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Bernard Mignon - One of the best experts on this subject based on the ideXlab platform.
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Feline polymorphonuclear neutrophils produce pro-inflammatory cytokines following exposure to Microsporum Canis
Veterinary Microbiology, 2012Co-Authors: Ludivine Cambier, A Mathy, J Tabart, Aline Baldo, E. T. Bagut, Nadine Antoine, Bernard MignonAbstract:The mechanisms involved in the establishment of the specific immune response against dermatophytes remain unknown. Polymorphonuclear neutrophils (PMNs) are recruited early during the infection process and participate in the elimination of dermatophytes. They could therefore be involved in the induction of the immune response during dermatophytoses by producing specific cytokines. The aim of this work was to assess the in vitro cytokine production by feline PMNs exposed to living arthroconidia from the dermatophyte species Microsporum Canis or stimulated with either a secreted or a structural component of M. Canis, the latter consisting of heat-killed arthroconidia. The levels of specific cytokines produced by PMNs were determined by capture ELISA and/or quantitative RT-PCR. Results showed that PMNs secrete TNFα, IL-1β and IL-8 following exposure to M. Canis living arthroconidia and stimulation with both a secreted component and heat-killed arthroconidia. The level of IL-8 mRNA was also increased in PMNs stimulated with M. Canis living arthroconidia. In conclusion, infective M. Canis arthroconidia induce the production of pro-inflammatory cytokines by feline PMNs that can be activated either by secreted or structural fungal components. Our results suggest that these granulocytes are involved in the initiation of the immune response against M. Canis.
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Subtilisin Sub3 is involved in adherence of Microsporum Canis to human and animal epidermis.
Veterinary microbiology, 2012Co-Authors: Elena Tatiana Băguţ, A Mathy, Ludivine Cambier, Aline Baldo, Nadine Antoine, Vasile Cozma, Bernard MignonAbstract:The aim of this study was to assess the role of the secreted keratinolytic subtilisin-like protease Sub3 in adherence of Microsporum Canis to epidermis from various susceptible species, in addition to cat for which this role was recently demonstrated. Firstly, we showed by immunostaining that Sub3 is not expressed in arthroconidia from an M. Canis SUB3 RNA-silenced strain but is present on the surface of arthroconidia from a SUB3 non-silenced parental strain. Secondly, comparative adherence assays using arthroconidia from both M. Canis strains and skin explants from humans, dogs, horses, rabbits, guinea pigs, mice and cats revealed that only 8–16% of arthroconidia from the SUB3 silenced strain adhered to different types of epidermis when compared to the control strain. Attempts to restore fungal adherence by the addition of recombinant Sub3 failed in the tested conditions. Overall results show for the first time that Sub3 is necessary for the adherence of M. Canis arthroconidia to epidermis from humans and other animal species than cat, supporting the idea that Sub3 plays a central role in colonization of keratinized host structures by M. Canis, whatever the host.
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secreted dipeptidyl peptidases as potential virulence factors for Microsporum Canis
Fems Immunology and Medical Microbiology, 2008Co-Authors: S Vermout, J Tabart, Aline Baldo, Bertrand Losson, Bernard MignonAbstract: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.
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secreted subtilisins of Microsporum Canis are involved in adherence of arthroconidia to feline corneocytes
Journal of Medical Microbiology, 2008Co-Authors: Aline Baldo, J Tabart, Bertrand Losson, S Vermout, Anne Mathy, Alfred Collard, Bernard MignonAbstract: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.
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reconstructed interfollicular feline epidermis as a model for Microsporum Canis dermatophytosis
Journal of Medical Microbiology, 2007Co-Authors: J Tabart, Aline Baldo, Bertrand Losson, S Vermout, Betty Nusgens, Charlesleon Lapiere, Bernard MignonAbstract: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.
Bertrand Losson - One of the best experts on this subject based on the ideXlab platform.
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secreted dipeptidyl peptidases as potential virulence factors for Microsporum Canis
Fems Immunology and Medical Microbiology, 2008Co-Authors: S Vermout, J Tabart, Aline Baldo, Bertrand Losson, Bernard MignonAbstract: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.
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secreted subtilisins of Microsporum Canis are involved in adherence of arthroconidia to feline corneocytes
Journal of Medical Microbiology, 2008Co-Authors: Aline Baldo, J Tabart, Bertrand Losson, S Vermout, Anne Mathy, Alfred Collard, Bernard MignonAbstract: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.
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reconstructed interfollicular feline epidermis as a model for Microsporum Canis dermatophytosis
Journal of Medical Microbiology, 2007Co-Authors: J Tabart, Aline Baldo, Bertrand Losson, S Vermout, Betty Nusgens, Charlesleon Lapiere, Bernard MignonAbstract: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.
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recombinant expression and antigenic properties of a 31 5 kda keratinolytic subtilisin like serine protease from Microsporum Canis
Fems Immunology and Medical Microbiology, 2003Co-Authors: F Descamps, Bertrand Losson, S Vermout, Michel Monod, Fra Da Ric D Brouta, Bernard MignonAbstract:A secreted 31.5-kDa keratinolytic subtilase (SUB3; AJ431180) is thought to be a Microsporum Canis virulence factor and represents a candidate for vaccination trials. In this study, the recombinant keratinase (r-SUB3) was produced by the Pichia pastoris expression system and purified to homogeneity. Recombinant SUB3 displayed identical biochemical properties with the native protease. Experimentally cutaneously infected guinea pigs showed specific lymphoproliferative response towards r-SUB3, while no specific humoral immune response was induced except for one animal. The heterologous expression of SUB3 provides a valuable tool for addressing further investigations on the role of this keratinase in the specific cellular immune response and on its use in vaccination trials in the cat.
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secreted metalloprotease gene family of Microsporum Canis
Infection and Immunity, 2002Co-Authors: F Brouta, Bertrand Losson, S Vermout, Frederic Descamps, Michel Monod, Bernard MignonAbstract:Keratinolytic proteases secreted by dermatophytes are likely to be virulence-related factors. Microsporum Canis, the main agent of dermatophytosis in dogs and cats, causes a zoonosis that is frequently reported. Using Aspergillus fumigatus metalloprotease genomic sequence (MEP) as a probe, three genes (MEP1, MEP2, and MEP3) were isolated from an M. Canis genomic library. They presented a quite-high percentage of identity with both A. fumigatus MEP and Aspergillus oryzae neutral protease I genes. At the amino acid level, they all contained an HEXXH consensus sequence, confirming that these M. Canis genes (MEP genes) encode a zinc-containing metalloprotease gene family. Furthermore, MEP3 was found to be the gene encoding a previously isolated M. Canis 43.5-kDa keratinolytic metalloprotease, and was successfully expressed as an active recombinant enzyme in Pichia pastoris. Reverse transcriptase nested PCR performed on total RNA extracted from the hair of M. Canis-infected guinea pigs showed that at least MEP2 and MEP3 are produced during the infection process. This is the first report describing the isolation of a gene family encoding potential virulence-related factors in dermatophytes.
F Brouta - One of the best experts on this subject based on the ideXlab platform.
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secreted metalloprotease gene family of Microsporum Canis
Infection and Immunity, 2002Co-Authors: F Brouta, Bertrand Losson, S Vermout, Frederic Descamps, Michel Monod, Bernard MignonAbstract:Keratinolytic proteases secreted by dermatophytes are likely to be virulence-related factors. Microsporum Canis, the main agent of dermatophytosis in dogs and cats, causes a zoonosis that is frequently reported. Using Aspergillus fumigatus metalloprotease genomic sequence (MEP) as a probe, three genes (MEP1, MEP2, and MEP3) were isolated from an M. Canis genomic library. They presented a quite-high percentage of identity with both A. fumigatus MEP and Aspergillus oryzae neutral protease I genes. At the amino acid level, they all contained an HEXXH consensus sequence, confirming that these M. Canis genes (MEP genes) encode a zinc-containing metalloprotease gene family. Furthermore, MEP3 was found to be the gene encoding a previously isolated M. Canis 43.5-kDa keratinolytic metalloprotease, and was successfully expressed as an active recombinant enzyme in Pichia pastoris. Reverse transcriptase nested PCR performed on total RNA extracted from the hair of M. Canis-infected guinea pigs showed that at least MEP2 and MEP3 are produced during the infection process. This is the first report describing the isolation of a gene family encoding potential virulence-related factors in dermatophytes.
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purification and characterization of a 43 5 kda keratinolytic metalloprotease from Microsporum Canis
Medical Mycology, 2001Co-Authors: F Brouta, F Descamps, Thomas Fett, Bertrand Losson, Charles Gerday, Bernard MignonAbstract:A keratinolytic protease secreted by a feline clinical isolate of Microsporum Canis cultivated in a broth containing feline keratin as the sole nitrogen source was purified from the culture filtrate by affinity chromatography on bacitracin-agarose and by hydrophobic chromatography on octyl-agarose. The enzyme had an apparent molecular mass of 43.5 kDa and the pI was 7.7. It had a significant activity against keratin azure, elastin-Congo red and denatured type I collagen (azocoll). Using the latter substrate, the optimum pH was around 8 and the apparent optimum temperature around 50 degrees C. The protease was strongly inhibited by 1,10-phenanthroline, phosphoramidon and EDTA. The first 13 N-terminal amino acid sequence showed a 61% homology with that of the extracellular metalloprotease of Aspergillus fumigatus and with the neutral protease I of A. oryzae, confirming that this 43.5 kDa keratinase is a metalloprotease. This keratinolytic metalloprotease could be a virulence-related factor involved in pathophysiological mechanisms of M. Canis dermatophytosis.
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purification and characterization of a 43 5 kda keratinolytic metalloprotease from Microsporum Canis
Medical Mycology, 2001Co-Authors: F Brouta, F Descamps, Thomas Fett, Bertrand Losson, Charles Gerday, Bernard MignonAbstract:A keratinolytic protease secreted by a feline clinical isolate of Microsporum Canis cultivated in a broth containing feline keratin as the sole nitrogen source was purified from the culture filtrate by affinity chromatography on bacitracin-agarose and by hydrophobic chromatography on octyl-agarose. The enzyme had an apparent molecular mass of 43·5 kDa and the pI was 7·7. It had a significant activity against keratin azure, elastin-Congo red and denatured type I collagen (azocoll). Using the latter substrate, the optimum pH was around 8 and the apparent optimum temperature around 50°C. The protease was strongly inhibited by 1,10-phenanthroline, phosphoramidon and EDTA. The first 13 N-terminal amino acid sequence showed a 61% homology with that of the extracellular metalloprotease of Aspergillus fumigatus and with the neutral protease I of A. oryzae, confirming that this 43·5 kDa keratinase is a metalloprotease. This keratinolytic metalloprotease could be a virulence-related factor involved in pathophysiolo...
F Descamps - One of the best experts on this subject based on the ideXlab platform.
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recombinant expression and antigenic properties of a 31 5 kda keratinolytic subtilisin like serine protease from Microsporum Canis
Fems Immunology and Medical Microbiology, 2003Co-Authors: F Descamps, Bertrand Losson, S Vermout, Michel Monod, Fra Da Ric D Brouta, Bernard MignonAbstract:A secreted 31.5-kDa keratinolytic subtilase (SUB3; AJ431180) is thought to be a Microsporum Canis virulence factor and represents a candidate for vaccination trials. In this study, the recombinant keratinase (r-SUB3) was produced by the Pichia pastoris expression system and purified to homogeneity. Recombinant SUB3 displayed identical biochemical properties with the native protease. Experimentally cutaneously infected guinea pigs showed specific lymphoproliferative response towards r-SUB3, while no specific humoral immune response was induced except for one animal. The heterologous expression of SUB3 provides a valuable tool for addressing further investigations on the role of this keratinase in the specific cellular immune response and on its use in vaccination trials in the cat.
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purification and characterization of a 43 5 kda keratinolytic metalloprotease from Microsporum Canis
Medical Mycology, 2001Co-Authors: F Brouta, F Descamps, Thomas Fett, Bertrand Losson, Charles Gerday, Bernard MignonAbstract:A keratinolytic protease secreted by a feline clinical isolate of Microsporum Canis cultivated in a broth containing feline keratin as the sole nitrogen source was purified from the culture filtrate by affinity chromatography on bacitracin-agarose and by hydrophobic chromatography on octyl-agarose. The enzyme had an apparent molecular mass of 43.5 kDa and the pI was 7.7. It had a significant activity against keratin azure, elastin-Congo red and denatured type I collagen (azocoll). Using the latter substrate, the optimum pH was around 8 and the apparent optimum temperature around 50 degrees C. The protease was strongly inhibited by 1,10-phenanthroline, phosphoramidon and EDTA. The first 13 N-terminal amino acid sequence showed a 61% homology with that of the extracellular metalloprotease of Aspergillus fumigatus and with the neutral protease I of A. oryzae, confirming that this 43.5 kDa keratinase is a metalloprotease. This keratinolytic metalloprotease could be a virulence-related factor involved in pathophysiological mechanisms of M. Canis dermatophytosis.
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purification and characterization of a 43 5 kda keratinolytic metalloprotease from Microsporum Canis
Medical Mycology, 2001Co-Authors: F Brouta, F Descamps, Thomas Fett, Bertrand Losson, Charles Gerday, Bernard MignonAbstract:A keratinolytic protease secreted by a feline clinical isolate of Microsporum Canis cultivated in a broth containing feline keratin as the sole nitrogen source was purified from the culture filtrate by affinity chromatography on bacitracin-agarose and by hydrophobic chromatography on octyl-agarose. The enzyme had an apparent molecular mass of 43·5 kDa and the pI was 7·7. It had a significant activity against keratin azure, elastin-Congo red and denatured type I collagen (azocoll). Using the latter substrate, the optimum pH was around 8 and the apparent optimum temperature around 50°C. The protease was strongly inhibited by 1,10-phenanthroline, phosphoramidon and EDTA. The first 13 N-terminal amino acid sequence showed a 61% homology with that of the extracellular metalloprotease of Aspergillus fumigatus and with the neutral protease I of A. oryzae, confirming that this 43·5 kDa keratinase is a metalloprotease. This keratinolytic metalloprotease could be a virulence-related factor involved in pathophysiolo...
Arquínigo Lavado, Denisse Katherine - One of the best experts on this subject based on the ideXlab platform.
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Efecto antimicótico del aceite esencial de Eucalyptus globulus sobre Trichophyton rubrum, Microsporum Canis y Epidermophyton floccosum, comparado con Clotrimazol
'Universidad Cesar Vallejo', 2019Co-Authors: Arquínigo Lavado, Denisse KatherineAbstract:Este estudio se realizó con el objetivo de evaluar el efecto antimicótico del aceite esencial de Eucalyptus globulus sobre Trichophyton rubrum, Microsporum Canis y Epidermophyton floccosum, comparado con Clotrimazol, in vitro. Se planteó un diseño experimental que tuvo como muestra 10 cultivos de cada uno de los dermatofitos. El aceite esencial se obtuvo por arrastre con vapor de agua y se utilizó al 100%. Se evaluó el efecto del aceite esencial de Eucalyptus globulus in vitro, mediante el método de difusión con pozos en agar Sabouraud. Los resultados muestran que el aceite esencial de Eucalyptus globulus tuvo mayor efecto sobre Microsporum Canis, con halo de inhibición de 19,6 mm. El análisis con la prueba de t de student indicó que existe diferencia altamente significativa (p
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Efecto antimicótico del aceite esencial de Eucalyptus globulus sobre Trichophyton rubrum, Microsporum Canis y Epidermophyton floccosum, comparado con Clotrimazol
'Universidad Cesar Vallejo', 2019Co-Authors: Arquínigo Lavado, Denisse KatherineAbstract:TesisTrujilloEscuela Académico Profesional de MedicinaEnfermedades Infecciosas y TransmisiblesEste estudio se realizó con el objetivo de evaluar el efecto antimicótico del aceite esencial de Eucalyptus globulus sobre Trichophyton rubrum, Microsporum Canis y Epidermophyton floccosum, comparado con Clotrimazol, in vitro. Se planteó un diseño experimental que tuvo como muestra 10 cultivos de cada uno de los dermatofitos. El aceite esencial se obtuvo por arrastre con vapor de agua y se utilizó al 100%. Se evaluó el efecto del aceite esencial de Eucalyptus globulus in vitro, mediante el método de difusión con pozos en agar Sabouraud. Los resultados muestran que el aceite esencial de Eucalyptus globulus tuvo mayor efecto sobre Microsporum Canis, con halo de inhibición de 19,6 mm. El análisis con la prueba de t de student indicó que existe diferencia altamente significativa (p