Publications by authors named "Stephane Valot"

Background: Intestinal parasitic diseases affect millions of people worldwide. Numerous commercial molecular methods detecting digestive parasites have been developed recently, including multiplex PCR assays able to identify multiple parasites at once. Several studies have demonstrated that the efficacy of these molecular methods is dependent on the specific protocols employed at each stage of the process including pretreatment, extraction and amplification.

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Article Synopsis
  • The study aimed to standardize qPCR procedures for diagnosing Mucorales by examining factors that influence DNA extraction and PCR amplification efficiency.
  • Two panels of samples were distributed to 26 laboratories, and results showed that using larger serum volumes for DNA extraction and larger input volumes for PCR significantly improved detection sensitivity.
  • Findings highlight the importance of optimizing laboratory techniques to enhance diagnosis of Mucormycosis, a serious fungal infection, which is critical for timely treatment in vulnerable patients.
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Unlabelled: Intestinal microsporidiosis caused by is an opportunistic infection that especially affects solid organ transplant (SOT) recipients. Management revolves around tapering the immunosuppressive regimen and/or using a specific anti-microsporidia treatment, but only fumagillin has demonstrated efficacy for treatment of this infection. Since fumagillin has been commercially discontinued, nitazoxanide is increasingly being used in this indication.

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This study investigates the diagnostic practices for mucormycosis among 30 French University Hospital mycology laboratories, in 2024. All laboratories perform both direct examination and culture, with fluorescent brighteners being the most commonly used method for direct examination. While 77 % of the participating laboratories routinely identify Mucorales to the species level, with 70 % having adopted Mucorales-specific quantitative PCR, primarily for the diagnosis of invasive fungal infections.

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Background: Patients with hematological malignancies are at a high risk of developing invasive fungal infections (IFI) because they undergo several cycles of treatment leading to episodes of neutropenia. In addition, they alternate between hospital stays and periods spent at home. Thus, when an IFI is diagnosed during their hospital stays, it is highly challenging to identify the origin of the fungal contamination.

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Pediatric diarrhea is a major public health problem worldwide. In France, continuous surveillance shows a winter epidemic peak and a more modest summer recrudescence. Few studies describe the infectious agents responsible for pediatric summer diarrhea in France.

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. Nowadays, most of the and epidemiological studies are based on gp60 gene subtyping using the Sanger sequencing (SgS) method. Unfortunately, SgS presents the limitation of being unable to detect mixed infections.

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Introduction: Fungemia is a severe invasive fungal infection that combines rapid progression and a high mortality rate. This type of infection is a vital emergency, and early diagnosis is crucial. Currently, only the BD-BACTEC® Automated Blood Culture System (Becton Dickinson, New Jersey, USA) has a medium specifically dedicated to the detection of fungal agents: the BD-BACTEC®MycosisIC/F bottle.

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is a known foodborne pathogen, ranked fifth out of 24 among foodborne parasites in terms of importance and a cause of many cryptosporidiosis outbreaks worldwide. In France, very few outbreaks were reported before 2017, and data recently obtained by the Expert Laboratory of the Cryptosporidiosis National Reference Center (CNR-LE-Cryptosporidiosis) have shown that outbreaks are in fact common and frequently underreported. In this work, we aim to report the characteristics of outbreaks detected in France during the period 2017-2020 and present a summary of investigations carried out by the CNR-LE-Cryptosporidiosis.

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Unlabelled: PCR-based methods applied to various body fluids emerged in recent years as a promising approach for the diagnosis of mucormycosis. In this study, we set up and assess the value of a qPCR to detect a wide variety of Mucorales species in a single tube. A pair of degenerated primers targeting the rDNA operon was used in a qPCR utilizing an intercalating fluorescent dye.

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Commercial multiplex PCR assay panels were developed to overcome the limitations of microscopic examination for parasitological diagnosis on stool samples. However, given the increased supply of this diagnostic approach, these assays must be evaluated to position them in a diagnostic algorithm. Analytical performances of the multiplex PCR assay G-DiaParaTrio, Allplex GI parasite and RIDAGENE parasitic stool panel for detecting Blastocystis sp.

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Background: Cryptosporidiosis outbreaks in South America are poorly documented. In March 2018, 51 cases of cryptosporidiosis were reported in Maripasoula, a village located in a remote forest area along the border between Surinam and French Guiana.

Method: To identify the origin of the epidemic, we performed epidemiological, microbiological, and environmental investigations.

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Nowadays, many commercial kits allowing the detection of digestive parasites by DNA amplification methods have been developed, including simplex PCR assays (SimpPCRa) allowing the identification of a single parasite, and multiplex PCR assays (MultPCRa) allowing the identification of several parasites at once. Thus, aimed at improving the diagnosis of intestinal protozoal infections, it is essential to evaluate the performances of these new tools. A total of 174 DNA samples collected between 2007 and 2017 were retrospectively included in this study.

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Diagnostic approaches based on PCR methods are increasingly used in the field of parasitology, particularly to detect . Consequently, many different PCR methods are available, both "in-house" and commercial methods. The aim of this study was to compare the performance of eight PCR methods, four "in-house" and four commercial methods, to detect species.

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The protozoan affects the digestive tract of humans and animals. Cryptosporidiosis leads to diarrhoea mimicking a cholera-like course with dehydration and may even result in death in immunodeficient patients, as patients with hyper-IgM syndrome. We describe a rare case of disseminated infection in a seven- year-old boy with CD40 L deficiency.

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Nowadays, many commercial kits allow the polymerase chain reaction (PCR) detection of deoxyribonucleic acid (DNA) in stool samples, the efficiency of which relies on the extraction method used. Mechanical pretreatment of the stools using grinding beads has been reported to greatly improve this extraction step. However, optimization of this key step remains to be carried out.

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Background: Nowadays, many commercial kits allow the detection of sp. in stool samples after deoxyribonucleic acid (DNA) extraction. Protocols of stool pretreatment have been proposed to optimize oocysts' DNA extraction.

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Cryptosporidiosis is currently recognized worldwide as a leading cause of moderate to severe diarrhea. In Europe, large water- and foodborne outbreaks have been reported, highlighting the widespread distribution of the parasite and its important health impact. Surveillance networks have been progressively set up and the aim of this study was to present recent epidemiological data obtained in France from 2017 to 2019 by the National Reference Center-Expert Laboratory of cryptosporidiosis (Centre National de Référence-Laboratoire Expert cryptosporidioses CNR-LE).

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The diagnosis of parasitic and fungal infections, historically based on the detection of these pathogens using direct diagnosis (macro/microscopic examination, culture) or serological methods, has considerably evolved in the last decades, especially with the development of molecular approaches and mass spectrometry. These techniques, as well as most analyses of parasitic and fungal serology, are mostly the preserve of Hospital University Centers Parasitology-Mycology laboratories. In 2016, the French association of medical parasitology and mycology teachers and hospital practitioners (Anofel) has provided a Catalogue of rare analyses, regularly updated and freely accessible on the Anofel website (https://anofel.

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Cryptosporidium spp. Enterocytozoon bieneusi and Encephalitozoon intestinalis are opportunistic pathogens responsible for gastrointestinal diseases. We evaluated the ParaGENIE Crypto-Micro Real-Time PCR kit (Ademtech, France), the first CE-IVD compliant PCR assay available for these pathogens.

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Background: External ophtalmomyiasis (EOM) is a zoonosis related to the presence of Oestrus ovis larvae at the ocular level in small ruminants (i.e. ovine, caprine).

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Article Synopsis
  • Cystic echinococcosis (CE) is a global parasitic infection that impacts over a million people.
  • Primary bone CE is extremely rare in humans, and vertebral involvement is even less common.
  • This report documents the first case of primary vertebral CE in Burgundy, France.
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Microscopy is the gold standard for the diagnosis of gastrointestinal parasites but is time-consuming and dependent on operator skills. Rapid diagnostic tests represent alternative methods but most evaluations have been conducted on a limited number of samples preventing their implementation in the clinical setting. We evaluated a new CE-IVD marked immunochromatographic assay (Crypto/Giardia K-SeT®, Coris Bioconcept) for the detection of G.

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