TABLE 6.

Increase in numbers of CFU over time for wild-type Edwardsiella ictaluri and the EsaU mutant, 65ST, following infection of HKDM and CCO cellsa

Cell type and time (h) postinfectionNo. of CFU of wild type/wellFold increase from time zerobNo. of CFU of 65ST/wellFold increase from time zerob
HKDM
    01,483 ± 33.3616 ± 83.3
    56,500 ± 2,179.44.3517 ± 120.2**0.85
    1053,333 ± 23,154.135.3817 ± 183.3***1.3
CCO cells
    0413 ± 48.1477 ± 8.8
    41,793 ± 218.34.3283 ± 18.6***0.59
    85,233 ± 611.912.7226 ± 21.9***0.47
  • a CCO and HKCM cells were infected in 24-well plates at MOIs of 1 CFU:10 HKDM cells and 1 CFU:1 CCO cell. CFU data are the means ± standard errors of the results for triplicate wells and are representative of one of three experiments. A significant difference for mutant compared to wild type following a log transformation of the CFU data are indicated by asterisks. **, P < 0.01; ***, P = 0.001.

  • b Time zero is at 90 min postinfection (30 min of exposure and 60 min of gentamicin killing).