FIG 6 .
Serum resistance of A. hydrophila E1 and E2 isolates compared to that of A. hydrophila ATCC 7966T. A. hydrophila 7966T, E1, and E2 were grown overnight, harvested, and resuspended in an equivalent amount of PBS. An aliquot (50 µl) of the bacterial cells was mixed with either PBS or serum and incubated at 37°C for 1 h. The CFU counts in the samples were then determined as described in Materials and Methods. A. hydrophila strains E1 and E2 demonstrated statistically significant increases in serum resistance compared to that of strain ATCC 7966T.