Zinc key to formation of hospital-acquired infections
A new study funded by U.S. National Institute for Occupational Safety and Health reports that foreign-born workers reported a lower rate of non-fatal work-related injuries than U.S.-born workers, based on data collected from the National Health Interview Survey from 1997 to 2005. The study, conducted by researchers in the Center for Injury Research and Policy
Full Post: Foreign-born workers report lower rate of non-fatal work-related injuries than U.S.-born workers
Hospital-acquired infections that are resistant to traditional antibiotic treatment have become increasingly common in recent years, confounding health care professionals and killing thousands of Americans.
Now, in studies that could lead to new ways to prevent this growing public health danger, a team of University of Cincinnati (UC) researchers is exploring a “zinc zipper” that holds bacterial cells together and plays a key role in such infections.
Hospital-acquired infections affect about 1.7 million people per year in the United States and result in an estimated 99,000 deaths annually, according to the Centers for Disease Control. About two-thirds of all hospital-acquired infections can be traced to two staphylococcal species, Staphylococcus aureus-including methicillin-resistant strains (MRSA) that are particularly difficult to treat-and Staphylococcus epidermidis.
In an article appearing in the Dec. 1 online edition of Proceedings of the National Academy of Sciences, researchers in UC’s department of molecular genetics, biochemistry and microbiology detailed findings that the presence of zinc is crucial to the formation of infection-causing biofilms.
Staphylococci can grow as biofilms, which are specialized communities of bacteria that are highly resistant to antibiotics and immune responses. They are remarkably adhesive and can grow on many surfaces, including implanted medical devices such as pacemakers, heart valve replacements and artificial joints. Preventing or inhibiting the growth of such biofilms would dramatically reduce the incidence of staph infections.
UC researchers in the lab of Andrew Herr, PhD, an assistant professor and Ohio Eminent Scholar in structural biology, found that zinc causes a protein on the bacterial surface to act like molecular Velcro, allowing the bacterial cells in the biofilm to stick to one another. Zinc chelation, or removal, prevented biofilm formation by Staphylococcus epidermidis and Staphylococcus aureus. The researchers used a chelation agent called DTPA (diethylenetriamine pentaacetic acid) to remove the zinc from a sample biofilm.
“We’ve shown that if you remove the zinc, you prevent the biofilm from forming, and if you add zinc back, the biofilm can grow,” says Herr. “So we’re hopeful that we can use this sort of approach to prevent these biofilms from ever taking hold in the first place.”
The most practical applications, Herr says, might involve coatings for implanted medical devices, or rinses that a surgeon could use to clear the area around the implant.
Systemic removal of zinc, such as through an intravenous injection, is impractical for now because DTPA is approved by the U.S. Food and Drug Administration only for people with radio isotope poisoning. In addition, zinc is known to activate immune cells and play many other important roles in the body, so a proper balance would need to be developed.
Rates of antibiotic-resistant head and neck infections increased in pediatric patients nationwide between 2001 and 2006, according to a report in the January issue of Archives of Otolaryngology-Head & Neck Surgery. Before the 1980s, infections with strains of the bacteria Staphylococcus aureus resistant to the antibiotic methicillin (methicillin-resistant Staphylococcus aureus, or MRSA) were most often
Full Post: MRSA head and neck infections increase among children
Pre-operative screening of patients for methicillin-resistant Staphylococcus aureus (MRSA) may be an effective way to reduce infection rates following otolaryngic surgeries, according to new research published in the January 2009 issue of Otolaryngology - Head and Neck Surgery. The study, conducted by researchers at the Massachusetts Ear & Eye Infirmary, is the first to review otolaryngic
Full Post: MRSA pre-screening effective in reducing otolaryngic surgical infection rates
An enzyme that lives in Methicillin-resistant Staphylococcus aureus (MRSA) and helps the dangerous bacterium to grow and spread infection through the human body has been visualised for the first time, according to a study out today in Proceedings of the National Academy of Sciences (PNAS). Now, armed with detailed information about the structure of
Full Post: MRSA’s weak point visualised by scientists
Swissmedic, the Swiss agency for therapeutic products, has approved Zevtera (ceftobiprole medocaril) for the treatment of complicated skin and soft tissue infections, including diabetic foot infections which have not spread to the bone. Ceftobiprole is licensed from and co-developed with Basilea Pharmaceutica Ltd. Janssen-Cilag will market ceftobiprole in Switzerland under the trade name Zevtera.
Full Post: Swiss approval for Zevtera in treatment of complicated skin and soft tissue infections
The redox-active pigments responsible for the blue-green stain of the mucus that clogs the lungs of children and adults with cystic fibrosis (CF) are primarily signaling molecules that allow large clusters of the opportunistic infection agent, Pseudomonas aeruginosa, to organize themselves into structured communities, report Massachusetts Institute of Technology geobiologists at American Society for Cell
Full Post: Evolutionary roots of ancient bacteria may open new line of attack on cystic fibrosis