Discrimination of Viable and Dead Fecal Bacteroidales Bacteria by Quantitative PCR with Propidium Monoazide

Propidium monoazide (PMA) was optimized to discriminate between viable and dead Bacteroides fragilis cells and extracellular DNA at different concentrations of solids using quantitative PCR. Conditions of 100 mu M PMA and a 10-min light exposure also excluded DNA from heat-treated cells of nonculturable Bacteroidales in human feces and wastewater influent and effluent.