Microbiology

The bacteria that sneak past the brain's defenses to cause deadly bacterial meningitis are clever adversaries - they convince their host that they are harmless yet then have freedom to cause disease by taking advantage of a molecular warning signal and inducing the brain's cellular armor to temporarily break down, letting in the bacterial horde.

The blood-brain barrier is a thin network of blood vessels whose cells abut each other very closely, forming protein junctions too tight for bacteria and viruses to fit through. The barrier's purpose is to prevent unwanted material from crossing over from the surrounding bloodstream into brain tissue.


A new study shows that the microbial communities we carry in and on our bodies, the human microbiome, contain the potential to uniquely identify individuals, much like fingerprints.

Researchers and demonstrated that personal microbiomes contain enough distinguishing features to identify an individual over time from among a research study population of hundreds of people. The study, the first to rigorously show that identifying people from microbiome data is feasible, suggests that we have surprisingly unique microbial inhabitants, but could raise potential privacy concerns for subjects enrolled in human microbiome research projects.


Consumers can reduce the risk of Campylobacter food poisoning by up to 99.2% by using disinfectant wipes in the kitchen after preparing poultry, according to a new study


Researchers have adapted an antiviral enzyme from bacteria called Cas9 into an instrument for inhibiting hepatitis C virus in human cells. Cas9 is part of the CRISPR genetic defense system in bacteria, which scientists have been harnessing to edit DNA in animals, plants and even human cells. In this case, Emory researchers are using Cas9 to put a clamp on RNA, which hepatitis C virus uses for its genetic material, rather than change cells' DNA.

Although several effective drugs are now available to treat hepatitis C infection, the approach could have biotechnology applications.


Though they are catching up nicely in obesity and heart disease rates now, historically the French have been something of a paradox; they drink a lot of booze, they eat a lot of cheese and they don't exercise, but they had lower cardiovascular disease rates than other countries despite all that. 

While nutritionists claimed dairy was making American people fat - it must be bad for our hearts because epidemiological papers put a curve of saturated fats next to a curve of heart disease - the French Paradox was quietly studied with much less mainstream media attention. Like with BPA, GMOs, vaccines, nuclear power, and human embryonic stem cells, the debate over saturated fats was more cultural than evidence-based, all the more reason for science to get involved.

Methicillin-resistant Staphylococcus aureus (MRSA), an antibiotic-resistant superbug, can cause life-threatening skin, bloodstream and surgical site infections or pneumonia - a new reports finds that cigarette smoke may make things even worse.

"We already know that smoking cigarettes harms human respiratory and immune cells, and now we've shown that, on the flipside, smoke can also stress out invasive bacteria and make them more aggressive," said senior author Laura E. Crotty Alexander, MD, assistant clinical professor of medicine at UC San Diego and staff physician at the Veterans Affairs San Diego Healthcare System.


Sulfolobus islandicus microbes can go dormant, ceasing to grow and reproduce, in order to protect themselves from infection by Sulfolobus spindle-shaped virus 9 (SSV9).

The dormant microbes are able to recover if the virus goes away within 24 to 48 hours, otherwise they die.  

Sulfolobus is a species of archaea (a domain of single-celled organisms distinct from bacteria) found in acidic hot springs all over the world, where free viruses are not as common as in other environments. These microbes will go dormant in the presence of just a few viruses, whether active or inactive. While inactivated virus particles cannot infect a host, researchers found they could still cause dormancy, and ultimately, death in Sulfolobus. 


Antibiotic resistance is poised to spread globally among bacteria frequently implicated in respiratory and urinary infection, according to new research.

A recent study shows that two genes that confer resistance against a particularly strong class of antibiotics can be shared easily among a family of bacteria responsible for a significant portion of hospital-associated infections. Drug-resistant germs in the same family of bacteria recently infected several patients at two Los Angeles hospitals. The infections have been linked to medical scopes believed to have been contaminated with bacteria that can resist carbapenems, potent antibiotics that are supposed to be used only in gravely ill patients or those infected by resistant bacteria.

Scientists writing in Nature Communications have discovered an antioxidant system that, like a generator kicking in when the power fails, helps sustain the liver when other systems are missing or compromised.

This understudy 'takes the stage' when the lead actor is sick and is fueled by methionine, an amino acid that can't be manufactured in the body and doesn't come from herbal teas or supplements.

People get it only by eating protein.


In parts of the country that do not have icebergs washing up on shore or falling from the sky, it is almost spring planting season. 

For tomatoes, that mean unless you use a toxic organic or synthetic chemical, there is a chance of bacterial infection, leading to stunted growth and less nutritional value. The discovery of new regulations of defense pathways for plants could lead to helping those home-grown tomatoes fight off certain bacteria better and even have implications for pear trees, roses, soybeans and rice.


Tomatoes infected with speck disease often have wilted leaves and damaged fruit. Credit: University of Missouri