P-202 - Electroflotation cartridge for rapid microbial enrichment to improve molecular detection limits for Dickeya dianthicola and Escherichia coli

Successful disease management is predicated on high quality surveillance tools for early detection of pathogenic organisms. While major advances in molecular diagnostics have enabled rapid and specific detection of microbes, early detection of low titers in the environment remains challenging. Thus, we developed a portable electroflotation device to concentrate small quantities of bacteria from large samples. As model organisms we used Escherichia coli DH5α and Dickeya dianthicola PL25 to determine if the device could be used to rapidly improve detection limits of Loop-mediated isothermal amplification (LAMP) assays, with primers targeting unique sequences derived from 16s rRNA and alcohol dehydrogenase genes for E. coli and D. dianthicola respectively. Assays were performed directly on 10-fold serial dilutions of each of the cultured bacteria in phosphate buffer (0.1 M, pH 6.6) to determine baseline detection limits, and results were compared to detection limits following bacteria recovery with electroflotation treatment of 1600 mL volumes of the same dilutions. Sample preparation with electroflotation improved detection limits by two orders of magnitude from 10⁴ CFU mL^-1 to 10² CFU mL^-1. Sample treatment with electroflotation may improve performance of a wide variety of diagnostic tools applied to biosecurity, agricultural diagnostics, epidemiological and microbial studies.