Nanopores may one day lead a revolution in DNA sequencing. By sliding DNA molecules one at a time through tiny holes in a thin membrane, it may be possible to decode long stretches of DNA at lightning speeds. Scientists, however, haven’t quite figured out the physics of how polymer strands like DNA interact with nanopores.
An international team of scientists, led by researchers at the Univ. of California, San Diego School of Medicine, have identified the genes encoding a molecule that famously defines Group A Streptococcus (strep), a pathogenic bacterial species responsible for more than 700 million infections worldwide each year.
Much as human DNA can be used as evidence in criminal trials, genetic information about microorganisms can be analyzed to identify pathogens or other biological agents in the event of a suspicious disease outbreak. The tools and methods used to investigate such outbreaks belong to the new field of microbial forensics, but the field faces substantial scientific and technical challenges, says a new report from the National Research Council.
Staph infections that become resistant to multiple antibiotics don't happen because the bacteria themselves adapt to the drugs, but because of a kind of genetic parasite they carry called a plasmid that helps its host survive the antibiotics. Plasmids are rings of bare DNA containing a handful of genes that are essentially freeloaders, borrowing most of what they need to live from their bacterial host.
Hospital germs can be fatal, since they are resistant to antibiotics. As a result, alternative methods of defense against bacteria are in demand. Fortunately, a German-French research team has been able to develop bone implants that keep the germs at bay. The solutions depends on a breakthrough that allows scientists to imbue apatite crystals with calcium phosphate.
Bacteria use threadlike appendages, called pili, to creep along a surface, and some disease-causing microbes extend pili in all directions to move. But until now researchers have been unable to explain why bacteria like these are able to travel in a straight line consistently. A new model developed to describe this movement shows that bacteria do not act as randomly as they appear to when moving.
Every once in a while in the U.S., bacterial meningitis seems to crop up out of nowhere, claiming a young life. Part of the disease’s danger is the ability of the bacteria to evade the body’s immune system, but scientists are now figuring out how the pathogen hides in plain sight. Their findings, which could help defeat these bacteria and others like it, appear in the Journal of the American Chemical Society.
For a century biologists have thought they understood how the gooey growth that occurs inside cells causes their protective outer walls to expand. Now, Stanford Univ. researchers have captured the visual evidence to prove the prevailing wisdom wrong. The finding may lead to new strategies for fighting bacterial diseases.
Chemists in the College of Arts and Sciences at Syracuse Univ. have figured out how to control multiple bacterial behaviors—potentially good news for the treatment of infectious diseases and other bacteria-associated issues, without causing drug resistance.
The smallest, most abundant marine microbe, Prochlorococcus, is a photosynthetic bacteria species essential to the marine ecosystem. An estimated billion upon billion of the single-cell creatures live in the oceans, forming the base of the marine food chain and occupying a range of ecological niches based on temperature, light and chemical preferences, and interactions with other species.
A credit-card-sized anthrax detection cartridge developed at Sandia National Laboratories and recently licensed to a small business makes testing safer, easier, faster and cheaper. Bacillus anthracis, the bacteria that causes anthrax, is commonly found in soils all over the world and can cause serious, and often fatal, illness in both humans and animals.
In the fight against “superbugs,” scientists have discovered a class of agents that can make some of the most notorious strains vulnerable to the same antibiotics that they once handily shrugged off. Recently discovered metallopolymers, when paired with the same antibiotics MRSA normally dispatches with ease, helped evade the bacteria’s defensive enzymes and destroyed its protective walls, causing the bacteria to burst.
Bacteriophages are viruses that target and kill bacteria. Recent research at Purdue Univ. shows that treating food products with select bacteriophages could significantly reduce concentrations of E. coli. The study demonstrated that an injection of bacteriophages nearly eradicated a toxin-producing strain of E. coli in contaminated spinach and ground beef, in some cases decreasing E. coli concentrations by about 99%.
Researchers have engineered a bacterium to synthesize pinene, a hydrocarbon produced by trees that could potentially replace high-energy fuels, such as JP-10, in missiles and other aerospace applications. With improvements in process efficiency, the biofuel could supplement limited supplies of petroleum-based JP-10, and might also facilitate development of a new generation of more powerful engines.
Joint BioEnergy Institute scientists have identified the genetic origins of a microbial resistance to ionic liquids and successfully introduced this resistance into a strain of E. coli bacteria for the production of advanced biofuels. The ionic liquid resistance is based on a pair of genes discovered in a bacterium native to a tropical rainforest in Puerto Rico.
Researchers in the U.K. have developed a new antibacterial material which has potential for cutting hospital acquired infections. The combination of two simple dyes with nanoscopic particles of gold is deadly to bacteria when activated by light, even under modest indoor lighting. And in a first for this type of substance, it also shows impressive antibacterial properties in total darkness.
Using genome sequencing, National Institutes of Health scientists and their colleagues have tracked the evolution of the antibiotic-resistant bacterium Klebsiella pneumoniae sequence type 258 (ST258), an important agent of hospital-acquired infections. Their results promise to help guide the development of new strategies to diagnose, prevent and treat this emerging public health threat.
It's a jungle in there. In the tightly woven ecosystem of the human gut, trillions of bacteria compete with each other on a daily basis while they sense and react to signals from the immune system, ingested food and other bacteria. Problems arise when bad gut bugs overtake friendly ones, or when the immune system is thrown off balance.
In biology, scientists typically conduct experiments first, and then develop mathematical or computer models afterward to show how the collected data fit with theory. In his work, Rob Phillips flips that practice on its head. The Caltech biophysicist tackles questions in cellular biology as a physicist would—by first formulating a model that can make predictions and then testing those predictions.
Capitalizing on the ability of an organism to evolve in response to punishment from a hostile environment, scientists have coaxed the model bacterium Escherichia coli to dramatically resist ionizing radiation and, in the process, reveal the genetic mechanisms that make the feat possible. The study provides evidence that just a handful of genetic mutations give E. coli the capacity to withstand doses of radiation.
The human relationship with microbial life is complicated. At almost any supermarket, you can pick up both antibacterial soap and probiotic yogurt during the same shopping trip. Although there are types of bacteria that can make us sick, a California Institute of Technology team is most interested in the thousands of other bacteria, many already living inside our bodies, that actually keep us healthy.
Fresh banana, a waft of flowers, blueberry: the scents in Shota Atsumi's laboratory in the Univ. of California, Davis Dept. of Chemistry are a little sweeter than most. That's because Atsumi and his team are engineering bacteria to make esters, molecules widely used as scents and flavorings, and also as basic feedstock for chemical processes from paints to fuels.
In a significant advance for the growing field of synthetic biology, Rice Univ. bioengineers have created a toolkit of genes and hardware that uses colored lights and engineered bacteria to bring both mathematical predictability and cut-and-paste simplicity to the world of genetic circuit design.
A team of Univ. of Notre Dame researchers have discovered a new class of antibiotics to fight bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and other drug-resistant bacteria. Called oxadiazoles, the new class was discovered through in silico (by computer) screening and has shown promise in the treatment of MRSA in mouse models of infection.
Paleontologists studying fossilized feathers have proposed that the shapes of certain microscopic structures inside the feathers can tell us the color of ancient birds. But new research from North Carolina State Univ. demonstrates that it is not yet possible to tell if these structures, thought to be melanosomes, are what they seem, or if they are merely the remnants of ancient bacteria.