bHealth care-associated infections with methicillin-resistant Staphylococcus aureus (MRSA) contribute to significant hospitalization costs. We report here a droplet digital PCR (ddPCR) assay, which is a next-generation emulsion-based endpoint PCR assay for high-precision MRSA analysis. Reference cultures of MRSA, methicillin-susceptible S. aureus (MSSA), and confounders were included as controls. Copan swabs were used to sample cultures and collect specimens for analysis from patients at a large teaching hospital. Swab extraction and cell lysis were accomplished using magnetic-driven agitation of silica beads. Quantitative PCR (qPCR) (Roche Light Cycler 480) and ddPCR (Bio-Rad QX100 droplet digital PCR system) assays were used to detect genes for the staphylococcal protein SA0140 (SA) and the methicillin resistance (mecA) gene employing standard TaqMan

The effect of synthetic fire ant venom alkaloid Solenopsin B (Sol B) on the human monocytic cell line U937 was examined to determine its ability to induce apoptosis and efficacy as a therapeutic agent. Sol B treated cells displayed a >50% reduction in viability along with DNA laddering, a hallmark of apoptosis. The apoptosis mechanism was further examined using DNA microarrays and quantitative RT‐PCR (qRT‐PCR). U937 cells were incubated in the presence of Sol B and total cellular RNA isolated. cDNA was synthesized, labeled with cy3/cy5 and hybridized to microarrays or used in qRT‐PCR RT2 Profiler(tm) PCR array analysis. Microarray analysis revealed that 661 genes and 620 ESTs were up regulated >1.5 fold, including several apoptosis and cell cycle genes. PCR arrays representing functional gene groupings of 90 apoptosis and 92 cell cycle genes showed up regulation of >90% and >70% respectively. Genes examined using both microarray and qRT‐PCR showed correlations of ~93% for apoptosis and ~79% for cell cycle genes. Further, transmission electron microscopy revealed Sol B treatment resulted in loss of cell membrane integrity further verifying the ability of Sol B to induce apoptosis. Collectively these findings indicate that Sol B induced programmed cell death in human cells by triggering the apoptotic pathway.

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