TABLE 4.

Accuracy of the quantification of L. monocytogenes organisms by RTi-PCR in three different food matrices^a

Approx no. of CFU/g	Relative accuracy
	Raw pork	Frankfurter sausages	Fermented sausages
106	101.12 ± 0.30	99.77 ± 0.52	98.62 ± 1.30
105	97.99 ± 1.37	100.60 ± 0.41	101.77 ± 3.85
104	100.16 ± 4.11	99.48 ± 2.56	103.80 ± 1.45
103	100.88 ± 2.89	100.12 ± 2.15	94.98 ± 2.53
102	BQ	BQ	BQ

^aSamples were filtered through nylon membranes with 11-μm pores. Approximate numbers of CFU per gram are initial sizes of the inocula. Relative accuracy was calculated as a percentage of log numbers of CFU per gram obtained by the RTi-PCR-based method and the L. monocytogenes standard method of enumeration (5). Values are expressed as means ± standard deviations of the results obtained in three independent experiments. All samples tested positive (n = 9). BQ, below the range of quantification.