Microbiology

A new paper says protective probiotics could fight the "chytrid" fungus that has been decimating amphibian populations worldwide. Jenifer Walke, PhD, a postdoctoral researcher at Virginia Tech University, Blacksburg, and collaborators have grown bacterial species from the skin microbiome of four species of amphibians.  A total of around 6,000 species of amphibians are known, roughly one third of which are threatened or have become extinct, said Walke. The fungus was discovered in 1997, but amphibians were being decimated as early as the 1970s.  Amphibians include frogs, toads,…

The immune system protects us from the constant onslaught of viruses, bacteria and other types of pathogens we encounter throughout life. It also remembers past infections so it can fight them off more easily the next time we encounter them. But the immune system can sometimes misbehave. It can start attacking its own proteins, rather than the infection, causing autoimmunity. Or, it can effectively respond to one variant of a virus, but then is unable to stop another variant of the virus. This is termed the original antigenic sin (OAS). OAS occurs when the initial successful immune response…

The discovery of unusual foraging activity in bacteria species populating our gut may explain how conditions like Inflammatory Bowel Disease (IBD) link to changes in the populations of bacteria in our gut. IBD affects 1 in every 250 people but its causes are unknown. Studies have shown that IBD patients have a different profile of gut microbes, which is called dysbiosis. All of us have trillions of beneficial bacteria in our gut, but the combination of different species, known as the microbiome, varies. A crucial question has been whether IBD causes our microbiome to change, or whether an…

10 percent of health care providers write an antibiotic prescription for nearly all (over 95 percent) of patients who walks in with a cold, bronchitis or other acute respiratory infection (ARI), according to a new study. The figure is at one end of a spectrum showing the remarkable variation in how providers use antibiotics. At the low end, 10 percent of providers prescribe antibiotics during 40 percent or fewer patient visits. The study suggests that differences in the routines of individual providers drives variation in antibiotic prescribing, more than differences in patient…

If probiotics have success for boosting human health (that is in doubt, despite the number of papers capitalizing on the craze) it may depend partly upon the food or other material carrying the probiotics, according to a paper in Applied and Environmental Microbiology. In the paper, the researchers investigated the probiotic strain Lactobacillus casei BL23 in a mouse model (so calibrate its relevance accordingly) of colitis; inflammation of the colon. The mice that ingested the probiotic in milk had reduced symptoms compared to those that were fed milk without the probiotic, and the ones that…

A loss of dietary diversity during the past 50 years could be a contributing factor to the rise in obesity, Type 2 diabetes, gastrointestinal problems and other diseases, according to a lecture by Mark Heiman, vice president and chief scientific officer at MicroBiome Therapeutics, at IFT15: Where Science Feeds Innovation hosted by the Institute of Food Technologists (IFT) in Chicago. Heiman said diet is the principal regulator of the GI microbiome, the ecosystem of the human GI tract. The microbiome contains trillions of bacteria (microbiota) in a solution of unabsorbed macro- and micro-…

Television commercials assure us that probiotic products are good for our health, with claims ranging from improved digestion to managing allergies and colds, If so, why wouldn't plants also benefit from certain microbes? In plants, beneficial bacteria and fungi are endophytes. Scientists have known for decades that plants like legumes (peas, beans, and lentils) have beneficial bacteria in nodules attached to their roots. These bacteria "fix" vital nitrogen, turning it into a form the plant can easily use. However, researchers have recently found some nitrogen-fixing bacteria actually live…

One Shake Shack French fry may lead you to eat a whole batch, and don't even get started on the power of Doritos. According to a new study using rats, that high-fat indulgence literally changes the populations of bacteria residing inside the gut and also alters the signaling to the brain. The result? The brain no longer senses signals for fullness, which can cause overeating--a leading cause of obesity.  The findings presented this week at the Annual Meeting of the Society for the Study of Ingestive Behavior liken a high fat diet to how a sudden significant shift in temperature might…

Trees that can tolerate soil pollution are also better at defending themselves against pests and pathogens. While studying the presence of genetic information (RNA) from fungi and bacteria in the trees, the researchers found evidence of a very large amount of RNA from a very common plant pest called the two-spotted spidermite. 99% of spidermite RNA was in higher abundance in trees without contamination, suggesting that the polluted plant's defense mechanisms, used to protect itself against chemical contamination, improves its resistance to a biological invader.  "It looks like the very…

In a step that they say overturns traditional assumptions and practice, researchers at the Tata Institute of Fundamental Research, Mumbai and Institute for Plasma Research, Gandhi Nagar have fashioned bacteria to emit intense, hard x-ray radiation. When one thinks of hard x-rays and bacteria it is usually that the bacteria are at the receiving end of the x-ray source - being imaged, irradiated for some modification or simply assessed for radiation damage. One hardly thinks of using bacteria as a source of x-rays, far from turning them into the brightest among such sources. The experiment…