlier research that found that around 40% of women had used yoghurt or Lactobacillus to try to prevent or treat thrush after antibiotics. These women also reported that they were concerned about getting thrush after antibiotics, and for a small number, the concern was so great that they would choose not to take the antibiotics (2).

She also found that more than two thirds of GPs and pharmacists that she surveyed thought that oral yoghurt or Lactobacillus could be effective to prevent thrush after antibiotics and they had recommended this therapy to women when prescribing or dispensing antibiotics.

Dr Pirotta said that “complementary therapies probably have a lot to offer in health care. It was disappointing to find that this type of Lactobacillus was not effective in this case. But this is a reminder that all medicines, even ‘natural’ ones, need to be tested, and wherever possible, treatments should be based on evidence.”

“This simple and relatively inexpensive study will change how GPs advise women about thrush prevention,” says Professor Michael Kidd, President of the Royal Australian College of General Practitioners.  “It demonstrates that research in general practice can help GPs deliver the best, most cost effective and evidence based care. We need to invest more in this kind of targeted medical research.”

Dr Pirotta was one of 15 early career scientists selected to take part in the 2004 Fresh Science Awards held recently in Melbourne. The one who most meets the program requirements will win a study tour of the UK courtesy of the British Council Australia.

Four thousand families around Sydney may be placing their young children at risk by spraying partially treated sewage from their onsite aerated sewage systems on lawns where children play.

The sewage may contain disease causing microorganisms such as viruses and Cryptosporidium which can cause gastroenteritis in children who play in areas sprayed with sewage.

Katrina Charles, a PhD student in the School of Civil and Environmental Engineering at the University of New South Wales and the Cooperative Research Centre for Water Quality and Treatment, says the domestic wastewater is safe to use provided the householder is aware of the risks and takes sensible precautions.

“Don’t spray the wastewater on lawn areas where kids play and don’t spray it on vegetable gardens” Ms Charles said.

“The best way to reuse this wastewater is through an underground irrigation system where the microorganisms become trapped and die in the soil but the water and nutrients are still available for the garden.”

Ms Charles has recently completed a study into the effectiveness of sewage treatment systems used in unsewered areas around Sydney.

She found that the disinfection used in these aerated treatment systems are not as effective as disinfection in larger sewage treatment plants and only remove a small number of disease causing microorganisms.

“Our results indicate that a safer way to reuse the wastewater is through an underground irrigation system.”

“These treatment and irrigation systems start from about $11,000 for an average block. But the value of water as a resource has never been plainer than in this drought. And underground irrigation systems not only dispose of sewage safely but provide water and nutrients for gardens.”

When there is an infected person in the house, sewage may contain a high number of disease causing microorganisms, including viruses, Cryptosporidium or bacteria. For example rotavirus which can be transmitted by sewage is the most common cause of severe gastroenteritis in young children worldwide.

Katrina was one of 15 early-career scientists who are presenting their work to the public and media as part of Fresh Science 2004. Fresh Science is a national competition aimed at getting the work of young scientists into public attention.

Irrigation on a football field Large sewage sprinkler near a dam
Environmental damage from over watering with sewage      
Sewage being used to water lawn  Watering the mail with sewage  Sprinklers near the vegie patch 
Katrina in the lab   Laying irrigation pipe 

 

Sampling for nutrients    
  Experimental site Goulburn boreholes

Plants can listen in on bacterial communication and can even mimic this communication, possibly in an attempt to stop any attacks, according to a breakthrough in scientific understanding announced today in Melbourne. [click to continue…]

Melbourne scientists plan to harness the strange appetite of newly discovered Australian bacteria to help purify arsenic-contaminated water. [click to continue…]

Are we viruses?

26 August 2001

in 2001

A radical new theory that could dramatically alter the way scientists view the evolution of life has been recently accepted for publication in the leading “Journal of Molecular Evolution”.  Supported by an increasing body of evidence, the theory proposes that the nucleus of our cells evolved from a virus that infected ancient bacteria-like organisms. [click to continue…]

A naturally occurring bacteria has been shown to control diseases that attack cereal crops such as wheat, and at the same time boost the growth of crops.

The research conducted by Flinders University PhD student, Justin Coombs, found the bacteria in a place it had never been discovered before – the tissues of cereal crop plants. [click to continue…]