Fig 1.
Viral RNA load in ferrets inoculated with influenza virus A/NL/16/98.
Immunocompetent (blue) and immunocompromised (red, green) ferrets were inoculated with influenza virus A/NL/16/98 (H3N2) and subsequently treated with Oseltamivir (green) or left untreated (blue, red). Virus RNA load in samples of the throat (A) and nose (C) was determined by qRT-PCR daily for 18 days. The area under the curve of panels A and C was used to estimate the total amount of viral RNA shedding from the throat (B) and nose (D) of the inoculated ferrets. The line and bar graphs depict the mean ± S.E.M. The asterisks indicates a statistically significant P value (***P<0.001).
Fig 2.
Emergence of Oseltamivir resistant viruses in ferrets.
The emergence of Oseltamivir resistant viruses was monitored in throat and nose samples from untreated immunocompetent ferrets (A), untreated immunocompromised ferrets (B) and Oseltamivir treated immunocompromised ferrets (C) by mutation-specific RT-PCR for the Oseltamivir-resistance mutation R292K. The green bars depict the presence of the wildtype genotype (292R) and the magenta the presence of the resistant genotype (292K). If both genotypes were present in one sample, the proportions of the genotypes are stacked.
Fig 3.
The frequency of the R292K mutation as determined by Illumina NGS in Oseltamivir treated immunocompromised ferrets.
The percentage of the R292K variant was determined in pooled throat/nose samples collected at 2, 4, 6, 8 and 10 dpi from immunocompromised ferrets that received Oseltamivir treatment. The graph depicts the frequency of the R292K mutation over time for each ferret separately, with circles, squares, triangles, down triangles, diamonds and open circles representing ferrets 1–6 respectively.
Table 1.
Amino acid substitution in hemagglutinin and neuraminidase sequences of OS treated immunocompromised ferrets by Illumina next generation sequencing.