Abstract:
Within the last five years, there has been an increase in community acquired Methicillin Resistant Staphylococcus aureus (MRSA). In this project, we propose to study the incidence of the Panton-Valentine (PVL) gene (and two other virulence genes yet to be determined) in the community acquired Methicillin Resistant Staphylococcus aureus (MRSA), hospital acquired MRSA, and in Methicillin Susceptible Staphylococcus aureus (MSSA). In addition to testing for the presence of this gene, anabiograms of MSSA and MRSA will be studied; additionally, clinical outcomes including length and cost of hospitalization will be studied.

Introduction:
The rate of community acquired MRSA infection is increasing, posing additional health-risks not only to immuno-compromised patients, but also to the general public.  These type of infections result in longer hosptilization and increased healthcare costs. There are known genes that produce antimicrobial resistance and are probably accompanied by virulence factors such as PVL. The prevalence of this gene has never been studied in this area before.

Objective:
A virulence gene that has been found in the Staphylococci known as the Panton-Valentine gene has been shown to produce a toxin known as Panton-Valentine leukocidin (PVL). This is a causative agent of Staphylococcal Necrotizing Pneumonia, among other invasive Staphylococcal infections. 

For the past several years, LDS hospital has been saving Staphylococcus aureus isolates for use in conducting this research. These saved samples will be used to study the incidence of the PVL gene (two other virulence genes will also be studied, however we are not sure what they are yet), and susceptibility patterns. The clinical outcomes will also be studied to determine length of hospitalization and cost of patient care. At this point, the number of patient samples is not known. (The number of isolates that will be studied will be determined at the next meeting with the research team at LDS hospital).

Methods and Materials:
The susceptibility patterns of the MRSA and MSSA we will be evaluated using a Dade Behring Microscan Walkaway. We will be comparing the anabiograms of the hospital acquired and community acquired strains. (The cost per susceptibility panel is yet to be determined).
 PCR will be used to replicate the extracted DNA from the MRSA and MSSA strains and we will then use the Tagman assay or ABI to determine the presence of the PVL gene. Per sample cost for PCR assay will be roughly two dollars.

The susceptibilities and the incidence of PVL gene (and two other toxin genes) between Hospital and community acquired MRSA and MSSA will then be compared and contrasted.

References:
Etienne, Jerome , et al. “Relationships between Stapylococcus aureus Genetic  Background, Virulence Factors, agr Groups (Alleles), and Human Disease.”  Infection and Immunity 70 (2002): 631-641.

Vandenesch, Francois, et al. “Community-Acquired Methicillin-Resistant Staphylococcus aureus Carrying Panton-Valentine Leukocidin Genes: Worldwide Emergence.”  Emerging Infectious Disease 9 (2003): 978-984.

Reviewers:
Nicole spend love 10/06/2004
Travis Price  10/06/2004