TABLE 1.

Detection limits for S. flexneri in various artificially contaminated foods

Food sample	Background count (CFU/ml)	Detection limit (CFU/ml)
		Nonfiltered	FTA filter
Cilantro	1.0 × 108	5.0 × 104	50
Tomato	9.0 × 103	5.0 × 102	5.0 × 102
Beef	4.0 × 104	NDa	40
Lettuce	4.0 × 104	ND	50
Alfalfa sprouts	2.0 × 108	50	50
Bean sprouts	5.0 × 106	50	50
Apple cider	0	ND	50b

^aND, not detected. 

^bRepresents 1 μl of suspension spotted onto an FTA filter.