Three single colonies recovered from WT mice infected with PMSS1 (Out1, with cagY PCR-RFLP equivalent to wild type cagY from PMSS1; Out2; Out3) had unique cagY PCR-RFPL patterns (A), and induced high, intermediate, or low IL8, respectively (B) (gray bars) compared to PMSS1 and its cagY deletion mutant (black bars). Complementation of ΔcagY with Out1 (ΔY [Out1]), Out2 (ΔY [Out2]), or Out3 (ΔY [Out3]) phenocopied the IL8 induction of the respective output strain (white bars). Data represent mean ± SEM of four replicates. *P≤0.05. (C) Out1, Out2 and Out3 also demonstrated decreasing translocation of phosphorylated CagA (α-PY99), which was phenocopied when PMSS1ΔcagY was complemented with the respective cagY gene. Differences in CagY (α-CagY) were also apparent by immunoblot. Arrowheads in panel A indicate unique bands.