Table 2.

Survival of bacterial cells after protease treatment

Treatment	CFUs (× 108 cells/ml)	Statistical significance a
Control	2.96 ± 0.55	-
Trypsin	2.66 ± 0.21	NS
Proteinase K	2.86 ± 0.31	NS

Counting of CFUs (colony-forming units), after plating on THY plates supplemented with 5% sheep blood, Streptococcus suis serotype 2, strain 235/02 treated with trypsin or proteinase K for digestion of surface proteins of live cells. No protease was used in the controls.

^a Statistical significance was calculated by applying the Student's t-test (P < 0.05) when comparing treatments to the control: NS, not significant.