Compared pathogenicity of mc88180, mcCu-1, A88BCU1 and ACU1B88 in seven-week old SPF chickens (experiment <i>ii</i>).

<p>On the first day of the experiment, SPF chickens were housed in five groups of 20 chickens of comparable sex and weight. On the same day, each bird was inoculated by the intranasal route with a standardized dose of the relevant virus (10⁵ EID₅₀ by bird, except for the ACU1 B88 virus which was inoculated with 10^3.6 EID₅₀ by bird). A group was kept as a mock-inoculated control receiving PBS only. See in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028064#pone.0028064.s003" target="_blank">Table S3</a> the summarized protocol of the animal experiment. <b>A</b>) % cumulated mortality at 5 days post infection, <b>B</b>) BF to body weights ratio (‰) at day 20 (n = 7 to 10 chickens depending on the group). The box plots show the median (horizontal line) flanked by the 2^nd and 3^rd quartile. The outer bars show the range of values. <b>C</b>) and <b>D</b>) Histological lesion scoring at day 4 and 20, respectively (n = 5 chickens per group). The outer bars show the range of values. <b>E</b>) VN titer at day 20 (in log₂, n = 10 chickens per group). <b>F</b>) Virus titer at day 4 (in log₁₀ EID_50/gr, n = 5 chickens per group). Treatments sharing the same lowercase letter do not differ significantly according to the kruskal-Wallis test (BF to body weights ratio, lesion score, VN titer and virus titer) or according to the Chi-squared test (% mortality), at the p≤0.05 confidence level.