Anna Carratala Ripolles

During my PhD, I mainly focused on characterizing the effect of environmental factors (namely temperature and sunlight) and disinfectants on the stability of human viral pathogens as contaminants of aquatic environments. In addition,I developed a novel source tracking tool to identify avian fecal contamination in environmental samples. Thanks to a research fellowship given by the Spanish Ministry of Science and Technology, I also had the opportunity to explore the diversity of marine viruses in Mediterranean coastal waters by genetic fingerprinting and by next generation sequencing. Later on, I became interested in the long-term effect of environmental stressors on virus communities, so I joined the LCE as a postdoc to investigate the adaptation of enteroviruses to ultraviolet radiation. For 4 years, I worked on developing UV-resistant viruses and characterizing their acquired phenotypic and genetic properties by combining directed evolution experiments, deep sequencing and population genetics. Out of the lab, I am passionate about nature, traveling and scuba diving.

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Domaines de recherche associés (31)

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Publications associées (31)

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Virus

Un virus est un agent infectieux nécessitant un hôte, souvent une cellule, dont les constituants et le métabolisme déclenchent la réplication. Le nom virus a été emprunté au par Ambroise Paré au la

Disinfectant

A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant ba

Mutation génétique

thumb|Un exemple de mutation homéotique : une drosophile Antennapedia Une est une modification rare, accidentelle ou provoquée, de l'information génétique (séquence d’ADN ou d’ARN) dans le génome.

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2022

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

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

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 ecology and dispersion, hinges on their ability to withstand the environmental conditions encountered. To understand how virus populations evolve under changing environmental conditions, we experimentally adapted echovirus 11 (E11) to four climate regimes. Specifically, we incubated E11 in lake water at 10 and 30 °C and in the presence and absence of sunlight. Temperature was the main driver of adaptation, resulting in an increased thermotolerance of the 30 °C adapted populations, whereas the 10 °C adapted strains were rapidly inactivated at higher temperatures. This finding is consistent with a source–sink model in which strains emerging in warm climates can persist in temperate regions, but not vice versa. A microbial risk assessment revealed that the enhanced thermotolerance increases the length of time in which there is an elevated probability of illness associated with swimming in contaminated water. Notably, 30 °C-adapted viruses also exhibited an increased tolerance toward disinfection by free chlorine. Viruses adapting to warm environments may thus become harder to eliminate by common disinfection strategies.

2020

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Control of Waterborne Human Viruses by Indigenous Bacteria and Protists Is Influenced by Temperature, Virus Type, and Microbial Species

Anna Carratala Ripolles, Charles Zeng Gan, Tamar Kohn, Margot Ninon Lauren Olive

Human viruses are ubiquitous contaminants in surface waters, where they can persist over extended periods of time. Among the factors governing their environmental persistence, the control (removal or inactivation) by microorganisms remains poorly understood. Here we determined the contribution of indigenous bacteria and protists to the decay of human viruses in surface waters. Incubation of echovirus 11 (E11) in freshwater from Lake Geneva and seawater from the Mediterranean Sea led to a 2.5-log10 reduction in the infectious virus concentration within 48 hours at 22°C, whereas E11 was stable in sterile controls. The observed virus reduction was attributed to the action of both bacteria and protists in the biologically active matrices. The effect of microorganisms on viruses was temperature-dependent, with a complete inhibition of microbial virus control in lake water at temperatures ≤ 16°C. Among three protist isolates tested (Paraphysomonas sp., Uronema marinum and Caecitellus paraparvulus), Caecitellus paraparvulus was particularly efficient at controlling E11 (2.1-log10 reduction over four days with an initial protists concentration of 103 cells × ml-1). In addition, other viruses (human adenovirus type 2 and bacteriophage H6) exhibited different grazing kinetics compared to E11, indicating that the efficacy of antiviral action also depended on the type of virus. In conclusion, indigenous bacteria and protists in lake water and seawater can modulate the persistence of E11. These results pave the way for further research to understand how microorganisms control human viral pathogens in aquatic ecosystems and to exploit this process as a treatment solution to enhance microbial water safety.

2020

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