TABLE 3.

Growth of ExPEC 408 and its derivatives in various media as determined using viable counts

StrainGrowth rate ina:
LB broth (pH 7.0)LB broth (pH 5.0)LB broth + 400 μM 2,2′-dipyridyl90% Chicken serum75% Human serum90% Human serumHuman urine
APEC O10.760.510.290.780.040.10NDb
APEC O2NDNDNDNDNDND0.69
DH5α0.440.330.000.31−1−10.16
ExPEC 4080.760.560.20c0.75−0.15c−0.09c0.66
408.10.750.570.18c0.77−0.30d−0.22d0.59
408.20.760.580.21c0.74−0.13c−0.12c0.63
  • a The growth rate was determined by calculating the slope of log-transformed data during exponential growth. Negative values reflect a decline in survival as determined using viable counts.

  • b ND, not determined.

  • c Significantly different (P < 0.05) than the value for the known positive control (APEC O1 or APEC O2) as determined using a two-tailed Student t test.

  • d Significantly different (P < 0.05) than the value for the known positive control and ExPEC wild-type strain 408 as determined using a two-tailed Student t test.