Department of Civil and Environmental Engineering , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States.
Department of Microbiology and Department of Pathobiology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States.
Environ Sci Technol. 2018 May 15;52(10):5682-5690. doi: 10.1021/acs.est.7b06562. Epub 2018 May 3.
Two rotavirus (RV) strains (sialidase-resistant Wa and sialidase-sensitive OSU) were irradiated with simulated solar UVA and visible light in sensitizer-free phosphate buffered solution (PBS) (lacking exogenous reactive oxygen species (ROS)) or secondary effluent wastewater (producing ROS). Although light attenuated for up to 15% through the secondary effluent wastewater (SEW), the inactivation efficacies increased by 0.7 log for Wa and 2 log for OSU compared to those in sensitizer-free phosphate buffered solution (PBS) after 4 h of irradiation. A binding assay using magnetic beads coated with porcine gastric mucin containing receptors for rotaviruses (PGM-MB) was developed to determine if inactivation influenced RV binding to its receptors. The linear correlation between the reduction in infectivity and the reduction in binding after irradiation in sensitizer-free solution suggests that the main mechanism of RV inactivation in the absence of exogenous ROS was due to damage to VP8*, the RV protein that binds to host cell receptors. For a given reduction in infectivity, greater damage in VP8* was observed with sialidase-resistant Wa compared to sialidase-sensitive OSU. The lack of correlation between the reduction in infectivity and the reduction in binding, in SEW, led us to include RNase treatment before the binding step to quantify virions with intact protein capsids and exclude virions that can bind to the receptors but have their capsid permeable after irradiation. This assay showed a linear correlation between the reduction in RV infectivity and RV-receptor interactions, suggesting that RV inactivation in SEW was due to compromised capsid proteins other than the VP8* protein. Thus, rotavirus inactivation by UVA and visible light irradiation depends on both the formation of ROS and the stability of viral proteins.
两种轮状病毒（RV）株（唾液酸酶抗性 Wa 和唾液酸酶敏感 OSU）在无敏化剂的磷酸盐缓冲液（PBS）（缺乏外源性活性氧（ROS））或二级出水（产生 ROS）中用模拟太阳 UVA 和可见光进行辐照。尽管二级出水（SEW）的光衰减高达 15%，但与无敏化剂磷酸盐缓冲液（PBS）相比，Wa 的失活功效增加了 0.7 对数，OSU 增加了 2 对数，辐照 4 小时后。开发了一种使用涂有猪胃粘蛋白（包含轮状病毒受体）的磁性珠的结合测定法来确定失活是否影响 RV 与其受体的结合。在无外源性 ROS 的情况下，感染性的降低与辐照后结合的降低之间的线性相关性表明，RV 失活的主要机制是由于 VP8的损伤，VP8是与宿主细胞受体结合的 RV 蛋白。对于给定的感染性降低，与唾液酸酶敏感的 OSU 相比，耐唾液酸酶的 Wa 中观察到 VP8的更大损伤。在 SEW 中，感染性降低与结合降低之间缺乏相关性，这导致我们在结合步骤之前进行 RNase 处理，以定量具有完整蛋白衣壳的病毒粒子，并排除经辐照后可以与受体结合但衣壳通透性增加的病毒粒子。该测定法显示 RV 感染性降低与 RV-受体相互作用之间存在线性相关性，表明 SEW 中 RV 的失活是由于衣壳蛋白（除 VP8蛋白外）受损所致。因此，UVA 和可见光辐照对轮状病毒的失活取决于 ROS 的形成和病毒蛋白的稳定性。
