TABLE 5.

Detection and quantitation of R. rickettsii DNA in clinical and experimental samples

Sample no.OriginType of sampleCt value (mean ± SE)No. of calculated DNA copies (mean ± SE)aAdditional information
1Human patientWhole blood26.19 ± 0.102.39 × 104 ± 0.20 × 105Acute RMSFc
2Human donorWhole blood>36≤1b
3Human donorSkin biopsy>36≤1b
4 M. pinetorum Whole blood27.69 ± 0.518.51 × 104 ± 2.74 × 104Acute experimental RMSF
5 M. pinetorum Brain29.41 ± 0.294.56 × 104 ± 1.03 × 104Acute experimental RMSF
6 M. pinetorum Brain29.08 ± 0.488.70 × 104 ± 2.42 × 104Fatal experimental RMSF
7 M. pinetorum Brain>37≤1Convalescent from experimental RMSF
8 M. pinetorum Lung30.57 ± 0.333.91 × 104 ± 2.07 × 104Acute experimental RMSF
9 M. pinetorum Lung28.26 ± 0.732.45 × 104 ± 0.81 × 105Fatal experimental RMSF
10 M. pinetorum Lung>37≤1Convalescent from experimental RMSF
11 Amblyomma tickWhole tick23.20 ± 0.583.45 × 106 ± 0.10 × 106Questing tick
12 Amblyomma tickWhole tick21.38 ± 0.271.17 × 107 ± 0.10 × 107Questing tick
13 Amblyomma tickWhole tick>37≤1bQuesting tick
  • a DNA copy numbers were calculated per milliliter of blood, milligram of tissue, or whole tick.

  • b The absence of amplification of rickettsial DNA was confirmed by an independent PCR assay.

  • c RMSF, Rocky Mountain Spotted fever.