Figure 4
Pharyngeal chlamydial burden in immunized chickens challenged with C. psittaci. Groups of chickens were immunized IN (A) or IM (B) as described above and challenged intranasally with 1 × 108 IFU of live C. psittaci 2 weeks after the booster immunization. To monitor bacterial burden, pharyngeal swabs were obtained from individual chickens (6/group) 2 weeks post challenge and C. psittaci was isolated from swabs in tissue culture. Chlamydial inclusions were detected by fluorescence microscopy using the Imagen immunofluorescence kit (Oxoid, UK) and enumerated. The data show the number of recoverable IFUs expressed as log10 IFU/ml. Comparison of the number of recoverable IFUs shed by Gel + EB + VCG35 (C) and Gel + EB + CpG (D) following IN and IM administration is also shown. Differences between experimental groups within each administration route were compared by One-way ANOVA with Tukey’s post multiple comparison test while differences in number of recoverable IFUs between IN and IM administration were compared by 2-tailed t-test at p* < 0.05 and p** < 0.01.
