Experimental dermatophytosis in hamsters inoculated with Trichophyton mentagrophytes in the cheek pouch

This study presents the results of T. mentagrophytes inoculation in the cheek pouch of the hamster, an immunologically privileged site. Forty two animals were used: 21 inoculated with 10(6) fungi in the cheek pouch (group 1) and 21 inoculated initially with 10(6) fungi in the foot pad and 15 days later in the cheek pouch, with the same amount of fungi (group 2). Animals were sacrificed at 20 hours, 3, 7, 14, 30, 60, and 120 days; samples from inoculated cheek pouch, and foot pads submitted to the foot pad test (FPT), were collected. Independent of group and time of evolution of infection, animals did not develop delayed hypersensitivity evaluated through the FPT. The pre-inoculation of fungi in the foot pad did not change the morphology of lesions induced in the cheek pouch. Therefore, in animals of group 1 and 2, the introduction of the fungus in the cheek pouch resulted in focal lesion composed of a sterile acute inflammatory infiltrate, with abscess formation that evolved to a macrophagic reaction, and later to resolution even in the absence of immune response detectable by FPT. Our results indicate that in spite of the important role of the immune response in the spontaneous regression of dermatophytosis, other factors are also an integral part in the defense against this fungal infection.

Dois Casos de Quérion por Trichophyton Mentagrophytes

Introdução: O Quérion é uma forma rara e infl amatória de tinea capitis causada por fungos dermatófi tos. O diagnóstico é difi cultado pela demora no exame cultural e possibilidade de várias etiologias no diagnóstico diferencial. O tratamento é prolongado e implica o recurso a antifúngicos sistémicos. Novos fármacos têm sido considerados após a descontinuação da griseofulvina em Portugal. Casos clínicos: Apresentamos duas crianças com lesões dolorosas do couro cabeludo com reação infl amatória exuberante, exsudativa e alopécia local acompanhadas de febre. O exame bacteriológico foi negativo e o micológico revelou Trichophyton mentagrophytes. Foram medicados com fl ucloxacilina endovenosa, antifúngicos orais (griseofulvina e itraconazol), corticoide e antifúngico tópicos. A resposta foi favorável com evolução lenta para a cura com área de alopécia residual. Conclusão: Estes casos destacam -se pela sua raridade e ilustram a exuberância das manifestações clínicas desta entidade. O diagnóstico precoce, a identificação e tratamento da fonte de contágio e as medidas de higiene e vigilância sanitária são primordiais para o controlo da infecção.

A propósito de uma epidemia de tinha no Rio de Janeiro, causada pelo Trichophyton mentagrophytes (Ch. Robin, 1853) Blanchard, 1896

Estudamos uma epidemia de tinha surgida, em 1945, no Instituto Nata¬lina Janot, da Fundação Abrigo Cristo Redentor, no Rio de Janeiro. Após rápida descrição do Instituto e breve relato do exame clinico, expomos os resultados do exame dos pelos, do exame macro e microscópico das culturas e das inoculações experimentais. Deante dos resultados obtidos e em face da orientação atual da sistemática dos dermatófitos, consideramos como agente etiológico da referida epidemia o Trichophyton mentagrophytes (CH. ROBIN, 1853) BLANCHARD, 1896, isolado em 16 doentes. Nosso estudo é precedido de uma revisão da literatura nacional sôbre tinhas.

Pets as the main source of two zoonotic species of the Trichophyton mentagrophytes complex in Switzerland, Arthroderma vanbreuseghemii and Arthroderma benhamiae

In cases of highly inflammatory dermatophytosis in humans, it is important to identify the possible source of animal transmission in order to prevent recurrence, family outbreaks or rapidly progressing epidemics. A survey of dermatophytes in pets during a 14-month period in Switzerland revealed, in addition to Microsporum canis, two different species of the Trichophyton mentagrophytes complex, Arthroderma benhamiae and Arthroderma vanbreuseghemii, all causing inflammatory dermatophytoses. Arthroderma benhamiae was only and frequently isolated from guinea pigs. Arthroderma vanbreuseghemii was isolated mainly from European short hair cats, but also from dogs and in one case from a pure-bred cat. Ninety-three percent of the cats carrying A. vanbreuseghemii were hunters and all had skin lesions. In contrast, cats with skin lesions that were strictly indoors were found to be almost exclusively infected by M. canis. Therefore, it can be suspected that infection with A. vanbreuseghemii occurred during hunting and that the natural source of this dermatophyte is either soil or an animal other than the cat, most probably a rodent.

Molecular analysis and mating behaviour of the Trichophyton mentagrophytes species complex.

Isolates of the Trichophyton mentagrophytes complex vary phenotypically. Whether the closely related zoophilic and anthropophilic anamorphs currently associated with Arthroderma vanbreuseghemii have to be considered as members of the same biological species remains an open question. In order to better delineate species in the T. mentagrophytes complex, we performed a mating analysis of freshly collected isolates from humans and animals with A. benhamiae and A. vanbreuseghemii reference strains, in comparison to internal transcribed spacer (ITS) and 28S rDNA sequencing. Mating experiments as well as ITS and 28S sequencing unambiguously allowed the distinction of A. benhamiae and A. vanbreuseghemii. We have also shown that all the isolates from tinea pedis and tinea unguium identified as T. interdigitale based on ITS sequences mated with A. vanbreuseghemii tester strains, but had lost their ability to give fertile cleistothecia. Therefore, T. interdigitale has to be considered as a humanized species derived from the sexual relative A. vanbreuseghemii.

Which Fungus Originally was Trichophyton mentagrophytes? Historical Review and Illustration by a Clinical Case.

Several dermatophytes producing numerous pyriform or round microconidia were called Trichophyton mentagrophytes. Among these dermatophytes are the teleomorph species Arthroderma benhamiae, Arthroderma vanbreuseghemii and Arthroderma simii, and other species such as Trichophyton interdigitale, Trichophyton erinacei and Trichophyton quinckeanum for which only the anamorph is known. Confusion exists about which fungus should be really called T. mentagrophytes and about the rational use of this name in practice. We report a case of beard ringworm (tinea barbae) with A. vanbreuseghemii. According to both clinical signs and the type of hair parasitism, this case was exactly compatible to the first description of a non-favic dermatophytosis by Gruby under the name of "mentagrophyte" from which was derived the dermatophyte epithet mentagrophytes. In addition, the phenotypic characters of the isolated fungus in cultures perfectly matched with those of the first description of a dermatophyte under T. mentagrophytes by Blanchard (Parasites animaux et parasites végétaux à l'exclusion des Bactéries, Masson, Paris, 1896). In conclusion, T. mentagrophytes corresponds to the fungus later named A. vanbreuseghemii. However, because the neotype of T. mentagrophytes was not adequately designated in regard to the ancient literature, we would privilege the use of A. vanbreuseghemii and abandon the name of T. mentagrophytes.

Avaliação in vitro da atividade antifúngica de extratos de plantas e óleo de eucalipto sobre Trichophyton mentagrophytes

O presente estudo teve como objetivo determinar a ação antifúngica de extratos de plantas medicinais e óleo de eucalipto frente ao dermatófito Trichophyton mentagropytes, visando a utilização da fitoterapia no controle. As plantas utilizadas na obtenção dos extratos foram arruda (Ruta graveolens), citronela (Cymbopogon nardus), cravo de defunto (Tagetes minuta), eucalipto (Eucalyptus spp), graviola (Annona muricata), fruta do conde (Annona spp), manga (Mangifera indica), romã (Punica granatum), flores e folhas de primavera (Bougainvillea spectabilis). Verificou-se que uso de 0,5% óleo de eucalipto no combate ao T. mentagropytes foi eficaz, já os extratos de citronela (4%) eucalipto (5%) e romã (8%) atuaram como fungistáticos e os restantes não devem ser usados contra este dermatófito porque não causaram nenhum efeito.

Experimental dermatophytosis in hamsters inoculated with Trichophyton mentagrophytes in the cheek pouch

Esse estudo apresenta os resultados obtidos quando da inoculação de Trychophyton mentagrophytes na bolsa jugal do hamster, local imunologicamente privilegiado. Foram utilizados 42 animais: 21 inoculados com 10(6) fungos na bolsa jugal (grupo 1) e, 21 inicialmente inoculados com 10(6) fungos no coxim plantar e, 15 dias após, na bolsa jugal com a mesma quantidade fúngica (grupo 2). Os animais foram sacrificados às 20 h, 3, 7, 14, 30, 60 e 120 dias; foram coletadas amostras da bolsa jugal inoculada, e das patas submetidas ao teste do coxim plantar (TCP). Independente do grupo e do tempo de evolução da infecção, os animais não desenvolveram hipersensibilidade tardia avaliada através do TCP. A pré-inoculação de fungos no coxim plantar não alterou a morfologia das lesões induzidas na bolsa jugal. Assim, nos animais do grupo 1 e grupo 2, a introdução do fungo na bolsa jugal, resultou em lesão focal, constituída por infiltrado inflamatório agudo estéril, com formação de abscesso, que evoluiu para reação macrofágica e, posteriormente, para a resolução mesmo na ausência de resposta imune detectável pelo TCP. Nossos resultados indicam que, apesar do importante papel da resposta imune na regressão espontânea da dermatofitose, outros fatores são, também, parte integral da defesa contra esta infecção fúngica.

Production of Trichophyton mentagrophytes antigens and their characterization in mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Susceptibilities of the dermatophytes Trichophyton mentagrophytes and T. rubrum microconidia to photodynamic antimicrobial chemotherapy with novel phenothiazinium photosensitizers and red light

Photodynamic antimicrobial chemotherapy (PACT) is a promising alternative to conventional chemotherapy that can be used to treat localized mycosis. The development of PACT depends on identifying effective and selective PS for the different pathogenic species. The in vitro susceptibilities of Trichophyton mentagrophytes and Trichophyton rubrum microconidia to PACT with methylene blue (MB), toluidine blue o (TBO), new methylene blue N (NMBN), and the novel pentacyclic phenothiazinium photosensitizer S137 were investigated. The efficacy of each PS was determined based on its minimal inhibitory concentration (MIC). Additionally, we evaluated the effect of PACT with NMBN and S137 on the survival of the microconidia of both species. 5137 showed the lowest MIC. MIC for S137 was 2.5 mu M both for T. mentagrophytes and T. rubrum, when a light dose of 5J cm(-2) was used. PACT with NMBN (10 mu M and 20J cm(-2)) resulted in a reduction of 4 logs in the survival of the T. rubrum and no survivor of T. mentagrophytes was observed. PACT with S137 at 1 mu M and 20J cm(-2) resulted in a reduction of approximately 3 logs in the survival of both species. When a S137 concentration of 10 mu M was used, no survivor was observed for both species at all light doses (5, 10 and 20J cm(-2)). (C) 2012 Elsevier B.V. All rights reserved.

Signature polymorphisms in the internal transcribed spacer region relevant for the differentiation of zoophilic and anthropophilic strains of Trichophyton interdigitale and other species of T. mentagrophytes sensu lato.

Summary Background Dermatophytes are the main cause of superficial mycoses in humans and animals. Molecular research has given useful insights into the phylogeny and taxonomy of the dermatophytes to overcome the difficulties with conventional diagnostics. Objectives The Trichophyton mentagrophytes complex consists of anthropophilic as well as zoophilic species. Although several molecular markers have been developed for the differentiation of strains belonging to T. mentagrophytes sensu lato, correct identification still remains problematic, especially concerning the delineation of anthropophilic and zoophilic strains of T. interdigitale. This differentiation is not academic but is essential for selection of the correct antimycotic therapy to treat infected patients. Methods One hundred and thirty isolates identified by morphological characteristics as T. mentagrophytes sensu lato were investigated using restriction fragment length polymorphism (RFLP) and sequence analysis of the polymerase chain reaction-amplified internal transcribed spacer (ITS) region of the rDNA. Results Species of this complex produced individual RFLP patterns obtained by the restriction enzyme MvaI. Subsequent sequence analysis of the ITS1, 5.8S and ITS2 region of all strains, but of T. interdigitale in particular, revealed single unique polymorphisms in anthropophilic and zoophilic strains. Conclusions Signature polymorphisms were observed to be useful for the differentiation of these strains and epidemiological data showed a host specificity among zoophilic strains of T. interdigitale/Arthroderma vanbreuseghemii compared with A. benhamiae as well as characteristic clinical pictures in humans when caused by zoophilic or anthropophilic strains. The delineation is relevant because it helps in determining the correct treatment and provides clues regarding the source of the infection.

Multiplication of an ancestral gene encoding secreted fungalysin preceded species differentiation in the dermatophytes Trichophyton and Microsporum.

Dermatophytes are human and animal pathogenic fungi which cause cutaneous infections and grow exclusively in the stratum corneum, nails and hair. In a culture medium containing soy proteins as sole nitrogen source a substantial proteolytic activity was secreted by Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. This proteolytic activity was 55-75 % inhibited by o-phenanthroline, attesting that metalloproteases were secreted by all three species. Using a consensus probe constructed on previously characterized genes encoding metalloproteases (MEP) of the M36 fungalysin family in Aspergillus fumigatus, Aspergillus oryzae and M. canis, a five-member MEP family was isolated from genomic libraries of T. rubrum, T. mentagrophytes and M. canis. A phylogenetic analysis of genomic and protein sequences revealed a robust tree consisting of five main clades, each of them including a MEP sequence type from each dermatophyte species. Each MEP type was remarkably conserved across species (72-97 % amino acid sequence identity). The tree topology clearly indicated that the multiplication of MEP genes in dermatophytes occurred prior to species divergence. In culture medium containing soy proteins as a sole nitrogen source secreted Meps accounted for 19-36 % of total secreted protein extracts; characterization of protein bands by proteolysis and mass spectrometry revealed that the three dermatophyte species secreted two Meps (Mep3 and Mep4) encoded by orthologous genes.

Ação antifúngica do resíduo líquido integral e fracionado do desfibramento da folha do sisal (Agave sisalana) sobre Malassezia pachydermatis, Tricophyton mentagrophytes e Candida albicans

Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC

Anti-Trichophyton Activity of Protocatechuates and Their Synergism with Fluconazole

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)