A novel approach to interrogating the effects of chemical warfare agent exposure using organ-on-a-chip technology and multiomic analysis.

Organ-on-a-chip platforms are utilized in global bioanalytical and toxicological studies as a way to reduce materials and increase throughput as compared to in vivo based experiments. These platforms bridge the infrastructure and regulatory gaps between in vivo animal work and human systems, with models that exemplify active biological pathways. In conjunction with the advent of increased capabilities associated with next generation sequencing and mass spectrometry based '-omic' technologies, organ-on-a-chip platforms provide an excellent opportunity to investigate the global changes at multiple biological levels, including the transcriptome, proteome and metabolome. When investigated concurrently, a complete profile of cellular and regulatory perturbations can be characterized following treatment with specific agonists. In this study, global effects were observed and analyzed following liver chip exposure to the chemical warfare agent, VX. Even though the primary mechanism of action of VX (i.e. acetylcholinesterase inhibition) is well characterized, recent in vivo studies suggest additional protein binding partners that are implicated in metabolism and cellular energetic pathways. In addition, secondary toxicity associated with peripheral organ systems, especially in human tissues, is not well defined. Our results demonstrate the potential of utilizing an organ-on-a-chip platform as a surrogate system to traditional in vivo studies. This is realized by specifically indicating significant dysregulation of several cellular processes in response to VX exposure including but not limited to amino acid synthesis, drug metabolism, and energetics pathways.

Real-time fluorogenic PCR assays for the detection of entA, the gene encoding staphylococcal enterotoxin A.

Staphylococcal enterotoxin A (SEA) is among the most potent of the growing list of known enterotoxins produced by Staphylococcus aureus. SEA, a 27 kDa monomeric protein, is encoded by the entA gene. We have developed two real-time fluorogenic PCR assays for the detection of nucleic acid sequences in entA. The assays are useful in detecting and identifying strains of S. aureus that produce SEA and can serve a confirmatory role in determining the presence of SEA in food samples. The assays were tested in two real-time PCR formats, using either dye-labeled DNA probes corresponding to each primer set that are degraded by the 5' exonuclease activity of Taq polymerase, or a PCR master mix that contains the DNA-binding dye SYBR Green. In both formats the assays have a limit of detection of between 1 and 13 copies of a S. aureus genome that contains a copy of entA. Neither assay cross-reacted with genomic DNA isolated from other strains of S. aureus or other species.