|Chikungunya fever - Re-emergence of an old disease. Lisa F.P. Ng, David M. Ojcius. Microbes and Infection, Volume 11, Issues 14-15, December 2009, Pages 1163-1164|
Saturday, 28 November 2009
Thursday, 26 November 2009
Multiple sclerosis (MS), a disease where the immune system attacks the brain and spinal cord, affects nearly 1 in 700 people in the United States. Patients with multiple sclerosis have a variety of neurological symptoms, including muscle weakness, difficulty in moving, and difficulty in speech.
Porphyromas gingivalis, a common oral bacterium in humans, produces a unique type of lipid, phosphorylated dihydroceramides (DHCs), which enhance inflammatory responses. These lipids are also likely produced by bacteria found in other parts of the body including the gastrointestinal tract. To determine if these lipids accentuate immune-mediated damage in autoimmune disease, researchers led by Robert B. Clark and Frank C. Nichols of the University of Connecticut Health Center administered phosphorylated DHCs in a mouse model of MS. The severity of disease was significantly enhanced by the addition of these lipids in a manner that was dependent on activation of the immune system. These data suggest that phosphorylated DHCs from bacteria commonly found in humans may trigger or increase the severity of autoimmune diseases such as multiple sclerosis.
The authors state that “while it is clear that the immune system in most individuals has the potential to attack self-tissues, the “tipping” factors that initiate and propagate autoimmune diseases such as multiple sclerosis in only a subset of individuals remain unknown. Overall, [their] results represent the first description that phosphorylated DHCs derived from common human bacteria are capable of enhancing autoimmune disease.” Thus, these lipids may function as “tipping” factors, playing a previously unrecognized role in initiating or exacerbating human autoimmune diseases. In future studies, Dr. Clark and colleagues plan to characterize the effects of phosphorylated DHCs on specific cells of the immune system and to identify how and where these lipids are deposited in tissues throughout the body. In addition to the role of these lipids in triggering and worsening MS, the authors believe that phosphorylated DHCs may have the potential to serve both as new markers of MS disease activity and as new targets for therapeutic intervention.
Nichols FC, Housley W, O’Conor C, Manning T, Wu S, Clark RB: Unique Lipids from a Common Human Bacterium Represent a New Class of TLR2 Ligands Capable of Enhancing Autoimmunity. Am J Pathol 175: 2430-2438.This work was supported by grants from the National MS Society (RG4070-A-6) (RBC) and the Patterson Trust Foundation (FN). There is a provisional patent application pending for the use of bacterial phosphorylated dihydroceramides. This application pertains to Dr. Frank Nichols and Dr. Robert B. Clark.
|Ljungan Virus: an Emerging Zoonosis? Anna Greene McDonald. Clinical Microbiology Newsletter, Volume 31, Issue 23, 1 December 2009, Pages 177-182|
Wednesday, 25 November 2009
A potentially dangerous and rapidly spreading strain of the "superbug" MRSA poses a much greater public health threat than previously thought, new research shows.
Community-associated MRSA (CA-MRSA) is spreading in hospitals and other health care facilities, according to a study in the December issue of Emerging Infectious Diseases. The CA-MRSA strain of superbug can be picked up in fitness centers, schools, and other public places, and is increasing the already significant burden of MRSA (methicillin-resistant Staphylococcus aureus) in hospitals, the researchers report. CA-MRSA and hospital-associated MRSA (HA-MRSA) are bacteria resistant to most common antibiotics.
HA-MRSA infections occur mostly in hospitals and other health care settings, including dialysis centers and nursing homes, and often strike mostly older adults, people having invasive medical procedures, and people with weakened immune systems. CA-MRSA is a leading cause of serious skin and soft tissue infections, entering the body through scrapes and cuts, the researchers say.
The study, which analyzed data from more than 300 microbiology labs across the U.S., found a sevenfold increase in the proportion of CA-MRSA in outpatients between 1999 and 2006. This community-associated strain is making its way into hospitals, the researchers say, increasing threats to patient safety because patients and their doctors move back and forth between inpatient and outpatient units of hospitals. "This emerging epidemic of community-associated MRSA strains appears to add to the already high MRSA burden in hospitals," Ramanan Laxminarayan, PhD, MPH, a senior fellow at Extending the Cure, a project at the Resources for the Future think tank in Washington, D.C., says in a news release. This major increase in CA-MRSA, the researchers say, has become a major concern.
Over the length of the study, the scientists report finding that the proportion of MRSA had increased more than 90% among outpatients with staph, and now accounts for more than 50% of all Staphyloccus aureus infections. This was due, the findings suggest, almost entirely to an increase in CA-MRSA strains. Similar increases in inpatients suggest these strains are spreading rapidly into hospitals. "MRSA has generally been a significant problem only in hospitals," says Eili Klein, MA, the lead author of the report and also a researcher at Resources for the Future. "But the findings from this study suggest there is a significant reservoir in the community as well." This suggests that the increased cases of CA-MRSA are causing that bug to spread from the community into hospitals, Klein says.
Hospitals need to take steps to stop this by stepping up infection control procedures, the researchers say, adding that the best way to contain MRSA and other superbugs is through surveillance and regular efforts aimed at infection control. "Community-associated methicillin-resistant Staphylococcus aureus has become a major problem in U.S. hospitals already dealing with high levels of hospital-associated MRSA," the researchers write. They conclude that "more rapid diagnostic methods are urgently needed to better aid physicians" in fighting MRSA.
SOURCES: News release, Emerging Infectious Diseases, Burness Communications. Klein, E. Emerging Infection Diseases, December 2009; vol 15.
|Foodborne Illness: An Acute And Long-term Health Challenge For The 21st Century|
The Center for Foodborne Illness Research & Prevention (CFI) has released a report that documents what is currently known about the long-term health outcomes associated with several foodborne illnesses. The report also discusses how under-reporting, inadequate follow-up and a lack of research make it difficult to assess the impact that foodborne illness is having on Americans.
CFI's report, The Long-Term Health Outcomes of Selected Foodborne Pathogens, calls for a new approach to foodborne illness research and surveillance and provides expert reviews about some of the long-term health outcomes for five foodborne pathogens. The outcomes range from hypertension and diabetes to kidney failure and mental retardation.
"Foodborne illness is a serious public health issue in the 21st century," says Dr. Tanya Roberts, Chair of CFI's Board of Directors and an author of the report. "But the vast majority of these illnesses are never reported to public health agencies, leaving us with many unanswered questions about the impact that foodborne illness is having on different populations, particularly young children and the elderly."
The five foodborne pathogens reviewed in this report include:
Other co-authors of the report include Patricia Buck, CFI's Executive Director; Martin J. Blaser, M.D.; J.K. Frenkel, M.D.; Bennett Lorber, M.D.; James Smith, Ph.D.; Phillip I. Tarr, M.D.
Source: Patricia Buck
Pew Health Group
|Endofungal bacteria as producers of mycotoxins. Gerald Lackner, Laila P. Partida-Martinez, Christian Hertweck. Trends in Microbiology, Volume 17, Issue 12, December 2009, Pages 570-576.|
XMRV is present in malignant prostatic epithelium and is associated with prostate cancer, especially high-grade tumors. PNAS USA September 8 2009 doi:10.1073/pnas.0906922106
Thursday, 19 November 2009
|Pseudomonas aeruginosa: a formidable and ever-present adversary|
Journal of Hospital Infection, Volume 73, Issue 4, December 2009, Pages 338-344
K.G. Kerr, A.M. Snelling
|Acinetobacter: an old friend, but a new enemy|
Journal of Hospital Infection, Volume 73, Issue 4, December 2009, Pages 355-363
|International Journal of Food Microbiology, Volume 136, Issue 2, 31 December 2009, Pages 169-178. Cronobacter Special Issue|
Tuesday, 17 November 2009
Monday, 16 November 2009
The story of tuberculosis, also called the “white plague,” is the story of the first modern day clinical trial. Selman Waksman was the first to discover that streptomycin was effective against M. tuberculosis; he subsequently won a Nobel Prize in medicine for this work. The history of tuberculosis is also the history of sanatoriums, where tuberculosis patients went to “take the cure” before anti-tuberculous therapy was available. These special hospitals allowed M. tuberculosis patients to breathe fresh, clean air; eat nutritious foods; and rest. The introduction of isoniazid in 1954 finally led to the closing of sanatoriums.
|Infectious Diseases and Famous People Who Succumbed to Them|
Clinical Microbiology Newsletter, Volume 31, Issue 22, 15 November 2009, Pages 169-172
Alice S. Weissfeld
|Detection of virulence genes in Staphylococcus aureus isolated from paper currency|
International Journal of Infectious Diseases, Volume 13, Issue 6, November 2009, Pages e450-e455
J. Dinesh Kumar, Yogesh K. Negi, Abhishek Gaur, Deepshikha Khanna
P. Marti-Lliteras, V. Regueiro, P. Morey, D.W. Hood, C. Saus, J. Sauleda, A.G.N. Agusti, J.A. Bengoechea, J. Garmendia. 2009. Nontypeable Haemophilus influenzae clearance by alveolar macrophages is impaired by exposure to cigarette smoke. Infection and Immunity, 77. 10: 4232-4242.)
Wednesday, 11 November 2009
Frigid Antarctica Loaded with Viruses | LiveScience: A lake in Antarctica was found to harbor a surprising variety of viruses. Here, an image of the Spanish, non-permanent camp in Byers Peninsula (Livingston Island, Antarctica). Credit: Science/AAAS.
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Antarctica's icy lakes are home to a surprisingly diverse community of viruses, including some that were previously unidentified, a new study finds.