TABLE 3.

Effect of rpoS mutation on invasion of cell lines^a

Strain	RAW2643 cells			HEp-2 cells
	Inoculum (CFU)	Mean no. of cells recovered at 4 h	Mean no. of cells recovered at 24 h	Inoculum (CFU)	Mean no. of cells recovered at 4 h	Mean no. of cells recovered at 24 h
PP844 (wild type)	2.6 × 108	8.6 × 105 ± 5.1 × 105	2.0 × 105 ± 1.0 × 105	8.0 × 108	1.3 × 104 ± 3.2 × 103	3.0 × 104 ± 1.3 × 104
KN100 (rpoS knockout mutant)	8.0 × 108	6.8 × 105 ± 1.5 × 105	2.2 × 105 ± 3.0 × 104	5.0 × 108	3.6 × 104 ± 2.2 × 104	2.9 × 104 ± 1.4 × 104
PP844 with pBBS1 (wild type + rpoS plasmid)	2.0 × 108	2.9 × 105 ± 5.7 × 103	1.7 × 105 ± 6.0 × 104	5.0 × 108	1.8 × 104 ± 4.3 × 103	2.3 × 104 ± 1.1 × 104
KN100 with pBBS1 (rpoS knockout mutant + rpoS plasmid)	8.0 × 108	3.7 × 105 ± 3.2 × 104	7.0 × 105 ± 2.0 × 104	3.0 × 108	4.1 × 104 ± 3.4 × 104	1.0 × 104 ± 1.5 × 103
E. coli JM83	2.2 × 107	<1.0 × 10° ± 0.0	ND	8.0 × 108	<1.0 × 10° ± 0.0	ND
S. enterica serovar Typhimurium	2.1 × 107	2.2 × 105 ± 7.2 × 104	ND	ND	ND	ND
Y. enterocolitica	ND	ND	ND	3.0 × 107	4.8 × 105 ± 1.0 × 105	ND

^aND, not done. Values are means ± standard deviations.