FIG 1.

Viral load and replication kinetics of RSV infection. HEp-2 and A549 cells were infected with RSV (RSV/A/Tracy [GA1], RSV/A/Ontario [ON], RSV/B/18537 [GB1], RSVB/Buenos Aires [BA]) at a multiplicity of infection (MOI) of 0.01. Samples were collected at 24, 48, 72, and 96 h postinoculation (hpi). RNA was isolated from media (extracellular) and cell lysate (intracellular) and copy numbers of RSV nucleocapsid (N) gene RNA were determined using quantitative real-time PCR (qRT-PCR). Levels of RSV N gene RNA in (A) HEp-2 cells at different time points after RSV inoculation, and (B) A549 cells at different time points after RSV inoculation. (C) Extracellular live virus was collected from the media of HEp-2 and A549 inoculated cell cultures. The extracellular virus concentrations were determined by a quantitative plaque assay and reported as log₁₀ plaque forming unit (PFU)/mL in HEp-2 cells. Data shown are from two individual experiments with two replicates per group in each experiment and are represented as mean ± SD.