Semi-automated repetitive sequence-based PCR amplification for species of the Scedosporium apiospermum complex

International audiencePurpose: The Scedosporium apiospermum species complex usually ranks second among the filamentous fungi colonizing the airways of patients with cystic fibrosis (CF), but little is known about the molecular epidemiology of the airway colonization.Methods: Polymerase chain reaction (PCR) amplification of repetitive sequences (rep-PCR) was applied to the retrospective analysis of a panel of isolates already studied by random amplification of polymorphic DNA (RAPD) and comprising 63 isolates recovered from sputa from 9 CF patients. Results were compared to those obtained previously by RAPD, and herein by beta-tubulin (TUB) gene sequencing and Multilocus Sequence Typing (MLST).Results: Within the panel of isolates studied, S. apiospermum sensu stricto and Sce-dosporium boydii, as expected, were the predominant species with 21 and 36 isolates, respectively. Four isolates from one patient were identified as Scedosporium auranti-acum, whereas two isolates belonged to the Pseudallescheria ellipsoidea subgroup of S. boydii. rep-PCR analysis of these isolates clearly differentiated the three species and P. ellipsoidea isolates, whatever the rep-PCR kit used, and also permitted strain differentiation. When using the mold primer kit, results from rep-PCR were in close agreement with those obtained by MLST. For both S. apiospermum and S. boydii, 8 genotypes were differentiated by rep-PCR and MLST compared to 10 by RAPD. All S. aurantiacum isolates shared the same RAPD genotype and exhibited the same rep-PCR profile and sequence type.Conclusions: These results illustrate the efficacy of rep-PCR for both species identification within the S. apiospermum complex and genotyping for the two major species of this comple

Common occurrence of Cryptosporidium hominis in asymptomatic and symptomatic calves in France

International audienceSymptomatic infection by the Apicomplexan Cryptosporidium spp. is presently considered the most frequent parasitic cause of acute diarrhea in both humans (especially severe in immunocompromised individuals and infants in both developed and developing countries) and cattle (calves), while asymptomatic infections are less often documented. Cryptosporidium (C.) hominis once considered to be restricted to humans accounts for the majority of pediatric cases in several countries. C. parvum can also infect cattle as well as C. bovis, C. andersoni, and C. ryanae. Recently, cattle C. hominis cryptosporidiosis has been reported, suggesting that the presence of C. hominis in calves was previously underestimated. The aim of this work was to characterize Cryptosporidium spp. infection in both asymptomatic and symptomatic dairy and beef calves from Metropolitan France. From February to November 2015, C. parvum or C. hominis infected calves were detected in farms from 5 geographic regions of France. Surprisingly, C. hominis was present in about one fifth of Cryptosporidium spp. infected calves, and exhibited genotypes which were previously reported in human and nonhuman primate. Further investigations are aimed at documenting direct or indirect C. hominis transmissions between and among livestock and humans

Evaluation of voriconazole anti-Acanthamoeba polyphaga in vitro activity, rat cornea penetration and efficacy against experimental rat Acanthamoeba keratitis

International audienceBackground: Acanthamoeba keratitis (AK) is a sight-threatening infectious disease. Its effective and safe medical therapy remains highly debated. Recently, voriconazole, a monotriazole with noted in vitro activity against a large variety of fungi, has been successfully used both topically and systemically to treat human AK cases.Objectives: To measure anti-Acanthamoeba polyphaga in vitro activity, anti-rat AK efficiency and rat cornea penetration of eye-drop and oral voriconazole.Methods: A. polyphaga was maintained in axenic cultures. In vitro, amoebicidal and cysticidal activities of voriconazole were measured using an XTT assay. AK lesions of Sprague Dawley rats were scored from grade 0 to grade 3. For 21 days, from day 7 post-infection, voriconazole (1% solution) eye drops were instilled or voriconazole was administered by gavage (60 mg/kg/day). After killing, superficial corneal epithelium scrapings were cultured and analysed by PCR, and eye-globe histology was performed. Cornea and plasma concentrations were determined using 2D HPLC separation and tandem MS.Results: In vitro, voriconazole inhibited trophozoite proliferation with an IC50 value of 0.02 mg/L and an IC90 value of 2.86 mg/L; no cysticidal effect was found. In AK rats, eye drops reduced clinical worsening from day 7 to day 14 post-infection and oral voriconazole was not effective. Voriconazole cornea concentrations were directly dependent on the frequency of eye-drop instillations, which resulted in lower plasma concentrations, whilst oral voriconazole resulted in lower cornea concentrations.Conclusions: Present data underline the need for high-frequency eye-drop instillation regimens for efficient AK therapy

Bacterial-based additives for the production of artificial snow: What are the risks to human health?

International audienceFor around two decades, artificial snow has been used by numerous winter sports resorts to ensure good snow cover at low altitude areas or more generally, to lengthen the skiing season. Biological additives derived from certain bacteria are regularly used to make artificial snow. However, the use of these additives has raised doubts concerning the potential impact on human health and the environment. In this context, the French health authorities have requested the French Agency for Environmental and Occupational Health Safety (Afsset) to assess the health risks resulting from the use of such additives. The health risk assessment was based on a review of the scientific literature, supplemented by professional consultations and expertise. Biological or chemical hazards from additives derived from the ice nucleation active bacterium Pseudomonas syringae were characterised. Potential health hazards to humans were considered in terms of infectious, toxic and allergenic capacities with respect to human populations liable to be exposed and the means of possible exposure. Taking into account these data, a qualitative risk assessment was carried out, according to four exposure scenarios, involving the different populations exposed, and the conditions and routes of exposure. It was concluded that certain health risks can exist for specific categories of professional workers (mainly snowmakers during additive mixing and dilution tank cleaning steps, with risks estimated to be negligible to low if workers comply with safety precautions). P. syringae does not present any pathogenic capacity to humans and that the level of its endotoxins found in artificial snow do not represent a danger beyond that of exposure to P. syringae endotoxins naturally present in snow. However, the risk of possible allergy in some particularly sensitive individuals cannot be excluded. Another important conclusion of this study concerns use of poor microbiological water quality to make artificial snow

Approches expérimentales des intéractions cellulaires, de l'infectivité et de la sensibilité aux antiparasitaires de Cryptosporidium parvum

L'infectivité et la pathogénicité de Cryptosporidium ainsi que les réponses entérocytaires à l'infection (production de cytokines, apoptose) conditionnent la physiopathologie. La protection immunologique implique principalement l'immunité à médiation cellulaire et les intéractions des lymphocytes T muqueux avec les entérocytes infectés. Le nombre des agents anti-cryptosporidiens candidats au traitement de la cryptosporidiose est restreint. Dans ce travail, nous avons étudié in vitro la réponse des lymphocytes T humains aux antigènes de C. parvum. Les lymphocytes T sont la cible de chémokines (IL-8, RANTES)sécrétées par les cellules entérocytaires infectées. Les lymphocytes TCD4+ activés par les antigènes de C. parvum augmentent leur expression de CD40L. Nous avons établi in vitro un modèle qui mime les intéractions des lymphocytes T systémiques avec la muqueuse intestinale infectée. Les lymphocytes T CD8+ migrant à travers une monocouche de cellules entérocytaires infectées expriment de novo le CD103. Afin de quantifier le risque lié à l'infectivité des oocystes de C. parvum, nous avons mis au point un modèle d'infection intestinale du souriceau nouveau-né avec détection cytofluorométrique des oocystes. Dans ce modèle, l'infectivité maximale peut être mesurée et un inoculum de l'ordre d'un oocyste est infectant. Cette méthode est applicable aux prélèvements provenant de l'environnement hydrique. Nous avons développé une méthode immunoenzymatique de détection du développement de C. parvum dans les cellules HTC-8 et l'avons appliquée à la mesure des effets anti-cryptosporidiens d'agents pharmacologiques.Elle a permis de démontrer que le nitazoxanide et ses métabolites tizoxanide et glucoronate de tizoxanide sont actifs dès le staded'invasion sporozoïtaire, alors que la nitazoxanide et le glucoronate de tizoxanide sont respectivement actifs sur les stades sexués et asexués.CAEN-BU Médecine pharmacie (141182102) / SudocSudocFranceF

Immunisation passive et active du poulain par des composants pariétaux de Rhodococcus equi

CAEN-BU Médecine pharmacie (141182102) / SudocSudocFranceF

Approche immunologique et parasitologique de l'épidémiologie des infections émergentes bovines et équines A NEOSPORA sp. et SARCOCYSTIS NEURONA en Basse-Normandie

Nos travaux en sérologie et en biologie moléculaire ont permis de mettre en évidence le rôle majeur de Neospora caninum dans la pathologie abortive chez l'espèce bovine en France, en particulier dans l'ouest du pays. Si l'ensemble du cycle biologique naturel de ce parasite n'est pas encore totalement élucidé, nos résultats confortent l'hypothèse d'une intervention de la faune sauvage dans la transmission et/ou le rôle de réservoir pour Neospora caninum dans notre pays. Nos résultats confirment aussi l'existence de troubles neurologiques associés à la détection d'ADN parasitaire dans le LCR d'un veau. Il semble aussi que ce parasite intervienne comme agent abortif dans une moindre mesure dans l'espèce équine. Des travaux supplémentaires sont nécessaires afin de pouvoir différencier les deux espèces de Neospora sp. présentes chez le cheval. Son rôle dans le syndrome EPM reste en revanche très faible selon nos résultats. Nos travaux font par contre apparaître de nombreux chevaux présentant des anticorps dirigés contre des protéïnes de Sarcocystis neurona bien que l'oppossum soit absent du continent européen.CAEN-BU Médecine pharmacie (141182102) / SudocSudocFranceF

Kinetics of antigen specific and non-specific polyclonal B-cell responses during lethal Plasmodium yoelii malaria

In order to study the kinetics and composition of the polyclonal B-cell activation associated to malaria infection, antigen-specific and non-specific B-cell responses were evaluated in the spleens of mice infected with Plasmodium yoelii 17 XL or injected with lysed erythrocytes or plasma from P. yoelii infected mice or with P. falciparum culture supernatants. Spleen/body weigth ratio, numbers of nucleated spleen cells and Immunoglobulin-containing and Immunoglobulin-secreting cells increased progressively during the course of infection,in parallel to the parasitemia. A different pattern of kinetics was observed when anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell plaque forming cells response were studied: maximum values were observed at early stages of infection, whereas the number of total Immunoglobulin-containing and Immunoglobulin-secreting cells were not yet altered. Conversely, at the end of infection, when these latter values reached their maximum, the anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell specific responses were normal or even infranormal. In mice injected with Plasmodium-derived material, a higher increase in antigen-specific PFC was observed, as compared to the increase of Immunoglobulin-containing and Immunoglobulin-secreting cell numbers. This suggested a "preferential" (antigen-plus mitogen-induced) stimulation of antigen-specific cells rather than a generalized non-specific (mitogen-induced) triggering of B-lymphocytes. On the basis of these and previous results, it is suggested that polyclonal B-cell activation that takes place during the course of infection appears as a result of successive waves of antigen-specific B-cell activation

Stratégie chirurgicale dans le cancer rectosigmoidien.

Colorectal cancer is frequent and diagnosed earlier thanks to the screening and to the progresses in the preoperative assessment. The precocity of the surgical resection takes advantage from the complete resection of vascular and nodes involvement. The rectal localisation of the cancer requires to take the reconstruction into account. If preoperative radiotherapy is helpful in T4 and T3 N2 and locally advanced tumour, the surgeon should consider the four approaches of rectal cancer: the anterior resection (Dixon-Wangensteen) (DW) with total mesorectal excision (TME), the colo-anal anastomosis with a J pouch, the abdomino-perineal approach (Miles procedure) requiring a definitive left colostomy, and in some rare cases the transanal local resection.SCOPUS: re.jinfo:eu-repo/semantics/publishe