Researchers from the University of Copenhagen and the Technical University of Denmark along with other collaborators in Denmark and the US found that the bacterium Pseudomonas aeruginosa can 'switch on' production of molecules that kill white blood cells – preventing the bacteria being eliminated by the body's immune system.

Medical researchers have long suspected that obscure bacteria living within the intestinal tract may help keep the human immune system in balance. An international collaboration co-led by scientists at NYU Langone Medical Center has now identified a bizarre-looking microbial species that can single-handedly spur the production of specialized immune cells in mice.

Leishmania is a deadly parasitic disease that affects over 12 million people worldwide, with more than 2 million new cases reported every year. Until recently, scientists were unsure exactly how the parasite survives inside human cells. That mystery has now been solved according to a new study published in Science Signaling by a team led by Dr. Martin Olivier – a scientist at the Research Institute of the McGill University Health Centre (RI-MUHC) and McGill University. It is hoped the new study will lead to the development of the first prophylactic treatment for leishmania.

Knowing what causes a disease may not make it easier to control and contain infection, but understanding how humans become infected and where the pathogens live may improve control. A National Science Foundation grant for $1.5 million over five years will allow an international team of researchers to investigate how changes in the environment affect a deforming tropical disease called Buruli ulcer.

Cheaters may prosper in the short term, but over time they seem doomed to fail, at least in the microscopic world of amoebas where natural selection favors the noble.

Five genetic regions have been identified that are unique to the most virulent strain of Clostridium difficile (C. difficile), the hospital superbug. Researchers writing in BioMed Central's open access journal Genome Biology studied the genome of the bacterium, looking for genes relating to motility, antibiotic resistance and toxicity.

A harmless shard from the shell of a common childhood virus may halt a biological process that kills a significant percentage of battlefield casualties, heart attack victims and oxygen-deprived newborns, according to research presented Sunday, September 6, 2009, at the 12th European meeting on complement in human disease in Budapest, Hungary.

In a finding with potentially major implications for identifying a viral cause of prostate cancer, researchers at the University of Utah and Columbia University medical schools have reported that a type of virus known to cause leukemia and sarcomas in animals has been found for the first time in malignant human prostate cancer cells.

Viruses have numerous tricks for dodging the immune system. In the September 7, 2009 issue of the Journal of Cell Biology, Stagg et al. reveal a key detail in one of these stratagems, identifying a protein that enables cyto¬megalovirus to shut down an antiviral defense (online August 31).

Prevention of H1N1 influenza virus through vaccination must be our top priority if disease patterns in the northern hemisphere follow those in the southern hemisphere this fall, writes Paul Hébert, Editor-in-Chief of CMAJ (Canadian Medical Association Journal) in an editorial http://www.cmaj.ca/press/cmaj091426.pdf (www.cmaj.ca).

A new study by researchers at Columbia University Mailman School of Public Health's Center for Infection and Immunity indicates that pediatric obsessive-compulsive disorder (OCD), Tourette syndrome and/or tic disorder may develop from an inappropriate immune response to the bacteria causing common throat infections. The mouse model findings, published online by Nature Publishing Group in this week's Molecular Psychiatry, support the view that this condition is a distinct disorder, and represent a key advance in tracing the path leading from an ordinary infection in childhood to the surfacing of a psychiatric syndrome. The research provides new insights into identifying children at risk for autoimmune brain disorders and suggests potential avenues for treatment.

New technology designed to analyse large numbers of novel marine microbes could lead to more efficient and greener ways to manufacture new drugs for conditions such as epilepsy, diabetes, flu and other viruses, as well as improving the manufacture of other products such as agrochemicals.

Transposons are mobile genetic elements found in the hereditary material of humans and other organisms. They can replicate and the new copies can insert at novel sites in the genome. Because this threatens the whole organism, molecular mechanisms have evolved which can repress transposon activity. Professor Klaus Förstemann of the Gene Center of Ludwig-Maximilians-Universität (LMU) in Munich and a team of researchers working with the fruitfly Drosophila melanogaster have now uncovered a new type of cellular defence that acts against DNA sequences present in high copy numbers inside the cell, even if they have not integrated into the genome. Small molecules of RNA (a class of nucleic acid closely related to the genetic material DNA) play the central role. "Transposons are genomic parasites, so to speak", says Förstemann. "If they are allowed to proliferate, the genome can become unstable or cancers can develop. We now want to find out whether mammalian cells possess this newly discovered defence mechanism and to elucidate precisely how it works." (EMBO Journal online, 30 July 2009.)

Researchers at the Center for Infection and Immunity (CII) at Columbia University Mailman School of Public Health are working with Argentina's National Institute of Infectious Diseases, the National Administration of Laboratories and Health Institutes (ANLIS), and Roche 454 Life Sciences to decode the complete genomic sequences of influenza pandemic (H1N1) 2009 virus from patients with severe respiratory disease. The scientists will be comparing sequences of viruses associated with the current outbreak in Argentina with those found in other locations to determine if there are differences that may be linked to higher mortality rates or provide insights into virus evolution.

A virus discovered last year in a rare form of skin cancer has also been found in people with the second most common form of skin cancer among Americans, according to researchers at the Ohio State University Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute.

More and more strains of bacteria are developing resistance to previously life-saving antibiotics. Researchers at TUM, the Technische Universitaet Muenchen, have shed light on a metabolic step that appears in many aggressive microorganisms -- such as tuberculosis and malaria pathogens -- and that may provide a promising target for a new class of antibiotics. The researchers present their results in the chemistry journal Angewandte Chemie.

The Rosetta Stone of bacterial communication may have been found.

Scientists are to study a group of proteins that are highly effective at killing bacteria and which could hold the key to developing new types of antibiotics.

It is based on detecting short, repetitive DNA segments in the genome of bacteria. Every single bacterial strain has such characteristic repeats. "With this method we are able to identify bacterial strains as well as clarify their genetic relationships. Furthermore, we can show how new pathogenic variants develop," says Manfred Höfle, researcher at the HZI. The results have now been published in the current issue of the scientific journal "Applied and Environmental Microbiology". The work is part of the two European Union funded projects "Healthy Water" and "AQUA-chip". Manfred Höfle is coordinator of both projects that deal with various aspects of the microbiological safety of both, drinking water and sea water.

Researchers at the University of Texas Medical Branch at Galveston have discovered two biochemical pathways that the Ebola virus relies on to infect cells. Using substances that block the activation of those pathways, they've prevented Ebola infection in cell culture experiments — potentially providing a critical early step in developing the first successful therapy for the deadly virus.

It's common knowledge that a protective navy of bacteria normally floats in our intestinal tracts. Antibiotics at least temporarily disturb the normal balance. But it's unclear which antibiotics are the most disruptive, and if the full array of "good bacteria" return promptly or remain altered for some time.

A novel bacterium that has been trapped more than three kilometres under glacial ice in Greenland for over 120 000 years, may hold clues as to what life forms might exist on other planets.

Call it advanced warfare on the most elemental of levels.

Complications following infection with the virus that causes flu (influenza virus) are one of the top ten causes of death in the United States. Although infection with influenza virus can directly cause death, many deaths following infection with influenza virus occur because the individual develops pneumonia due to secondary infection with bacteria such as Streptococcus pneumoniae. How influenza makes individuals more sensitive to pneumonia-causing secondary bacterial infections is not well understood. However, Jane Deng and colleagues, at the University of California, Los Angeles, have now determined, through studies in mice, one mechanism by which influenza might sensitize individuals to secondary bacterial pneumonia.

Sulfolobus islandicus, a microbe that can live in boiling acid, is offering up its secrets to researchers hardy enough to capture it from the volcanic hot springs where it thrives. In a new study, researchers report that populations of S. islandicus are more diverse than previously thought, and that their diversity is driven largely by geographic isolation.

It appears that some superbugs have evolved to develop the ability to manipulate the immune system to everyone's advantage.

Researchers in the "Molecular Infection Biology group" at the Helmholtz Centre for Infection Research (HZI) in Braunschweig and the Braunschweig Technical University could now demonstrate for the first time that bacteria of the Yersinia genus possess a unique protein thermometer – the protein RovA - which assists them in the infection process. RovA is a multi-functional sensor: it measures both the temperature of its host as well as the host's metabolic activity and nutrients. If these are suitable for the survival of the bacteria, the RovA protein activates genes for the infection process to begin. These results have now been published in the current online edition of the PLoS Pathogens science magazine.

What happens if the next big influenza mutation proves resistant to the available anti-viral drugs? This question is presenting itself right now to scientists and health officials this week at the World Health Assembly in Geneva, Switzerland, as they continue to do battle with H1N1, the so-called swine flu, and prepare for the next iteration of the ever-changing flu virus.

A novel vaccine strategy using virus-like particles (VLPs) could provide stronger and longer-lasting influenza vaccines with a significantly shorter development and production time than current ones, allowing public health authorities to react more quickly in the event of a potential pandemic.

Dengue fever is the most common infectious disease transmitted by mosquitoes – some 100 million people around the world are infected. Researchers at the Hygiene Institute at Heidelberg University Hospital were the first to present a three-dimensional model of the location in the human cell where the virus is reproduced. Their research provides an insight into the exact process of viral replication and serves as a model for other viruses whose replication is still unclear, such as the hepatitis C virus. In addition, it offers new approaches for developing measures to prevent or treat dengue fever. Up to now, neither a vaccine nor a specific antiviral therapy exists.