This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Species of microsporidia that infect humans and non-human primates have been detected in drinking water sources. Recently, Encephalitozoon intestinalis and Enterocytozoon bieneusi, were included on US EPA's drinking water Contaminant Candidate List and Occurrence Priorities List and were included as Biodefense Category B pathogens of concern for waterborne transmission by the NIH. Furthermore, according to the Centers for Disease Control and Prevention, incidents of waterborne disease outbreaks documented in the United States doubled in 1999 and 2000 and half of these were due to contaminated groundwater supplies. Over a quarter of the United States' population derives their potable water supplies from karstic aquifers, which appear to be more prone to outbreaks than other aquifers because of potential shorter residence times, lack of filtration and geochemical conditions that may favor microbial migration over sorption to the porous media. Limited laboratory and field research has been performed to quantitatively determine the subsurface transport and fate behavior of waterborne pathogens in karstic systems, and no studies have been performed on the microsporidia. A multiplex immunomagnetic bead separation (IMBS) method was developed using a pan-microsporidian antiserum for capture of most, if not all of the species of microsporidia that infect humans. The IMBS was standardized against serial dilutions of microsporidia suspended in saline and river water sediment followed by direct and nested PCR using rDNA primers and the lower limits of detection were determined to be 10-100 spores per liter of water. Recent grab water samples of three one-liter volumes from the Bogue Falaya River in Covington, LA and one of the Edwards Aquifer, San Antonio, TX ground water form wells were evaluated for the presence of microsporidia using the IMBS method. No microsporidia were detected while control samples spiked with 10 E. intestinalis spores per liter were positive. Studies are continuing to model the dispersion and transport of microsporidia in karstic water sytesm.
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