Figure 4.

Figure 4. Infectious virus titres and pyrosequencing analysis of ferret nasal washes from 50:50 WT:NA-H275Y+PA-I38T clinical isolate inoculated donor and airborne transmission infected recipient ferrets. Donor ferrets (n=4) were infected via the intranasal route with 5 log10TCID50/mL with 50:50 WT: NA-H275Y+PA-I38T clinically isolated virus and co-housed with naïve recipient ferrets (RF1) virus separated by an airborne virus permeable barrier, infected RF1s were then co-housed with RF2 ferrets. Nasal wash samples were titrated by TCID50 assay for each Group A-D Donor-RF1-RF2 transmission pairs, LOD is shown as a dotted horizontal line, and all values beyond LOD equal zero viral titre (panel a). The relative proportion of virus encoding WT PA (white bars) and PA-I38T (dark blue bars) and WT NA (white bars) and NA-H275Y (light blue bars) were determined by pyrosequencing analysis and are shown side-by-side in bar charts for each donor (panel b), RF1 (panel c) and RF2 (panel d) ferret.