Detection of enterovirus in environmental waters: A new optimized method compared to commercial real-time RT-qPCR kits

International audienceDespite the progress in water and wastewater treatment technologies, waterborne diseases are still amajor concern of public health. In the reported water-related outbreaks, viruses constitute one of themain causal agents. Enteroviruses are one of the most viruses monitored in water and are often usedas an indicator of viral pollution. Isolation and identification of this virus are now regularly based onmolecular tools. However published or commercial protocols for detection of these viruses in waterare frequently lacking of validation processes and performance evaluation in such complex samples. Amethod for enterovirus detection in environmental water has been developed, its performance has beenevaluated and compared with several commercial kits.The sensitivity of commercial methods in clinical samples, ranged between 89% and 100%, while thesensitivity in seeded environmental matrices fell between 16% and 91%. This method showed the bestperformance in environmental samples and was subsequently applied on surface and treated wastewa-ter. The results showed the large dissemination of enteroviruses in an urbanized river. The results alsoemphasized the importance of good knowledge of the method’s limits for its utilization in environmentalsamples in order to minimize false negatives and to avoid underestimating viral concentration

Detection of enterovirus in environmental waters: A new optimized method compared to commercial real-time RT-qPCR kits

International audienceDespite the progress in water and wastewater treatment technologies, waterborne diseases are still amajor concern of public health. In the reported water-related outbreaks, viruses constitute one of themain causal agents. Enteroviruses are one of the most viruses monitored in water and are often usedas an indicator of viral pollution. Isolation and identification of this virus are now regularly based onmolecular tools. However published or commercial protocols for detection of these viruses in waterare frequently lacking of validation processes and performance evaluation in such complex samples. Amethod for enterovirus detection in environmental water has been developed, its performance has beenevaluated and compared with several commercial kits.The sensitivity of commercial methods in clinical samples, ranged between 89% and 100%, while thesensitivity in seeded environmental matrices fell between 16% and 91%. This method showed the bestperformance in environmental samples and was subsequently applied on surface and treated wastewa-ter. The results showed the large dissemination of enteroviruses in an urbanized river. The results alsoemphasized the importance of good knowledge of the method’s limits for its utilization in environmentalsamples in order to minimize false negatives and to avoid underestimating viral concentration

Effect of Cell Cycle Arrest on the Activity of Nucleoside Analogues against Human Immunodeficiency Virus Type 1

Human immunodeficiency virus (HIV) reverse transcription can be notably affected by cellular activation, differentiation, and division. We hypothesized that changes in the cell cycle could also affect HIV susceptibility to nucleoside analogues, which compete with natural nucleotides for incorporation into viral DNA and inhibit viral replication through premature termination of reverse transcription. Proliferating HeLa-derived indicator cells were arrested in the S/G(2) phase with etoposide, a topoisomerase II inhibitor, or in the G(1)/S phase with aphidicolin, a polymerase α inhibitor. Cell cycle arrest by both agents induced a remarkable decrease in HIV susceptibility to zidovudine (AZT). This decrease was seen both with a single-cycle infectivity assay and with a viral DNA quantitation assay, indicating that the effect of cell cycle arrest was exerted at the reverse transcription stage. The increase in the 50% inhibitory concentration (IC(50)) seen with arrested cells was strongest for AZT (23-fold) and stavudine (21-fold) but more modest for other drugs (lamivudine, 11-fold; dideoxyinosine, 7-fold; and nevirapine, 3-fold). In drug-resistant reverse transcriptase mutants, the increase in AZT IC(50) (relative to that in dividing cells) was most prominent with a Q151M mutant and was comparable to the wild type in other drug-resistant mutants. Quantitation of intracellular pools of dTTP and AZT 5′-triphosphate (AZTTP) showed that etoposide treatment induced a significant increase in intracellular dTTP and consequently a decrease in AZTTP/dTTP ratios, suggesting that the decrease in viral susceptibility to AZT was caused by reduced incorporation of the analogue into nascent viral DNA. These results emphasize the importance of cellular proliferation and deoxynucleoside triphosphate metabolism in HIV susceptibility to nucleoside analogues and underscore the need to study the activities of drugs of this class with natural target cells under physiological conditions of activation and proliferation

Viral dynamics of the Seine River in Paris area: analysis of the climate impact

International audienc

Viral dynamics of the Seine River in Paris area: analysis of the climate impact

International audienc

Functional Central Polypurine Tract Provides Downstream Protection of the Human Immunodeficiency Virus Type 1 Genome from Editing by APOBEC3G and APOBEC3B

Lentiviruses utilize two polypurine tracts for initiation of plus-strand viral DNA synthesis. We have examined to what extent human immunodeficiency virus type 1 plus-strand initiation at the central polypurine tract (cPPT) could protect the viral genome from DNA editing by APOBEC3G and APOBEC3B. The presence of a functional cPPT, but not of a mutated cPPT, extensively reduced editing by both APOBEC3G and APOBEC3B of sequences downstream, but not upstream, of the cPPT, with significant protection observed as far as 400 bp downstream. Thus, in addition to other potential functions, the cPPT could help protect lentiviruses from editing by cytidine deaminases of the APOBEC family

Assessing infectivity of emerging enveloped viruses in wastewater and sewage sludge: Relevance and procedures

International audienc

First Detection of Monkeypox Virus Genome in Sewersheds in France: The Potential of Wastewater-Based Epidemiology for Monitoring Emerging Disease

A monkeypox virus outbreak has been spreading in multiple nonendemic countries since May 2022. The atypical clinical profile of patients has led to a very likely underestimation of the number of cases at the beginning of the epidemic. The detection and quantification of the Monkeypox virus genome in sewersheds in Paris (France) correlated temporally with the identification of the first case of infection and the spread of the disease within the population connected to the sewage system