p-nitrophenylglycerol--a superior antiswarming agent for isolating and identifying pathogens from clinical material.

The antiswarming agent p-nitrophenylglycerol (PNPG) has been found invaluable for the recognition and isolation of pathogenic bacteria from specimens contaminated with swarming strains of Proteus spp. PNPG is cheap, stable and non-toxic. All strains tested grew well in its presence and produced characteristic morphology. PNPG was without effect on the results of a variety of identification tests performed directly on colonies from media containing PNPG. This permitted identification without the need for further subculture.