The Effect of Culture Medium Surfactants on Cytometric Analysis of Mycobacterium Avium Subsp. Paratuberculosis

The purpose of this study is to identify the susceptibility of dormant MAP cells to detergents used in agriculture. MAP cultures were grown in two media differing only in primary carbon source,Tween 80 and glycerol. Both cultures were analyzed with the fluorescent dyes CTC and Syto24. CTC is a fluorescent dye used for detection of respiring cells via electron transport chain; Syto24 is a fluorescent dye that binds to DNA. Preliminary results of this study indicate that Tween 80 influences the permeability of the dyes and may impair binding by nucleic acid stains used for viability assays, confounding efforts to analyze dormancy in mycobacterium. Identification of the negative interaction between Tween 80 in culture medium and viability assays means that alternate carbon sources should be used when investigating dormancy in MAP