Emerging infectious diseases present a profound threat to global health, economic development, and political stability, and therefore represent a significant national security concern for the United States. The increased prevalence of international travel and globalized trade further amplify the threat of infectious disease outbreaks of catastrophic effect. The key to containing and eradicating an outbreak before it goes global is rapid identification of index cases and initial clusters of affected individuals. This depends upon establishment of a biosurveillance network that effectively reaches infectious disease hotspots in even the most remote regions of the world and provides a network-integrated, location-appropriate diagnostic capability. At present, there are two critical needs which must be addressed in order to extend biosurveillance activities beyond centralized laboratory facilities: 1) A simple, reliable, and safe method for immediate stabilization of clinical specimens in the field; and 2) A flexible sample processing platform that enables in-field preparation of clinical specimens for rapid, on-site analysis using a variety of diagnostic assay platforms. These needs are not necessarily mutually exclusive; in fact, we propose that they are most efficiently addressed by a deployable sample processing platform that immediately stabilizes the information content of clinical specimens through transformation of the inherently unstable analytes of interest into stable equivalents that are appropriately formatted for downstream analysis. In order to address this problem, we have developed a sample processing pipeline and microfluidics-based platform modules enabling: 1) Extraction of total RNA from finger-stick quantities of human whole blood; and 2) Microscale synthesis of appropriately-formatted cDNA products that capture the information content of blood RNA in a stable form that supports pathogen detection and/or characterization via PCR and/or Second Generation Sequencing (SGS). Through this research we have discovered new, effective solutions for problems that thus far have hindered use of digital microfluidics (DMF) in biomedical applications. Our work reveals a clear path forward to fieldable, automated sample processing systems that will enable rapid, on-site identification of usual-suspect and novel pathogens in clinical specimens for improved biosurveillance.
Ceragenins were used to create biofouling resistant water-treatment membranes. Ceragenins are synthetically produced antimicrobial peptide mimics that display broad-spectrum bactericidal activity. While ceragenins have been used on bio-medical devices, use of ceragenins on water-treatment membranes is novel. Biofouling impacts membrane separation processes for many industrial applications such as desalination, waste-water treatment, oil and gas extraction, and power generation. Biofouling results in a loss of permeate flux and increase in energy use. Creation of biofouling resistant membranes will assist in creation of clean water with lower energy usage and energy with lower water usage. Five methods of attaching three different ceragenin molecules were conducted and tested. Biofouling reduction was observed in the majority of the tests, indicating the ceragenins are a viable solution to biofouling on water treatment membranes. Silane direct attachment appears to be the most promising attachment method if a high concentration of CSA-121a is used. Additional refinement of the attachment methods are needed in order to achieve our goal of several log-reduction in biofilm cell density without impacting the membrane flux. Concurrently, biofilm forming bacteria were isolated from source waters relevant for water treatment: wastewater, agricultural drainage, river water, seawater, and brackish groundwater. These isolates can be used for future testing of methods to control biofouling. Once isolated, the ability of the isolates to grow biofilms was tested with high-throughput multiwell methods. Based on these tests, the following species were selected for further testing in tube reactors and CDC reactors: Pseudomonas ssp. (wastewater, agricultural drainage, and Colorado River water), Nocardia coeliaca or Rhodococcus spp. (wastewater), Pseudomonas fluorescens and Hydrogenophaga palleronii (agricultural drainage), Sulfitobacter donghicola, Rhodococcus fascians, Rhodobacter katedanii, and Paracoccus marcusii (seawater), and Sphingopyxis spp. (groundwater). The testing demonstrated the ability of these isolates to be used for biofouling control testing under laboratory conditions. Biofilm forming bacteria were obtained from all the source water samples.
