UV Inactivation of Rotavirus and Tulane Virus Targets Different Components of the Virions

Abstract

Enteric viruses are shed in fecal material by humans and other animals and are common contaminants in wastewater and surface water. Wastewater treatment plants often disinfect this effluent with low-pressure and medium-pressure UV lamps, which emit 254-nm and 220- to 280-nm irradiation, respectively. It is not known whether this treatment is efficacious against enteric viruses or how such treatments may inactivate these enteric viruses. This study examined UV disinfection for two enteric viruses: rotavirus (RV) (strain OSU with double-stranded RNA and a three-layer capsid) and Tulane virus (TV) (a cultivable surrogate for human norovirus with single-stranded RNA and a single-layer capsid). Viruses were treated with UV irradiation at 220 or 254 nm under conditions relevant to wastewater stabilization ponds, whose water is often used for irrigation. TV was susceptible to 220- or 254-nm UV at similar levels. It appears that UV irradiation inactivated TV by mutagenizing both its genome and capsid binding proteins. RV was more susceptible to UV at 220 nm than to UV at 254 nm. UV irradiation of RV at either 220 or 254 nm resulted in a virus that retained its ability to bind to its host cell receptor. After 220-nm treatment, the VP7 segment of the RV genome could not be amplified by PCR, suggesting that this treatment mutagenized the viral genome. However, this correlation was not observed when UV at 254 nm was used. Thus, RV and TV, with different genome and capsid contents, are targeted by UV irradiation in different ways. IMPORTANCE UV irradiation is becoming common for disinfection in water treatment plants, but little is known about the effectiveness of this treatment for enteric RNA viruses. Here, we observed that 220-nm UV irradiation was efficacious against rotavirus (RV) and Tulane virus (TV). UV irradiation at 254 nm inactivated TV to a greater extent than RV. Additional assays showed that UV irradiation compromised different portions of the RV and TV life cycles. UV irradiation decreased the binding of TV to its host receptor and mutagenized the TV genome. UV irradiation at 220 nm appeared to allow RV–host receptor interaction but halted RV genome replication. These findings provide knowledge about the disinfection of waterborne viruses, information that is important for the safe reuse or release of treated wastewater.

UV-C irradiation is highly effective in inactivating SARS-CoV-2 replication

“…Non-contact disinfection technologies are highly desirable, and UV radiation, in particular UV-C (200 – 280 nm) has been suggested to be able to inactivate different viruses, including SARS-CoV 8–12 . The interaction of UV-C radiations with viruses has been extensively studied 13–15 , and direct absorption of the UV-C photon by the nucleic acid basis and/or capsid proteins leading to the generation of photoproducts that inactivate the virus was suggested to be one of the main UV-C-associated virucidal mechanisms 16,17 . Some models have been proposed to correlate the nucleic acid structure with the required dose to inactivate the virus, but a reliable model is still unavailable 18 .…”

Control Measures for SARS-CoV-2: A Review on Light-Based Inactivation of Single-Stranded RNA Viruses

“…In adenoviruses (dsDNA virus), DNA damage is only responsible for the loss of infectivity at UV wavelengths above 240 nm, whereas damage to other viral components contributes to the loss of infectivity at UV wavelengths below 240 nm [ 94 ]. Similarly, the inactivation rate of Tulane virus (calicivirus with ssRNA) was found to be the same at 220 nm and 254 nm, whereas porcine rotavirus (OSU strain; dsRNA) was more sensitive to UV light at 220 nm than at 254 nm [ 95 ]. Further, UV-light treatment on Tulane virus resulted in damage to both its capsid binding protein and genome, whereas the porcine rotavirus was only inactivated via mutagenesis of its genome [ 95 ].…”

“…Similarly, the inactivation rate of Tulane virus (calicivirus with ssRNA) was found to be the same at 220 nm and 254 nm, whereas porcine rotavirus (OSU strain; dsRNA) was more sensitive to UV light at 220 nm than at 254 nm [ 95 ]. Further, UV-light treatment on Tulane virus resulted in damage to both its capsid binding protein and genome, whereas the porcine rotavirus was only inactivated via mutagenesis of its genome [ 95 ]. These findings should prompt researchers to be prudent in selecting viral surrogates—MS2 bacteriophage is a common surrogate for enteric viruses in the validation studies of viral clearance in samples treated by polychromatic UV reactor, despite the fact that enteric viruses may have different UV spectral sensitivities [ 93 , 96 ].…”

Dry Heat as a Decontamination Method for N95 Respirator Reuse

“…We used the previously established molecular assays with a slight modification to analyze the primary structural target of Tulane virus by the dry heat treatment. 13,14 An RNase assay, a binding assay using magnetic beads coated with the host cell receptors, and a two-step RT-qPCR assay were applied to examine the integrity of capsid proteins, binding proteins, and viral genomes, respectively. Details of the molecular assays are explained in Text S3.…”