TABLE 4.
Clinical variables (geometric mean ± SD) and antibody titer to E. equi antigen in 38 sheep infected with different variants of A. phagocytophila
| A. phagocytophila variant(s) | n | Result (mean ± SD)
|
||||
|---|---|---|---|---|---|---|
| Rectal temp (°C) | No. of neutrophils (109 cells/liter)a | Absolute no. of infected neutrophils (109 cells/liter)a | No. of seropositive sheepb (%) | Mean antibody titer in seropositive sheep | ||
| A. phagocytophila variant 1 | 14c | 40.74 ± 1.015 | 0.80 ± 0.182 | 0.024 ± 0.004 (3.1 ± 2.91) | 13 (93) | 1:386 |
| A. phagocytophila variant 2 | 21 | 40.64 ± 1.014 | 1.48 ± 0.227 | 0.193 ± 0.006 (13.1 ± 3.07) | 9 (43) | 1:320 |
| A. phagocytophila prototype and variant 1 | 2 | 41.54 ± 1.005 | 1.38 ± 1.154 | 0.067 ± 0.013 (4.6 ± 1.53) | 2 (67) | 1:452 |
| A. phagocytophila variant 1 and variant 5 | 1 | 40.40 | 1.62 | 0.008 (0.5) | 0 | Negative |
a
The number of neutrophils and infected neutrophils in sheep infected with A. phagocytophila variant 1 and those infected with A. phagocytophila variant 2 were significantly different: P < 0.03 and P < 0.004, respectively. Percent values are given in parentheses.
b
Comparison of A. phagocytophila variant 1 and A. phagocytophila variant 2: Yates corrected χ2 = 6.98 and P < 0.01.
c
Clinical data from one of the A. phagocytophila variant 1-infected sheep were not available.