RESUMO

An unneutered female cat of unknown age presented bloody lesions on the edematous face, and respiratory signs. Cytology and culture from the skin sample collected with fine-needle aspiration showed yeasts inside activated macrophages, and fungal growth characteristic of Histoplasma spp., which was molecularly confirmed that was Histoplasma capsulatum var. capsulatum. The cat was successfully treated with oral itraconazole (10 mg/kg/daily) for 120 days. This is the first case report of feline histoplasmosis confirmed molecularly in Brazil.

RESUMO

This study describes an ex vivo model that creates an environment for dermatophyte biofilm growth, with features that resemble those of in vivo conditions, designing a new panorama for the study of antifungal susceptibility. Regarding planktonic susceptibility, MIC ranges were 0.125-1 µg ml-1 for griseofulvin and 0.000097-0.25 µg ml-1 for itraconazole and terbinafine. sMIC50 ranges were 2->512 µg ml-1 for griseofulvin and 0.25->64 µg ml-1 for itraconazole and terbinafine. CLSM images demonstrated a reduction in the amount of cells within the biofilm, but hyphae and conidia were still observed and biofilm biomass was maintained. SEM analysis demonstrated a retraction in the biofilm matrix, but fungal structures and water channels were preserved. These results show that ex vivo biofilms are more tolerant to antifungal drugs than in vitro biofilms, suggesting that environmental and nutritional conditions created by this ex vivo model favor biofilm growth and robustness, and hence drug tolerance.

Assuntos

RESUMO

The aim of this study was to establish an ex vivo model for dermatophyte biofilm growth, using hair from dogs and cats. Strains of Microsporum canis, M. gypseum, Trichophyton mentagrophytes and T. tonsurans were assessed for in vitro and ex vivo biofilm production. All T. mentagrophytes and T. tonsurans isolates and 8/12 M. canis and 1/7 M. gypseum isolates formed biofilms in vitro, while all tested isolates presented biofilm growth on ex vivo models. T. mentagrophytes and M. canis formed more homogeneous and better-structured biofilms with greater biomass production on cat hair but T. tonsurans formed more biofilm on dog hair. Confocal and scanning electron microscopy demonstrated fungal hyphae colonizing and perforating the hair shaft, abundant fungal conidia, biofilm extracellular matrix and biofilm water channels. The present study demonstrated an ex vivo model for the performance of studies on biofilm formation by dermatophytes, using dog and cat hair.

Assuntos

RESUMO

A Malassezia pachydermatis é um fungo oportunista amplamente relatado em carnívoros domésticos, mas que possui uma escassez de estudos e relatos quando se analisam os canídeos e felídeos selvagens, apesar de que hoje já se sabe que este fungo representa um potencial patógeno em quadros de otites e dermatites fúngicas nesses animais. Faz-se então, como objetivo do presente trabalho, relatar um diagnóstico de Malassezia pachydermatis em amostra de pelos e escamas de um Cachorro-do-mato (Cerdocyon thous) por meio do diagnóstico micológico, o qual incluiu exame direto, por análise microscópica da amostra clínica e cultura fúngica em àgar sabouraud simples e àgar sabouraud acrescido de cloranfenicol e cicloheximida.

Malassezia pachydermatis is an opportunistic fungus widely reported in domestic carnivores but has a shortage of studies and reports when canids and wild felids are analyzed, although it is now known that this fungus represents a potential pathogen in otitis and fungal dermatitis in these animals. The objective of this work is to report a diagnosis of Malassezia pachydermatis in a sample of hairs and scales of a Cerrado (Cerdocyon thous), using a mycological diagnosis, which included a direct examination by microscopic analysis of clinical sample and fungal culture on simple sabouraud agar plus saber agar plus chloramphenicol and cycloheximide.

Assuntos

RESUMO

A Malassezia pachydermatis é um fungo oportunista amplamente relatado em carnívoros domésticos, mas que possui uma escassez de estudos e relatos quando se analisam os canídeos e felídeos selvagens, apesar de que hoje já se sabe que este fungo representa um potencial patógeno em quadros de otites e dermatites fúngicas nesses animais. Faz-se então, como objetivo do presente trabalho, relatar um diagnóstico de Malassezia pachydermatis em amostra de pelos e escamas de um Cachorro-do-mato (Cerdocyon thous) por meio do diagnóstico micológico, o qual incluiu exame direto, por análise microscópica da amostra clínica e cultura fúngica em àgar sabouraud simples e àgar sabouraud acrescido de cloranfenicol e cicloheximida.(AU)

Malassezia pachydermatis is an opportunistic fungus widely reported in domestic carnivores but has a shortage of studies and reports when canids and wild felids are analyzed, although it is now known that this fungus represents a potential pathogen in otitis and fungal dermatitis in these animals. The objective of this work is to report a diagnosis of Malassezia pachydermatis in a sample of hairs and scales of a Cerrado (Cerdocyon thous), using a mycological diagnosis, which included a direct examination by microscopic analysis of clinical sample and fungal culture on simple sabouraud agar plus saber agar plus chloramphenicol and cycloheximide.(AU)

Assuntos

RESUMO

As shown by recent research, most of the clinically relevant fungi, including dermatophytes, form biofilms in vitro and in vivo, which may exhibit antimicrobial tolerance that favour recurrent infections. The aim of this study was to determine the minimum inhibitory concentrations (MICs) of itraconazole (ITC), voriconazole (VCZ) and griseofulvin (GRI) against Trichophyton rubrum, Trichophyton tonsurans, Trichophyton mentagrophytes, Microsporum canis and Microsporum gypseum in planktonic and biofilm growth. For the planktonic form, susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI), document M38-A2, while biofilm susceptibility was evaluated using the XTT colorimetric essay. The planktonic growth of all strains was inhibited, with MIC values ranging from 0.00195 to 0.1225 µg/mL for VRC, 0.00195 to 0.25 µg/mL for ITC and <0.0039 to 4 µg/mL for GRI, while a 50-fold increase in the MIC was required to significantly reduce the metabolic activity (P < .05) of dermatophyte biofilms. In brief, the ability of dermatophytes to form biofilms may be a contributing factor for the recalcitrance of dermatophytoses or the dissemination of the disease.

Assuntos

RESUMO

PURPOSE: The aim of this study was to evaluate the in vitro and ex vivo biofilm-forming ability of dermatophytes on a nail fragment. METHODOLOGY: Initially, four isolates of Trichophyton rubrum, six of Trichophyton tonsurans, three of Trichophyton mentagrophytes, ten of Microsporum canis and three of Microsporum gypseum were tested for production biomass by crystal violet assay. Then, one strain per species presenting the best biofilm production was chosen for further studies by optical microscopy (Congo red staining), confocal laser scanning (LIVE/DEAD staining) and scanning electron (secondary electron) microscopy. RESULTS: Biomass quantification by crystal violet assay, optical microscope images of Congo red staining, confocal microscope and scanning electron microscope images revealed that all species studied are able to form biofilms both in vitro and ex vivo, with variable density and architecture. M. gypseum, T. rubrum and T. tonsurans produced robust biofilms, with abundant matrix and biomass, while M. canis produced the weakest biofilms compared to other species. CONCLUSION: This study sheds light on biofilms of different dermatophyte species, which will contribute to a better understanding of the pathophysiology of dermatophytosis. Further studies of this type are necessary to investigate the processes involved in the formation and composition of dermatophyte biofilms.

Assuntos

RESUMO

The present study described clinical and epidemiological aspects of three cases of feline histoplasmosis and compared them to previously described cases. A detailed mycological identification and antifungal susceptibility profile of each isolate are presented. Secondarily, a serological survey for anti-Histoplasma antibodies was performed with domestic and wild cats. Diseased animals presented nodular to ulcerated skin lesions and respiratory disorders as main clinical signs. H. capsulatum var. capsulatum was isolated and the strains showed to be susceptible to antifungal drugs. Considering that feline histoplasmosis is uncommonly observed in veterinary clinics, diagnosis, and clinical management in endemic areas should be improved.

Assuntos