TABLE 3.
Sialic acid transport by P. multocida wild type and pm1709 mutant
| Strain | Genotype | Mean ± SD
|
|
|---|---|---|---|
| Growtha (A600) | Residual Neu5Acb concn (μg/ml) | ||
| TF5 | Wild type | 1.77 ± 0.03 | 7.3 ± 8.5d |
| TF5P | nanP | 1.05 ± 0.03c | 940 ± 37.5 |
a
Cells from overnight cultures grown in HTM without aeration were diluted to an A600 of 0.02 in fresh HTM and allowed to grow aerobically for 6 h in the presence of approximately 1 mg of Neu5Ac/ml. The data shown are for three independent experiments. Note that growth of the wild type and the mutant strain was identical in unsupplemented HTM.
b
At the end of the 6-h growth period, cells were collected by centrifugation, and the Neu5Ac remaining in the spent culture medium was quantified by colorimetric assay.
c
Mutant not stimulated by sialic acid (Student t test; P = 0.0004).
d
Wild-type transported exogenous sialic acid (Student t test; P = 0.0003)