Microbiology

Signals from the immune system that help repel common parasites  like tapeworms, roundworms and other helminths can inadvertently cause a dormant viral infection to become active again, which may explain how complex interactions between infectious agents and the immune system have the potential to affect illness. The scientists identified specific signals in mice that mobilize the immune system to fight parasites that infect nearly a quarter of all humans. The same signals cause an inactive herpes virus infection in the mice to begin replicating again. The researchers speculated that the…

 By revealing the mechanisms that allow the bacteria to rapidly clog up medical devices, a group of researchershas moved a step closer to preventing infections of the common hospital pathogen, Staphylococcus aureus. The researchers have shown that the bacteria colonizes into large groups, called biofilms, using a biological glue, and form thin, slimy, thread-like structures called streamers. The streamers adhere to a surface and are able to trap passing cells as they flow through medical devices such as stents and catheters, becoming more rigid and eventually clogging up the whole…

Antibodies and their derivatives can protect plants and humans against viruses but members of this class of drugs are usually highly specific against components of a particular virus, and mutations in the virus that change these components can make them ineffective. But a mini-antibody called 3D8 scFv can chew up viral DNA and RNA regardless of specific sequences and protect mammalian cells and genetically manipulated mice against different viruses. Sukchan Lee, from Sungkyunkwan University in Korea, and colleagues had previously discovered that 3D8 has both DNase and RNase activity (that is…

Smartphones are everywhere, and they may tell something about you that you didn't realize could be told. When we touch things we give it our 'germs' and that knowledge could tell researchers something about our personal microbial world. Our phones can be biological and environmental sensors. To test our biological connection with phones, University of Oregon researchers sequenced microbes from the dominant-hand index fingers and thumbs of 17 subjects and from the touchscreens of their smartphones, during a recent Robert Wood Johnson Foundation workshop in Princeton, New Jersey…

Many pathogenic bacteria use special secretion systems to deliver toxic proteins into host cells and now researchers have determined the structure of a crucial part of one of these systems – which are possible targets for novel antibiotics.  Bacteria secrete a broad range of specific proteins that can affect the behavior or survival of cells in their environment. Among the specialized transport systems responsible for the export of such factors are so-called Type VI secretion systems. In collaboration with Axel Mogk of the Center for Molecular Biology Heidelberg (ZMBH), biochemist Petra…

People who get a blacklegged tick bite may be getting more pathogens than they expected.  A new study found that ticks are almost twice as likely as previously believed to be infected with two pathogens—the bacterium that causes Lyme disease and the protozoan that causes babesiosis.   Almost 30 percent of the ticks were infected with the agent of Lyme disease. One-third of these were also infected with at least one other pathogen. The agents of Lyme disease and babesiosis were found together in 7 percent of ticks. The researchers collected thousands of blacklegged ticks from over…

Populating the gastrointestinal (GI) tracts of mice with Bacteroides species producing a specific enzyme helped protect the good commensal bacteria from the harmful effects of antibiotics, according to a new paper in Antimicrobial Agents and Chemotherapy. Yes, in some cases antibiotic resistance is a friend. Antibiotics are powerful weapons against pathogens but most are relatively indiscriminate, killing the good bacteria along with the bad. Thus, they may render patients vulnerable to invasion by virulent, antibiotic-resistant pathogens that frequently populate hospitals. The novel aspect…

During a three week field trip, ecologists studied an entire glacier and found that microbes drastically reduce surface reflectivity and have an impact on the amount of sunlight that is reflected into space. The researchers say they work will help improve climate change models, because they have neglected the role of microbes in darkening the Earth's surface.  The study was carried out on the Mittivakkat Glacier in south east Greenland during the summer of 2012, which was the hottest summer and thus the fastest melting season recorded for 150 years. Stefanie Lutz, a PhD student at the…

You have seen lots of claims about probiotics - Activia and that stuff the sportscaster sells. You can save your money. Anything you are consuming with that kind of impact could just as easily be doing as much harm as good, but your yogurt is not making a difference, it is just a delicious placebo. The microbiome is a system so turning one knob isn't doing anything meaningful but it's among the latest miracle health fads. A study in the Journal of Agricultural and Food Chemistry even says the benefits of good bacteria outweight the negatives of much-maligned white bread. Isn't white…

Phytoplankton are tiny, photosynthetic organisms and essential to life on Earth, supplying us with roughly half the oxygen we breathe. Phytoplankton have their own requirements to carry out critical cellular activity - the element phosphorus. But in some parts of the world's ocean, P is in limited supply. How do phytoplankton survive when phosphorus is difficult to find? Phytoplankton can alter their biochemical make-up according to the availability of nutrients in the water. When phosphorus (P) is particularly abundant in the water, phytoplankton produce and store a form of P called…