Growth Kinetics of H1N1 Viruses from the 2007–2008 Season Sensitive or Resistant to Oseltamivir.

<p>Two sensitive (A/Paris/497/2007 and A/Paris/1149/2008) and two resistant (A/Paris/644/2007 and A/Paris/1170/2008) viruses from the 2007–2008 influenza season, as well as the reference strain A/Solomon Islands/3/2006 and an isolate from the 2003–2004 season (A/Paris/650/2004), were amplified and titrated on MDCK cells. The indicated viruses were then used to infect MDCK SIAT-1 cells <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000103#ppat.1000103-Matrosovich1" target="_blank">[31]</a> at an m.o.i. of 0.001 and incubated for 72 hours at 35°C in the presence of 1 μg/ml TPCK trypsin. At the indicated time points, the supernatants were harvested and virus titers were determined by plaque assays on MDCK cells.