TABLE 4.

Comparison of results obtained from the PCR, VIDAS, and culture methods^a

Source (no. of samples)	PCR result or CT value	VIDAS result	Culture resultb
Cheese product plant (132)	22.49	Negative	Positive
	38.13	Negative	Positive
	37.79	Negative	Negative
Cheese product company (140)	25.75	Negative	Positive
	26.31	Positive	Positive
	27.25	Positive	Positive
	28.84	Positive	Positive
	31.26	Positive	Positive
	34.08	Negative	Positive
	34.40	Negative	Positive
	Negative	Positive	Negative
Whey powder company (154)	All negative	7 positives	7 of 7 negative
6 food product companies (686)	36.64	All negative	1 of 1 negative
3 dairy product companies (309)	All negative	All negative	Not performed
2 food and cheese companies (320)	All negative	All negative	Not performed
Total (1,741)	11 positive	12 positive	9 positive

^aA total of 1,741 environmental samples from 14 food-processing facilities were screened by PCR and VIDAS methods. Culture analyses were performed for a total of 19 samples that were positive according to the PCR or VIDAS method. Salmonella isolates were obtained from 9 of 11 PCR-positive samples and 4 of 12 VIDAS-positive samples. VIDAS failed to detect Salmonella in 5 culture-positive samples.

^bCulture analyses were performed for all samples that were positive with PCR or VIDAS screening.