Table 4.
Subtype identification and cross-reactivity comparison of SEP aMPV subtype-specific RT-qPCR test with commercial kits.
| Sample | Subtype | aMPV-A, Ct a | aMPV-B, Ct | aMPV-C, Ct | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| SEP b | Kit 1 c | Kit 2 d | SEP | Kit 1 | Kit 2 | SEP | Kit 1 | Kit 2 | ||
| MEX/1863/2019 | A | 24.9 | 27.5 | 27.0 | – | – | 26.2 | – | – | n/a e |
| MEX/1877/2019 | – f | 38.8 | 38.8 | – | – | 29.0 | – | – | n/a | |
| MEX/1878/2019 | 31.5 | 35.0 | 37.3 | – | – | 33.1 | – | – | n/a | |
| MEX/2390/2020 | 25.6 | 27.6 | 28.5 | – | – | 30.3 | – | – | n/a | |
| MEX/2392/2020 | 24.8 | 27.2 | 28.1 | – | – | 32.2 | – | – | n/a | |
| MEX/2948/2021 | 29.6 | 29.9 | 30.6 | – | – | 30.9 | – | – | n/a | |
| MEX/2721/2021 | 34.7 | 31.7 | 31.8 | – | – | 33.2 | – | – | n/a | |
| MEX/2582/2021 | 29.2 | 26.7 | 27.3 | – | – | 32.4 | – | – | n/a | |
| MEX/2566/2021 | 35.6 | 32.2 | 31.1 | – | – | 29.8 | – | – | n/a | |
| MEX/2939/2021 | 31.6 | 26.5 | 26.5 | – | – | 33.8 | – | – | n/a | |
| US/CA/24–003038-001/2023 | 31.1 | 33.1 | 35.1 | – | 33.9 | – | – | – | n/a | |
| US/CA/24–003038-001/2023 | 32.4 | 35.2 | 37.1 | – | – | – | – | – | n/a | |
| US/CA/24–003038-001/2023 | 26.3 | 28.7 | 30.2 | – | – | – | – | – | n/a | |
| US/CA/24–003038-001/2023 | 23.2 | 25.6 | 27.4 | – | – | – | – | – | n/a | |
| UK/CVL14-1/1985 | 30.6 | 28.2 | 26.7 | – | 37.6 | 36.2 | – | – | n/a | |
| US/GA/11281543/2024 | B | – | – | – | 20.2 | 24.0 | 22.8 | – | – | n/a |
| US/GA/11281545_2/2024 | – | – | – | 16.0 | 20.0 | 19.1 | – | – | n/a | |
| US/GA/11283628/2024 | – | – | – | 17.4 | 21.0 | 20.0 | – | – | n/a | |
| US/GA/11283629/2024 | – | – | – | 21.0 | 24.9 | 23.6 | – | – | n/a | |
| US/GA/11283951/2024 | – | – | – | 20.6 | 24.4 | 23.1 | – | – | n/a | |
| US/GA/11283954_H1A/2024 | – | – | – | 19.2 | 22.8 | 21.6 | – | – | n/a | |
| US/GA/11284245_dead/2024 | – | – | – | 15.7 | 19.3 | 18.4 | – | – | n/a | |
| US/GA/11284246/2024 | – | – | – | 16.7 | 20.3 | 19.3 | – | – | n/a | |
| US/GA/11284269_1/2024 | – | – | – | 15.4 | 18.9 | 18.0 | – | – | n/a | |
| US/GA/11284396/2024 | – | – | – | 15.5 | 19.1 | 18.1 | – | – | n/a | |
| US/NC/126/2024 | – | – | – | 21.8 | 28.4 | 28.4 | – | – | n/a | |
| US/NC/1124/2024 | – | – | – | 32.0 | 35.3 | 33.9 | – | – | n/a | |
| USA/NC/1724/2024 | – | – | – | 33.4 | 36.5 | 35.3 | – | – | n/a | |
| US/NC/9123/2023 | – | – | – | 30.8 | 34.2 | 32.5 | – | – | n/a | |
| Hungary/657/4/1989 | – | – | – | 36.5 | 35.2 | 32.6 | – | – | n/a | |
| US/MN/1a/1997 | C | – | – | – | – | – | – | 20.2 | 19.8 | n/a |
| US/CO/97/1997 | – | – | – | – | – | – | 18.3 | 18.3 | n/a | |
| US/MN/2a/1997 | – | – | – | – | – | – | 16.2 | 16.2 | n/a | |
| US/CO-01/1997 | – | – | – | – | – | – | 20.7 | 20.9 | n/a | |
| US/MN/1b/1997 | – | – | – | – | – | – | 20.2 | 20.1 | n/a | |
| US/CO-02/1997 | –- | – | – | – | – | – | 18.7 | 19.2 | n/a | |
a
Ct values, RT-qPCR cycle threshold values.
b
SEP, In house SEP aMPV subtype-specific RT-qPCR test.
c
Kit 1, VetMax Avian Metapneumovirus Kit (Thermo Fisher Scientific, France).
d
Kit 2, RealPCR AMPV A/B Multiplex RNA Mix (IDEXX, France).
e
n/a, not applicable.
f
no Ct value could be determined at the end of the 40 RT-qPCR cycles.