Figure 5.
Contact transmission of SC35 and SC35F recombinant viruses in guinea pigs. Donor Hartley guinea pigs (filled squares; n = 6) were experimentally inoculated intranasally with 5*105 p.f.u. of (A) SC35, (B) SC35-PB1SC35F, (C) SC35-PB2SC35F, (D) SC35-NASC35F, (E) SC35-HASC35F, (F) SC35-HA111T, (G) SC35-HA146S, (H) SC35-HA340R and (I) SC35F-HAmono recombinant viruses. Sentinel guinea pigs were introduced into the same cage, allowing direct contact between the animals (half-filled squares; n = 2 (A, C, D, F, G, H, I); n = 6 (B and E were repeated independently and results could be confirmed)). To obtain viral titers in the upper respiratory tract, nasal washes of sentinel and donor animals were determined on days 1, 3, 6 and 9 p.i. by plaque assay on MDCK cells. (J) Hematoxylin staining of the trachea and bronchioles of SC35-HASC35F and SC35-PB1SC35F infected guinea pigs.