Characterization of a new potential virulence factor of Microsporum canis, the secreted subtilisin Sub6

in Mycoses (2011), 54(suppl 2), 112-113

Implication de la protéase à sérine de type subtilisine sub3 dans l'adhérence de Microsporum canis à l'épiderme de différentes espèces animales et l'épiderme humain

Poster (2011)

Rôle des cellules Th17 dans les maladies infectieuses et auto-immunes

in Annales de Médecine Vétérinaire (2011), 154

Cytokinic response and MHC class II expression in feline dendritic cells exposed to Microsporum canis components

Conference (2010)

Secreted subtilisin Sub3 from Microsporum canis is required for adherence to but not for invasion of the epidermis

in British Journal of Dermatology (2010), 162(5), 990-997

Fungalysin and dipeptidyl-peptidase gene transcription in Microsporum canis strains isolated from symptomatic and asymptomatic cats

in Veterinary Microbiology (2010), 146(1-2), 179-182

Cytokinic response of feline dermatophytes towards Microsporum canis and fungal components

Conference (2009)

Immunization and dermatophytes

Conference (2009)

Secreted subtilisins of Microsporum canis are involved in adhesion of arthroconidia to feline corneocytes

Poster (2008)

Microsporum canis is a pathogenic fungus that causes a superficial skin infection called dermatophytosis mainly in cats, dogs and humans. Like other dermatophytoses, the physiopathology of this dermatosis ... [more ▼]

Microsporum canis is a pathogenic fungus that causes a superficial skin infection called dermatophytosis mainly in cats, dogs and humans. Like other dermatophytoses, the physiopathology of this dermatosis remains largely unknown. From a fungal perspective, the infection process can be divided in three steps: adhesion of M. canis arthroconidia to corneocytes, conidial germination, and fungal invasion of the keratin network. The mechanisms involved in adherence of M. canis to epidermis have never been investigated. However, several previously characterized secreted fungal endoproteases like subtilisins (Sub), including the keratinolytic protease Sub3, are secreted in vivo and could be involved in the first pathogenic steps. The objective of this study were (1) to develop an in vitro model to study M. canis adherence to feline corneocytes and (2) to assess whether the Sub are involved in fungal adhesion. An arthroconidial suspension was spread over the surface of reconstituted feline epidermis (RFE). Co-cultures were incubated for varying lengths of time and adherent conidia were labelled using Calcofluor white and counted. In subsequent assays arthroconidia were exposed to the serine protease inhibitor chymostatin or a mixture of two anti-Sub3 monoclonal antibodies (Mabs) one hour prior to the adherence assay. In our model, adherence of M. canis arthroconidia to RFE is time-dependent, beginning within two hours and still increasing after six hours. Chymostatin and Mabs inhibit M. canis adherence to RFE by 53 and 23 % respectively, which suggests that subtilisins and particularly Sub3, are fungal virulence factors involved in the adherence process. [less ▲]

Reconstructed interfollicular feline epidermis as a model for the screening of antifungal drugs against Microsporum canis.

in Veterinary Dermatology (2008), 19(3), 130-133

A fully differentiated reconstructed interfollicular feline epidermis (RFE) was recently developed in vitro. It was shown to be relevant for the study of Microsporum canis-epidermal interactions. In this ... [more ▼]

A fully differentiated reconstructed interfollicular feline epidermis (RFE) was recently developed in vitro. It was shown to be relevant for the study of Microsporum canis-epidermal interactions. In this study, RFE was evaluated as a potential model for the in vitro screening of drugs against M. canis. As a preliminary step, the minimum inhibitory concentration of miconazole nitrate against M. canis IHEM 21239 grown on Sabouraud's dextrose agar was determined to be 0.3 microg mL(-1). RFE grown at the air-liquid interface was cultured for 24 h in RFE culture medium, supplemented with either miconazole (range 0.1-1 microg mL(-1)) or its solvent (dimethylsulfoxide). Then, RFE was inoculated in triplicate with 1 x 10(5 )M. canis arthroconidia and incubated for five additional days. To evaluate fungal growth, RFE was processed for routine histopathology, three serial sections being performed across the block at 100 microm intervals. No fungal growth was detected invading or on the surface of infected RFE in the presence of miconazole concentrations equal to or higher than 0.3 microg mL (final concentration in the culture medium). This study demonstrates that RFE is an adequate model for the in vitro screening of drugs against M. canis and potentially against other skin pathogens. [less ▲]