TABLE 4.

Quantitative detection of R. equi bacteria in BAL fluid^a

Approx R. equi CFU/ml	Approx no. of R. equi genome eq/reactionb	Signal ratioc	CTd	Relative accuracye
1 × 107	5 × 105	9/9	20.67 ± 0.10	100.05
1 × 106	5 × 104	9/9	24.10 ± 0.10	103.59
1 × 105	5 × 103	9/9	27.82 ± 0.04	88.95
1 × 104	5 × 102	9/9	30.93 ± 0.13	113.53
1 × 103	5 × 101	9/9	34.68 ± 0.20	95.57
1 × 102	5 × 100	9/9	37.90 ± 0.21	NAf
1 × 101	5 × 10−1	0/9	>50	NA
1	5 × 10−2	0/9	>50	NA
0g	0	0/9	>50	NA

^aResults from three independent experiments with three replicates each. Overall efficiency E is 0.94, and linearity R² is 0.99.

^bEstimated number of R. equi genome equivalents in each PCR run assuming 100% DNA extraction efficiency (each reaction mixture contained 5 μl of a DNA preparation of 100 μl extracted from 1 ml BAL fluid).

^cNumber of positive results out of nine reactions.

^dAs defined in Table 3, footnote d.

^eDegree of correspondence between the quantitative results obtained by standard plate counting (R. equi CFU/ml) and the results obtained by the choE Q-PCR method (27, 29).

^fNA, not applicable.

^gNoncontaminated BAL fluid.