Friday, March 9, 2012

Immunization For MRSA Infection On The Horizon


New Hope For Total Joint Replacement Patients: Immunization For MRSA On The Horizon


Methicillin resistant staph aureus (MRSA) infections are more a more serious problem than other strains staph  infection.  MRSA can result in prolonged disability, amputation and even death.  Five percent of the US population are carrying MRSA in their nasal canals.  Current prevention efforts are focused on identifying these carriers and treating them with an eradication protocol around the time of knee replacement surgery to minimize this infection.  A vaccine would be a huge break through in minimizing the risk of MRSA infection.  
MRSA growing on culture plate in laboratory
Half of the infections after total knee replacement are from MRSA.  An artificial knee joint infected with MRSA has to be surgically removed, then the patient is treated with IV antibiotics for a 6 weeks.  Then a third operation is performed to return knee implants into the joint.  This is both time consuming and expensive.  With the increasing incidence of total joint replacement surgeries, the prevalence of MRSA-infected implants is expected to rise. 
A team of investigators from the University of Rochester Medical Center has developed a vaccine that can prevent bacterial infection of orthopaedic implants. Their findings were presented at the Orthopaedic Research Society (ORS) 2012 Annual Meeting in San Francisco, California. 
The team, led by Edward Schwarz, PhD, Professor of Orthopaedics and Associate Director of the Center for Musculoskeletal Research, has generated an antibody that prevents MRSA bacteria from dividing properly. 
"What makes the staph such a challenging pathogen is that is has an ironclad cell wall. But that is also its Achilles' heel," Dr. Schwarz said. He explained that if the cell wants to divide, it has to "unzip the cell wall" to break into two "daughter cells." Their team produced an antibody that targets a component of the zipper, Gmd-preventing normal bacterial cell division by causing them to form clusters of cells. 
The researchers tested the antibody prior to implantation of a MRSA-infected pin to simulate an infected joint replacement. They monitored bacterial growth and found that their antibody protected 50 percent of their sample from infection. Further analysis found that the antibody prevented formation of sequestrum, or a piece of dead bone, which is a hallmark of osteomyelitis. Additionally, immunization led to decreased bacterial presence on the pins themselves. 
This immunization technology appears to be a promising treatment to prevent the MRSA infection/reinfection of orthopaedic implants.  Hopefully it will be perfected and brought to market soon.  

1 comment:

Anonymous said...

I have a friend who is in research at Phyzer in St. Louis. He told me that they have a vaccine that has been submitted to the government for approval that in tests has demonstrated it is 95% effective in preventing MRSA infections in knee surgeries. Approval is coming to late for me as I developed MRSA in March of 2011. Knee replacement is scheduled for Dec. 4th, 2012.