Table 1.
Bacterial strains used in this study.
Table 2.
Monoclonal IgG antibodies used in this study
Fig 1.
Endpoint SBA and OPA titers for sera from mice immunized with S. Enteritidis or S. Typhimurium phase 1 flagellin proteins.
(A, B) SBA, and (C, D) OPA titers produced by individual mice immunized with S. Enteritidis phase 1 flagellin (A, C, closed squares), S. Typhimurium phase 1 flagellin (B, D, closed circles) or non-immune PBS controls (NI, closed triangles). * P value is indicated. Individual points are the average of triplicate wells from a single experiment. Solid bar = mean, dashed line = assay detection limit.
Fig 2.
Immunogold labeling of S. Enteritidis strain S15 with polyclonal antisera against S. Enteritidis flagellin.
Flagella labeled with (A) PBS control sera, (B,C) sera from mice immunized with S. Enteritidis phase 1 flagellin. Bars, 100 nm (A, C) and 500 nm (B).
Fig 3.
Comparison of SBA titers of S. Enteritidis anti-FliC polyclonal antibodies against heterologous Salmonella serovars.
SBA titer produced by pooled sera (n = 10) from mice immunized with S. Enteritidis phase 1 flagellin against the target strains S. Enteritidis S15, S. Typhimurium D65, S. Paratyphi A ATCC9150, and S. Typhi Ty2. Dashed line = detection limit. Data shown is the average and standard deviation of triplicate wells, and representative of two independent experiments. P values were assessed by paired t-test.
Fig 4.
OPA and SBA activity for monoclonal antibodies specific for the phase 1 flagellin proteins of S. Enteritidis and S. Typhimurium.
OPA was assessed for (A) S. Enteritidis S15 and (B) S. Typhimurium D65 with phase 1 serovar specific (CA6IE2 [S. Enteritidis]; AH12IE6 [S. Typhimurium]) and broadly-reactive (CB7IH2) anti-flagellin antibodies. SBA was assessed for (C) S. Enteritidis S15 and (D) S. Typhimurium D65 with phase 1 serovar specific (CA6IE2, JB11IG4 [S. Enteritidis]; AH12IE6 [S. Typhimurium]),) and broadly-reactive (CB7IH2, AE9IB4) anti-flagellin antibodies, tested individually or mixed in equal amounts. The total protein concentration of the individual or combined antibodies is indicated. Each point is the average of triplicate wells from a single experiment.
Fig 5.
Passive immunization with monoclonal FliC antibodies and protection against lethal challenge.
CD-1 mice (n = 10 /group) were intravenously administered PBS or 50 μg of either a monoclonal IgG specific for S. Enteritidis FliC (CA6IE2) or a monoclonal IgG specific for S. Typhimurium FliC (AH12IE6). Two to 3 hours later, they were infected intraperitoneally with 1 x 105 CFU of S. Typhimurium D65, and monitored for 14 days recording mortality and overall health. P value by log-rank survival analysis versus control mice administered CA6IE2.