Micoses superficiais na cidade de Manaus, AM, entre março e novembro/2003

Identification of primary metabolites in fungal species of Trichophyton mentagrophyte and Trichophyton rubrum by NMR spectroscopy

BACKGROUND

Superficial mycoses are fungal infections limited to the outermost layers of the skin and its appendages. The chief causative agents of these mycoses are dermatophytes and yeasts. The diagnosis of dermatophytosis can be made by direct mycological examination with potassium hydroxide (10%-30%) of biological material obtained from patients with suspected mycosis, providing results more rapid than fungal cultures, which may take days or weeks. This information, together with clinical history and laboratory diagnosis, ensures that the appropriate treatment is initiated promptly. However, false negative results are obtained in 5%-15%, by conventional methods of diagnosis of dermatophytosis.

OBJECTIVES

To study the metabolic profiles of the commonly occurring dermatophytes by NMR spectroscopy.

PATIENTS/MATERIALS

We have used 1D and 2D Nuclear Magnetic Resonance (NMR) experiments along with Human Metabolome Database (HMDB) and Chenomx database search for identification of primary metabolites in the methanol extract of two fungal species: Trichophyton mentagrophyte (T. mentagrophyte) and Trichophyton rubrum (T. rubrum). Both standard strains and representative number of clinical isolates of these two species were investigated. Further, metabolic profiles obtained were analysed using multivariate analysis.

RESULTS

We have identified 23 metabolites in the T. mentagrophyte and another 23 metabolites in T. rubrum. Many important metabolites like trehalose, proline, mannitol, acetate, GABA and several other amino acids were detected, which provide the necessary components for fungal growth and metabolism. Altered metabolites were defined between Trichophyton mentagrophyte and T. rubrum strains.

CONCLUSION

We have detected many metabolites in the two fungal species T. mentagrophyte and T. rubrum by using NMR spectroscopy. NMR spectroscopy provides a holistic snapshot of the metabolome of an organism. Key metabolic differences were identified between the two fungal strains. We need to perform more studies on metabolite profiling of the samples from these species for their rapid diagnosis and prompt treatment.

Epidemiology of dermatomycoses in children in Northern Mato Grosso 2015-2020

OBJECTIVES

Dermatomycoses, fungal diseases that affect the superficial layers of skin, hair, or nails, are a public health concern due to their high prevalence. In Brazil, dermatomycoses are not notifiable diseases, so only fragmented epidemiological studies have been reported in the national literature. To evaluate the epidemiological profile of dermatomycoses in preschoolers and school children in Sinop, Mato Grosso (MT), Brazil.

METHODS

Classic methods were used to perform 782 mycological examinations to identify dermatophytosis, cutaneous candidosis, and pityriasis versicolor in preschoolers and school children aged between 6 months and 12 years in 11 educational institutions in Sinop - MT.

RESULTS

Among the evaluated clinical specimens, 5.2% tested positive for dermatophytosis, with 58.45% of these cases corresponding to tinea capitis, followed by skin (tinea corporis and tinea pedis) and toenail (tinea unguium) lesions; zoophilic fungi predominated. Microsporum canis and Trichophyton mentagrophytes complex were isolated in 53.66% and 24.39% of the cases, respectively. Regarding cutaneous candidosis, 9.1% of the specimens tested positive for this disease, with 59.16% and 12.7% of the cases corresponding to toenails and interdigitoplantar lesions, respectively. Candida albicans caused 70.43% of the lesions. The remaining specimens (85.7%) tested positive for pityriasis versicolor; children aged between 6 and 12 were the most affected (71.79%).

CONCLUSION

Our results agree with most epidemiological studies carried out in Brazil and demonstrate the high frequency of mycoses in preschoolers and school children, a result of poor personal hygiene and favorable weather conditions in Northern Mato Grosso, Brazil.

Mycoses in northeastern Brazil: epidemiology and prevalence of fungal species in 8 years of retrospective analysis in Alagoas

Superficial and cutaneous mycoses are common in tropical countries, caused by dermatophytes, yeast, and non-dermatophyte molds in different clinical specimens. In order to define the epidemiology of mycoses and the profile of their etiological agents in Alagoas (northeastern Brazil) between 2009 and 2016, we obtained data of patients from the main laboratories of Alagoas, by examining clinical samples with direct microscopy and culture on Sabouraud dextrose agar and Chromagar^®Candida. A total of 3316 patients were confirmed with mycoses (595 men/2716 women) and 40.25 of average age. Positive samples totaled 3776, mainly vaginal secretion (1593/42.2%), toenails (876/23.2%), and fingernails (589/15.6%). Yeasts were the most isolated (3129/82.9%), including 3012 Candida spp. (79.8%), 57 Malassezia spp. (1.5%), 42 Trichosporon sp. (1.1%), 10 Geotrichum spp. (0.3%), and 8 Rhodotorula spp. (0.2%). Candida albicans was the most frequent species (715/18.9%), followed by C. krusei (194/5.1%), C. tropicalis (24/0.6%), and 2079 unspecified species (55.1%). Among 17.1% filamentous fungi, 14.8% dermatophytes were distributed as 211 Trichophyton sp. (5.6%), 125 T. rubrum (3.3%), 106 T. tonsurans (2.8%), 72 T. mentagrophytes (1.9%), 2 Microsporum sp. (0.1%), 15 M. canis (0.4%), and 26 Epidermophyton sp. (0.7%). Other fungi represented the minority: Fusarium sp. and Aspergillus sp. These are the first clinical data on the Alagoas population affected by fungi pathogens, confirming a higher incidence of candidiasis (mainly vulvovaginal and onychomycosis) and dermatophytes, providing a better understanding of different mycoses in northeastern Brazil.

Recurrent and disseminated pityriasis versicolor: A novel clinical form consequent to Malassezia-host interaction?

Pityriasis versicolor is a superficial fungal infection caused by Malassezia spp. The aim of this study is to propose the definition of a new clinical entity: the recurrent and disseminated pityriasis versicolor (RDPV). All patients with RDPV were enrolled over an eight-month period. Clinical and epidemiological data were obtained, Malassezia (M.) species were isolated in cultures and identified by phenotypic and molecular characterization, skin biopsies were taken from active lesions, serum levels of immunoglobulin E were obtained and therapeutic schemes were evaluated. A total of 16 patients were included (11 male, 5 female). The most frequently isolated species were M. japonica (n = 3) and M. furfur (n = 3). This is the first study that isolates M. japonica in patients with pityriasis versicolor; interestingly, those were recalcitrant patients. Seven patients (43.8%) had no cure with any of the proposed treatments; among those, 5 (71.4%) had increased serum IgE levels. The most effective treatment was itraconazole 200 mg daily for 28 days. The RDPV has very different features from the classic form, including a poor response to treatment, and the isolation of different Malassezia species; therefore, we propose a hypothesis for the definition of a new clinical condition (RDPV), which could be a result of the interaction Malassezia-host.

Prevalence of Dermatophytic Infection and the Spectrum of Dermatophytes in Patients Attending a Tertiary Hospital in Addis Ababa, Ethiopia

Background. Dermatophytosis is common worldwide and continues to increase. Objective. This study was undertaken to determine the prevalence of dermatophytosis and the spectrum of ringworm fungi in patients attending a tertiary hospital. Methods. Samples were collected from 305 patients. A portion of each sample was examined microscopically and the remaining portion of each sample was cultured onto plates of Sabouraud's dextrose agar containing chloramphenicol with and without cycloheximide. Dermatophyte isolates were identified by studying macroscopic and microscopic characteristics of their colonies. Result. Of 305 samples, fungi were detected in 166 (54.4%) by KOH of which 95 were dermatophytes while 242 (79.4%) samples were culture positive of which 130 isolates were dermatophytes. Among dermatophyte isolates T. violaceum was the most common (37.7%) cause of infection. Tinea unguium was the predominant clinical manifestation accounting for 51.1% of the cases. Patients with age group 25–44 and 45–64 years were more affected. T. violaceum was the most common pathogen in tinea unguium and tinea capitis, whereas T. mentagrophytes was the most common pathogen in tinea pedis. Conclusion. Further intensive epidemiological studies of ring worm fungus induced dermatophytosis which have public health significance are needed.

Yeasts of the genital region of patients attending the dermatology service at Hospital São Paulo, Brazil

BACKGROUND

The knowledge of the diversity of yeasts that make up the skin microbiota of human beings is essential for the efficient monitoring of infections to which a person may be predisposed.

AIMS

This study identified yeasts comprising the genital skin microbiota of patients attending the Dermatology Service at the Hospital São Paulo-UNIFESP, Brazil.

METHODS

Samples were collected from the genital region of each patient and cultured on Sabouraud dextrose agar. Individual colonies were carefully transferred to tubes daily. Yeasts were identified based on classical methodologies and confirmed using a commercial kit.

RESULTS

Eighty-three patients were included in the study. Approximately 80% were women and 20% were men. The average age was 55 years. Hypertension, diabetes, kidney transplant and AIDS were the main underlying diseases reported by the patients. The most prevalent yeasts were Candida parapsilosis (36.1%), Rhodotorula mucilaginosa (9.2%), Rhodotorula glutinis (8.3%), Candida tropicalis (5.5%) and Trichosporon inkin (1.8%). Approximately 78% of the isolates were obtained in pure cultures. Trichosporon inkin was isolated only from women, in contrast to literature describing a high prevalence in males.

CONCLUSIONS

Our results suggest that Candida albicans is not the main yeast found on genital skin as previously thought, and opportunistic pathogens such as C. parapsilosis, C. tropicalis, Rhodotorula spp. and T. inkin make up the genital skin microbiota, representing a risk for infection in immunocompromised subjects. These results also indicate that women are carriers of T. inkin, the etiological agent of white piedra and trichosporonosis.

Fungal agents in different anatomical sites in Public Health Services in Cuiabá, state of Mato Grosso, Brazil

INTRODUCTION

A contribution to the regional epidemiological profile of the most common fungal agents in Public Health Services in Cuiabá, state of Mato Grosso, including university hospitals and polyclinics.

METHODS

Clinical specimens (n = 1,496) from 1,078 patients were collected, submitted to direct mycological exam (potash or stick tape method) and cultured in specific mediums. Dermatophytic and non-dermatophytic agents were identified according to micromorphology (Ridell technique).

RESULTS

The majority of the 1,496 specimens were skin (n = 985) and nail exams (n = 472). Of the 800 positive cultures, 246 (30.8%) corresponded to dermatophytes and 336 (42%) to yeasts of the genus Candida, 190 (23.7%) to other yeasts, 27 (3.4%) to non-dermatophytic filamentous fungi and one (0.1%) the agent of subcutaneous mycosis. Lesions considered primary occurred in greater numbers (59.5%) than recurrent lesions (37.4%), with a greater concentration of positivity occurring on the arms and legs.

CONCLUSIONS

Comorbidities, allergies and diabetes mellitus were conditions associated with greater positivity in direct mycological exams and cultures. Positive culture was considered a definitive diagnosis of fungal infection and confirmed 47.8% of diagnostic hypotheses.

Superficial mycoses in Paraíba: a comparative analysis and bibliographical revision

A survey of the incidence of clinically diagnosed cases of superficial mycosis was carried out using individual report cards in four Family Health units in Patos-PB, in 2007. We had a sample of 197 positive records with Pityriasis and Tinea as the most incident mycoses. There was a higher prevalence among female patients who were between 11 - 20 years of age. A high number of non-identified infections was found: 46,19%. The identification of the agents of such non-identified infections is not possible as they are not infections of compulsory notification.

Clinical aspects of patients with pityriasis versicolor seen at a referral center for tropical dermatology in Manaus, Amazonas, Brazil

BACKGROUND

Pityriasis versicolor (tinea versicolor) is a chronic superficial mycosis caused by yeasts of the Malassezia spp. genus commensal of the keratinized layers of the skin. Under conditions not yet understood, it becomes pathogenic determining the clinical manifestations of the disease. It is a recurrent skin condition and persistent hypopigmentation may remain after treatment, causing social problems to those affected.

OBJECTIVE

To describe the clinical and epidemiological features of patients diagnosed with tinea versicolor treated at a referral center for dermatology (Alfredo da Matta Foundation).

METHODS

Case-studies in which cutaneous manifestations and epidemiological characteristics of patients diagnosed with tinea versicolor treated at Alfredo da Matta Foundation were detailed.

RESULTS

One hundred and sixteen patients were included in the study from January to August 2008. Most subjects were male, of mixed ethnicity and young age. Most were students who were predisposed to the development of macules. The majority had extensive injuries and past history of the disease.

CONCLUSION

The results revealed a high proportion of individuals with extensive clinical manifestations and duration of the disease.

Aspectos epidemiológicos de pacientes com lesões ungueais e cutâneas causadas por Scytalidium spp

FUNDAMENTO: As dermatomicoses causadas por fungos filamentosos não dermatófitos são infecções raras, exceto as onicomicoses, cuja prevalência vem crescendo nos últimos anos. Dentre esses agentes etiológicos destacam-se o Scytalidium dimidiatum e o S. hyalinum, fungos emergentes responsáveis por micoses em unhas e pele. OBJETIVO: Investigar as características epidemiológicas das onicomicoses e micoses de outras localizações causadas pelos fungos do gênero Scytalidium, utilizando-se como parâmetros sexo, idade e localizações das lesões. MÉTODOS: Avaliaram-se 81 amostras com cultura positiva para o gênero em estudo, oriundas de 74 pacientes encaminhados ao Laboratório de Investigação em Dermatologia (ID) situado na cidade do Rio de Janeiro (RJ), no período de 1997 a 2006. As amostras foram submetidas a confirmação diagnóstica por exame direto e cultura. RESULTADOS: A prevalência de onicomicoses por Scytalidium spp. foi de 0,87%, entre as idades de 41 e 60 anos (48,64%). Em relação à localização das lesões, os pés foram mais acometidos (91,36%), com predomínio do hálux esquerdo. No exame direto, as estruturas mais encontradas foram hifas hialinas; na cultura, a espécie S. dimidiatum foi a mais frequente. CONCLUSÃO: As onicomicoses por Scytalidium spp. são raras e o S. dimidiatum foi a espécie mais isolada neste laboratório no período em estudo.

In vitro response of cutaneous mycosis fungal agents to the most widely used systemic antifungals in dermatology

BACKGROUND

The high frequency of cutaneous mycosis justify the need to evaluate the possible contribution of in vitro profile of susceptibility to antifungal agents.

OBJECTIVE

To evaluate whether there is variability in in vitro susceptibility by filamentous fungi, previously isolated from cutaneous mycosis, to fluconazole, ketoconazole, itraconazole and terbinafine.

METHODS

Fungi were isolated and identified by classical methods and the antifungal susceptibility test was performed using the method of broth microdilution, according to a protocol recommended by the Clinical Laboratory Standards Institute (CLSI), through M38-A document.

RESULTS

Amongst the 80 filamentous fungi identified, Trichophyton genus represented 81%. The four examined drugs showed great variation for Trichophyton spp and Microsporum spp. Fusarium spp was resistant to all tested drugs. Terbinafine was the most effective drug against the majority of the isolated fungi.

CONCLUSION

There was great variability in response profiles to the tested antifungals. The definition of a reference test method will offer higher objectivity for physicians to choose the appropriate therapy.

In vitro susceptibility testing of dermatophytes isolated in Goiania, Brazil, against five antifungal agents by broth microdilution method

The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 ºC allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.