TABLE 3.
Evaluation of degree of cytotoxicity expressed in Vero cells compared with genotype results
| Genotype | Hemolysin-positive isolates
|
Hemolysin-negative isolates
|
||||
|---|---|---|---|---|---|---|
| No. of isolates | CTa range | Mean ± SEb CT | No. of isolates | CT range | Mean ± SE CT | |
| 1 (ahh1) | 38 | 2-256 | 32.37 ± 8.97 | 8 | 0-16 | 3.00 ± 2.10 |
| 2 (asa1) | 10 | 2-16 | 9.20 ± 1.96 | 1 | 0 | 0 |
| 3 (ahh1 and asa1) | 5 | 4-32 | 12.0 ± 5.06 | 0 | 0 | 0 |
| 4 (ahh1 and A. hydrophila aerA) | 46 | 0-256 | 79.48 ± 13.38c | 2 | 0-16 | 8.00 ± 8.0 |
| 5 (no hemolysin genes detected) | 4d | 0-16 | 5.0 ± 3.79 | 14e | 0-2 | 0.14 ± 0.14 |
a
CT in Vero cells. Values are the titers obtained in cell culture assays.
b
SE, standard error of the mean.
c
P < 0.001 compared to the mean CTs for the other genotypes.
d
None of the four hemolysin-positive isolates produced a hemolysin-aerolysin amplicon in the multiplex PCR assay; one isolate each of A. caviae and A. sobria was cytotoxic.
e
One isolate (A. schubertii) showed a low level of cytotoxicity.