Publications de Tamar Kohn | EPFL Graph Search

Publications associées (102)

Oxidation of Virus Proteins during UV(254) and Singlet Oxygen Mediated Inactivation

Tamar Kohn, Krista Rule Wigginton, Jonathan Paz Montoya

Despite the widespread use of UV254 irradiation and solar disinfection for water treatment, little is known about the photochemical pathways that lead to virus inactivation by these treatments. The goal of this study was to identify reactions that occur in ...

2010

Inactivation of bacteriophage MS2 with potassium ferrate(VI)

Tamar Kohn, Anne Thérèse Sigstam, Timothy Strathmann

Ferrate [Fe(VI); FeO42-] is an emerging oxidizing agent capable of controlling chemical and microbial water contaminants. Here, inactivation of MS2 coliphage by Fe(VI) was examined. The inactivation kinetics observed in individual batch experiments was wel ...

Amer Chemical Soc2012

Salt Supersaturation as an Accelerator of Influenza A Virus Inactivation in 1 μL Droplets

Tamar Kohn, Athanasios Nenes, Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler, Céline Terrettaz, Laura José Costa Henriques

Influenza A virus (IAV) spreads through exhaled aerosol particles and larger droplets. Estimating the stability of IAV is challenging and depends on factors such as the respiratory matrix and drying kinetics. Here, we combine kinetic experiments on millime ...

2024

UV radiation induces genome-mediated, site-specific cleavage in viral protein

Tamar Kohn, Yury Tsybin, Laure Menin, Krista Rule Wigginton, Michele Cascella, Anne Thérèse Sigstam, Hisham Ben Hamidane

Much research has been dedicated to understanding the molecular basis of UV damage to biomolecules, yet many questions remain regarding the specific pathways involved. Here we describe a genome-mediated mechanism that causes sitespecific virus protein clea ...

2012

Waterborne Virus Transport and Risk Assessment in Lake Geneva Under Climate Change

Tamar Kohn, Chaojie Li

Climate changes influence lake hydrodynamics and radiation levels and thus may affect the fate and transport of waterborne pathogens in lakes. This study examines the impact of climate change on the fate, transport, and associated risks of four waterborne ...

2024

Subtle differences in virus composition affect disinfection kinetics and mechanisms

Tamar Kohn, Krista Rule Wigginton, Michele Cascella, Brian Pecson, Anne Thérèse Sigstam

Viral disinfection kinetics have been studied in depth, but the molecular-level inactivation mechanisms are not understood. Consequently, it is difficult to predict the disinfection behavior of non-culturable viruses, even when related, culturable viruses ...

American Society for Microbiology2013

Spatial and temporal presence of a wastewater-derived micropollutant plume in Lake Geneva

Tamar Kohn, Florence Bonvin, Rebecca Rutler

This study discusses the occurrence and environmental risk associated with a micropollutant plume originating from the direct discharge of treated wastewater into the Vidy Bay of Lake Geneva, Switzerland. The temporal variations and spatial extent of the p ...

2011

Ammonia as an in-situ sanitizer: inactivation kinetics and mechanisms of the ssRNA virus MS2 by NH3

Tamar Kohn, Loïc Decrey

Sanitizing human and animal waste (e.g., urine, fecal sludge or grey water) is a critical step in reducing the spread of disease and ensuring microbially safe reuse of waste materials. Viruses are particularly persistent pathogens and can be transmitted th ...

2015

Virus inactivation mechanisms: impact of disinfectants on virus function and structural integrity

Tamar Kohn, Brian Pecson, Krista Rule Wigginton, Anne Thérèse Sigstam, Franziska Sara Bosshard

Oxidative processes are often harnessed as tools for pathogen disinfection. Although the pathways responsible for bacterial inactivation with various biocides are fairly well understood, virus inactivation mechanisms are often contradictory or equivocal. I ...

Amer Chemical Soc2012

Reactivity of Alkyl Polyhalides toward Granular Iron: Development of QSARs and Reactivity Cross Correlations for Reductive Dehalogenation

Tamar Kohn

Attempts to develop quantitative structure-activity relationships (QSARs) for reductive dehalogenation have been hindered by the unavailability of high quality predictor variables, have included relatively few compounds, and on occasion have relied on data ...

2010

Expiratory Aerosol pH: The Overlooked Driver of Airborne Virus Inactivation

Athanasios Nenes, Tamar Kohn, Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos, Aline Laetitia Schaub, Shannon Christa David, Walter Hugentobler

Respiratory viruses, including influenza virus and SARS-CoV-2, are transmitted by the airborne route. Air filtration and ventilation mechanically reduce the concentration of airborne viruses and are necessary tools for disease mitigation. However, they ign ...

2023

Virus inactivation in stored human urine, sludge and animal manure under typical conditions of storage or mesophilic anaerobic digestion

Tamar Kohn, Loïc Decrey

Viruses represent major disease transmitting agents carried by human excreta and animal manure. Understanding virus inactivation is therefore essential in preventing microbial spread due to inadequate treatment of these materials. Here, we investigated the ...

Royal Soc Chemistry2017

Viral Transfer and Inactivation through Zooplankton Trophic Interactions

Tamar Kohn, Virginie Bachmann, Xavier Fernandez Cassi, Margot Ninon Lauren Olive

Waterborne viruses are responsible for numerous diseases and are abundant in aquatic systems. Understanding the fate of viruses in natural systems has important implications for human health. This research quantifies the uptake of bacteriophage T4 and the ...

2020

Sunlight-mediated inactivation of health-relevant microorganisms in water: A review of mechanisms and modeling approaches

Tamar Kohn, Krista Rule Wigginton, Yang Liu

Health-relevant microorganisms present in natural surface waters and engineered treatment systems that are exposed to sunlight can be inactivated by a complex set of interacting mechanisms. The net impact of sunlight depends on the solar spectral irradianc ...

2018

Salt enhances the thermostability of enteroviruses by stabilizing capsid protein interfaces

Tamar Kohn, Matteo Dal Peraro, Alessio Prunotto, Simon Meister

Enteroviruses are common agents of infectious disease that are spread by the fecal-oral route. They are readily inactivated by mild heat, which causes the viral capsid to disintegrate or undergo conformational change. While beneficial for the thermal treat ...

American Society for Microbiology2020

Estimated transmission dynamics of SARS-CoV-2 variants from wastewater are unbiased and robust to differential shedding

Tamar Kohn, Timothy R. Julian, Charles Zeng Gan

The COVID-19 pandemic has accelerated the development and adoption of wastewater-based epidemiology. Wastewater samples can provide genomic information for detecting and assessing the spread of SARS-CoV-2 variants in communities and for estimating importan ...

2025

Inactivation and tailing during UV254 disinfection of viruses: contributions of viral aggregation, light shielding within viral aggregates and recombination

Tamar Kohn, Michael Jon Mattle

UV disinfection of viruses frequently leads to tailing after an initial exponential decay. Aggregation, light shielding, recombination or resistant virus sub-populations were proposed as explanations; however, none of these options has conclusively been de ...

Amer Chemical Soc2012

Adaptation of Human Enterovirus to Warm Environments Leads to Resistance against Chlorine Disinfection

Tamar Kohn, Timothy R. Julian, Anna Carratala Ripolles, Virginie Bachmann

Sunlight, temperature, and microbial grazing are among the environmental factors promoting the inactivation of viral pathogens in surface waters. Globally, these factors vary across time and space. The persistence of viral pathogens, and ultimately their e ...

2020

Mechanisms of Human Adenovirus Inactivation by Sunlight and UVC Light as Examined by Quantitative PCR and Quantitative Proteomics

Tamar Kohn, Romain Hamelin, Florence Armand, Franziska Sara Bosshard

Human adenoviruses (HAdV) are important pathogens in both industrialized and developing nations. HAdV has been shown to be relatively resistant to monochromatic UVC. Polychromatic UVC, in contrast, is a more effective means of disinfection, presumably due ...

American Society for Microbiology2013

Quantitative PCR for determining the infectivity of bacteriophage MS2 upon inactivation by heat, UVB and singlet oxygen: advantages and limitations of an enzymatic treatment to reduce false-positive results

Tamar Kohn, Brian Pecson

Health risks posed by waterborne viruses are difficult to assess because it is tedious or impossible to determine the infectivity of many viruses. Recent studies hypothesized that quantitative PCR (qPCR) could selectively quantify infective viruses if prec ...

American Society for Microbiology2009