Staph 'detectives' pioneer new test

[Source: CYNDY COLE, Sun Staff Reporter] - The microbes responsible for staph infections and other illnesses sickening an estimated 10 million annually in the U.S. have new enemies at Northern Arizona University. Researchers here and at the University of Maryland have designed an inexpensive, 10-minute blood test that would be the first to detect staph and a few other infections. The groundbreaking discovery could lead to nonsurgical treatments for heart and joint infections, drug-resistant staph infections, bone infections and more. In short, it's an entirely new way to diagnose and fight chronic infectious diseases.

Northern Arizona University associate professors Jeff Leid and Tim Vail have helped design a test that checks for antibodies microbial networks, including the drug-resistant pathogen that makes staph infection a bigger domestic killer than AIDS, at an estimated 18,650 deaths annually.

That morning gunk on your teeth or the film on your shower curtain is a distant cousin of what they're seeking. That gunk is called biofilm, or colonies of microbial life bound together. "It develops kind of an armor," Vail said.

Biofilms are strong enough to survive anti-microbial agents, bleach, or strong antibiotics, which is a particular problem with staph and other infectious diseases that kill about 70,000 people annually in the United States. Vail and Leid's device seeks out biofilm via the blood and delivers results in about 10 minutes.

It could be used by implant makers to ensure products are sterile before implantation, to monitor the health of patients who have received artificial organ or joint implants, and to diagnose staph or yeast infections. Next, they are working on building nanoparticles -- possibly containing iron oxide, silica and specific antibodies -- that seek out specific biofilms, bind to them, and can be heated via an MRI to destroy the infection.

If this were to work, a patient receiving a heart device or knee replacement wouldn't need surgery to identify or eradicate some common infections. Tests of treatments in rabbits have been promising, said Leid, associate director of NAU's Center for Microbial Genetics and Genomics, and he's been told the development could become a billion dollar enterprise. The test is simple to use and could be a part of rural clinics or third-world medicine. "It's not a complicated apparatus. It's not something that you'd have to pay half-a-million to have in a clinical lab," said Vail, an associate professor of biochemistry.

Cyndy Cole can be reached at 913-8607 or at ccole@azdailysun.com.

NAU researchers develop new device for finding bacteria

[Source: Northern Arizona University] - Infection-causing bacteria can't hide from researchers at Northern Arizona University, who recently helped develop the first diagnostic tool to detect them. A patent is pending for the new Lateral Flow Assay device to detect the microorganisms bound together in a protective wall, known as biofilms, which attach to inanimate substances, such as rocks in streams or catheters in humans, or to living tissue such as human heart valves and bone. Certain bacteria produce biofilms, which act as a defense against drugs and the immune system, making it difficult to treat an infection. Biofilms cause more than 70% of community and hospital-acquired infections, such as staph infections, according to the U.S. Centers for Disease Control and Prevention.

The cost associated with treating these infections in the U.S. is about $5 billion a year, said Jeff Leid, an associate professor in the Department of Biological Sciences and associate director for NAU's Center for Microbial Genetics and Genomics. "Biofilms are an important problem with implanted medical devices as well as in the establishment of chronic infections," Leid said. "They are notoriously less susceptible to antibiotics than their single-cell, non-community orientated bacteria and are less susceptible to attack and killing from the human immune system."

Leid explained that because of this, patients often suffer chronic and recurring infections. "Without a specific way for physicians and health-care workers to diagnose these infections, patient treatment may be delayed," he explained. Developed by a team of faculty and students from NAU and the University of Maryland, the Lateral Flow Assay works in similar ways to the test used to diagnose strep throat. The device identifies the presence of biofilm-specific antibodies in patients by allowing the antibodies to bind to biofilm-specific proteins on the device.

"If physicians and other health-care workers can diagnose these infections early, there will be a much greater chance for clinical treatments to work and for patient health to improve dramatically," Leid explained. Leid invented the device in collaboration with Tim Vail, an associate professor of Biochemistry at NAU, Jennifer Kofonow, an NAU biology graduate student, Mark Shirtliff, an assistant professor in biomedical sciences at the University of Maryland, and Rebecca Brady, a biomedical sciences graduate student at the University of Maryland. In March, the group presented the diagnostic assay at the international Biofilms 2007 meeting in Canada. "When we showed the slide documenting the assay's utility in detecting a biofilm infection from the serum of an infected animal, the crowd of more than 500 scientists went silent in awe. It was amazing," Leid said. Dr. Steve Fry at Airpark Medical Center in Scottsdale, Ariz., is hoping the Lateral Flow Assay will help him diagnose his patients' medical problems faster. "This new device will allow doctors to test drugs and materials simultaneously and will save time and money," Fry said. The researchers are working to fine-tune the treatment protocols for using the new device. "The next move is trying to find a company that is interested in licensing the technology so that it can be developed and sold as a clinical product," Leid said.