TABLE 2.
Comparison of the amplification characteristics (Ct values) of Orien16S and Otsu47 qPCR assays with samples of Orientia tsutsugamushi, Ca. Orientia chuto, and Ca. Orientia chiloensis.
| qPCR Cta values | qPCR Ct values | ||||
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| Strain | Orien16S | Otsu47 | Strain | Orien16S | Otsu47 |
| O. tsutsugamushi Karp | 28.29 | 30.19 | O. tsutsugamushi TA686 | 28.08 | 28.25 |
| O. tsutsugamushi Kato | 29.32 | 30.24 | O. tsutsugamushi Volner | 26.23 | 27.36 |
| O. tsutsugamushi Gilliam | 27.99 | 29.11 | O. tsutsugamushi Ikeda | 21.66 | 22.19 |
| O. tsutsugamushi TA-763 | 21.73 | 22.77 | O. tsutsugamushi Domrow | 28.89 | 30.82 |
| O. tsutsugamushi TH-1814 | 29.46 | 30.27 | O. tsutsugamushi Middleton | 30.75 | 32.03 |
| O. tsutsugamushi TH-1817 | 29.03 | 30.26 | O. tsutsugamushi Hicks | 30.5 | 31.3 |
| O. tsutsugamushi AFC-3 | 20.59 | 22.19 | O. tsutsugamushi Faulkner | 21.89 | 20.68 |
| O. tsutsugamushi AFC-30 | 31.58 | 32.65 | O. tsutsugamushi UT76 | 29.78 | 30.73 |
| O. tsutsugamushi AFPL-12 | 30.07 | 31.26 | O. tsutsugamushi UT221 | 30.82 | 32.05 |
| O. tsutsugamushi MAK-110 | 28.68 | 29.18 | O. tsutsugamushi FPW1038 | 30.45 | 31.24 |
| O. tsutsugamushi MAK-119 | 28.87 | 29.98 | O. tsutsugamushi FPW2016 | 27.49 | 28.17 |
| O. tsutsugamushi MAK-243 | 28.57 | 29.36 | O. tsutsugamushi CRF136 | 33.58 | 33.44 |
| O. tsutsugamushi 18030642 | 26.65 | 26.97 | O. tsutsugamushi TM1073 | 36.26 | 37.63 |
| O. tsutsugamushi 18-032460 | 18.78 | 20.7 | O. tsutsugamushi TM1324 | 34.69 | 35.86 |
| O. tsutsugamushi BSR178 | 20.85 | 20.75 | O. tsutsugamushi UT661 | 36.12 | 35.38 |
| O. tsutsugamushi Buie | 29.22 | 29.8 | O. tsutsugamushi Sido | 22.84 | 23.3 |
| O. tsutsugamushi Calcutta | 28.31 | 29.88 | O. tsutsugamushi Kawasaki | 29.23 | 29.42 |
| O. tsutsugamushi Brown | 29.21 | 30.29 | Ca. O. chuto | 28.43 | 42.82 |
| O. tsutsugamushi Citrano | 24.32 | 25.35 | Ca. O. chiloensis Pt1 | 42.3 | Negative |
| O. tsutsugamushi Garton | 29.45 | 30.46 | Ca. O. chiloensis Pt2 | 36.56 | Negative |
| O. tsutsugamushi Woods | 30.32 | 30.91 | Ca. O. chiloensis Pt3 | 31.25 | Negative |
| O. tsutsugamushi 18-032111 | 19.43 | 20.52 | Ca. O. chiloensis Pt4 | 26.27 | Negative |
| O. tsutsugamushi TH1812 | 27.53 | 28.61 | Ca. O. chiloensis Pt5 | 32.25 | Negative |
| O. tsutsugamushi TA678 | 25.77 | 26.87 | pOrien6b 1000 copies | 28.67 | 28.68 |
aCt, cycle threshold. The cut-off Ct values for Orien16S and Otsu47 were not applied since reliable and consistent exponential curves were presented in all samples with a Ct value.
bpOrien6 plasmid served as positive control.