Table 1. PRV-Om challenge trials, overview of samples and analyses.
| Duration (weeks) | Sampling, weeks post challenge (WPC) | Number of fish sampled, injected+cohabitants | Samples from | Analyses | |||||
|---|---|---|---|---|---|---|---|---|---|
| Trial 1 | Rainbow trout and Atlantic salmon | ||||||||
| 1A | Tank 1 | 20 virus injected | 8 | 0, 1, 2, 4, 6, 8 | 4+41,2 | Blood | RT-qPCR* | ||
| Spleen | RT-qPCR | ||||||||
| Rainbow trout | Heart | RT-qPCR; histology3 | |||||||
| 20 cohabitants | Head kidney | RT-qPCR | |||||||
| 1B | Tank 2 | 20 virus injected | 8 | 0, 1, 2, 4, 6, 8 | 4+41,2 | Blood | RT-qPCRR | ||
| Spleen | RT-qPC | ||||||||
| Atlantic salmon | Heart2 | RT-qPCR; histology3 | |||||||
| 20 cohabitants | Head kidney | RT-qPCR | |||||||
| Trial 2 | Rainbow trout | ||||||||
| Tank 1 | 40 virus injected | 4 | 1, 2, 3 | 5 | Blood | RT-qPCR | |||
| “Early stage infection” | |||||||||
| Tank 2 | 30 virus injected | 14 | 4, 8, 12 | 5+5 | Blood | RT-qPCR; IF** | |||
| Spleen | viperin, Mx*** RT-qPCR | ||||||||
| 30 cohabitants | Heart | RT-qPCR; histology | |||||||
| Tank 3 | 30 virus injected | 14 | 6, 10, 14 | 5+5 | Blood | RT-qPCR; IF | |||
| Spleen | viperin, Mx RT-qPCR | ||||||||
| 30 cohabitants | Heart | RT-qPCR; histology | |||||||
| Tank 4 | 40 mock injected | 14 | 4, 10, 12, 14 | 5+54 | Blood | RT-qPCR; IF | |||
| Spleen | viperin, Mx RT-qPCR | ||||||||
| 40 cohabitants | Heart | RT-qPCR; histology | |||||||
| Trial 3 | Atlantic salmon | ||||||||
| Tank 1 | 90 virus injected | 16 | 4, 6, 8, 10, 12, 14, 16 | 8+8 | Blood | RT-qPCR; IF, Hgb**** | |||
| 90 cohabitants | Spleen | viperin, Mx RT-qPCR | |||||||
| Heart | RT-qPCR; histology | ||||||||
| Tank 2 | 50 non-infected fish | 16 | 4, 6, 8, 10, 12, 14, 16 | 4 | Blood | RT-qPCR; IF | |||
| Spleen | viperin, Mx RT-qPCR | ||||||||
| Heart | RT-qPCR; histology | ||||||||
1 Trial 1, samples for RT-qPCR–exceptions from 4+4. 1A: 4 WPC: 4 injected + 3 cohabitants, 8 WPC: 3 injected + 5 cohabitants. 1B: 6 WPC: 3 injected + 3 cohabitants, 8 WPC: 2 injected + 4 cohabitants
2 Trial 2, samples for histology—exceptions from 4+4. 1A 8 WPC: 3 injected + 6 cohabitants, 1B: 6 WPC: 3 injected + 3 cohabitants, 8 WPC: 2 injected + 5 cohabitants
3 Trial 1, 1A and 1B: Additional organs for histology: liver, kidney, spleen, exocrine pancreas, pyloric caeca, red and white skeletal muscle
4 Trial 2: Samples for histology: 4 WPC: 3 injected + 3 cohabitants, 10 and 12 WPC: 5 injected only. 14 WPC: 3 injected + 2 cohabitants
* RT-qPCR = RT-qPCR for PRV-Om
** IF = Immunofluorescence immunostaining for PRV-Om
*** Mx = Myxovirus resistance protein
**** Hgb = haemoglobin