Strains were maintained at room temperature on NAP and subcultured weekly. Seven-day-old NBP cultures of E. tracheiphila
were diluted with glycerol (1:1) and placed at –80°C for long-term storage. Because of slow growth, 7-day-old plate or slant cultures were used in inoculation experiments in order to acquire sufficient inoculum. Such cultures maintained pathogenicity
for several weeks.