Table 1.

Toxicity detection of mutant strain △dotU on EPC cells

	Cytotoxicitya (%)
Strain	1 h	2 h
TH0426	23.1 ± 0.33	68.3 ± 0.71
△dotU	12.5 ± 0.67**	32.7 ± 0.81***
C-dotU	18.2 ± 0.24	46.8 ± 0.51

Date are the means for three experiments and presented as mean ± SD

^aCell counts of bacteria that attach and invade EPC cell. *p < 0.05 (significant) versus corresponding values of TH0426

** and *** indicate p < 0.01 and p < 0.001 respectively