Analysis of fatty acid compositionĀ 
S. aureus strains were grown to exponential phase (OD600 ~ 0.5), at which time 10-50 ml of each culture (~100 mg of wet cells) were pelleted, washed twice with phosphate-buffered saline (PBS), and stored at -80°C. Fatty acids were saponified and methylated, and then analyzed by gas chromatographic analysis of fatty acid methyl esters (GC-FAME) as a fee for service at the Center for Microbial Identification and Taxonomy (Norman, OK).