Fig 6.

The STM4467-encoded ADI has no effect on NO₂⁻ generation by macrophages. J774A.1 macrophage cells were infected with the wild-type (WT) strain (14028s), an STM4467 deletion mutant (CH102 ΔSTM4467), or strain CH102 harboring plasmid p4467 (ΔSTM4467/p4467). At 18 h after infection, levels of NO₂⁻ production in the supernatants of macrophages were determined by using the Griess reaction. Note that NO₂⁻ was nearly absent from macrophages without (−) S. Typhimurium infection. Means and standard deviations from three independent experiments are shown. “ns” indicates that the nitrite levels of bacteria are not significantly different from those of the WT strain.