Table 1.
Inactivation method | No. of oocysts inoculated | Wna | Cell culture wells positiveb (%) by: |
||
---|---|---|---|---|---|
IFA | PCR | RT-PCR | |||
70°C, 30 min | 10 | 20 | 0 | 0 | 0 |
100 | 20 | 0 | 0 | 0 | |
3×(LiqN2, 2 min/ 95°C, 1 min)c | 10 | 20 | 0 | 0 | 0 |
100 | 20 | 10 | 5 | 0 | |
UV irradiation, ∼60 mJ/cm2 | 10 | 20 | 0 | 25 | 0 |
100 | 20 | 0 | 60 | 0 | |
0.5 kGy gamma irradiation | 100 | 20 | 0 | 55 | 0 |
100 | 15 | 0 | 45 | 0 | |
100 | 20 | 0 | 10 | 0 | |
None (mock infectionsd) | 100 | 20 | 0 | 5 | 15 |
100 | 20 | 0 | 10 | 13e | |
25 | 10 | 0 | 0 | 0 | |
25 | 10 | 0 | 10 | 0 | |
25 | 10 | 0 | 0 | 20 | |
None (unseeded wells) | 0 | 20 | 0 | 0 | 0 |
None (untreated viable oocysts) | 10 | 40 | 62 | 65 | 45 |
Number of cell culture wells inoculated with each dose of oocysts.
Average of replicate experiments performed in two laboratories.
Three cycles of freezing in liquid nitrogen for 2 min followed by thawing at 95°C for 1 min.
Mock infections involved inoculating oocysts onto cell monolayers and then immediately processing the monolayers according to each of the detection assays.
Wn = 15.