RESUMO
Microsporum canis is a widely distributed dermatophyte, which is among the main etiological agents of dermatophytosis in humans and domestic animals. This fungus invades, colonizes and nourishes itself on the keratinized tissues of the host through various virulence factors. This review will bring together the known information about the mechanisms, enzymes and their associated genes relevant to the pathogenesis processes of the fungus and will provide an overview of those virulence factors that should be better studied to establish effective methods of prevention and control of the disease. Public databases using the MeSH terms "Microsporum canis", "virulence factors" and each individual virulence factor were reviewed to enlist a series of articles, from where only original works in English and Spanish that included relevant information on the subject were selected. Out of the 147 articles obtained in the review, 46 were selected that reported virulence factors for M. canis in a period between 1988 and 2023. The rest of the articles were discarded because they did not contain information on the topic (67), some were written in different languages (3), and others were repeated in two or more databases (24) or were not original articles (7). The main virulence factors in M. canis are keratinases, fungilisins and subtilisins. However, less commonly reported are biofilms or dipeptidylpeptidases, among others, which have been little researched because they vary in expression or activity between strains and are not considered essential for the infection and survival of the fungus. Although it is known that they are truly involved in resistance, infection and metabolism, we recognize that their study could strengthen the knowledge of the pathogenesis of M. canis with the aim of achieving effective treatments, as well as the prevention and control of infection.
Assuntos
Microsporum , Fatores de Virulência , Microsporum/patogenicidade , Microsporum/genética , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Animais , Humanos , Fenótipo , Dermatomicoses/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismoRESUMO
Wild animals can be natural reservoirs of different microorganisms, essential for monitoring these pathogens for the generation of knowledge and creation of tools aimed at programs for the prevention and control of infectious diseases, including zoonoses. The objective was to report the fungal diversity in the skin of pacas in captivity in Acre, Western Amazon, Brazil. Twenty-six animals were evaluated, from which skin samples were collected by superficial scraping, hair avulsion, and sterile plastic brush. The samples were seeded on Mycosel agar, and the phenotypic characteristics of the colonies were analyzed. In 80.8% of the samples, different fungi were isolated, from the genera Candida, Microsporum,and Trichophyton, among others. This is the first description of the identification of fungi in the skin of pacas and suggests that these animals can be considered essential reservoirs of saprophytic or pathogenic microorganisms with zoonotic potential in the Western Amazon.(AU)
Animais silvestres podem ser reservatórios naturais de diferentes microrganismos, sendo fundamental o monitoramento destes patógenos para a geração de conhecimento e criação de ferramentas direcionadas a programas de prevenção e controle de enfermidades infecciosas, incluindo as zoonoses. Assim, objetivou-se relatar a diversidade fúngica da pele de pacas criadas em cativeiro no Acre, Amazônia Ocidental, Brasil. Foram avaliados 26 animais, dos quais amostras cutâneas foram colhidas por raspagem superficial, avulsão pilosa e escova plástica estéril. As amostras foram semeadas em ágar Mycosel e as características fenotípicas das colônias foram analisadas. Em 80,8% das amostras houve isolamento de diferentes fungos, dos gêneros Candida, Microsporum e Trichophyton, dentre outros. Esta é a primeira descrição da identificação de fungos na pele de pacas e sugere que estes animais podem ser considerados importantes reservatórios de microrganismos saprófitas ou patogênicos, de potencial zoonótico, na Amazônia Ocidental.(AU)
Assuntos
Animais , Roedores/microbiologia , Infecções Bacterianas e Micoses/diagnóstico , Animais Selvagens/microbiologia , Trichophyton/patogenicidade , Brasil , Candida/patogenicidade , Microsporum/patogenicidadeRESUMO
Microsporum canis is a zoophilic dermatophyte and the most common fungus isolated from dogs and cats worldwide. To invade skin, this pathogen uses different enzymes, which may be associated with virulence, that contribute to the fungal pathogenicity. The aim of this study is to compare the expression of enzymes that may be associated with virulence, and thermotolerance of M. canis strains isolated from dogs, cats, and humans. The in vitro expression of the enzymes keratinase, catalase, urease, hemolysin, and aspartic protease was evaluated in 52 M. canis strains recently isolated from 14 human patients, 12 dogs, 15 symptomatic, and 11 asymptomatic cats. In addition, thermotolerance was assessed by comparative analysis of fungal growth at 25 °C and 35 °C. Keratinase activity was low in 34 and moderate in 18 strains. Aspartic-protease activity was low in 7, moderate in 33, and high in 12 strains. Hemolysin activity was low in 44 and moderate in 8 strains. All strains were classified as low producers of catalase. All but three strains produced urease in vitro, with a broad range of activity. The strains presented in vitro growth at the two studied temperatures were classified as presenting low (36.5%), medium (44.3%), or high (19.2%) thermotolerance. There was no statistically significant difference in the new putative virulence-associated factors studied among the different hosts, which suggests that they may have a similar role on human, cat, and dog infection. Also, no difference was observed between strains isolated from symptomatic and asymptomatic cats. This suggests that these factors have a limited impact on the fate of feline dermatophytosis caused by M. canis.
Assuntos
Doenças do Gato , Dermatomicoses/veterinária , Doenças do Cão , Microsporum/patogenicidade , Fatores de Virulência/análise , Animais , Doenças do Gato/microbiologia , Gatos , Doenças do Cão/microbiologia , Cães , Humanos , VirulênciaRESUMO
Despite worldwide prevalence of superficial mycoses, the immune response in dermatophytosis has scarcely been investigated. In this study, we developed a model of superficial skin infection in C57BL/6 mice with Microsporum canis, a highly prevalent human pathogen. This model mimics mild inflammatory human dermatophytosis, characterized by neutrophil recruitment and fungal invasion limited to the epidermis and exhibits the establishment of a specific T helper type 17 immune response during infection. By using IL-17RA- or IL-17A/F-deficient mice we showed that, in the absence of a functional IL-17 pathway, M. canis extensively colonizes the epidermis and promotes an exaggerated skin inflammation and a shift to an IFN-γ-mediated (T helper type 1) response. IL-17 signaling was not involved in neutrophil influx to skin or fungal invasion to deeper tissues. Finally, this study shows that skin langerin-expressing cells contribute to the antifungal T helper type 17 response in vivo. In conclusion, these data directly show a dual function of IL-17 cytokines in dermatophytosis by controlling superficial infection and down-modulating a T helper type 1 antifungal response.
Assuntos
Interações Hospedeiro-Patógeno/imunologia , Microsporum/imunologia , Transdução de Sinais/imunologia , Células Th17/imunologia , Tinha/imunologia , Animais , Modelos Animais de Doenças , Epiderme/imunologia , Epiderme/microbiologia , Epiderme/patologia , Humanos , Interleucina-17/genética , Interleucina-17/imunologia , Interleucina-17/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microsporum/patogenicidade , Infiltração de Neutrófilos/imunologia , Receptores de Interleucina-17/genética , Receptores de Interleucina-17/imunologia , Receptores de Interleucina-17/metabolismo , Células Th17/metabolismo , Tinha/microbiologia , Tinha/patologiaRESUMO
This paper described a case of a capuchin monkey (Sapajus libidinosus) with non-pruritic skin lesions. During the physical examination, multifocal areas of alopecia with crusts, erythema and scaling compatible with dermatophytosis were reported on the right fore and hind limbs and on tail. Fungal culture findings revealed a diagnosis of dermatophytosis due to Microsporum canis. The animal was successfully treated with itraconazole. This is the first report of a dermatophytosis case in S. libidinosus and the first description of an effective treatment in this species.
O presente trabalho relata o caso de um macaco capuchinho (Sapajus libidinosus) com lesões de pele não-pruriginosas. Durante o exame físico foram encontradas lesões multifocais com crostas, eritema e descamação compatíveis com dermatofitose, nos membros anterior e posterior direitos, bem como na cauda. O animal não tinha outras alterações. O diagnóstico de dermatofitose por Microsporum canis foi realizado através de cultura fúngica das lesões. O animal foi tratado com sucesso com itraconazol. Este é o primeiro relato de um caso de dermatofitose em S. libidinosus e a primeira descrição de um tratamento eficaz para esta espécie.
Assuntos
Animais , Macaca/fisiologia , Microsporum/patogenicidade , Tinha/veterinária , Itraconazol/uso terapêutico , Técnicas de CulturaRESUMO
This paper described a case of a capuchin monkey (Sapajus libidinosus) with non-pruritic skin lesions. During the physical examination, multifocal areas of alopecia with crusts, erythema and scaling compatible with dermatophytosis were reported on the right fore and hind limbs and on tail. Fungal culture findings revealed a diagnosis of dermatophytosis due to Microsporum canis. The animal was successfully treated with itraconazole. This is the first report of a dermatophytosis case in S. libidinosus and the first description of an effective treatment in this species.(AU)
O presente trabalho relata o caso de um macaco capuchinho (Sapajus libidinosus) com lesões de pele não-pruriginosas. Durante o exame físico foram encontradas lesões multifocais com crostas, eritema e descamação compatíveis com dermatofitose, nos membros anterior e posterior direitos, bem como na cauda. O animal não tinha outras alterações. O diagnóstico de dermatofitose por Microsporum canis foi realizado através de cultura fúngica das lesões. O animal foi tratado com sucesso com itraconazol. Este é o primeiro relato de um caso de dermatofitose em S. libidinosus e a primeira descrição de um tratamento eficaz para esta espécie.(AU)
Assuntos
Animais , Macaca/fisiologia , Tinha/veterinária , Microsporum/patogenicidade , Técnicas de Cultura , Itraconazol/uso terapêuticoRESUMO
In humans worldwide, Microsporum sp. is a frequent agent of dermatophytsosis. When considering the emergence of resistant fungi and the clinical relevance of dermatophytosis, terpene antifungal activity is of great interest. Linalool is a monoterpene alcohol with pharmacological properties. In this study, antifungal in vitro activity of linalool and ketoconazole (as a positive control) were evaluated against clinical isolates of M. canis and M. gypseum. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of each drug were determined by broth microdilution. The effects of the drugs (1/2MIC, MIC, 2xMIC) on radial mycelial growth, conidial production and germination were analysed. The effect on the fungal cell membrane (release of intracellular material) was also investigated. Linalool (MIC: 128 µg/mL) and ketoconazole (MIC: 64 µg/mL) were effective in inhibiting all dermatophytes studied. The MFC values of linalool ranged between 128 and 256 µg/mL, whereas ketoconazole showed MFC values of from 64 to 256 µg/mL. Linalool (at MIC and 2xMIC) and ketoconazole (at 1/2MIC, MIC, 2xMIC) inhibited mycelial growth (P < 0.05). The drugs (1/2MIC, MIC, 2xMIC) were also active on conidiogenesis and conidia germination, causing complete inhibition (P < 0.05). Linalool caused leakage of intracellular material. Our study supports the use of linalool as a potential antifungal agent against M. canis and M. gypseum.
Assuntos
Antifúngicos/farmacologia , Microsporum/efeitos dos fármacos , Monoterpenos/farmacologia , Monoterpenos Acíclicos , Cetoconazol/farmacologia , Testes de Sensibilidade Microbiana , Microsporum/patogenicidadeRESUMO
The genera Trichophyton, Microsporum, and Epidermophyton include filamentous fungi that cause dermatophytosis, a superficial infection of the skin, stratum corneum, nail beds, and hair follicles. The ability of dermatophytes to adhere to these substrates and adapt to the host environment is essential for the establishment of infection. Several fungal enzymes and proteins participate in this adaptive response to the environment and to keratin degradation. Transcription factors such as PacC and Hfs1, as well as heat shock proteins, are involved in sensing and adapting to the acidic pH of the skin in the early stages of fungal-host interaction. During dermatophyte growth, with keratin as the sole carbon source, the extracellular pH shifts from acidic to alkaline. This creates an environment in which most of the known keratinolytic proteases exhibit optimal activity. These events culminate in the establishment and maintenance of the infection, which can be chronic or acute depending on the dermatophyte species. This review focuses on these and other molecular aspects of the dermatophyte-host interaction.
Assuntos
Epidermophyton/patogenicidade , Interações Hospedeiro-Patógeno , Microsporum/patogenicidade , Tinha/microbiologia , Tinha/patologia , Trichophyton/patogenicidade , Animais , Epidermophyton/enzimologia , Humanos , Hidrólise , Queratinas/metabolismo , Microsporum/enzimologia , Trichophyton/enzimologiaRESUMO
Dermatophytoses are cosmopolitan contagious mycoses of the skin and concern a wide range of mammals, including man, and more rarely birds. These mycoses are rarely diagnosed in New World Primates. The most frequent tinea of the subhuman Primates is microsporosis due to Microsporum canis or trichophytosis by Trichophyton mentagrophytes and T. simii. The main clinical features are regular alopecia with erythema and squamosis, usually non-pruriginous although various degree of inammation may modify this typical aspect. As a consequence, an accurate clinical examination, a good differential diagnosis and laboratory analyses are required for a correct identification. Alouatta guariba are primates found from the Amazon region up to the Argentina Norwest. Due to the population development and expansion of the urban perimeters thes animals are loosing their space in their own natural habitat and being exposed to more closed relationship with domestic animals and humans. This report contains five cases of dermatophytoses caused by Microsporum canis in Alouatta sp., which were treated in a private clinic in Porto Alegre, RS, Brazil.(AU)
Assuntos
Animais , Microsporum/patogenicidade , Primatas/classificação , Micoses/patologiaRESUMO
Dermatophytoses are cosmopolitan contagious mycoses of the skin and concern a wide range of mammals, including man, and more rarely birds. These mycoses are rarely diagnosed in New World Primates. The most frequent tinea of the subhuman Primates is microsporosis due to Microsporum canis or trichophytosis by Trichophyton mentagrophytes and T. simii. The main clinical features are regular alopecia with erythema and squamosis, usually non-pruriginous although various degree of inammation may modify this typical aspect. As a consequence, an accurate clinical examination, a good differential diagnosis and laboratory analyses are required for a correct identification. Alouatta guariba are primates found from the Amazon region up to the Argentina Norwest. Due to the population development and expansion of the urban perimeters thes animals are loosing their space in their own natural habitat and being exposed to more closed relationship with domestic animals and humans. This report contains five cases of dermatophytoses caused by Microsporum canis in Alouatta sp., which were treated in a private clinic in Porto Alegre, RS, Brazil.