News

New research by scientists at the University of Toronto, Canada, shows that mice infected with Tritrichomonas muris protozoa are more likely to develop colitis – an inflammation of the colon. While investigating the causes of colitis in rodents, the research team noticed that their mice subjects were more susceptible to the disease if they had already been infected by the parasite. Further study showed that the presence of T. muris increased the amount of immune cells and the chemicals they produce in the animal’s gut, leaving the intestine lining more likely to be inflamed – giving colitis an increase chance of developing. This finding could help scientists to better understand similar interactions between hosts, like humans, and their parasites.

Studies have previously shown that people working in pig production facilities carried livestock-associated multidrug-resistant Staphylococcus aureus (MRSA) in their nasal passages. Now, new research by scientists at Johns Hopkins University, USA, suggests that the workers may also be developing skin infections caused by these bacteria. The investigation showed that individuals carrying livestock-associated MRSA were nearly nine times more likely to have recently reported a skin infection. As the ready use of antibiotics in livestock may be contributing to the rise of drug-resistant bacteria, this may be another case to support better control of antibiotic use.

Francisella tularensis is a bacterium that causes tularemia – a sometimes lethal disease that can affect a range of animals, including humans and rabbits. Until now, it was a mystery as to how the bacteria could cause such severe symptoms, but scientists at the University of Washington, USA, have made a step forward. The research team discovered a set of proteins that help spread toxins within the infected individual, by allowing F. tularensis to grow inside macrophages – the white blood cells that are supposed to destroy pathogens. Although the researchers have revealed the secret to some of F. tularensis’ toxins, they conclude that further investigation is needed to understand how these proteins act on the cells they infect.

Herpesviruses have long been thought to be species-specific in their infectivity, but a new study led by researchers at the Leibniz Institute for Zoo and Wildlife Research, Germany, has found that gammaherpesviruses appear to be able to swap hosts relatively easily. While studying this group of herpesvirus, the scientists noticed that some species of vampire bats carried viruses previously found in cattle – their main food source. Through comparing huge datasets of gammaherpesvirus sequences, the international team’s findings suggested that herpesviruses have often jumped between species, and mostly through bats and primates. As herpesvirus infections are usually life-long ones, it is important to understand how they switch hosts, and how easily.

Salmon poisoning in dogs has been a long-standing problem that has caused fatalities to animals across the Pacific Northwest region of America. The threat comes from a bacterium called Neorickettsia helminthoeca, carried by a fluke worm, which is in turn carried by common freshwater snails that salmon like to eat. It was previously thought to be low risk since the development of antibiotics to treat N. helminthoeca infection, as it appeared that dogs were unable to be infected a second time, but a new discovery by researchers at Oregon State University, USA, has changed everything. Another similar bacterium, named ‘SF agent’, has been found in salmonid fish for the first time ever, and dogs infected with this new microbe present similar symptoms. Antibiotics can be used to treat it, but fighting this infection may not offer immunity to actual salmon poisoning – which could lead to problems when an owner assumes their pet is immune.

Researchers at Kobe University, Japan, have found that a new species of orchid called Lecanorchis tabugawaensis did not produce its own nutrients after absorbing energy from the sun, but instead relies on its symbiotic relationship with fungi. This means L. tabugawaensis is mycoheterotrophic – it uses the fungi it is in symbiosis with rather than photosynthesis for energy. Other mycoheterotrophic plants exist, and scientists are fascinated by all of them, least of all because of their rarity – generally, these ‘cheating’ plants are small in size and only found in the dark undergrowth of forests.

In a recent study, a team of researchers from the University of Wisconsin-Madison and Great Lakes Bioenergy Research Center, both USA, have discovered a way of boosting the productivity of an industrial yeast. Saccharomyces cerevisiae – traditionally used in baking and alcohol fermentation – produces energy by breaking down a type of sugar in plants called glucose. However, the yeast is not interested in xylose, a much more abundant type of plant sugar. By giving S. cerevisiae strains the option of xylose or starvation, the research team managed to isolate a ‘super strain’ capable of breaking down the more common sugar. This result could potentially mean better and increased biofuel production.

As with all other marsupials, Tasmanian devil babies are born at a very early stage of development, before their immune systems have fully developed. But how are they protected from pathogens in their new environment? New research from scientists at the University of Sydney, Australia, suggests that it’s all down to mum. The study shows that Tasmanian devil mothers produce antimicrobial compounds in their pouch lining, skin and milk, which combat the potentially disease-causing microbes present inside the pouch microbiome. Further investigation showed that some of these compounds were effective against problematic human pathogens, such as meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis.

Have you ever wondered about what happens to Escherichia coli’s resistance to antibiotics in space? A partnership between NASA’s Ames Research Center and Stanford University, both USA, has led to the creation of the E. coli AntiMicrobial Satellite (EcAMSat). This project will be investigating the effects of space microgravity – the weightlessness of being in space – on the bacterium’s resistance levels, important because astronauts’ immune systems are often weakened when on missions. The study will see various strains of E. coli sent into space, with their resistance to different concentrations of antibiotics tracked using a special kind of dye. The results  from this project could be useful in the future for prescribing the right dose of antibiotics for future astronauts.

Deep sea-dwelling archaea are being attacked by viruses far more than previously thought, suggests a new study by scientists across Italy, Japan, Australia and the US. Viruses are the main cause of death for bacteria and archaea in the ocean, but it was not known the extent of which viruses were killing off deep water archaea. The researchers found that archaea were infected by viruses up to twice as often as bacteria were infected, and the archaea die-off was resulting in massive amounts of carbon being released into the atmosphere – up to 0.5 gigatonnes per year. The study suggests that archaea and their viruses may play a much bigger role in both deep-sea ecosystems and the Earth’s biogeochemical cycles than we previously thought.