Publications by authors named "Francis Delpeyroux"

Enterovirus 71 (EV-A71) is a major public health problem, causing a range of illnesses from hand-foot-and-mouth disease to severe neurological manifestations. EV-A71 strains have been phylogenetically classified into eight genogroups (A to H), based on their capsid-coding genomic region. Genogroups B and C have caused large outbreaks worldwide and represent the two canonical circulating EV-A71 subtypes.

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Background: Poliomyelitis outbreaks due to pathogenic vaccine-derived polioviruses (VDPVs) are threatening and complicating the global polio eradication initiative. Most of these VDPVs are genetic recombinants with non-polio enteroviruses (NPEVs) of species C. Little is known about factors favoring this genetic macroevolution process.

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To assess circulation of the Sabin 2 poliovirus vaccine strain in Madagascar after its withdrawal from the oral polio vaccine in April 2016, a reinforced poliovirus surveillance was implemented in three regions of Madagascar from January 2016 to December 2017. Environmental samples and stool specimens from healthy children were screened using the Global Polio Laboratory Network algorithm to detect the presence of polioviruses. Detected polioviruses were molecularly typed and their genomes fully sequenced.

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Article Synopsis
  • - Genetic recombination significantly influences the evolution of positive sense RNA viruses when multiple viruses infect the same cell, leading to new genetic combinations.
  • - The main method of recombination involves the viral polymerase, which creates chimeric genomes by switching DNA templates during replication, though there are indications of recombination that doesn't rely on this polymerase activity.
  • - It's unclear how often these non-replicative recombination events occur, how they differ from polymerase-driven recombination, or if they involve non-virus-specific sequences, suggesting a broader mechanism beyond just RNA viruses.
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  • * The primary way recombination happens is through the viral polymerase switching templates during replication, but some events may occur independently of this enzyme.
  • * The implications and mechanisms of non-replicative recombination are still unclear, potentially indicating a broader evolutionary role that extends beyond just viral sequences.
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  • - Enterovirus A71 (EV-A71) is a major cause of hand-foot-and-mouth disease (HFMD) and has the potential to cause serious neurological issues, with various genogroups classified based on genetic sequences.
  • - Despite genogroups B and C causing major outbreaks, genogroups E and F are recently identified with limited knowledge about their circulation in Africa, highlighting the need for effective detection methods.
  • - A newly developed real-time RT-PCR assay can accurately detect all genogroups of EV-A71 in biological samples, showing strong sensitivity and reproducibility, and has identified multiple strains in a study of enterovirus samples from Africa.
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Due to the risk of poliovirus importation from Ukraine in 2015, a combined surveillance program monitoring the circulation of enteroviruses (EVs) in healthy children from at-risk areas and in the environment was conducted in Romania. Virological testing of stool samples collected from 155 healthy children aged from two months to six years and of 186 sewage water samples collected from different areas was performed. A total of 58 (37.

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  • A new treatment strategy called consecutive alternating administration (CAA) was developed for enterovirus infections using a combination of antiviral drugs, showing no drug resistance and increased effectiveness in a mouse model infected with coxsackievirus B1 (CVB1).
  • Researchers analyzed brain samples from mice treated with CAA and monotherapies for viral RNA mutations using next-generation sequencing, revealing specific genetic changes associated with drug effects.
  • The findings suggest that the CAA method leads to distinct mutations in the viral genome, which may contribute to the treatment's high efficacy and prevention of drug resistance.
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  • - The Enterovirus D (EV-D) species, particularly EV-D68 and EV-D70, have caused outbreaks in humans for decades but have received little research attention until recent severe respiratory diseases linked to EV-D68.
  • - Newly identified EV-D types (EV-D94, EV-D111, and EV-D120) were discovered in Africa but have not been reported elsewhere, with some strains suggesting a possible zoonotic origin from non-human primates.
  • - Genetic analysis of EV-D111 strains indicates recent zoonotic transmission and potential genetic recombination with EV-D94, raising concerns about misclassification during poliovirus detection in Central Africa, where both viruses coexist.
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RNA recombination is a major driving force in the evolution and genetic architecture shaping of enteroviruses. In particular, intertypic recombination is implicated in the emergence of most pathogenic circulating vaccine-derived polioviruses, which have caused numerous outbreaks of paralytic poliomyelitis worldwide. Recent experimental studies that relied on recombination cellular systems mimicking natural genetic exchanges between enteroviruses provided new insights into the molecular mechanisms of enterovirus recombination and enabled to define a new model of genetic plasticity for enteroviruses.

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  • Enteroviruses (EVs), including Non-Polio Enteroviruses (NPEVs) and circulating vaccine-derived polioviruses (cVDPVs), are prevalent in the Democratic Republic of Congo (DR Congo), but their genetic diversity was previously understudied.
  • This research analyzed EVs from both healthy children and Acute Flaccid Paralysis (AFP) patients, focusing on the genetic characteristics of these viruses and investigating the potential reasons behind the emergence of cVDPVs in the region.
  • Findings revealed that a significant percentage of healthy children were infected by EVs, with evidence of genetic recombination in cVDPVs, suggesting complex viral evolution and interactions in the local population.
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A variety of viruses can cause acute flaccid paralysis (AFP). However, the causative agent, sometimes, remains undetermined. Metagenomics helps in identifying viruses not diagnosed by conventional methods.

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Article Synopsis
  • * A study in Madagascar identified 23 EV-A isolates from healthy children, revealing eight different types and significant genetic diversity, along with evidence of recent genetic recombination between strains.
  • * Despite no reported outbreaks of HFMD from EV-A in Madagascar, the findings highlight an urgent need for monitoring viral circulation and evolution to prevent potential future outbreaks.
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Since the identification of the first enteroviruses, the classification and the nomenclature of these viruses were modified several times. Even the base of the classification was changed during the 2000s when genetic criteria superseded the historical serological criteria used to identify enteroviruses. Product of these modifications, the current classification and nomenclature are confusing for students, researchers and practitioners who discover them for the first time; coxsackieviruses A and B, echoviruses and polioviruses are gathered into different species while surprisingly, in view of the etymology, the rhinoviruses now belong the genus Enterovirus.

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Article Synopsis
  • Human enteroviruses are diverse, with over 100 serotypes across four species, causing various illnesses, making their detection and classification crucial for research and understanding viral evolution.
  • A new rapid and sensitive method was developed to detect and classify all human enteroviruses from mixed samples, using specially designed primers to target key viral genome regions.
  • This method successfully sequenced the full genomes of most enteroviruses tested, allowing for differentiation of various types in both mixed and pure samples.
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In 2017, numerous cases of acute haemorrhagic conjunctivitis (AHC) were reported in the Caribbean and in South America. Preliminary reports identified adenoviruses and enteroviruses in some patient samples but, until now, none of the etiologic agents have been fully characterized. We report the full-length genomic sequences of 4 coxsackievirus A24 (CV-A24) isolates collected from AHC patients in French Guiana during this outbreak (May and June 2017).

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  • Researchers studied genome sequences from 8 enterovirus A71 isolates (EV-A71) to investigate their genetic characteristics.
  • Findings confirmed the presence of genogroup C and identified a new genogroup E in West Africa.
  • The analysis revealed significant geographic spread and genetic mixing between EV-A71 and local enteroviruses, which could lead to the development of more harmful strains.
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Suramin was previously shown to bind to the EV-A71 capsid through its naphthalenetrisulfonic acid groups, thereby reducing virus-cell binding and inhibiting viral replication. Here, we identify VP1-145 as the critical amino acid that accounts for the differential sensitivity of EVA-71 viruses to suramin. A single Q or G to E substitution at VP1-145 results in an approximately 30-fold shift of IC or IC values reproducing the inhibition profile observed with field isolates expressing either the 145Q or E mutation.

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The attenuated Sabin strains contained in the oral poliomyelitis vaccine are genetically unstable, and their circulation in poorly immunized populations can lead to the emergence of pathogenic circulating vaccine-derived polioviruses (cVDPVs). The recombinant nature of most cVDPV genomes and the preferential presence of genomic sequences from certain cocirculating non-polio enteroviruses of species C (EV-Cs) raise questions about the permissiveness of genetic exchanges between EV-Cs and the phenotypic impact of such exchanges. We investigated whether functional constraints limited genetic exchanges between Sabin strains and other EV-Cs.

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Human enterovirus 71 (EV-A71) causes hand, foot and mouth disease (HFMD). EV-A71 circulates in many countries and has caused large epidemics, especially in the Asia-Pacific region, since 1997. In April 2012, an undiagnosed fatal disease with neurological involvement and respiratory distress occurred in young children admitted to the Kantha Bopha Children's Hospital in Phnom Penh, Cambodia.

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Enteroviruses are among the most common viruses infecting humans and can cause diverse clinical syndromes ranging from minor febrile illness to severe and potentially fatal diseases. Enterovirus species C (EV-C) consists of more than 20 types, among which the three serotypes of polioviruses, the etiological agents of poliomyelitis, are included. Biodiversity and evolution of EV-C genomes are shaped by frequent recombination events.

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Unlabelled: RNA viruses present an extraordinary threat to human health, given their sudden and unpredictable appearance, the potential for rapid spread among the human population, and their ability to evolve resistance to antiviral therapies. The recent emergence of chikungunya virus, Zika virus, and Ebola virus highlights the struggles to contain outbreaks. A significant hurdle is the availability of antivirals to treat the infected or protect at-risk populations.

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Poliovirus (PV)-induced apoptosis seems to play a major role in central nervous system (CNS) tissue injury, a crucial feature of the pathogenesis of poliomyelitis. We have previously shown that calcium (Ca2+) flux from the endoplasmic reticulum (ER) to the cytosol during PV infection is involved in apoptosis induction in human neuroblastoma cells. We show here that PV infection is associated with a transient upregulation of Herp (homocysteine-induced ER protein), a protein known to promote the degradation of ER-resident Ca2+ channels.

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Background: Efficient implementation of the global eradication strategies consisting of Acute Flaccid Paralysis (AFP) surveillance and mass immunization campaigns led to interruption of indigenous wild poliovirus transmission in Cameroon in 1999.

Objectives: This study describes type 1 and type 3 wild poliovirus (WPV) importation, incidence, geographic distribution and control since the original interruption of transmission in Cameroon.

Study Design: Stool samples from AFP patients under the age of 15 years in Cameroon were collected nationwide and subjected to virus isolation on RD and L20B cell cultures.

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