TABLE 7.

Survival of S. typhimurium SL1344(pACYC184) inoculated onto boiled rice or boiled egg white and challenged in acidified LB^a

Challenge substance and food source	Inoculum (CFU)	No. of surviving bacteria (CFU)	% Survival	pH of LB after treatment
LB (pH 2.5)
Rice	2.97 × 106	0	<0.01b	2.50
Egg white	9.40 × 105	3.07 × 105	32.66b	2.50
PBS (pH 7.4)d
Rice	1.72 × 106	9.40 × 105	54.57c
Egg white	9.40 × 105	1.72 × 106	100.00c

^aExperiments were performed in duplicate, and numbers are means. 

^bPercent survival of S. typhimurium inoculated onto the surface of 0.1 g of boiled rice on egg white and challenged with LB (pH 2.5). 

^cPercent survival of S. typhimurium inoculated onto the surface of 0.1 g of boiled rice or egg white and challenged with PBS (pH 7.4). 

^dPBS was used as a control.