Microbiology

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. "We can…

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,…

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…

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…

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…

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. Our body produces antioxidants and some vitamins and supplements augment that, says Ed Schmidt, a professor in Montana State University's Department of…

It's been around for centuries but it seems like beer has never been more popular. Microbreweries are cranking out special stouts, IPAs, lagers and pilsners. And the flavors and aromas of each of those brews all come down to chemistry. This week, in honor of St. Patrick's Day, ACS Reactions takes on craft beer chemistry.  Sip on the video here: Read more about beer and Saint Patrick here: So many new choices means a lot can go wrong pairing beer and food. That's why we are here to save your holiday. Weekend Science: The Chemistry Of Pairing Food And Beer  Beer consumers…

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…

Salt-loving, halophilic, microbes could donate proteins to clean up radioactive strontium and caesium ions from the Fukushima Dai-ichi Nuclear Power Plant incident in Japan. The X-ray structure of a beta-lactamase enzyme from one such microbe, the halophile Chromohalobacter sp. 560, shows it has highly selective cesium binding sites.  A 1.8 to 2.9 angstrom resolution structure for this enzyme. Anomalous X-ray diffraction also revealed binding sites in the protein for Sr2+ and Cs+ ions, the team reports. It is well known that proteins from halophilic bacteria have an abundance of acidic…

There is microbiology and then there is micro-micro-microbiology. The existence of ultra-small bacteria has been debated for decades, but now there is comprehensive electron microscopy and DNA-based evidence of the elusive microbes that are about as small as life can get.  The cells have an average volume of 0.009 cubic microns (a micron is one millionth of a meter). About 150 of these bacteria could fit inside an Escherichia coli cell and more than 150,000 cells could fit onto the tip of a human hair.  The diverse bacteria were found in groundwater and are thought to be quite…