Macquarie University

How superbug A. baumannii survives metal stress and resists antibiotics

Work is underway into how science can stop the superbug A. baumanniii after research exposes a weak link in the deadly but poorly understood pathogen.

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The deadly hospital pathogen Acinetobacter baumannii can live for a year on a hospital wall without food and water. Then, when it infects a vulnerable patient, it resists antibiotics as well as the body’s built-in infection-fighting response. The World Health Organization (WHO) recognises it as one of the three top pathogens in critical need of new antibiotic therapies.

Now, an international team, led by Macquarie University researchers Dr. Ram Maharjan and Associate Professor Amy Cain, have discovered how the superbug can survive harsh environments and then rebound, causing deadly infections. They have found a single protein that acts as a master regulator. When the protein is damaged, the bug loses its superpowers allowing it to be controlled, in a lab setting. The research is published in Nucleic Acids Research.

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The largest cosmic blast ever, pinpointed with Macquarie researcher help

The location of the brightest cosmic explosion ever recorded was pinpointed at 2.4 billion light years from Earth by a team of astronomers, which included a Macquarie University researcher.

The blast, known as a gamma-ray burst (GRB), was first picked up by sensors on veteran spacecraft Voyager 1 last October, only arriving at Earth 19 hours later.

It was then detected by several gamma-ray space telescopes, such as NASA’s Swift and Fermi, and the European Space Agency’s INTEGRAL.

But two papers published this week show it was spectroscopic data collected by the European Southern Observatory’s (ESO) Very Large Telescope that finally helped locate the origin of the blast in a previously unknown galaxy.

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Skin samples reveal where southern right whales feed

And how their shifting use of Antarctic waters shows effects of climate change.

Scientists have analysed chemicals in the skin of southern right whales to give new insights into the animals’ distribution, as well as long-term environmental changes in the Southern Ocean.

The research was published this week in Proceedings of the National Academy of Sciences (PNAS).

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How teamwork makes superbugs more deadly and drug-resistant

Posted for Macquarie University

Written by Mary O’Malley,

Some of the world’s most deadly and drug-resistant pathogens work collaboratively to become more powerful and infectious, a new study has found.

Dr Lucie Semenec and researchers from Macquarie University and University of Newcastle have characterised for the first time the mutually beneficial relationship between Klebsiella pneumoniae and Acinetobacter baumannii, microorganisms responsible for such conditions as pneumonia, urinary tract infections and bloodstream infections.

Due to their multiple drug resistance, these two notorious pathogens are on a World Health Organisation priority list for urgent need of new antibiotics. These pathogens are commonly present in polymicrobial infections, acute and chronic diseases caused by various combinations of viruses, bacteria, fungi and parasites. Some studies in the US and Europe have found them co-existing in about 40 percent of all hospitalised patients.

“This research is significant because diagnostic methods commonly look for the most dominant pathogen and therefore treatment is targeted at that,” says Dr Semenec.

“New drugs now can be informed in future research by the molecular mechanisms we find in this work,” says Dr Semenec.

The Nature Communications study outlines how Klebsiella feeds Acinetobacter through its metabolic by-products.  In return, Acinetobacter protects Klebsiella from high concentrations of drugs through antibiotic-degrading enzymes that it secretes.

“We have found that they have a mutually beneficial relationship to one another that enables Klebsiella to survive in antibiotic concentrations significantly higher than it can on its own,” Dr Semenec says.

Co-lead author, Associate Professor Amy Cain of Macquarie University, says the research highlights the pressing need for improved screening for mixed infections in hospital settings.

“It’s important to understand that together these bugs are more infectious, more resistant to treatment and they feed off each other,” she says.

The study investigated two strains previously co-isolated from a single lung infection and examined them using multiple screening and analysis mechanisms, from microscopy to genomics and infections in living organisms. It involved a team of researchers from Macquarie University and University of Newcastle.

“Rather like photographing a sculpture from different angles so you can see it its entirety, we really needed a combination of methods to understand this interaction,” Dr Semenec says.

Caterpillar in vivo infection studies allowed the researchers to uncover that these two pathogens are more deadly when they co-infect. These experiments were performed using the ethical Galleria mellonella (greater wax moth larvae) animal model alternative at the Macquarie Galleria Research Facility, the first of its kind in Australia.

Nature Communications


Solved: the secret to long lived leaves

How long will a leaf live? It’s an economic decision made by every tree.

Monkey puzzle tree leaves can live for over two decades. And Picea growing in the Gongga Mountains in China can thrive for thousands of years, growing slowly in severe environments with leaves that last twenty years on average. 

On the other hand, maple leaves last a season, while blueberry leaves may last just three months.

So, what determines the lifespan of a tree leaf?

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Stopping poaching by the numbers

Maths model helps rangers protect national parks, despite tight budgets.

Math could be used to prevent elephant poaching.
Image credit: Pixabay

Mathematics can help reduce poaching and illegal logging in national parks, researchers have found.

A team of applied mathematicians including Macquarie University’s David Arnold has developed an algorithm that predicts which areas inside park boundaries offer the greatest possibilities for criminals – and how rangers can most efficiently combat them.

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Hunting molecules that signal pain

Researchers close in on an objective measure for physical distress.

Pain self-assessments are naturally subjective. An independent pain measure will help treatment.
Image credit: Jim De Ramos

A new microscope-based method for detecting a particular molecule in the spinal cord could help lead to an accurate and independent universal pain scale, research from Australia’s Macquarie University suggests.

An accurate way of measuring pain is of critical importance because at present degrees of discomfort are generally assessed by asking a patient to estimate pain on a one-to-10 scale. The situation is even more acute in the treatment of babies, the very old and animals, where speech is absent.

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Device makes electric vehicle charging a two-way street

New tech means cars can power houses, as well as the other way round.

A new device turns electric vehicles into chargers for houses and stranded cars.

Researchers led by Seyedfoad Taghizadeh from Australia’s Macquarie University are looking to commercialise the technology, which may significantly increase the appeal of the vehicles.

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Citizen scientists deserve more credit, researchers argue

Academic journal rules are penalising citizen scientists and indigenous knowledge, say US and Australian scientists.

Listing indigenous citizen scientists as co-authors on a cane toad paper proved challenging.
Credit: Wikimedia Commons

Citizen scientists should be included as authors on journal papers, researchers say.

In a paper published in the journal Trends in Ecology and Evolution, a team led by biologist Dr Georgia Ward-Fear from Macquarie University in Australia and Dr Greg Pauly from the Natural History Museum of Los Angeles argues that newfound respect for indigenous knowledge and changes in technology mean that non-professionals are taking greater roles in science work.

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Underwater grandmothers reveal big population of lethal sea snakes

A novel citizen science project in New Caledonia finds an ‘astonishing’ number of venomous reptiles in a popular swimming spot.

Fantastic grandmother Monique Mazière photographing sea snake number 79, nicknamed Déborah. Credit: Claire Goiran/UNC

A group of snorkelling grandmothers is helping scientists better understand marine ecology by photographing venomous sea snakes in waters off the city of Noumea, New Caledonia.

Two years ago the seven women, all in their 60s and 70s, who call themselves “the fantastic grandmothers”, offered to help scientists Dr Claire Goiran from the University of New Caledonia and Professor Rick Shine from Australia’s Macquarie University in their quest to document the sea snake population in a popular swimming spot known as Baie des citrons.

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