TABLE 1.

Quantification of Campylobacter spp. in artificially and naturally contaminated chicken samples

Sample type	Cell concentration ± SDe (CFU/ml), as determined by:
	Selective plate countsa	Flotation and real-time PCRb
Spiked	2.6 × 107 ± 5.6 × 106	1.3 × 107 ± 1.5 × 106
	2.6 × 106 ± 5.6 × 105	1.4 × 106 ± 1.3 × 105
	2.6 × 105 ± 5.6 × 104	1.9 × 105 ± 3.3 × 104
	2.6 × 104 ± 5.6 × 103	1.9 × 104 ± 0.8 × 103
	2.6 × 103 ± 5.6 × 102	3.5 × 103 ± 1.8 × 102
Naturally contaminated	0.0c	0.0c
	1.0 × 104 ± 7.1 × 102	1.3 × 104 ± 1.2 × 103
	2.8 × 106 ± 4.2 × 105	1.1 × 106 ± 4.1 × 105
	8.6 × 102 ± 8.5 × 101	2.8 × 102 ± 0.8 × 102d

^aChicken rinse samples were plated on Preston agar and counted to acquire initial cell counts.

^bReal-time PCR measurements were calculated from a standard curve made for cells instead of DNA, since no DNA was purified after flotation. The standard curve had a linear range of amplification from 2.6 × 10⁷ until 2.6 × 10³ and was described by the equation y = −3.673x + 46.285 (R² = 0.9944).

^cA total of 27 unspiked samples did not contain any Campylobacter spp. as determined by both methods.

^dThis sample fell outside the linear range of amplification but was quantified by extrapolation of the standard curve.

^eData are from independent triplicate measurements.