Afolayan Olamide T, Webb Cathy C, Cannon Jennifer L
Department of Food Science and Technology, Center for Food Safety, University of Georgia, 1109 Experiment Street, Griffin, GA, 30223, USA.
Food Environ Virol. 2016 Mar;8(1):70-8. doi: 10.1007/s12560-015-9219-z. Epub 2015 Oct 29.
Human noroviruses (NoVs) are a major source of foodborne illnesses worldwide. Since human NoVs cannot be cultured in vitro, methods that discriminate infectious from non-infectious NoVs are needed. The purpose of this study was to evaluate binding of NoV genotypes GI.1 and GII.4 to histo-blood group antigens expressed in porcine gastric mucin (PGM) as a surrogate for detecting infectious virus following thermal (99 °C/5 min), 70% ethanol or 0.5% levulinic acid (LV) plus 0.01 or 0.1% sodium dodecyl sulfate (SDS) sanitizer treatments and to determine the limit of detection of GI.1 and GII.4 binding to PGM. Treated and control virus samples were applied to 96-well plates coated with 1 µg/ml PGM followed by RNase A (5 ng/µl) treatment for degradation of exposed RNA. Average log genome copies per ml (gc/ml) reductions and relative differences (RD) in quantification cycle (Cq) values after thermal treatment were 1.77/5.62 and 1.71/7.25 (RNase A) and 1.73/5.50 and 1.56/6.58 (no RNase A) for GI.1 and GII.4, respectively. Treatment of NoVs with 70% EtOH resulted in 0.05/0.16 (GI.1) and 3.54/10.19 (GII.4) log reductions in gc/ml and average RD in Cq value, respectively. LV (0.5%) combined with 0.1 % SDS provided a greater decrease of GI.1 and GII.4 NoVs with 8.97 and 8.13 average RD in Cq values obtained, respectively than 0.5% LV/0.01 % SDS. Virus recovery after PGM binding was variable with GII.4 > GI.1. PGM binding is a promising surrogate for identifying infectious and non-infectious NoVs after capsid destruction, however, results vary depending on virus strain and inactivation method.
人诺如病毒（NoVs）是全球食源性疾病的主要来源。由于人诺如病毒无法在体外培养，因此需要能够区分感染性和非感染性诺如病毒的方法。本研究的目的是评估诺如病毒GI.1和GII.4基因型与猪胃粘蛋白（PGM）中表达的组织血型抗原的结合情况，以此作为检测经热（99℃/5分钟）、70%乙醇或0.5%乙酰丙酸（LV）加0.01%或0.1%十二烷基硫酸钠（SDS）消毒剂处理后的感染性病毒的替代方法，并确定GI.1和GII.4与PGM结合的检测限。将处理后的病毒样品和对照病毒样品应用于包被有1μg/ml PGM的96孔板，随后用核糖核酸酶A（5ng/μl）处理以降解暴露的RNA。GI.1和GII.4经热处理后每毫升平均基因组拷贝数（gc/ml）的减少量和定量循环（Cq）值的相对差异（RD）分别为1.77/5.62和1.71/7.25（核糖核酸酶A）以及1.73/5.50和1.56/6.58（无核糖核酸酶A）。用70%乙醇处理诺如病毒后，gc/ml分别降低0.05/0.16（GI.1）和3.54/10.19（GII.4），Cq值的平均RD分别为上述数值。0.5%LV与0.1%SDS联合使用对GI.1和GII.4诺如病毒的降低效果比0.5%LV/0.01%SDS更好，获得的Cq值平均RD分别为8.97和8.13。PGM结合后病毒的回收率因GII.4＞GI.1而有所不同。PGM结合是衣壳破坏后鉴定感染性和非感染性诺如病毒的一种有前景的替代方法，然而，结果因病毒株和灭活方法而异。
