This week in animal research: w/e 28 November
Vultures feed off rotten, stinking, filthy carcasses and by doing so are getting rid of a lot of bacteria from the ecosystem for us. Surprisingly, contrary to us, vultures have more bacteria on the outside than within. They have very dirtyfaces – averaging 528 kinds of bacteria – compared to only 76 types in the gut. Their gut is designed to kill off bacteria, destroying a vast majority of the microbes they consume and leaving very few behind. The few that do survive are the ones that cause a lot of problems for humans. Figuring out how vultures cope with those dangerous microbes might be able to give humans the same skill.
"They're sticking their heads into decaying carcasses, so it's not surprising that their faces have so many kinds of bacteria," explains study co-author Gary Graves, the curator of birds for the Smithsonian National Museum of Natural History said. "But when you get to the lower intestine, it's dominated by a small number of very common bacteria. There's a huge reduction from what they actually consumed. People oftentimes don't recognize the enormous ecosystem services that vultures offer to humans. It's a free, mobile sanitation department. They're discarding and consuming and getting rid of millions of pounds of decaying flesh that could threaten public health."
Studies on zebrafish show that lumps caused by TB bacteria create their own network of blood vessels which can be disrupted by human medicines aimed at disrupting the blood-vessel formation (such as anti-cancer medicines). Such medicines reduced the infection burden and limited the spread of TB in the fish larvae.
Professor Philip Crosier, of Auckland University, said:
"This discovery presents the opportunity to screen for cheap, small molecules that might do the same job as the biological agents.The formation of these granulomas that we can model in zebrafish are almost identical to what you would see in humans. As the fish are transparent, the granulomas that form on the exterior surface of the zebrafish can be easily visualised."
Over 45 million turkeys are eaten by Americans each Thanksgiving, according to the U.S. Department of Agriculture. But turkey are not only good for feeding you on that day, they might save your life one day. Indeed, a biological machine that produces a potential life-saving antibiotic is found in Turkeys. The machine in question is a bacterium capable of producing the MP1 antibiotic, known to kill staph infections, strep throat, several gastrointestinal diseases and roughly half of all infectious bacteria. So be thankful for your meal and for your life.
“Our research group is certainly thankful for turkeys,” said BYU microbiologist Joel Griffitts, whose team is exploring how the turkey-born antibiotic comes to be. “The good bacteria we’re studying has been keeping turkey farms healthy for years and it has the potential to keep humans healthy as well.”
An Ebola vaccine that uses a chimpanzee cold virus that carries non-infectious Ebola proteins on its surface has shown promising results in a clinical trial. Twenty volunteers who were immunised in the US produced antibodies in response to the virus and no major side-effects were observed. Four trials are currently underway, and health authorities are hopeful that this vaccine could be offered to health workers in West Africa by January.
Nobel Laureate Shinya Yamanaka has shown that genetic mutations that cause Duchenne muscular dystrophy can be corrected using genome editing. Muscular dystrophy is a degenerative disease caused by a defect in a gene that makes dystrophin protein. Without dystrophin muscle fibres become damaged and waste away. Even though there is no hope to correct all the defective genes in a patient’s body, injections of healthy cells could provide enough dystrophin to boost their existing muscle tissue.
Chris Mason, professor of regenerative medicine at UCL, said: “It’s a lovely approach. If these cells integrate into muscle in animals I’d expect it to work in humans because skeletal muscle is skeletal muscle.”
Nervous tissue is extremely complex, starting off as a flat sheet of cells before buckling and folding itself into a hollow tube, which eventually forms a brain and spinal cord. This makes it hard to grow on a biodegradable scaffold, as researchers have done with windpipes, bladders and other organs.
Andrea Meinhardt and her colleagues at Dresden University of Technology have used to Sasai technique to embed single-cell suspensions of embryonic mouse stem cells into a 3D nutrient gel in a Petri dish. When left these can begin to form spherical structures similar to those found in the neural plate. This presents an early development in growing patterned spinal cord tissue - a key step in the creating treatments for spinal disorders such as spina bifida.
Original Paper: Meinhardt, A., et al. (2014). 3D Reconstitution of the Patterned Neural Tube from Embryonic Stem Cells. Stem Cell Reports, DOI: 10.1016/j.stemcr.2014.09.020.