ScienceDaily February 10, 2013. National Institutes of Health (NIH) scientists have identified a promising lead for developing a new type of drug to treat infection caused by Staphylococcus aureus, notable drug-resistant pathogen. They have discovered a transport system for toxins that are thought to contribute to severe staph infections - phenol-soluble modulins (PSMs). The transport system, Pmt, is common to all S. aureus PSMs and critical for bacterial proliferation and disease development in a mouse model. Their experiments suggest that a drug interfering with Pmt’s function could not only prevent production of the PSM toxins, but also directly lead to bacterial death. This research is reported in Nature Medicine.
A team led by Lora V. Hooper, an associate professor of immunology and microbiology at The University of Texas Southwestern Medical Center, and including UT Arlington assistant professor of biology Jorge Rodrigues examined the bacteriophages, or phages, produced by genetic information harbored in the chromosome of the mammalian gut bacterium Enterococcus faecalis. They found that a phage unique to Enterococcus faecalis strain V583 in mice acts as a predator, infecting and harming other similar, competing bacterial strains. They believe these lab results suggest what goes on in the human intestine.
“This organism is using phage as a way to compete in your gut. If the phage is released and gets rid of all the other microbes, then strain V583 will have more nutrients available,” Rodrigues said. “It opens up new questions about the role of phages in the gut system. Ultimately, you could use this as a technique to control bacteria in a natural way.”
The findings were presented in October in the Proceedings of the National Academy of Sciences in a paper called, “A composite bacteriophage alters colonization by an intestinal commensal bacterium.” Other co-authors were members of Hooper’s lab: Breck A. Duerkop, Charmaine V. Clements and Darcy Rollins.
A research team at the Walter and Eliza Hall Institute has identified one of the crucial molecules that instructs the parasite how to employ its invisibility cloak to hide from the immune system, and helps its offspring to remember how to ‘make’ the cloak.
Research published in the journal Cell Host & Microbe details the first molecule found to control the genetic expression of PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1), a protein that is known to be a major cause of disease during malaria infection.
PfEMP1 plays two important roles in malaria infection. It enables the parasite to stick to cells on the internal lining of blood vessels, which prevents the infected cells from being eliminated from the body. It is also responsible for helping the parasite to escape destruction by the immune system, by varying the genetic code of the PfEMP1 protein so that at least some of the parasites will evade detection. This variation lends the parasite the ‘cloak of invisibility’ which makes it difficult for the immune system to detect parasite-infected cells, and is part of the reason a vaccine has remained elusive.
Battelle Memorial Institute (Columbus, Ohio) announced that it has made an investment of an undisclosed amount in CosmosID for the development of a metagenomics software-based solution for microbial identification.
The investment from Battelle is part of $4 million in financing that CosmosID recently received to support its efforts “to deliver pathogen identification in a single, rapid, and accurate service,” Battelle said, adding that it is partnering with the College Park, Md.-based company to develop and market microbial metagenomics toolkits for public safety and medical treatment applications.
CosmosID’s technology called MetaSeq Genomics uses unassembled reads from next-generation sequencing, probabilistic algorithms, and reference databases to identify pathogens, and antibiotic resistance and virulence factors. The software, which is scalable and updated iteratively, is targeted for diagnostic test development in the markets of public safety and security, medical treatment, environmental monitoring, and drug development, Battelle said.
Privately held CosmosID was founded in 2007 by Rita Colwell, former director of the US National Science Foundation and currently distinguished professor at Johns Hopkins University Bloomberg School of Public Health and the University of Maryland.
Though viruses are the most abundant life form on Earth, our knowledge of the viral universe is limited to a tiny fraction of the viruses that likely exist. An international team of researchers from the University of Pittsburgh, Washington University in St. Louis, and the University of Barcelona have found that raw sewage is home to thousands of novel, undiscovered viruses, some of which could relate to human health. Read more about developing new techniques to look for novel viruses in unique places around the world.
A team of scientists from The Scripps Research Institute has successfully reengineered an important antibiotic to kill the deadliest antibiotic-resistant bacteria. The compound could one day be used clinically to treat patients with life-threatening and highly resistant bacterial infections.
The synthesized compound, which was described in the Journal of the American Chemical Society, is an analogue of the well-known commercial antibiotic vancomycin. The new analogue was prepared in an elegant total synthesis, a momentous achievement from a synthetic chemistry point of view.
Infection with some strains of strep turn deadly when a protein found on their surface triggers a widespread inflammatory reaction. Researchers describe the precise architecture of a superstructure formed when the bacterial protein called M1 links with a host protein, fibrinogen, that is normally involved in clotting blood. The proteins form scaffolds with M1 joints and fibrinogen struts that assemble into dense superstructures. Frontline immune cells called neutrophils mistake these thick networks for blood clots and overreact, releasing a chemical signal that can dilate vessels to the point where they leak. Read about this research in NATURE.
The Earth Microbiome Project (EMP) is a proposed massively multidisciplinary effort to analyze microbial communities across the globe from many environments. The first EMP Conference is scheduled for June 2011 in Shenzhen, China. The goal is to understand microbes (Bacterial, Archaeal, Eukaryal and Viral) in terms of whom they are and what they do; it is the grand challenge of microbial ecology. Read more at the Earth Microbiome Project website.
A new study into Staphylococcus aureus, the bacterium which is responsible for severe chronic infections worldwide, reveals how the bacteria have developed a strategy of hiding within host cells to escape the immune system as well as many antibacterial treatments. The research, published by EMBO Molecular Medicine, demonstrates how ‘phenotype switching’ enables bacteria to adapt to their environmental conditions, lie dormant inside host cells and become a reservoir for relapsing infections.
ScienceDaily (June 14, 2010) — For a successful infection, bacteria must outwit the immune system of the host. To this aim, they deliver so-called virulence factors through a transport channel located in the bacterial membrane. In some bacteria this transport channel is formed like a syringe, enabling them to inject virulence factors directly into the host cell. Scientists from the Max Planck Society and the Federal Institute for Materials Research and Testing have now succeeded for the first time in elucidating basic principles of the assembly of this transport channel. This is an important starting point for the development of new drugs that might interfere considerably earlier than antibiotics in the course of infection. The research is published in Nature Structural & Molecular Biology.