Figure 3

Decay of GII.4 HuNoVs after exposure to acid pH and proteolytic enzyme treatments. GII.4 HuNoV gc from fully intact capsids were quantified using RNase treatment followed by RNA amplification by RT-qPCR. The filled-in circle (●) represents native GII.4 HuNoV gc at pH 8.0. The filled-in square (■) and outlined square (□) represent GII.4 HuNoV gc treated at pH 1.3 alone and at pH 1.3 with 1,500 units/mL pepsin, respectively. The filled-in triangle (▲), outlined triangle (∆) and filled-in diamond (♦) represent GII.4 HuNoV gc after treatment at pH 8.0 with 0.1 mg/mL chymotrypsin, 100 mg/mL chymotrypsin, and 100 mg/mL trypsin, respectively. Each treatment was applied for 4 h at 37 °C. The log (C/C₀) values were calculated by dividing the mean GII.4 HuNoV gc values following treatment by the mean native GII.4 HuNoV gc values at pH 8.0. Each data point is an average of at least two replicates. Error bars indicate standard deviations. The Mann–Whitney U test was used to compare groups⁶⁴.