NIH/NIAID On the resistance of Staphylococcus aureus to neutrophil microbicides

Staphylococcus aureus strain MW2 was exposed to the following neutrophil microbicides, hydrogen peroxide (H2O2), hypochlorous acid (HOCl) and azurophilic granule proteins. At the indicated time points, bacterial cultures were centrifuged and bacteria were lysed with RLT buffer (Qiagen) using a FastPrep system. Purification of MW2 RNA and subsequent preparation of labeled cDNA target was performed as described in Methods. Labeling of samples, GeneChip hybridization and scanning were performed according to standard Affymetrix protocols. Experiments were performed in triplicate, using three bacterial cultures from separate days for each treatment. These analyses provide an enhanced view of the mechanisms used by CA-MRSA to circumvent destruction by the human innate immune system. Keywords: time course with three treatments 48 samples total: MW2 with the following treatments, untreated, GP (azurophilic granule proteins), H2O2 (hydrogen peroxide) or HOCl (hypochlorous acid) at 4 time points in triplicate