Shotaro Torii

The primary concentration and molecular process are critical to implement wastewater-based epidemiology for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the previously developed methods were optimized for nonenveloped viruses. Few studies evaluated if the methods are applicable to the efficient recovery of enveloped viruses from various types of raw sewage. This study aims (1) to compare the whole process recovery of Pseudomonas phage φ6, a surrogate for enveloped virus

Polyethylene glycol (PEG) precipitation is one of the conventional methods for virus concentration. This technique has been used to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater. The procedures and seeded surrogate viruses were different among implementers; thus, the reported whole process recovery efficiencies considerably varied among studies. The present study compared five PEG precipitation procedures, with different operational parameters, for the RT-

The disinfection susceptibilities of viruses vary even among variants, yet the inactivation efficiency of a certain virus genotype, species, or genus was determined based on the susceptibility of its laboratory strain. The objectives were to evaluate the variability in susceptibilities to free chlorine, UV₂₅₄, and ozone among 13 variants of coxsackievirus B5 (CVB5) and develop the model allowing for predicting the overall inactivation of heterogeneous CVB5. Our results showed that the

Inactivation kinetics of enterovirus by disinfection is often studied using a single laboratory strain of a given genotype. Environmental variants of enterovirus are genetically distinct from the corresponding laboratory strain, yet it is poorly understood how these genetic differences affect inactivation. Here we evaluated the inactivation kinetics of nine coxsackievirus B3 (CVB3), ten coxsackievirus B4 (CVB4), and two echovirus 11 (E11) variants by free chlorine and ultraviolet irradiation (UV

Repeated pressurization caused integrity loss at the surface of reverse osmosis membranes resulting in a dramatic decrease in virus removal.

Virucidal efficacies of disinfectants are typically assessed by infectivity assay utilizing a single type of host cell. Enteroviruses infect multiple host cells <i>via</i> various entry routes, and each entry route may be impaired differently by a given disinfectant. Yet, it is unknown how the choice of host cells affects the observed inactivation kinetics. Here, we evaluated the inactivation kinetics of echovirus 11 (E11) by free chlorine, ultraviolet (UV) irradiation, and heat, using three dif

Abstract Waterborne outbreaks caused by protozoan, bacterial, and viral pathogens continue to pose serious public health threats. However, comprehensive monitoring of all three major pathogen types remains uncommon, primarily due to the technical difficulty of simultaneously concentrating and characterizing these diverse microorganisms from a single water sample. Here, we evaluated a membrane adsorption followed by bead-beating-based direct nucleic acid extraction for its sensitivity in detectin

The sensitivity of enteroviruses to disinfectants varies among genetically similar variants and coincides with amino acid changes in capsid proteins, although the effect of individual substitutions remains unknown. Here, we employed reverse genetics to investigate how amino acid substitutions in coxsackievirus B5 (CVB5) capsid proteins affect the virus' sensitivity to free chlorine and heat treatment. Of ten amino acid changes observed in CVB5 variants with free chlorine resistance, none signifi

ウイルスの遊離塩素耐性は水質に依存し，不活化に必要なCT値が水温，pHごとに定められてきた．近年，同じウイルス種内でも塩素耐性に違いがあることが示された．本研究は，高耐性株の存在が実際の浄水の塩素処理効率に及ぼす影響を評価することを目的とした．多摩川，相模川のF特異RNA大腸菌ファージGI型の塩素耐性を評価し，同種内の遊離塩素耐性のばらつきを考慮した不活化モデルを作成した．GI型野生株の86％（30/35株）で，実験室株MS2, frより塩素耐性が高かった．また，MS2の8 log不活化が期待できるCT値では，GI型野生株の全体不活化率が，5.3-5.6 logにとどまると算定された．環境水中におけるウイルスの消毒効果の推測では，実験室株によって代替するのではなく，種内の遊離塩素耐性のばらつきを算入した不活化モデルを採用すべきである．

Abstract Disinfection is key to controlling the infection risk caused by viral contaminations. Recent disinfection guidelines often refer to a single virus resistant to the disinfectant of interest, despite a large variation in sensitivity to disinfectants between viruses or even strains within the same species. Here, we show a statistical framework to integrate multiple experimental datasets and measure the variation in sensitivity to disinfectants across different virus species by a parametric

• Simultaneous detection of protozoa, bacteria, and viruses in water • 0.8 µm MCE membrane with MgCl 2 offers highest recovery efficiency • rRNA targeting and preamplification improve detection sensitivity • This method achieves as high sensitivity as IFAT for Giardia detection Waterborne outbreaks caused by protozoan, bacterial, and viral pathogens continue to pose serious public health threats. However, comprehensive monitoring of all three major pathogen types remains uncommon, primarily due

Abstract The sensitivity of enteroviruses to disinfectants varies among genetically similar variants and coincides with amino acid changes in capsid proteins, though the effect of individual substitutions remains unknown. Here, we employed reverse genetics to investigate how amino acid substitutions in coxsackievirus B5 (CVB5) capsid proteins affect its sensitivity to free chlorine and heat treatment. Of ten amino acid changes hypothesized to coincide with free chlorine resistance, none signific

This folder contains the experimental data to the figures shown in the main manuscript and Supporting Information. - Figure 1 (Inactivation curves for E11 by free chlorine, UV, and heat) - Figure 2 (Inactivation curves for CVA9, CVB1, E7, E9, and E13) - Figure S1 (Loss of attachment and the PCR-target by free chlorine treatment) - Figure S2 (Flow cytometric analysis)