Degradation and inactivation of adenovirus in water by photo-electro-oxidation

Abstract

The present study analyzed the efficiency of the photo-electro-oxidation process as a method for degradation and inactivation of adenovirus in water. The experimental design employed a solution prepared from sterile water containing 5.10 7 genomic copies/L (gc/L) of a standard strain of human adenovirus type 5 (HAdV-5) divided into two equal parts, one to serve as control and one treated by photo-electro-oxidation (PEO) for 3 hours and with a 5A current. Samples collected throughout the exposure process were analyzed by real-time polymerase chain reaction (qPCR) for viral genome identification and quantitation. Prior to gene extraction, a parallel DNAse treatment step was carried out to assess the integrity of viral particles. Integrated cell culture (ICC) analyses assessed the viability of infection in a cell culture. The tested process proved effective for viral degradation, with a 7 log 10 reduction in viral load after 60 minutes of treatment. The DNAse-treated samples exhibited complete reduction of viral load after a 75 minute exposure to the process, and ICC analyses showed completely non-viable viral particles at 30 minutes of treatment.Keywords: adenovirus, advanced oxidation process, photo-electro-oxidation, water. Degradação e inativação de adenovírus na água por fotoeletrooxidação ResumoO presente estudo analisou a eficiência do processo de fotoeletrooxidação como metodologia para a degradação e inativação de adenovírus em água. A concepção experimental emprega uma solução preparada a partir de água estéril contendo 5,10 7 cópias genômicas/L (gc/L) de uma amostra padrão de adenovírus humano tipo 5 (HAdV-5), dividida em duas partes iguais, uma para servir como controle e outra tratada por fotoeletrooxidação (PEO) durante 3 horas e com uma corrente de 5A. As amostras recolhidas durante o processo de exposição foram analisadas por PCR quantitativo em tempo real (qPCR) para identificação e quantificação do genoma viral. Antes da extração de ácidos nucleicos, um passo de tratamento com DNAse paralelo foi realizado para avaliar a integridade das partículas virais. Um ensaio de qPCR integrado à cultura de células (ICC-qPCR) permitiu analisar a viabilidade de infecção em uma cultura de células. O processo mostrou-se eficaz testada para a degradação viral, com uma redução de 7 log 10 da carga viral após 60 minutos de tratamento. As amostras tratadas com DNAse exibiram redução completa da carga viral após uma exposição de 75 minutos ao processo, e a análise de ICC-qPCR mostrou partículas virais completamente não-viáveis em 30 minutos de tratamento.Palavras-chave: adenovírus, processo de oxidação avançada, fotoeletrooxidação, água.

Advanced Oxidation Processes for Water and Wastewater Viral Disinfection. A Systematic Review

“…On the other hand, they are frequently characterized by low selectivity and reaction rates. Their application may be restricted by high operational costs associated with the use of UV irradiation and electric power (Monteiro et al, 2015 ; Rasalingam et al, 2014 ).…”

“…Exposure for 75 min was required for the complete abatement of DNAse-treated samples used to study intact viruses only. Completely non-viable adenoviruses were obtained after 30 min, as was evidenced by integrated cell culture quantitative polymerase chain reaction (ICC/qPCR) analysis (Monteiro et al, 2015 ).…”

“…1 ). They are based on the production of highly reactive oxygen species (ROS), characterized by the non-selectivity on the target and can be used as pre- or post-treatment to a biological process (Galeano et al, 2019 ; Kokkinos et al, 2020 ; Monteiro et al, 2015 ). The principal oxidizing agent is the hydroxyl radical, being the second most powerful oxidant after fluorine.…”

“…Their diversity and polymorphic nature have been recognized and are continuously unraveled (Cantalupo et al, 2011 ; Giannakis et al, 2017b ; Marjanovic et al, 2018 ) Enteric viruses are listed as emerging biological contaminants on the United States Environmental Protection Agency (USEPA) Contaminant Candidate List (Gomes et al, 2019 ). Water treatment technologies are required to achieve a 99.99% (4-log) reduction in sample viral concentrations after treatment, to be considered efficient by USEPA and Health Canada (Monteiro et al, 2015 ).…”

Photo-assisted electrochemical advanced oxidation processes for the disinfection of aqueous solutions: A review

“…In this way, E. coli bacteria treated with a Ag/AgBr/TiO 2 electrode were found to be substantially damaged, forming pits and holes in the cell walls ( Hou et al., 2012 ). DSA anodes coupled with a Ti/TiO 2 cathode can also be employed for the inactivation of adenovirus, with UV irradiation and 5 A of applied current, promoting the UV photo-assisted production of • OH radical species ( Monteiro et al., 2015 ).…”