Tag Archives: bacteria
For years, researchers have puzzled over conflicting results about the workings of type III CRISPR-Cas systems, a type of immune system found in many species of bacteria. Some data showed that this mechanism would target the virus’s DNA, while other experiments suggested it could only disable a virus once it had started replicating itself. New results suggest both mechanisms play a role.
Experiments in pneumococcal bacteria show how an RNA interference mechanism known as CRISPR can be used to prevent the uptake of genetic material from the environment. Harnessing this mechanism could be a new way to manipulate bacterial evolution in ways that might be medically useful. More »
Bacteria know that they are too small to make an impact individually. So they wait; they multiply, and then they engage in behaviors that are only successful when all cells participate in unison. There are hundreds of behaviors that bacteria carry out in such communities. Now researchers have discovered that bacteria form an unusual solitary wave, a behavior that has never been observed or described before in a living system. More »
Virulence factors evolved nearly a billion years ago as opportunistic agents injected by bacteria to hijack the machinery of infected cells. Researchers at The Rockefeller University have discovered the molecular makeup of one such factor used by Salmonella — a ubiquitin ligase — that appears to take over a key process that regulates a wide range of cellular duties, from cell-cycle progression to cell death and even communication between cells. More »
Before the advent of antibiotics, pneumonia claimed so many lives — and was so feared — that it was called the “captain of the ship of death.” Now, at a time when new antibiotics have proved futile, researchers are using a different tactic to keep this ship at bay: an enzyme so effective at killing Streptococcus pneumoniae that it has been put on the front lines in the battle against infectious disease. More »
Bacteria respond to dwindling food supplies through their ability to sense temperature changes in their environment. When nutrients are sufficiently abundant, bacteria are drawn to warm regions. As they continue to grow and their food supply decreases, they swim to cooler regions and slow their metabolism. A chemical signal initially mediates this switch, which is then reinforced via changes in gene expression. More »