Growth temperature tolerance. Using loopful of diluted culture, streak a line across each of 3 plates of Abeyta-
Hunt-Bark agar. Inoculate up to 4 cultures or lines per plate. Incubate one plate at 25°C, one at 35-37°C, and one at
42°C under microaerophilic atmosphere for 3 days. More growth than the initial inoculum is a positive test.