Personne :
Toulouse, Marie-Josée

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Département de biochimie et de microbiologie, Faculté des sciences et de génie, Université Laval
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Voici les éléments 1 - 4 sur 4
  • Publication
    A simple and rapid fluorescent neuraminidase enzymatic assay on a microfluidic chip
    (Elsevier Science, 2012-09-15) Zhang, Fang; Duchaine, Caroline; Toulouse, Marie-Josée; Turgeon, Nathalie; Li, Dongqing
    Neuraminidase enzymatic assay is an inexpensive, reliable, and quick method of detecting viruses. However, the assay in conventional laboratories requires a large amount of samples and reagents and multiple steps, which makes the conventional assay labor intensive and time consuming. This article reports a novel and simple method for conducting the neuraminidase enzymatic assay on a microfluidic chip. By using 4-methylumbelliferyl-N-acetyl-a-d-neuraminic acid as the fluorescent substrate and applying an electric field, the newly developed assay is simple, fast, and automatic. Fluorescence of the enzymatic reaction product was recorded as the assay result, and the fluorescence intensity quantitatively indicates the concentration of the sample, which proves that the novel assay on a microfluidic chip has a potential to be developed into a portable device for on-site detection of environmental samples.
  • Publication
    Accès libre
    Validation de la neuraminidase à titre de marqueur enzymatique pour la détection de virus dans l’air
    (2019) Toulouse, Marie-Josée; Duchaine, Caroline
    Les méthodes connues de détection des virus dans l’air sont complexes et ne permettent pas de détecter rapidement plusieurs types de virus à la fois. De plus, peu d’informations sont disponibles concernant l’efficacité des échantillonneurs à récolter et à préserver l’infectivité des virus. Ce projet avait pour objectif d’étudier la détection des virus dans l’air basée sur la présence d’un marqueur enzymatique, soit la neuraminidase. Une enzyme purifiée et des souches de virus influenza ont été utilisés comme modèles. L’efficacité de trois échantillonneurs à récolter les virus dans l’air a été comparée et les effets de l’aérosolisation et de l’échantillonnage dans deux chambres d’aérosolisation sur l’acitivité de la neuraminidase et sur l’infectivité des virus ont été étudiés. Les résultats obtenus démontent la stabilité de la neuraminidase et valident son utilisation comme marqueur enzymatique pour la détection générique, simple, rapide et abordable des virus dans des échantillons d’air.
  • Publication
    Accès libre
    Comparison of five bacteriophages as models for viral aerosol studies
    (American Society for Microbiology, 2014-04-29) Duchaine, Caroline; Toulouse, Marie-Josée; Moineau, Sylvain; Martel, Bruno; Turgeon, Nathalie
    Bacteriophages are perceived to be good models for the study of airborne viruses because they are safe to use, some of them display structural features similar to those of human and animal viruses, and they are relatively easy to produce in large quantities. Yet, only a few studies have investigated them as models. It has previously been demonstrated that aerosolization, environmental conditions, and sampling conditions affect viral infectivity, but viral infectivity is virus dependent. Thus, several virus models are likely needed to study their general behavior in aerosols. The aim of this study was to compare the effects of aerosolization and sampling on the infectivity of five tail-less bacteriophages and two pathogenic viruses: MS2 (a single-stranded RNA [ssRNA] phage of the Leviviridae family), F6 (a segmented double-stranded RNA [dsRNA] phage of the Cystoviridae family), FX174 (a single-stranded DNA [ssDNA] phage of the Microviridae family), PM2 (a double-stranded DNA [dsDNA] phage of the Corticoviridae family), PR772 (a dsDNA phage of the Tectiviridae family), human influenza A virus H1N1 (an ssRNA virus of the Orthomyxoviridae family), and the poultry virus Newcastle disease virus (NDV; an ssRNA virus of the Paramyxoviridae family). Three nebulizers and two nebulization salt buffers (with or without organic fluid) were tested, as were two aerosol sampling devices, a liquid cyclone (SKC BioSampler) and a dry cyclone (National Institute for Occupational Safety and Health two-stage cyclone bioaerosol sampler). The presence of viruses in collected air samples was detected by culture and quantitative PCR (qPCR). Our results showed that these selected five phages behave differently when aerosolized and sampled. RNA phage MS2 and ssDNA phage FX174 were the most resistant to aerosolization and sampling. The presence of organic fluid in the nebulization buffer protected phages PR772 and F6 throughout the aerosolization and sampling with dry cyclones. In this experimental setup, the behavior of the influenza virus resembled that of phages PR772 and F6, while the behavior of NDV was closer to that of phages MS2 and FX174. These results provide critical information for the selection of appropriate phage models to mimic the behavior of specific human and animal viruses in aerosols.
  • Publication
    Accès libre
    Neuraminidase activity as a potential enzymatic marker for rapid detection of airborne viruses
    (Elsevier, 2011-10-24) Duchaine, Caroline; McNicoll, François; Toulouse, Marie-Josée; Turgeon, Nathalie; Liav, Avraham; Barbeau, Jean; Jim, Ho; Grund, Christian
    Viruses offer a limited range of targets for their detection. To date, PCR and RT-PCR have been widely used for detection of viruses. In the case of environmental air sampling, the ability to detect a broad range of viruses would constitute a significant advantage for preventing outbreaks of airborne-transmitted viral infections. Given that neuraminidase is found on some respiratory virus species of medical or agricultural importance, this enzyme could theoretically be used to detect several different airborne viruses in a single assay. The aim of the present study was to evaluate the potential of neuraminidase activity as a marker for rapid detection of airborne viruses. We first validated the use of a low-pathogenic strain of Newcastle disease virus (NDV) as a model airborne virus. Our findings revealed that neuraminidase activity-based assays are almost as sensitive as RT-PCR assays currently used for detection of NDV. We also validated the utilization of a neuraminidase substrate specific to viral neuraminidase. Experiments conducted in a controlled chamber demonstrated that the neuraminidase activity is preserved after aerosolization, air sampling using impingement and handling. Finally, we tested our method with swine barn air samples. Our results demonstrate that neuraminidase activity-based assays are suitable for detection of viruses in air samples.