Validation of candidate microorganisms Microbes identified through broad-range rDNA analysis as potentially impacting S. aureus colonization will be further evaluated based on targeted QPCR measurements. Based on our preliminary results and previously published studies that suggest their interference with S. aureus growth, both S. epidermidis, (femA) and Corynebacterium spp., (rpoB PCR) will be enumerated by Q-PCR (Table, below). Primer sets for Q-PCR assays of novel microbial groups will be designed for detection of rDNA operons (i.e. 16S-ITS-23S genes) through the ARB software package (21). In the case of previously recognized microbial groups and/or species, PCR primer sets may be identified by literature search.