TABLE 1

Bacterial strains used in this study

StrainRelevant characteristic(s) or genotypeSource or reference
S. Typhi
    Ty2Wild type; Vi+ATCC 700931
    STY2Ty2 ΔviaB::Kanr40
    SW74Ty2 ΔtviB-vexE::Cmr; Vi22
    SW483Ty2 ΔviaB ΔfliC15
S. Typhimurium
    IR715Nalidixic acid-resistant derivative of ATCC 14028; wild type41
    SW478IR715 phoN::Kanr42
    SW474IR715 phoN::tviA-Cmr15
    SW681IR715 phoN::Kanr ΔfliC fljB::MudCm16