Microbiology

An Ochre starfish, in healthier times. Amanda Bates, Author provided By Amanda Bates, University of Southampton We live in a time when our climate is warming more rapidly than ever before. Rising temperature and associated changes in weather are driving shifts in the distributions of species on Earth. Some are thriving in these new climate conditions and have even moved into new regions that were historically inhospitable. One concern for us humans is how harmful species – diseases or pests – are responding to a changing climate. An example is the malaria parasite, which is transmitted to…

Campylobacter's persistence in the kitchen is boosted by organic matter from chicken carcasses - "chicken juice" - and that means better cleaning of surfaces used for food preparation is an easy way to keep illness from happening. Campylobacter aren't particularly hardy bacteria, so one area of research has been to understand exactly how they manage to survive outside of their usual habitat, the intestinal tract of poultry. They are sensitive to oxygen, but during biofilm formation the bacteria protect themselves with a layer of slime. This also makes them more resistant to antimicrobials and…

The adult human body is made up of about 37 trillion cells. Microbes, mainly bacteria, outnumber body cells by 10 to 1. This huge community of microbes, called the microbiome, affects the health, development and evolution of all multicellular organisms, including humans, according to the latest craze in health supplement marketing and plenty of science papers latching onto the fad. Symbiotic microbes can help prevent infection by disease-causing pathogens but sometimes the interaction goes the other way, with a pathogen or disease disrupting the normal community of symbiotic bacteria. In a…

Credit: Filip Bunkens/Flickr By Meredith Knight, Genetic Literacy Project Who wants a healthy gut? Apparently a lot of people. The probiotics industry is expected to reach $45 billion annually in the next 4 years, just selling add-ons to the bacteria we already walk around with. That’s aside from the billions going into the pharmaceutical and agricultural research and development of the microbiome and its potential for new drugs. But for all the amazing properties and disease-related effects that have been attributed to our gut flora, researchers are now starting to urge caution, especially…

It's hard to have our steak and eat it too. Red meat was once implicated in a wave of studies and linked to heart disease and other maladies, before being absolved. But the microbiome and the surge in advertising for probiotics to promote 'healthy' gut bacteria has implicated red meat again - this time by correlating a nutrient that the authors say is changed by gut bacteria into an atherosclerosis-causing metabolite, which means hardening of the arteries. Writing in Cell Metabolism, Dr. Stanley Hazen, of the Cleveland Clinic and colleagues implicated a bacteria in the gut that converts L-…

The microbes living in people's guts are much less diverse than those in humans' closest relatives, the African apes. What does that mean? No one knows, but the microbiome is all the latest rage in marketing, with probiotics advertised on television and a segment of the research community rushing to create studies to capitalize on that. The researchers analyzed the genetic makeup of bacteria in fecal samples from humans, chimpanzees, bonobos and gorillas to draw their conclusions. Based on their analysis of humans and the three lineages of ape, the researchers determined that within the…

A recent study has found that some Methicillin-resistant Staphylococcus aureus (MRSA) bugs in United Kingdom hospitals can be traced back to a type of bacteria found in farm animals. A strain of drug-resistant bacteria carried by some livestock –Staphylococcus aureus CC398 – has also been found in patients.  People and animals generally harbor distinct variants of CC398, which the team say evolved from the same original bacteria. However, the CC398 strain found in livestock can be transmitted to humans, and the study shows that this has happened on many occasions. It provides new…

There may soon be a new way to use stem cells in the fight against brain cancer. A team has created a way to genetically engineer stem cells so that they can produce and secrete tumor-killing toxins that eradicate cancer cells remaining in mouse brains after their main tumor has been removed. The stem cells are placed at the site encapsulated in a biodegradable gel. This method solves the delivery issue that probably led to the failure of recent clinical trials aimed at delivering purified cancer-killing toxins into patients' brains.  Cytotoxins are deadly to all cells, but since the…

Can probiotic yogurt help with lupus? While most of science disagrees, corporate marketing departments have embraced every chance to imply their product helps with digestion and whatever else can sell product. A new paper in  Applied and Environmental Microbiology adds to that, finding that Lactobacillus species, commonly seen in yogurt cultures, correlate in the guts of mouse models, with mitigation of lupus symptoms, while Lachnospiraceae, a type of Clostridia, correlate with worsening. In the study, the investigators first showed that mouse models of lupus had higher levels of…

Given a critical change in the environment, how exactly do species adapt?  To find the answer you need controlled experiments and a variable. A team recently did just that to to get at the heart of this evolutionary question, by measuring the growth rates and DNA mutations of 8 different species of Pseudomonas bacteria. They controlled a single but vital variable during growth, the dose of the antibacterial drug rifampicin, and challenged 480 populations from 8 different strains of Pseudomonas (3840 total) with adapting to the minimal concentration of rifampicin that is needed to…