Showing results 21 to 34 of 34
   Secreted subtilisins of Microsporum canis are involved in adherence of arthroconidia to feline corneocytes.Baldo, Aline  ; ; et alin Journal of Medical Microbiology (2008), 57(Pt 9), 1152-1156 Microsporum canis is a pathogenic fungus that causes a superficial cutaneous infection called dermatophytosis, mainly in cats and humans. The mechanisms involved in adherence of M. canis to epidermis have ... [more ▼] Microsporum canis is a pathogenic fungus that causes a superficial cutaneous infection called dermatophytosis, mainly in cats and humans. The mechanisms involved in adherence of M. canis to epidermis have never been investigated. Here, a model was developed to study the adherence of M. canis to feline corneocytes through the use of a reconstructed interfollicular feline epidermis (RFE). In this model, adherence of arthroconidia to RFE was found to be time-dependent, starting at 2 h post-inoculation and still increasing at 6 h. Chymostatin, a serine protease inhibitor, inhibited M. canis adherence to RFE by 53%. Moreover, two mAbs against the keratinolytic protease subtilisin 3 (Sub3) inhibited M. canis adherence to RFE by 23%, suggesting that subtilisins, and Sub3 in particular, are involved in the adherence process. [less ▲] Detailed reference viewed: 31 (12 ULg)Secreted dipeptidyl peptidases as potential virulence factors for Microsporum canis.; Baldo, Aline ; et alin FEMS Immunology & Medical Microbiology (2008), 54(3), 299-308 Dermatophytoses caused by Microsporum canis are frequently encountered in cats and dogs; they are highly contagious and readily transmissible to humans. In this study, two single genes, respectively ... [more ▼] Dermatophytoses caused by Microsporum canis are frequently encountered in cats and dogs; they are highly contagious and readily transmissible to humans. In this study, two single genes, respectively coding for dipeptidyl peptidases IV and V (DppIV and DppV), were isolated and characterized. Both proteins share homology with serine proteases of the S9 family, some of which display properties compatible with implication in pathogenic processes. Both genes are expressed in vivo in experimentally infected guinea-pigs and in naturally infected cats, and when the fungus is grown on extracellular matrix proteins as the sole nitrogen and carbon source. DppIV and V were produced as active recombinant proteases in the yeast Pichia pastoris; the apparent molecular weight of rDppV is 83 kDa, whereas rDppIV appears as a doublet of 95 and 98 kDa. Like other members of its enzymatic subfamily, rDppIV has an unusual ability to cleave Pro-X bonds. This activity does not enhance the solubilization of keratin by fungal secreted endoproteases, and the protease probably acts solely on small soluble peptides. RDppV showed no ability to induce delayed-type hypersensitivity (DTH) skin reactions in guinea-pigs, despite the known immunogenic properties of homologous proteins. [less ▲] Detailed reference viewed: 20 (3 ULg)Secreted subtilisins of Microsporum canis are involved in adhesion of arthroconidia to feline corneocytesMignon, Bernard ; ; Mathy, Anne et alConference (2008) Detailed reference viewed: 18 (10 ULg)RNA silencing in the dermatophyte Microsporum canis; ; Baldo, Aline et alin FEMS Microbiology Letters (2007), 275(1), 38-45 Dermatomycoses caused by Microsporum canis are frequent in domestic animals and easily transmissible to humans. Several proteases secreted by this fungus were identified as potential virulence factors ... [more ▼] Dermatomycoses caused by Microsporum canis are frequent in domestic animals and easily transmissible to humans. Several proteases secreted by this fungus were identified as potential virulence factors, but the construction of deficient strains is required to investigate their role in the pathogenesis of the disease. Using target genes encoding two of these proteases, a first evaluation of the utility of RNA-mediated silencing as a reverse genetic tool in dermatophytes was carried out. SUB3 and DPPIV, respectively coding for a subtilisin and a dipeptidyl peptidase, were both down-regulated, by means of two plasmid constructs designed to express an RNA hairpin that corresponds to part of their respective sequence. The degree of attenuation was evaluated by enzymatic assay of the transformants culture supernatants, and by real-time reverse transcriptase-polymerase chain reaction. Enzymatic activities and expression levels varied from less than 5% to 100% of that of control transformants obtained with plasmid without hairpin inserts. Inhibition was globally more efficient for SUB3 than for DPPIV. These results show that RNA silencing can be used for functional genomics in M. canis, and particularly to circumvent the limits and technical difficulties of conventional disruption methods. [less ▲] Detailed reference viewed: 61 (5 ULg)Reconstructed interfollicular feline epidermis as a model for Microsporum canis dermatophytosis; Baldo, Aline ; et alin Journal of Medical Microbiology (2007), 56(7), 971-975 Microsporum canis is a pathogenic fungus that causes a superficial cutaneous infection called dermatophytosis. The complexity of mechanisms involved in dermatophytic infections makes relevant in vivo ... [more ▼] Microsporum canis is a pathogenic fungus that causes a superficial cutaneous infection called dermatophytosis. The complexity of mechanisms involved in dermatophytic infections makes relevant in vivo studies particularly difficult to perform. The aim of this study was to develop a new in vitro model of M. canis dermatophytosis using feline fetal keratinocytes in reconstructed interfollicular epidermis, and to investigate its relevance in studying the host-pathogen relationship. Histological analysis of reconstructed interfollicular feline epidermis (RFE) revealed a fully differentiated epidermis. A proliferation assay showed replicating cells only in the basal layer, indicating that RFE is a well-stratified living tissue, leading to the formation of a horny layer. Histopathological analysis of RFE infected by M. canis arthroconidia revealed that the fungus invades the stratum corneum and produces SUB3, a keratinase implicated in the infectious process. In view of these results, an M. canis dermatophytosis model on RFE seems to be a useful tool to investigate mechanisms involved in natural M. canis feline infections. [less ▲] Detailed reference viewed: 25 (3 ULg) Les mécanismes d'adhérence des champignons responsables de mycoses superficiellesBaldo, Aline ; Mathy, Anne ; et alin Annales de Médecine Vétérinaire (2007), 151 Detailed reference viewed: 45 (8 ULg)Reconstructed interfollicular feline epidermis as a model for the screening of drugs against Microsporum canisMignon, Bernard ; ; Baldo, Aline et alin Veterinary Dermatology (2007), 18 Detailed reference viewed: 22 (5 ULg)Kinetics of Microsporum canis adherence using an in vitro model of reconstituted feline epidermisBaldo, Aline ; ; et alConference (2006) Detailed reference viewed: 7 (1 ULg)A randomized, double-blinded, placebo-controlled study on the efficacy of a new antifungal (compound MNLP1242) against Microsporum canis dermatophytosis in experimentally infected guinea pigsMignon, Bernard ; ; Baldo, Aline et alin Veterinary Dermatology (2006), 17 Detailed reference viewed: 49 (9 ULg)Recent findings on the pathogenesis of dermatophytoses in dogs and catsMignon, Bernard ; ; et alin Revista Scientia Parasitologica (2006), 7(3/4), 7-15 Detailed reference viewed: 11 (3 ULg)Two Microsporum canis dipeptidyl peptidase genes with possible involvement in fungal virulence; Baldo, Aline ; et alConference (2006) Detailed reference viewed: 9 (3 ULg)A new in vitro model of Microsporum canis dermatophytosis in reconstituted feline skin; Baldo, Aline ; et alConference (2006) Detailed reference viewed: 13 (4 ULg)Vaccination against dermatophytosis in domestic animals : Past, present and futureMignon, Bernard ; ; et alConference (2006) Detailed reference viewed: 25 (9 ULg)Evaluation of immunogenicity and protective efficacy of a Microsporum canis metalloprotease subunit vaccine in guinea pigsBaldo, Aline ; ; et alConference (2004) Detailed reference viewed: 12 (3 ULg)
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