Cyanobacterial harmful algal blooms (cHABs) are a threat to the sustainability of recreational waterways and drinking water production. The cyanotoxins associated with the cyanoHABs pose a significant public health threat due to their toxicity in humans, pets, and other animals. Therefore, the quantification and monitoring of cyanotoxins in freshwater systems susceptible to cHABs is important for public health and safety. The cyanotoxin microcystin is a toxic secondary metabolite produced by multiple cyanobacterial genera distributed globally. In nature, over 200 congeners of microcystin exist. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) is the gold-standard for quantifying microcystin in recreational waters, but is not ideal for informing the public about current toxin levels due to cost, and length of time to obtain results. Furthermore, a lack of certified reference materials makes it difficult to quantify all microcystins in a given sample. This study compared two screening assays to quantitate microcystin against targeted LC-MS/MS methods. These assays included the Abraxis strip-test and 96-well plate ELISA. The congener-specific recognition of each assay was initially compared, then the screening assays were applied to a consistent monitoring program with the Milwaukee Health Department to ensure the safety of Veteran’s Lagoon-a recreational waterway in Milwaukee, WI. Our results indicate that the strip test tended to give a slight underestimate of total microcystin in Veteran’s Lagoon samples, and provided decreased sensitivity to certain congeners, but provided a rapid indication of toxin levels compared to LC-MS/MS methods. Similar results were seen with the 96-well plate ELISA, with quantitation being much less rapid than the strip-test.  Future monitoring of recreational freshwater using the strip test can provide necessary toxin analysis that can be rapidly communicated to the public that would otherwise take longer using LC-MS/MS or 96-well plate ELISA.

Quantitative comparison of microcystin abundance in water by LCMSMS, Abraxis strip-test, and Abraxis ELISA methods

2019 Spring National Meeting

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