Persistence of the 2009 Pandemic Influenza A (H1N1) Virus in Water and on Non-Porous Surface

Knowledge of influenza A virus survival in different environmental conditions is a key element for the implementation of hygiene and personal protection measures by health authorities. As it is dependent on virus isolates even within the same subtype, we studied the survival of the 2009 H1N1 pandemic (H1N1pdm) virus in water and on non-porous surface. The H1N1pdm virus was subjected to various environmental parameters over time and tested for infectivity. In water, at low and medium salinity levels and 4°C, virus survived at least 200 days. Increasing temperature and salinity had a strong negative effect on the survival of the virus which remained infectious no more than 1 day at 35°C and 270 parts per thousand (ppt) of salt. Based on modeled data, the H1N1pdm virus retained its infectivity on smooth non-porous surface for at least 7 days at 35°C and up to 66 days at 4°C. The H1N1pdm virus has thus the ability to persist in water and on glass surface for extended periods of time, even at 35°C. Additional experiments suggest that external viral structures in direct contact with the environment are mostly involved in loss of virus infectivity

Cryptosporidium parvum, a potential cause of colic adenocarcinoma

<p>Abstract</p> <p>Background</p> <p>Cryptosporidiosis represents a major public health problem. This infection has been reported worldwide as a frequent cause of diarrhoea. Particularly, it remains a clinically significant opportunistic infection among immunocompromised patients, causing potentially life-threatening diarrhoea in HIV-infected persons. However, the understanding about different aspects of this infection such as invasion, transmission and pathogenesis is problematic. Additionally, it has been difficult to find suitable animal models for propagation of this parasite. Efforts are needed to develop reproducible animal models allowing both the routine passage of different species and approaching unclear aspects of <it>Cryptosporidium </it>infection, especially in the pathophysiology field.</p> <p>Results</p> <p>We developed a model using adult severe combined immunodeficiency (SCID) mice inoculated with <it>Cryptosporidium parvum </it>or <it>Cryptosporidium muris </it>while treated or not with Dexamethasone (Dex) in order to investigate divergences in prepatent period, oocyst shedding or clinical and histopathological manifestations. <it>C. muris</it>-infected mice showed high levels of oocysts excretion, whatever the chemical immunosuppression status. Pre-patent periods were 11 days and 9.7 days in average in Dex treated and untreated mice, respectively. Parasite infection was restricted to the stomach, and had a clear preferential colonization for fundic area in both groups. Among <it>C. parvum</it>-infected mice, Dex-treated SCID mice became chronic shedders with a prepatent period of 6.2 days in average. <it>C. parvum</it>-inoculated mice treated with Dex developed glandular cystic polyps with areas of intraepithelial neoplasia, and also with the presence of intramucosal adenocarcinoma.</p> <p>Conclusion</p> <p>For the first time <it>C. parvum </it>is associated with the formation of polyps and adenocarcinoma lesions in the gut of Dex-treated SCID mice. Additionally, we have developed a model to compare chronic <it>muris </it>and <it>parvum </it>cryptosporidiosis using SCID mice treated with corticoids. This reproducible model has facilitated the evaluation of clinical signs, oocyst shedding, location of the infection, pathogenicity, and histopathological changes in the gastrointestinal tract, indicating divergent effects of Dex according to <it>Cryptosporidium </it>species causing infection.</p

The Early Royal Society and Visual Culture

Recent studies have fruitfully examined the intersection between early modern science and visual culture by elucidating the functions of images in shaping and disseminating scientific knowledge. Given its rich archival sources, it is possible to extend this line of research in the case of the Royal Society to an examination of attitudes towards images as artefacts –manufactured objects worth commissioning, collecting and studying. Drawing on existing scholarship and material from the Royal Society Archives, I discuss Fellows’ interests in prints, drawings, varnishes, colorants, images made out of unusual materials, and methods of identifying the painter from a painting. Knowledge of production processes of images was important to members of the Royal Society, not only as connoisseurs and collectors, but also as those interested in a Baconian mastery of material processes, including a “history of trades”. Their antiquarian interests led to discussion of painters’ styles, and they gradually developed a visual memorial to an institution through portraits and other visual records.AH/M001938/1 (AHRC

Variable adhesion of Listeria monocytogenes isolates from food-processing facilities and clinical cases to inert surfaces.

One hundred one strains of Listeria monocytogenes isolated from seafood and cheese industry samples and from patients with listeriosis were assessed using a microtiter plate method for adhesion to polystyrene and stainless steel surfaces. The adhesion rate for these strains ranged from 3.10 to 35.29% with an inoculum of 8 x 10(8) cells per well. A strong correlation was found between adhesion to polystyrene and stainless steel microtiter plates, indicating that the intrinsic ability of L. monocytogenes to adhere to inert surfaces is stronger than the influence of the surface's physicochemical properties. The clinical strains were less adherent to inert surfaces than were the industrial strains. By integrating other factors such as location of the industrial strains, contamination type of the clinical strains, serotype, and pulsotype into the analysis, some weak but significant differences were noted. For the industrial isolates, the number of cells attached to both surfaces differed significantly depending on whether they were isolated from food or food-processing environments in the seafood and cheese industry. For clinical isolates, sporadic strains exhibited greater adhesion to polystyrene than did epidemic strains. Strains belonging to the pulsed-field gel electrophoretype clusters A and M (lineages II and I, respectively) were less able to adhere to polystyrene and stainless steel than were strains in the more common clusters

Le religieux interrogé par les chercheurs. Constructions disciplinaires

Issus de journées d’étude consacrées au « religieux interrogé par les chercheurs », les articles rassemblés dans ce numéro des Cahiers d’Étude du Religieux – Recherches Interdisciplinaires examinent comment la recherche, dans différentes disciplines, appréhende et construit l’objet religieux. Les deux premiers textes abordent des questions épistémologiques. Anthony Feneuil montre, à partir de l’exemple de Karl Barth, comment la théologie peut contribuer à la réflexion en sciences des religions alors que Julien Cavagnis interroge le thème du « retour du religieux » à partir d’une lecture croisée des trois œuvres de M. Foucault, M. de Certeau et L. Kolakowski. Bien qu’elle s’inscrive dans une perspective différente, Esther Pinon, dans son étude sur les religions romantiques, révèle de même la nature potentiellement problématique de l’objet religieux, qu’elle propose de dépasser par un recours fécond au doute. Dans le texte suivant, la difficulté d’appréhender un objet aux contours mouvants est abordée par le prisme de l’ésotérisme, que David Bisson se propose d’expliciter en adoptant une approche à la croisée des études culturelles et de la psychologie sociale. Trois textes abordent ensuite la question du point de vue du chercheur en mettant en évidence les présupposés propres à certains types de questionnement. Alors qu’Anne Lancien examine l’influence du modèle de laïcité adopté par la France sur les analyses de l’objet « laïcité » menées par les chercheurs, Jérôme Gidoin propose une réflexion sur la posture de l’ethnologue enquêtant sur le culte des ancêtres des Vietnamiens dans un contexte bouddhique en France. Les présupposés des chercheurs, et la nécessité de s’en affranchir, sont également au cœur du texte suivant, l’étude de Christophe Lemardelé sur l’anthropologie du sacrifice. Le dernier volet de ce numéro, enfin, présente deux textes interrogeant l’objet religieux dans sa spatialité, avec dans un premier temps, une enquête de Frédéric Knerr sur les évolutions et les transformations de l’histoire diocésaine française, puis une analyse de Vassilis Pnevmatikakis démontrant l’importance du facteur ecclésiologique dans l’étude géopolitique de l’Église orthodoxe en France

Development of Cryptosporidium parvum-Induced Gastrointestinal Neoplasia in Severe Combined Immunodeficiency (SCID) Mice: Severity of Lesions Is Correlated with Infection Intensity

We reported previously that Cryptosporidium parvum was able to induce intestinal tumors in severe combined immunodeficiency (SCID) mice treated with corticoids. To further characterize this Cryptosporidium-induced cell transformation, SCID mice treated with dexamethasone were challenged with C. parvum oocysts, and euthanatized sequentially after infection for histologic examination. Ki-67 was used as a marker of cellular proliferation. Our previous results were confirmed, and it was also found that mice receiving higher inocula (106–107) experienced more severe neoplastic development. Additionally, neoplastic changes were observed not only in the caecum but also in the stomach and duodenum of some animals. Interestingly, SCID mice (6/6) inoculated with 105–107 oocysts showed high grade intraepithelial neoplasia or adenomas with high grade dysplasia in the caecum after Day 46 post-infection (PI). Immunohistochemistry for Ki-67 staining indicated the neoplastic process associated to cryptosporidiosis, and evidenced the first immunohistochemical alterations at early stages of the process, even at 3 weeks PI

Electrospun Filtering Membrane Designed as Component of Self-Decontaminating Protective Masks

International audienceThe 2019 coronavirus outbreak and worsening air pollution have triggered the search for manufacturing effective protective masks preventing both particulate matter and biohazard absorption through the respiratory tract. Therefore, the design of advanced filtering textiles combining efficient physical barrier properties with antimicrobial properties is more newsworthy than ever. The objective of this work was to produce a filtering electrospun membrane incorporating a biocidal agent that would offer both optimal filtration efficiency and fast deactivation of entrapped viruses and bacteria. After the eco-friendly electrospinning process, polyvinyl alcohol (PVA) nanofibers were stabilized by crosslinking with 1,2,3,4-butanetetracarboxylic acid (BTCA). To compensate their low mechanical properties, nanofiber membranes with variable grammages were directly electrospun on a meltblown polypropylene (PP) support of 30 g/m2. The results demonstrated that nanofibers supported on PP with a grammage of around only 2 g/m2 presented the best compromise between filtration efficiencies of PM0.3, PM0.5, and PM3.0 and the pressure drop. The filtering electrospun membranes loaded with benzalkonium chloride (ADBAC) as a biocidal agent were successfully tested against E. coli and S. aureus and against human coronavirus strain HCoV-229E. This new biocidal filter based on electrospun nanofibers supported on PP nonwoven fabric could be a promising solution for personal and collective protection in a pandemic context