FIG 6.
Cyclopropane fatty acids are important for virulence in mice. (A) C3H/HeN (ItyR) mice were infected intraperitoneally with S. Typhimurium strains wild-type (blue open diamonds), cfa mutant (red open squares), and cfa/pJK674 (green open squares) with 3000 CFU. Mice were monitored daily, and moribund mice were euthanized. *, P = 0.0463 between cfa mutant and cfa mutant with complementing plasmid pJK674 using Gehan-Breslow-Wilcoxon test. (B) Competitive survival experiment of cfa mutant versus wild type in C3H/HeN (ItyR). Mice were inoculated intraperitoneally with a mixture of cfa mutant and wild-type S. Typhimurium strains. Three independent mice were assayed for each time period postinfection. The competitive index (CI) of the cfa mutant versus the wild type was determined for both the liver (blue closed diamonds) and the spleen (red closed circles). A CI of 1 indicates that both strains grew equally well in vivo. (C) The competitive index data from panel B were combined from days 4 to 17 postinfection and a Wilcoxon signed rank test was performed. A double asterisk (**) indicates P < 0.0001.