Table 1.

Bacterial strains used in these studies

Species	Strain No	Source	Gram stain	Growth conditions*
Lactobacillus acidophilus (LA)	4356	ATCC	Positive	MRS, 37° C
Streptococcus thermophilus (ST)	BAA-250	ATCC	Positive	TSA-sb, 37° C, 5% CO2
Enteroinvasive E coli (EIEC)	O29:NM	J Fierer UCSD	Negative	TSB-y, 37° C, 5% CO2

*See text for definition of abbreviations used.