Poliovirus (PV) remains endemic in three countries and is responsible for sporadic outbreaks in several others. Clinical surveillance for acute flaccid paralysis (AFP) is the gold standard for PV surveillance. However, as few as 1 in 100 to 1 in 1000 PV infections will develop AFP, particularly in well-vaccinated populations. Environmental surveillance of wastewater using a bag-mediated filtration system is currently being investigated to detect sub-clinical circulation of poliovirus. However, the filter samples will be collected remotely and evaluated centrally, which requires a shipping period. During this shipping period, bacterial and fungal growth may degrade PV on the filter surface. Inhibition of fungal and bacterial growth is necessary to ensure PV survival on filters during transit from field collection to the processing lab. Shipping on icepacks at 4°C is costly, thus finding an alternative is ideal. Preservative agents were investigated as an alternative to reduce microbial growth while not affecting PV recovery from its performance methods. Preservatives investigated included sodium azide, calcium propionate, o-phenylphenol, and sodium benzoate. Preservative solution or PBS control was pumped into the positively charged Virocap filter and eluted with beef extract, pH 9.50. After 1.5 hours, the eluate was pumped out, pH adjusted, and dosed with 10^2 PFU/mL PV1. Filters were run in duplicate and samples were plated on BGMK cells for enumeration by plaque assay. 0.0195% sodium azide eluate had a 64% recovery when compared to PV expressed in the PBS control eluate. 0.1% calcium propionate had a 102% recovery, 2% sodium benzoate had a 101% recovery, and 0.02% o-phenylphenol had a 111.1% recovery. Sodium azide is not recommended as a good preservative for PV due to low recovery, but 0.1% calcium propionate, 2% sodium benzoate, and 0.02% o-phenylphenol should be investigated further for PV preservation and recovery in wastewater over time.

Entamoeba histolytica is a water-born pathogen that is estimated to cause 100,000 deaths annually in developing countries. The disease is prevalent especially in tropical areas with poor sanitary conditions, and is treatable with appropriate antimicrobial medication. Therefore, detection of the pathogen is vital in diagnosis. We developed a sensitive electrochemical assay utilizing novel yeast-scFv detection probes targeted at E. histolytica parasite antigens in stool samples. I have previously tested the assay in solution (buffer and stool dilution) with several antigens and proved sensitivity. This project is a stability study of the assay assembled on the electrodes. I tested factors including temperature, pH, humidity, pressure, and light sensitivity to determine the optimal conditions for long-term storage and transport, as well as the limit that one factor can be pushed while maintaining sensitivity. The significance of this project is to maximize the assay’s shelf life and thus to minimize the cost of manufacture and transportation of the assembled product. Consequently, it will benefit clinicians and patients in poor countries where the disease is prevalent, as a broader population of people around the globe.

Pew Research found that 77% of Democrats believe in climate change compared to 43% of Republicans. This project aimed to measure the impact of community led climate change education on individuals in a traditionally Republican district. This was done with a new approach in bridging the communication gap by bringing together community leaders to discuss climate change in the hope of disentangling the climate conversation from partisan arguments and to promote a dialogue that considers the inter-generational nature of this public health concern. I hypothesized that people will accept information about climate change when it is presented by a community member or relative. I, along with my research team, hosted a community-wide educational forum in Maple Valley and Granger, small rural towns in Washington. The Maple Valley forum was led by a city council member, with five local students who taught their community about climate change using the stories collected from regional farmers and the knowledge they learned in their high school science class. We surveyed the participants (N = 30) before and after the forum to assess whether their perceptions have changed as a result of the forum. After coding the surveys into quantitative data, the effectiveness of the forum was analyzed using a paired t-test. This research will help us assess and refine educational methods for communicating the science and impacts of climate change to rural communities.

Public health concern in the U.S and across the world regarding the impact of environmental hazards on human health is becoming more evident as we develop tools to see disparities in exposure and health outcome. Pollutants in the air and water can have lifelong consequences for the quality of lives of many people. Therefore, our toxicology laboratory is examining the result of pesticide exposure and toxicity in children, and how it may cause harm to normal development. Our research centers on studying exposure using blood, urine, and oral buccal samples obtained as part of a Children’s Health study on Yakima Valley. We have determined blood pesticide, urinary metabolite concentrations, cholinesterase activity, paraoxonase activity, and genome wide variation in 200 families. We have analyzed buccal samples from farmworker and non-farmworker families that were collected during different pesticide spray seasons. We are studying these buccal swab samples of children and their parents to identify bacteria present within them. We are utilizing targeted 16S ribosomal polymerase chain reaction (PCR) to determine the phylogenetic composition of the microbiome in saliva samples. The microbiome refers to the vast colonization of microbes within the body. There are more bacterial cells in our bodies than human cells even though they are only about 10% of the total mass. We hope to find a difference in microbe composition and metabolism for samples from agricultural seasons (pesticide use and non-spray seasons), and for child and adult samples. We have already analyzed pilot samples and found consistent results. Recently, we have begun PCR-based analysis and sequencing the remainder of the cohort buccal samples to characterize the diversity of oral microbiomes. If a link is found between the microbiome, pesticides, metabolic traits, and host genotype then we can more fully describe risk and metabolic biomarkers for exposed populations. 

 Widespread use of tetracyclines in marine and fresh water aquaculture has resulted in tetracycline resistant (Tcr) bacteria in these environments. Previously, 15 of 25 Tcr Chilean bacteria were shown to carry seven different tet genes. The tet(A) was the most commonly identified gene [n=6]. In the present study, we reexamined nine bacteria that were previously negative for the 22 tet genes tested using PCR assays for the identification of tet(W), tet(X), and tet(39). Three of the isolates’ genera designation differed between phenotypic and 16S sequencing identification. The 16S identifications were used in the current study. Six (67%) of the isolates including 3 Acinetobacter spp., 1 Pseudomonas spp., 1 Psychrobacter spp., and 1 Corynebacterium spp. carried the tet(39) gene. None of the isolates carried either tet(W) or tet(X) genes. In the present study, 6 of the isolates carried the tet(39) gene making it as common as the tet(A) in the original study. Of the 4 genera identified 3 [Pseudomonas, Psychrobacter, and Corynebacterium] represented new genera not previously identified as carrying the tet(39) gene. We are currently testing the strains for their ability to transfer tet(39) by conjugation and/or transformation. The tet(39) gene was first identified in Acinetobacter spp. from freshwater trout farms, sewage and human clinical samples from Europe between 1986-1997. Since then the tet(39) gene has been identified in fish farms in Thailand, a polluted river in Nigeria and clinical samples in the US. This study shows that the tet(39) gene has been present in bacteria from Chilean fish farms since 1999. The tet(39) gene has wider host range in water associated bacteria than previously recognized and should be considered when examining Tcr water bacteria in the future. The current study illustrates that aquaculture contaminates the local environment into surrounding soils and water sources with antibiotic resistant bacteria and genes.