(Press-News.org) Irvine, Calif., March 14, 2012 — UC Irvine researchers have discovered how Salmonella, a bacterium found in contaminated raw foods that causes major gastrointestinal distress in humans, thrives in the digestive tract despite the immune system's best efforts to destroy it.
Their findings help explain why Salmonella is difficult to eradicate and point to new approaches for possible treatments. Most people infected with Salmonella suffer from diarrhea, fever and abdominal cramps for up to seven days before the infection resolves.
Lead researcher Manuela Raffatellu, a UCI assistant professor of microbiology & molecular genetics, and colleagues identified a novel molecular mechanism that allows Salmonella to survive. Results of their study appear in the March issue of Cell Host & Microbe.
Pathogens like Salmonella flourish and cause disease in humans through a process by which they acquire metal ions, such as zinc, from the body. One of the body's key immune responses is to flood the infected area with antimicrobial proteins that include calprotectin, which removes zinc. Without enough of this vital element, most pathogens eventually die.
Raffatellu's team found, however, that salmonellae overcome this immune response by expressing specialized transporter proteins that enable the bacteria to acquire zinc in spite of calprotectin reducing the amount available in the digestive tract. This distinctive mechanism lets salmonellae continue proliferating.
At the same time, calprotectin inadvertently promotes Salmonella growth by killing the microbes that normally reside within the intestines and help the immune system battle pathogenic bacteria.
"We're beginning to learn more about the mechanisms that allow pathogens like Salmonella to evade our natural defenses and make us sick," Raffatellu said. "In light of this, if we can devise therapies that block the acquisition of zinc and other metals by Salmonella specifically, we can fight this infection."
Additionally, she said, the new findings may have relevance for other illnesses, such as inflammatory bowel disease and colon cancer, in which high levels of calprotectin are detected.
###
Also contributing to the study, which was supported by grants from the National Institutes of Health, were Janet Z. Liu, Stefan Jellbauer, Adam Poe, Vivian Ton, Michele Pesciaroli, Martin Hosking, Robert A. Edwards and Thomas E. Lane of UCI; Thomas Kehl-Fie, Nicole A. Restrepo, Walter J. Chazin and Eric P. Skaar of Vanderbilt University; Andrea Battistoni of the University of Rome; Thomas Vogl and Johannes Roth of the University of Munster, Germany; and Paolo Pasquali of the Superior Health Institute in Rome.
About the University of California, Irvine: Founded in 1965, UCI is a top-ranked university dedicated to research, scholarship and community service. Led by Chancellor Michael Drake since 2005, UCI is among the most dynamic campuses in the University of California system, with nearly 28,000 undergraduate and graduate students, 1,100 faculty and 9,000 staff. Orange County's second-largest employer, UCI contributes an annual economic impact of $4 billion. For more UCI news, visit www.today.uci.edu.
News Radio: UCI maintains on campus an ISDN line for conducting interviews with its faculty and experts. Use of this line is available for a fee to radio news programs/stations that wish to interview UCI faculty and experts. Use of the ISDN line is subject to availability and approval by the university.
UCI maintains an online directory of faculty available as experts to the media. To access, visit www.today.uci.edu/experts. For UCI breaking news, visit www.zotwire.uci.edu.
END
Few people know about the participation of Brazil in Word War I. Although Brazil remained neutral during most of the conflict, it eventually sent a fleet to support the war effort against the central powers. It was the only Latin-American country to do so. But the Brazilian expedition encountered an unexpected and treacherous enemy in the African coast against which -like all other Armies- it was not prepared for: the Spanish flu.
The Spanish flu swept the globe in 1918-1919 and in a few months made more victims than the total number of battlefield deaths during the ...
NEW YORK, March 14, 2012 – A new study by researchers at NYU Langone Medical Center reveals that the presence of Helicobacter pylori (H. pylori) bacteria is associated with elevated levels of glycosylated hemoglobin (HbA1c), an important biomarker for blood glucose levels and diabetes. The association was even stronger in obese individuals with a higher Body Mass Index (BMI). The results, which suggest the bacteria may play a role in the development of diabetes in adults, are available online in The Journal of Infectious Diseases.
There have been several studies evaluating ...
Two teams of astronomers have used data from NASA's Chandra X-ray Observatory and other telescopes to map the distribution of dark matter in a galaxy cluster known as Abell 383, which is located about 2.3 billion light years from Earth. Not only were the researchers able to find where the dark matter lies in the two dimensions across the sky, they were also able to determine how the dark matter is distributed along the line of sight.
Dark matter is invisible material that does not emit or absorb any type of light, but is detectable through its gravitational effects. ...
BOSTON (March 14, 2012) — A research team has identified epigenetic signatures, markers on DNA that control transient changes in gene expression, within reprogrammed skin cells. These signatures can predict the expression of a wound-healing protein in reprogrammed skin cells or induced pluripotent stem cells (iPSCs), cells that take on embryonic stem cell properties. Understanding how the expression of the protein is controlled brings us one step closer to developing personalized tissue regeneration strategies using stem cells from a patient, instead of using human embryonic ...
Freezing eggs or ovarian tissue for the sole purpose of delaying childbearing for social reasons may prove too costly for society, according to a recent analysis by a University of Illinois at Chicago researcher.
Fertility preservation -- freezing eggs or ovarian tissue -- was originally intended for women undergoing medical treatments that could affect their fertility.
But now, fertility centers around the country are offering these technologies to women who are not undergoing treatment, but who are "trying to create a backup plan for delaying pregnancy," says Dr. ...
The American Cancer Society (ACS), the American Society for Colposcopy and Cervical Pathology (ASCCP), and the American Society for Clinical Pathology (ASCP) have released new guidelines for the prevention and early detection of cervical cancer. The guidelines generally advise a reduction in the number of tests women get over their lifetime to better ensure that they receive the benefits of testing while minimizing the harms, and include a preference for co-testing using the Pap test and HPV test for women age ages 30 to 65.
The finalized updated guidelines recommend:
Women ...
British Airways has made it even easier to find the perfect holiday with the launch of a new 'Holiday Finder' tool on ba.com.
Andrew Crawley, commercial director, British Airways said: "We have been developing ways to make choosing the right holiday even easier, so we are excited to launch the new 'Holiday Finder' on ba.com. Now customers can be inspired and find a bargain that's just right for them at the same time."
A new section called 'Not sure where and when' has been added to ba.com homepage and this is where customers will find a link to the 'Holiday ...
MATERIALS -- POWGEN open for business . . .
The Spallation Neutron Source's Powder Diffractometer POWGEN has launched a rapid access sample mail-in system for users who use the flexible general-purpose instrument for a wide range of structural studies of novel materials. The instrument will be made available to rapid access users for a few days each cycle, offering data collection for two temperatures between 12 degrees Kelvin and 300 degrees Kelvin per sample. Users with a new material to test will not have wait six months for beam time. If response is good, the instrument ...
Broader screening to identify people infected with hepatitis C virus (HCV) would likely be cost effective, according to a new report published in Clinical Infectious Diseases and available online (http://cid.oxfordjournals.org/content/early/2012/02/27/cid.cis011.abstract). Significantly reducing HCV-related mortality and morbidity, however, will require a coordinated effort that emphasizes not only increased testing but also linking those infected with the treatment they need.
The HCV epidemic peaked many years ago, but roughly 4 million U.S. residents still suffer the ...
Troy, N.Y. – Rensselaer Polytechnic Institute Biologist Lee Ligon has found a previously unknown connection between breast cancer tumor cells and the surrounding healthy tissue. The results provide new information on the earliest stages of breast cancer metastasis.
The results were published March 7, 2012, in the journal PLoS One, in a paper titled "Cadherin-23 Mediates Heterotypic Cell-Cell Adhesion between Breast Cancer Epithelial Cells and Fibroblasts." Ligon was joined in the research by Rensselaer doctoral student Maria Apostolopoulou. The research was funded by ...
