Virus disinfection mechanisms: the role of virus composition, structure, and function

Virus inactivation by chemical disinfectants is an important instrument for infection control in medical settings, but the mechanisms involved are poorly understood. In this study, we systematically investigated the effects of several antiviral treatments on hepatitis C virus (HCV) particles as model for enveloped viruses. Studies were performed with authentic cell culture-derived viruses, and the influence of chemical disinfectants, heat, and UV treatment on HCV was analyzed by the determination of infectious particles in a limiting-dilution assay, by quantitative reverse transcription-PCR, by core enzyme-linked immunosorbent assay, and by proteolytic protection assay. All different inactivation methods resulted in a loss of HCV infectivity by targeting different parts of the virus particle. Alcohols such as ethanol and 2-propanol did not affect the viral RNA genome integrity but disrupted the viral envelope membrane in a capsid protection assay. Heat and UV treatment of HCV particles resulted in direct damage of the viral genome since transfection of viral particle-associated RNA into permissive cells did not initiate RNA replication. In addition, heat incubation at 80°C disrupted the HCV envelope, rendering the viral capsid susceptible to proteolytic digest. This study demonstrated the molecular processes of viral inactivation of an enveloped virus and should facilitate the development of effective disinfection strategies in infection control not only against HCV but also against other enveloped viruses.

Section: Discussionmentioning

confidence: 99%

Mechanisms of Methods for Hepatitis C Virus Inactivation

Pfaender

Brinkmann

Todt

et al. 2015

“…Because damage to the virus capsid is the only or primary damage inflicted by several of the inactivation methods, the methods that offer the most promise are those that rely on binding to an intact viral capsid, such as the capture of virus by HBGA, followed by detection of viral RNA by RT-qPCR (71). Ultimately, a more basic understanding of the mechanisms of disinfection is needed, including answers to questions such as which residues of the viral capsid and/or genome are involved during disinfection and whether these changes are similar for different enteric viruses (72). Such information could provide us with important insights on how to measure loss of infectivity in human noroviruses without an in vitro cell culture assay.…”

Section: Fig 7 Reductions In Tuv Infectivity and In Tuv And Human Normentioning

confidence: 99%

Comprehensive Comparison of Cultivable Norovirus Surrogates in Response to Different Inactivation and Disinfection Treatments

Cromeans

Park

Costantini

et al. 2014

177

174

g Human norovirus is the leading cause of epidemic and sporadic acute gastroenteritis. Since no cell culture method for human norovirus exists, cultivable surrogate viruses (CSV), including feline calicivirus (FCV), murine norovirus (MNV), porcine enteric calicivirus (PEC), and Tulane virus (TuV), have been used to study responses to inactivation and disinfection methods. We compared the levels of reduction in infectivities of CSV and Aichi virus (AiV) after exposure to extreme pHs, 56°C heating, alcohols, chlorine on surfaces, and high hydrostatic pressure (HHP), using the same matrix and identical test parameters for all viruses, as well as the reduction of human norovirus RNA levels under these conditions. At pH 2, FCV was inactivated by 6 log 10 units, whereas MNV, TuV, and AiV were resistant. All CSV were completely inactivated at 56°C within 20 min. MNV was inactivated 5 log 10 units by alcohols, in contrast to 2 and 3 log 10 units for FCV and PEC, respectively. TuV and AiV were relatively insensitive to alcohols. FCV was reduced 5 log 10 units by 1,000 ppm chlorine, in contrast to 1 log 10 unit for the other CSV. All CSV except FCV, when dried on stainless steel surfaces, were insensitive to 200 ppm chlorine. HHP completely inactivated FCV, MNV, and PEC at >300 MPa, and TuV at 600 MPa, while AiV was completely resistant to HHP up to 800 MPa. By reverse transcription-quantitative PCR (RT-qPCR), genogroup I (GI) noroviruses were more sensitive than GII noroviruses to alcohols, chlorine, and HHP. Although inactivation profiles were variable for each treatment, TuV and MNV were the most resistant CSV overall and therefore are the best candidates for studying the public health outcomes of norovirus infections.

“…First, compared to bacterial pathogens, viruses are more resistant to disinfection by standard water disinfection treatments (2, 5, 6). Second, for those conditions that do indeed neutralize viruses, the molecular mechanism(s) responsible for inactivation is unclear (7,8). Third, it is only recently that technologies such as quantitative PCR (qPCR) and deep genome sequencing have allowed for the detection of viral genomes in water samples (1, 4, 9, 10).…”

mentioning

confidence: 99%

Solar and Temperature Treatments Affect the Ability of Human Rotavirus Wa To Bind to Host Cells and Synthesize Viral RNA

Romero‐Maraccini

Shisler

Nguyen

2015

Rotavirus, the leading cause of diarrheal diseases in children under the age of five, is often resistant to conventional wastewater treatment and thus can remain infectious once released into the aquatic environment. Solar and heat treatments can inactivate rotavirus, but it is unknown how these treatments inactivate the virus on a molecular level. To answer this question, our approach was to correlate rotavirus inactivation with the inhibition of portions of the virus life cycle as a means to identify the mechanisms of solar or heat inactivation. Specifically, the integrity of the rotavirus NSP3 gene, virus-host cell interaction, and viral RNA synthesis were examined after heat (57°C) or solar treatment of rotavirus. Only the inhibition of viral RNA synthesis positively correlated with a loss of rotavirus infectivity; 57°C treatment of rotavirus resulted in a decrease of rotavirus RNA synthesis at the same rate as rotavirus infectivity. These data suggest that heat treatment neutralized rotaviruses primarily by targeting viral transcription functions. In contrast, when using solar disinfection, the decrease in RNA synthesis was responsible for approximately one-half of the decrease in infectivity, suggesting that other mechanisms, including posttranslational, contribute to inactivation. Nevertheless, both solar and heat inactivation of rotaviruses disrupted viral RNA synthesis as a mechanism for inactivation.O f all waterborne microbes that can cause pathogenic diseases, viruses remain the most challenging for study in aquatic environments (1-4). This is for several reasons. First, compared to bacterial pathogens, viruses are more resistant to disinfection by standard water disinfection treatments (2, 5, 6). Second, for those conditions that do indeed neutralize viruses, the molecular mechanism(s) responsible for inactivation is unclear (7,8). Third, it is only recently that technologies such as quantitative PCR (qPCR) and deep genome sequencing have allowed for the detection of viral genomes in water samples (1, 4, 9, 10).Enteric viruses include rotavirus, adenovirus, coxsackievirus, and norovirus (4). Rotavirus is the leading cause of diarrhea hospitalizations for children under 5 years of age and is responsible for the deaths of an estimated 453,000 children each year (11). Despite this impact on human health, little is known as to what conditions result in the best disinfection of rotavirus in wastewater and drinking water. In addition, it is unclear how a disinfectant functions on a molecular level to inactivate rotavirus.Rotavirus is a nonenveloped virus with a double-stranded, segmented RNA genome. Six structural proteins make up the capsid, including VP4 and VP7. For rotavirus to attach to its host cell, VP4 binds to the host cell receptors, and after a multistep process involving the VP4, VP7, and other cellular proteins, rotavirus enters the host cell through endocytosis. Upon penetration, rotavirus loses its outer capsid (VP7 and VP4), and the double-layered particle is transported to the cell cytopl...