Publications by authors named "Philippe Perot"

Background: Cervical cancer screening programs are increasingly relying on sensitive molecular approaches as primary tests to detect high-risk human papillomaviruses (hrHPV), the causative agents of cervix cancer. Although hrHPV infection is a pre-requisite for the development of most precancerous lesions, the mere detection of viral nucleic acids, also present in transient infections, is not specific of the underlying cellular state, resulting in poor positive predictive values (PPV) regarding lesional states. There is a need to increase the specificity of molecular tests for better stratifying individuals at risk of cancer and to adapt follow-up strategies.

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Background: Ticks are significant vectors of pathogens, including viruses, bacteria, and protozoa. With approximately 900 tick species worldwide, many are expanding their geographical range due to changing socioeconomic and climate factors. The Danube Delta, one of Europe's largest wetlands, is an ecosystem that, despite its ecological importance, remains understudied concerning the risk of introducing new tick-borne viruses.

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  • A novel human circovirus, named HCirV-1, was discovered in a 66-year-old immunocompromised woman suffering from sudden hepatitis.
  • Researchers found HCirV-1 genetic material in the patient's liver cells and also in her blood, stool, and urine over an extended period.
  • HCirV-1 is recognized as an emerging human pathogen that can persist in individuals with weakened immune systems.
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In this multicenter study conducted in France, we challenged the hypothesis of the transmission of pathogens other than spp. in 22 patients developing erythema migrans following a tick bite. Using a combination of high-throughput microfluidic PCRs and agnostic metagenomics on skin biopsies and blood samples, no microorganisms other than spp.

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FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients' bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors.

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The human skin virome, unlike commensal bacteria, is an under investigated component of the human skin microbiome. We developed a sensitive, quantitative assay to detect cutaneous human resident papillomaviruses (HPV) and polyomaviruses (HPyV) and we first used it to describe these viral populations at the skin surface of two patients with atopic dermatitis (AD) and psoriasis (PSO). We performed skin swabs on lesional and non-lesional skin in one AD and one PSO patient at M0, M1 and M3.

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Background: Metagenomic next-generation sequencing (mNGS) allows untargeted identification of a broad range of pathogens, including rare or novel microorganisms. Despite the recognition of mNGS as a valuable diagnostic tool for infections, the most relevant indications for this innovative strategy remain poorly defined. We aimed to assess the determinants of positivity and clinical utility of mNGS.

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  • Human Circovirus 1 and 2 were recently detected in a few cases of hepatitis in France and among drug users in China, raising concerns about their potential impact on the safety of plasma derivatives.
  • Researchers conducted tests on 48 plasma pools from healthy donors in Europe, the USA, and Japan to check for these viruses.
  • The findings showed no presence of Human Circovirus 1 and 2, suggesting that these viruses are not commonly found in plasma donations.
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The improvement of our knowledge of the virosphere, which includes unknown viruses, is a key area in virology. Metagenomics tools, which perform taxonomic assignation from high throughput sequencing datasets, are generally evaluated with datasets derived from biological samples or in silico spiked samples containing known viral sequences present in public databases, resulting in the inability to evaluate the capacity of these tools to detect novel or distant viruses. Simulating realistic evolutionary directions is therefore key to benchmark and improve these tools.

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  • A study involving 20 COVID-19 cases identified cerebral microangiopathy in six patients, marked by changes in white matter and small artery diseases as seen on MRI.
  • The condition featured perivascular alterations such as vacuolization, macrophage clusters, and large axonal swellings, suggesting blood-brain barrier disruption without evidence of direct viral presence in the brain.
  • Detection of the SARS-CoV-2 spike protein in brain endothelial cells, particularly within the Golgi apparatus, indicates a unique interaction that might affect vascular permeability and contribute to long-term neurological effects of COVID-19.
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  • Metagenomic next-generation sequencing (mNGS) was utilized to study patients with primary or secondary immune deficiencies (PIDs and SIDs) who exhibited immunopathological issues.
  • The study involved 30 symptomatic and 59 asymptomatic patients, with mNGS revealing Aichi virus (AiV) in tissue from some infected patients, confirming the potential link between AiV and immunodysregulation.
  • Results showed that AiV was associated with significant clinical symptoms, including multiorgan involvement, and symptoms improved after treatment, supporting the idea that AiV may be a causal factor in these patients.
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  • Renal arcuate vein thrombosis (RAVT) is a rare condition that can cause kidney problems in young adults, but we don’t fully understand how often it happens or why it occurs.
  • Researchers looked at five young patients with RAVT found during kidney tests, and they noticed that four of them used a lot of pain medication called NSAIDs, which might be linked to the problem.
  • They also found signs of a virus called SARS-CoV-2 in one patient’s kidney, suggesting that this virus could harm blood vessels in the kidneys, making the situation worse.
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  • Allogenic hematopoietic stem cell transplantation (HSCT) and gene therapy (GT) are potential cures for severe combined immunodeficiency (SCID), but patients often face late-onset issues like persistent hepatitis.
  • A study of SCID patients revealed that 11 out of 44 experienced persistent hepatitis linked to chronic enteric viral infections, particularly enteric viruses not found in non-hepatitis SCID patients.
  • Treatments like retransplantation or gene therapy showed promise, as 5 patients achieved remission of hepatitis and viral clearance, highlighting the importance of addressing immune dysregulation in these patients.
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In March 2022, a 61-year-old woman in France who had received a heart-lung transplant sought treatment with chronic hepatitis mainly characterized by increased liver enzymes. After ruling out common etiologies, we used metagenomic next-generation sequencing to analyze a liver biopsy sample and identified an unknown species of circovirus, tentatively named human circovirus 1 (HCirV-1). We found no other viral or bacterial sequences.

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We present Microseek, a pipeline for virus identification and discovery based on RVDB-prot, a comprehensive, curated and regularly updated database of viral proteins. Microseek analyzes metagenomic Next Generation Sequencing (mNGS) raw data by performing quality steps, de novo assembly, and by scoring the Lowest Common Ancestor (LCA) from translated reads and contigs. Microseek runs on a local computer.

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Background: Encephalitis is a worldwide public health issue, with a substantially high burden among children in southeast Asia. We aimed to determine the causes of encephalitis in children admitted to hospitals across the Greater Mekong region by implementing a comprehensive state-of-the-art diagnostic procedure harmonised across all centres, and identifying clinical characteristics related to patients' conditions.

Methods: In this multicentre, observational, prospective study of childhood encephalitis, four referral hospitals in Cambodia, Vietnam, Laos, and Myanmar recruited children (aged 28 days to 16 years) who presented with altered mental status lasting more than 24 h and two of the following minor criteria: fever (within the 72 h before or after presentation), one or more generalised or partial seizures (excluding febrile seizures), a new-onset focal neurological deficit, cerebrospinal fluid (CSF) white blood cell count of 5 per mL or higher, or brain imaging (CT or MRI) suggestive of lesions of encephalitis.

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The animal reservoir of SARS-CoV-2 is unknown despite reports of SARS-CoV-2-related viruses in Asian Rhinolophus bats, including the closest virus from R. affinis, RaTG13 (refs. ), and pangolins.

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  • * Next generation sequencing (NGS) successfully identified European bat lyssavirus type 1a in the patient's brain tissue, confirming the cause of death, despite the diagnosis not suggesting rabies.
  • * The findings highlight the importance of NGS in detecting rare viruses and suggest that individuals in close contact with bats should consider rabies vaccinations, which are effective against EBLV-1.
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Ticks are involved in the transmission of various pathogens and several tick-borne diseases cause significant problems for the health of humans and livestock. The composition of viral communities in ticks and their interactions with pathogens, is poorly understood, particularly in Eastern Europe, an area that represents a major hub for animal-arthropod vectors exchanges (e.g.

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  • - Clinical metagenomics detects a wide range of pathogens, including new microorganisms, but often struggles with low pathogen levels in samples due to high host nucleic acid background.
  • - Solutions like high sequencing depth and viral genome enrichment have been explored, but total nucleic acid quantities typically fall below recommended levels, necessitating random amplification techniques.
  • - The study highlights that using optimized random amplification methods significantly improves virus recovery rates, achieving good genome coverage even with less than 100-1000 genome copies per mL of plasma from a dataset of three million reads.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which originated in Wuhan, China, in 2019, is responsible for the COVID-19 pandemic. It is now accepted that the wild fauna, probably bats, constitute the initial reservoir of the virus, but little is known about the role pets can play in the spread of the disease in human communities, knowing the ability of SARS-CoV-2 to infect some domestic animals. In this cross-sectional study, we tested the antibody response in a cluster of 21 domestic pets (9 cats and 12 dogs) living in close contact with their owners (belonging to a veterinary community of 20 students) in which two students tested positive for COVID-19 and several others ( = 11/18) consecutively showed clinical signs (fever, cough, anosmia, ) compatible with COVID-19 infection.

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Background: Human encephalitis represents a medical challenge from a diagnostic and therapeutic point of view. We investigated the cause of 2 fatal cases of encephalitis of unknown origin in immunocompromised patients.

Methods: Untargeted metatranscriptomics was applied on the brain tissue of 2 patients to search for pathogens (viruses, bacteria, fungi, or protozoans) without a prior hypothesis.

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  • * A study involving 68 OSCCs and 14 potentially malignant disorders in non-smoking, non-drinking patients found HPV DNA present in a substantial portion of cases, but no evidence connecting high-risk HPV types to OSCC development.
  • * Some viral sequences from Trichomonas vaginalis virus (TVV) were identified, but the study concludes that current findings suggest that high-risk HPV types do not contribute to OSCCs in this specific
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