TABLE 1.
Infection rates of CHIKVs in A. albopictus at days 7, 10, and 14 after infection
| Viremic blood meal | Infection rate (no. of infected mosquitoes/total no. in group [%]) at:a |
Titer at day 14 p.i. (log10 TCID50/ml [n])b | ||
|---|---|---|---|---|
| Day 7 p.i. | Day 10 p.i. | Day 14 p.i. | ||
| Mock (defibrinated sheep blood) | 0/15 (0) | 0/13 (0) | 0/26 (0) | ND |
| WT | 15/16 (94) | 22/22 (100) | 30/35 (86) | 4.99 ± 0.50 (11) |
| E1-K61T | 36/41 (88) | 14/16 (88) | 36/44 (82) | 4.65 ± 0.91 (12) |
| E2-D59N | 30/33 (91) | 14/15 (93) | 40/43 (93) | 5.44 ± 0.64 (11) |
| E1-K61T E2-D59N | 34/42 (81) | 12/13 (92) | 33/44 (75) | 5.04 ± 0.90 (11) |
A. albopictus mosquitoes were fed a blood meal of equivalent amounts of WT and the indicated mutant CHIKVs. Mosquitoes were collected at different days postinfection (p.i.), dissected, and analyzed for viral antigen expression in the abdomen using indirect immunofluorescence microscopy (expressed as rate of infection). None of the values for mutant viruses were significantly different (P > 0.05) from the WT level at any of the days tested, as judged by a Fisher's exact test.
Whole mosquitoes were collected at day 14 postinfection and homogenized, and titers of infectious virus were determined on Vero cells. The data are expressed as log10 TCID50/ml ± standard deviation, and the number of individual mosquitoes tested per group is indicated in parentheses. ND, not determined.