Vincent Thomas

Vincent Thomas
Bioaster Technology Research Institute · Paris Pasteur Institute

PharmD, PhD, HDR (Docent)

About

61
Publications
44,919
Reads
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3,669
Citations
Additional affiliations
January 2013 - May 2015
Enterome
Position
  • R&D Manager
January 2013 - May 2015
Enterome
Position
  • Senior Researcher
May 2006 - December 2012
STERIS
Position
  • R&D lab manager

Publications

Publications (61)
Article
Full-text available
Large viruses infecting algae or amoebae belong to the NucleoCytoplasmic Large DNA Viruses (NCLDV) and present genotypic and phenotypic characteristics that have raised major interest among microbiologists. Here, we describe a new large virus discovered in Acanthamoeba castellanii co-culture of an environmental sample. The virus, referred to as Lau...
Article
Full-text available
The incidence of lung and other diseases due to nontuberculous mycobacteria (NTM) is increasing. NTM sources include potable water, especially in households where NTM populate pipes, taps, and showerheads. NTM share habitats with free-living amoebae (FLA) and can grow in FLA as parasites or as endosymbionts. FLA containing NTM may form cysts that p...
Article
Full-text available
Over the past years, gut microbiota became a major field of interest with increasing reports suggesting its association with a large number of human diseases. In this context, there is a major interest to develop analysis tools allowing simple and cost-effective population pattern analysis of these complex ecosystems to follow changes over time. Wh...
Article
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There is growing interest in exploring the chickens' intestinal microbiota and understanding its interactions with the host. The objective is to optimize this parameter in order to increase the productivity of farm animals. With the goal to isolate candidate probiotic strains, specific culturomic methods were used in our study to culture commensal...
Article
Full-text available
Background: There is a growing interest in using gut commensal bacteria as "next generation" probiotics. However, this approach is still hampered by the fact that there are few or no strains available for specific species that are difficult to cultivate. Our objective was to adapt flow cytometry and cell sorting to be able to detect, separate, isol...
Article
Full-text available
Background There is a growing interest in using gut commensal bacteria as “next generation” probiotics. However, this approach is still hampered by the fact that there are few or no strains available for specific species that are difficult to cultivate. Our objective was to adapt flow cytometry and cell sorting to be able to detect, separate, isola...
Article
Full-text available
Faecal microbiota transplantation (FMT) is widely reported to be an effective treatment against recurrent Clostridioides difficile infections. Recent clinical studies support the therapeutic use of FMT for several other pathologies including inflammatory bowel disease, several types of cancer, and other functional or metabolic disorders. Initial gu...
Article
Full-text available
We report the isolation, culture, and genome sequencing of isolate POC01, a strictly anaerobic bacterium isolated from a healthy donor, representing a previously uncultured member of the Oscillospiraceae family.
Article
Introduction The FunHoMic project is a Marie Skłodowska-Curie Innovative Training Network comprising 13 PhD students, 8 academic partners and 3 industry partnersaimingto understand the interplay between fungi, hostsand microbiota to improve prevention and treatment of fungal infections. Importance About 2 billion people suffer fungal infections, w...
Article
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Candida albicans is a major fungal pathogen of humans. It exists as a commensal in the oral cavity, gut or genital tract of most individuals, constrained by the local microbiota, epithelial barriers and immune defences. Their perturbation can lead to fungal outgrowth and the development of mucosal infections such as oropharyngeal or vulvovaginal ca...
Preprint
Full-text available
Background: There is a growing interest in using gut commensal bacteria as next generation probiotics. However, this approach is still hampered by the fact that there are few or no strains available for specific species that are difficult to cultivate. Our objective was therefore to adapt flow cytometry and cell sorting to be able to detect, separa...
Article
Full-text available
Amoeba-infecting viruses have raised scientists' interest due to their novel particle morphologies, their large genome size, and their genomic content challenging previously established dogma. We report here the discovery and the characterization of Cedratvirus lausannensis, a novel member of the Megavirales, with a 0.75-1 µm long amphora-shaped pa...
Article
Full-text available
Despite huge interest, there are still no universally accepted standards to conduct clinical studies in the field of gut microbiota analysis. Stool material is frequently used as a proxy of gut microbiota, but many different protocols can be used for collection and DNA extraction. Whereas 16S rRNA encoding gene amplification and sequencing has been...
Article
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Leprosy is a curable neglected disease of humans caused by Mycobacterium leprae that affects the skin and peripheral nerves and manifests clinically in various forms ranging from self-resolving, tuberculoid leprosy to lepromatous leprosy having significant pathology with ensuing disfiguration disability and social stigma. Despite the global success...
Article
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Free-living amoebae are ubiquitous protozoa commonly found in water. Among them, Acanthamoeba and Vermamoeba (formerly Hartmannella) are the most represented genera. In case of stress, such as nutrient deprivation or osmotic stress, these amoebae initiate a differentiation process, named encystment. It leads to the cyst form, which is a resistant f...
Article
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Prion contamination is a risk during device reprocessing, being difficult to remove and inactivate. Little is known of the combined effects of cleaning, disinfection and sterilization during a typical reprocessing cycle in clinical practice. To investigate the combination of cleaning, disinfection and/or sterilization on reducing the risk of surfac...
Chapter
The term “protozoa” encompasses a wide variety of eukaryotic species that are widespread in nature as free-living organisms or associated with other organisms in a commensalistic, mutualistic or parasitic lifestyle. Several protozoan species can cause serious infections that can be life-threatening in the immunocompromized. Despite their increasing...
Article
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The development of a biofilm constitutes a survival strategy by providing bacteria a protective environment safe from stresses such as microbicide action and can thus lead to important health-care problems. In this study, biofilm resistance of a Bacillus subtilis strain (called hereafter ND(medical)) recently isolated from endoscope washer-disinfec...
Article
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Hemozoin crystals are normally formed in vivo by Plasmodium parasites to detoxify free heme released after hemoglobin digestion during its intraerythrocytic stage. Inhibition of hemozoin formation by various drugs results in free heme concentration toxic for the parasites. As a consequence, in vitro assays have been developed to screen and select c...
Data
Decontamination tests. (DOC)
Article
Full-text available
The risk associated to the contamination of drinking water networks by Legionella is well described. These bacteria can naturally resist to various stress, they can survive in biofilms for extended periods of time and proliferate in very high numbers by invading Free-Living Amoebae (FLA). FLA themselves can be highly resistant to disinfection treat...
Article
Full-text available
Free-living amoebae are protozoa found in soil and water. Among them, some are pathogenic and many have been described as potential reservoirs of pathogenic bacteria. Their cell cycle is divided into at least two forms, the trophozoite and the cyst, and the differentiation process is named encystment. As cysts are more resistant to disinfection tre...
Article
Full-text available
Despite increasing concerns of direct pathogenicity and/or their role as hosts for other microorganisms there are currently no standard methods for the inactivation of amoebae that belong to the genus Acanthamoeba. Methods used to grow amoebae and produce cysts for these tests may be important as they can dramatically modify cyst susceptibility. We...
Article
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The term 'Chlamydia-like organisms' encompasses obligate intracellular bacterial species phylogenetically close to Chlamydiaceae. Most are associated with free-living amoebae, and several could be responsible for respiratory tract infections and abortion in human and animals. Despite increasing concern about their pathogenic role, the prevalence, b...
Article
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A biofilm can be defined as a community of microorganisms adhering to a surface and surrounded by a complex matrix of extrapolymeric substances. It is now generally accepted that the biofilm growth mode induces microbial resistance to disinfection that can lead to substantial economic and health concerns. Although the precise origin of such resista...
Article
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Despite numerous reports on biocide activities, it is often difficult to have a reliable and relevant overview of bacterial resistance to disinfectants because each work challenges a limited number of strains and tested methods are often different. The aim of this study was to evaluate the bactericidal activity of three different disinfectants comm...
Article
In natural, industrial and medical environments, microorganisms mainly live as structured and organised matrix-encased communities known as biofilms. In these communities, microorganisms demonstrate coordinated behaviour and are able to perform specific functions such as dramatic resistance to antimicrobials, which potentially lead to major public...
Article
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The biocidal activity of peracetic acid (PAA) and benzalkonium chloride (BAC) on Pseudomonas aeruginosa biofilms was investigated by using a recently developed confocal laser scanning microscopy (CLSM) method that enables the direct and real-time visualization of cell inactivation within the structure. This technique is based on monitoring the loss...
Article
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Mycoplasma is minute bacteria that can be found ubiquitously in the environment and also in human, animal and plant tissues. In addition to their public health importance as aetiological agents of infections and possible association with certain cancers, mycoplasma is a major contamination concern in biotechnology. These bacterial cells are very sm...
Article
Full-text available
The formation of multicellular communities known as biofilms is the part of bacterial life cycle in which bacteria display cooperative behaviour and differentiated phenotypes leading to specific functions. Bacillus subtilis is a Gram-positive bacterium that has served for a decade as a model to study the molecular pathways that control biofilm form...
Article
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Some virus species can resist surprisingly harsh environmental conditions, being able to survive on surfaces for long times and often presenting high resistance to disinfection. Viruses can be transmitted to susceptible hosts via these contaminated surfaces. This is a major concern not only in healthcare, research, and manufcaturing settings, with...
Article
Full-text available
Free-living amoebae that belong to the genus Acanthamoeba are widespread in the environment, including water. They are responsible for human infections and can host pathogenic microorganisms. Under unfavorable conditions, they form cysts with high levels of resistance to disinfection methods, thus potentially representing a threat to public health....
Article
This study proposes a high throughput method based on Confocal Laser Scanning Microscopy (CLSM) combined with the use of 96-wells microtiter plates compatible with high resolution imaging for the study of biofilm formation and structure. As an illustration, the three-dimensional structures of biofilms formed by 60 opportunistic pathogens were thus...
Article
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Free-living amoebae serve as hosts for a variety of amoebae-resisting microorganisms, including giant viruses and certain bacteria. The latter include symbiotic bacteria as well as bacteria exhibiting a pathogenic phenotype towards amoebae. Amoebae-resisting bacteria have been shown to be widespread in water and to use the amoebae as a reservoir, a...
Article
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An increasing number of microorganisms, including bacteria but also viruses and eukaryotes, have been described as benefiting from interaction with free-living amoebae (FLA). Beneficial interaction can be due to resistance to predation conferring ecological advantage, intracellular survival and/or intracellular proliferation. This review highlights...
Article
The gut microbiota naturally protects the host against infections by pathogens. This microbiota can be disrupted in case of antibiotic treatments leading to the loss of the barrier effect and consequently to new colonization and opportunistic infections. We previously developed in our laboratory a trixenic mouse model microbiota displaying coloniza...
Article
Full-text available
Some virus species can resist harsh environmental conditions, surviving on surfaces for long periods with the possibility of being transmitted to susceptible hosts. Studies are limited on the efficacy of disinfectants against viruses dried onto surfaces, in particular, with the identification of new pathogenic non-enveloped viruses that are expecte...
Article
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The complex ecology of free-living amoebae (FLA) and their role in spreading pathogenic microorganisms through water systems have recently raised considerable interest. In this study, we investigated the presence of FLA and amoebae-resisting bacteria (ARB) at various stages of a drinking water plant fed with river water. We isolated various amoebal...
Article
Full-text available
Free-living amoebae have been detected in a large number of man-made water systems, including drinking water distribution systems. Some of these amoebae can host amoebae-resisting bacteria, and thus act potentially as reservoirs and vehicles for a number of pathogens. The objectives of this study were to characterize the amoebae and amoebae-resisti...
Article
It has been suspected that some species belonging to the alphaproteobacteria might cause pneumonia in humans. It is thus of special interest to isolate new members of this phylum, and to further characterize their pathogenicity. The amoebal co-culture method allowed the isolation of various new bacterial species during the last few years, including...
Article
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Since the discovery that Legionella pneumophila can survive and grow within free-living amoebae, there has been an increasing number of microbial species shown to have similar relationships. These include many bacterial species, fungi, other protozoa (e.g. Cryptosporidium) and viruses. Among bacteria, mycobacteria are of particular importance becau...
Article
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We investigated the zoonotic potential of Waddlia chon-drophila, a new Chlamydia-like abortigenic agent in ruminants. Anti-Waddlia antibody reactivity was tested by immunofluorescence and Western blot. Waddlia seroprevalence was higher in women who had had sporadic and recurrent miscarriages than in control women (p < 0.001). Waddlia spp. may repre...
Article
Virulent Mycobacterium kansasii (mainly subtype 1) may cause lung infections, whereas certain other strains (essentially subtype 3) are commonly non-pathogenic mycobacteria colonizing the human lower respiratory tract of patients. Determining the clinical significance of a strain isolated from a respiratory sample represents a major challenge for c...
Article
Full-text available
The genus Rickettsiella comprises various intracellular bacterial pathogens of arthropods, exhibiting a chlamydia-like developmental cycle. Species may be divided into two main groups, the R. popilliae-R. grylli group and the R. chironomi group. Previous phylogenetic studies based on the 16S ribosomal RNA encoding gene showed that two Rickettsiella...
Article
Full-text available
Accumulating evidence supports a role for Chlamydia-related organisms as emerging pathogens for human and animals. Assessment of their pathogenicity requires strain availability, at least for animal models and serological studies. As these obligate intracellular species are able to grow inside amoebae, we used co-culture with Acanthamoeba castellan...
Article
Full-text available
Free-living amoebae (FLA) are ubiquitous organisms that have been isolated from various domestic water systems, such as cooling towers and hospital water networks. In addition to their own pathogenicity, FLA can also act as Trojan horses and be naturally infected with amoeba-resisting bacteria (ARB) that may be involved in human infections, such as...
Article
Full-text available
The aim of this study was to compare the efficiency of different disinfectants applicable to Legionella control in domestic water systems. A domestic water supply simulation unit that allowed simulation of real-world conditions was developed for this purpose. The system, consisting of seven identical rigs, was used to compare treatment efficiency u...
Article
Full-text available
Since it has been isolated in 1977, pneumonia epidemics involving Legionella pneumophila (Lp) are in constant progress. Contamination essentially occurs by inhalation of water droplets generated from water distribution networks. The ecology of Lp is complex, this bacteria growths inside protozoa and can persist in biofilms in the viable but not cul...
Article
Full-text available
Aims: Monitoring of microbial changes during and after application of various disinfection treatments in a model domestic water system. Methods and results: A pilot-scale domestic water system consisting of seven galvanized steel re-circulation loops and copper dead legs was constructed. Culture techniques, confocal laser scanning microscopy aft...
Article
Full-text available
The gut microbiota naturally protects the host against infections by pathogens. This microbiota can be disrupted in case of antibiotic treatments leading to the loss of the barrier effect and consequently to new colonization and opportunistic infections. We previously developed in our laboratory a trixenic mouse model microbiota displaying coloniza...