Preparation of heat-killed K. pneumoniae
K. pneumoniae was purchased from ATCC (Manassas, Virginia) and
grown overnight in brain heart infusion (BHI) broth (Eiken chemical,
Tochigi, Japan) at 37°C. The bacterial number was determined by the
absorbance at 600 nm (0.1=1x108/ml). K.
pneumoniae was subjected to incubation at 70°C for 30 minutes to
generate heat-killed K. pneumoniae .