José Júlio Costa Sidrim

The anatomical distribution and antimicrobial susceptibility of yeast species isolated from healthy dogs.

The aim of this work was to identify the predominant yeast species present at different anatomical sites in healthy dogs and to determine their in vitro antimicrobial susceptibility using a broth microdilution assay. Samples were collected from the preputial, vaginal, oral and perianal mucosae and the isolates cultured were identified according to their morphological characteristics and biochemical profile. Malassezia pachydermatis was the most commonly isolated yeast, followed by Candida parapsilosis, Candida tropicalis, Candida albicans, Saccharomyces cerevisiae and Rhodotorula spp. Minimum inhibitory concentrations of the azole derivatives ketoconazole, itraconazole and fluconazole against Candida spp. were 0.03-16 microg/mL, 0.06 to >16 microg/mL and 0.5-64 microg/mL, respectively and Candida isolates were sensitive to caspofungin and amphotericin B. Although all isolates of M. pachydermatis were sensitive to itraconazole, fluconazole, ketoconazole and amphotericin B, they were found to be resistant to caspofungin. The study has highlighted that Candida spp., M. pachydermatis, S. cerevisiae and Rhodotorula spp. are part of the normal canine surface microbiota and some of these organisms exhibit in vitro resistance to commonly used antimicrobials.

Chemical composition, toxicity and larvicidal and antifungal activities of Persea americana (avocado) seed extracts

The present study had the aim of testing the hexane and methanol extracts of avocado seeds, in order to determine their toxicity towards Artemia salina, evaluate their larvicidal activity towards Aedes aegypti and investigate their in vitro antifungal potential against strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis through the microdilution technique. In toxicity tests on Artemia salina, the hexane and methanol extracts from avocado seeds showed LC50 values of 2.37 and 24.13 mg mL-1 respectively. Against Aedes aegypti larvae, the LC50 results obtained were 16.7 mg mL-1 for hexane extract and 8.87 mg mL-1 for methanol extract from avocado seeds. The extracts tested were also active against all the yeast strains tested in vitro, with differing results such that the minimum inhibitory concentration of the hexane extract ranged from 0.625 to 1.25mg L-(1), from 0.312 to 0.625 mg mL-1 and from 0.031 to 0.625 mg mL-1, for the strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis, respectively. The minimal inhibitory concentration for the methanol extract ranged from 0.125 to 0.625 mg mL-1, from 0.08 to 0.156 mg mL-1 and from 0.312 to 0.625 mg mL-1, for the strains of Candida spp., Cryptococcus neoformans and Malassezia pachydermatis, respectively.O presente estudo teve como objetivo testar os extratos hexânico e metanolico das sementes do abacate, a fim de determinar sua toxicidade em Artemia salina, avaliar a atividade larvicida frente ao Aedes aegypti, bem como verificar o potencial antifungico in vitro contra cepas de Candida spp, Cryptococcus neoformans e Malassezia pachydermatis, atraves da tecnica de microdiluicao. Os extratos hexânico e metanolico das sementes de abacate apresentaram no teste de toxicidade frente a Artemia salina, valores de LC50 2,37 e 24,13mg L-1, respectivamente; contra as larvas do Aedes aegypti os resultados obtidos foram LC50 16,7mg L-1 para o extrato hexânico e 8,87mg L-1 para o extrato metanolico das sementes do abacate. Os extratos testados tambem foram ativos contra todas as cepas de leveduras, testadas in vitro, apresentando diferentes resultados, onde o MIC do extrato hexânico variou de 0,625 a 1,25mg mL-1, de 0,312 a 0,625mg mL-1 e de 0,031 a 0,625mg mL-1 para as cepas de Candida spp., Cryptococcus neoformans e Malassezia pachydermatis, respectivamente. O intervalo de MIC para o extrato metanolico foi de 0,125 a 0,625mg mL-1, 0,08 a 0,156mg mL-1 e de 0,312 a 0,625mg mL-1, para as exemplares de Candida spp., Cryptococcus neoformans e Malassezia pachydermatis, respectivamente.

Tinea capitis in a dermatology center in the city of Fortaleza, Brazil: the role of Trichophyton tonsurans

Background  Over a 3‐year period (March 1999 to March 2002), 944 patients with scalp lesions attended a dermatology reference center in the city of Fortaleza, Ceará, Brazil. Clinical specimens were examined at the Specialized Medical Mycology Center, Federal University of Ceará, Fortaleza‐CE, Brazil, to detect patients with tinea capitis.

Candida species isolated from the gastrointestinal tract of cockatiels (Nymphicus hollandicus): in vitro antifungal susceptibility profile and phospholipase activity.

Over the past years, the incidence of yeast infections, especially candidiasis, has increased. It is known that birds, including cockatiels, harbor potentially pathogenic yeasts to human beings in their gastrointestinal tract. Thus, this work aims at determining the in vitro antifungal susceptibility and phospholipase activity of Candida spp. isolated from the gastrointestinal tract and stools of cockatiels. Sixty cockatiels were assessed and samples were collected from oral cavity, crop and cloaca and stools were collected from cages where birds were kept. Yeast species were identified according to morphological and biochemical characteristics. Amphotericin B, itraconazole and fluconazole were tested against 39 C. albicans; 12 C. tropicalis; 7 C. parapsilosis and 1 C. krusei, through broth microdilution test. These same isolates were also tested for phospholipase production, on egg yolk agar. For amphotericin B, itraconazole and fluconazole, MICs were 0.25-1 μg/mL, 0.03125 to ≥16 μg/mL and 0.5 to ≥64 μg/mL, respectively, and resistance to itraconazole and fluconazole was observed in 14 (35.89%) and 4 (10.26%) C. albicans isolates, respectively. All C. albicans were positive for phospholipase production, out of which 74.36% presented high enzymatic activity. Among non-albicans Candida species, 40% produced phospholipase. The results show that cockatiels might represent a hazard to human health, as sources of infections caused by resistant Candida spp., especially to immunocompromised individuals, children and elderly.

Histoplasmosis in HIV-positive patients in Ceará, Brazil: clinical-laboratory aspects and in vitro antifungal susceptibility of Histoplasma capsulatum isolates

This study contains a descriptive analysis of histoplasmosis in AIDS patients between 2006 and 2010 in the state of Ceará, Brazil. Additionally, the in vitro susceptibility of Histoplasma capsulatum isolates obtained during this period was assessed. We report 208 cases of patients with histoplasmosis and AIDS, describing the epidemiological, clinical, laboratory and therapeutic aspects. The in vitro antifungal susceptibility test was carried out by the microdilution method, according to Clinical and Laboratory Standards Institute, with H. capsulatum in the filamentous and yeast phases, against the antifungals amphotericin B, fluconazole, itraconazole, voriconazole and caspofungin. In 38.9% of the cases, histoplasmosis was the first indicator of AIDS and in 85.8% of the patients the CD4 cell count was lower than 100 cells/mm(3). The lactate dehydrogenase levels were high in all the patients evaluated, with impairment of hepatic and renal function and evolution to death in 42.3% of the cases. The in vitro susceptibility profile demonstrated there was no antifungal resistance among the isolates evaluated. There was a significant increase in the number of histoplasmosis cases in HIV-positive patients during the period surveyed in the state of Ceará, northeastern Brazil, but no antifungal resistance among the recovered isolates of H. capsulatum.

Epidemiologia e ecologia das dermatofitoses na cidade de Fortaleza: o Trichophyton tonsurans como importante patógeno emergente da Tinea capitis

Dermatophytosis is the most common skin infectious disturbance in the world. In this research 2.297 patients were evaluated with suspected clinical lesions of dermatophytosis. It was observed that, 534 (23.2%) patients tested positive for dermatophytes. T. rubrum was the most prevalent specie (49.6%; p £ 0.05), followed by T. tonsurans (34.4%), M. canis (7%) and T. mentagrophytes (6.2%). When the species isolated was correlated with the respective anatomical localization, it was observed that T. tonsurans was the most frequent isolated in scalp lesions (73,9%; p £ 0.01). On the other hand, T. rubrum was the main specie involved in body lesions (72.8%; p £ 0.05). Therefore, in scalp infections it was observed that, there was an absolute prevalence of T. tonsurans. This evidence is different from the statistical data collected in the southeast and south of Brazil, as well as from other areas of the world, which still show M. canis as the most frequent microorganism isolated in Tinea capiti.Dermatophytosis is the most common skin infectious disturbance in the world. In this research 2,297 patients were evaluated with suspected clinical lesions of dermatophytosis. It was observed that, 534 (23.2%) patients tested positive for dermatophytes. T. rubrum was the most prevalent specie (49.6%; p < or = 0.05), followed by T. tonsurans (34.4%), M. canis (7%) and T. mentagrophytes (6.2%). When the species isolated was correlated with the respective anatomical localization, it was observed that T. tonsurans was the most frequent isolated in scalp lesions (73.9%; p < or = 0.01). On the other hand, T. rubrum was the main specie involved in body lesions (72.8%; p < or = 0.05). Therefore, in scalp infections it was observed that, there was an absolute prevalence of T. tonsurans. This evidence is different from the statistical data collected in the southeast and south of Brazil, as well as from other areas of the world, which still show M. canis as the most frequent microorganism isolated in Tinea capitis.

Minimum inhibitory concentrations of amphotericin B, azoles and caspofungin against Candida species are reduced by farnesol

The objective of this study was to evaluate the antifungal activity of farnesol and its interaction with traditional antifungals against drug-resistant strains of Candida species. To do so, we studied the minimum in vitro inhibitory concentration (MIC) of amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), caspofungin (CAS) and farnesol against 45 isolates of Candida spp., i.e., 24 C. albicans, 16 C. parapsilosis and 5 C. tropicalis through the use of the broth microdilution method. Then, the isolates were tested with the combination of farnesol plus drugs to which they were previously found to be resistant. Additionally, the strains were pre-incubated at sub-inhibitory farnesol concentrations and their antifungal susceptibilities were re-evaluated. We found the MIC values for farnesol varied from 4.68-150 µM for Candida spp., with 19 isolates having a MIC > 1 mg/l, 18 a MIC ≥ 64 mg/l, 35 having a MIC ≥ 1 mg/l and 6 isolates a MIC ≥ 2 mg/l or were resistant to AMB, FLC, ITC and CAS, respectively. Significant MIC reductions were observed when farnesol and antifungal drugs were combined (P < 0.05) and when Candida strains were incubated with farnesol (P < 0.05). We conclude that the in vitro effects of farnesol improved the activity of traditional antifungals to which the Candida spp. isolates were resistant. These results support further investigation of the role of farnesol in the balance of the sterol biosynthetic pathway and how it interferes with cell viability.

Dengue in Patients with Central Nervous System Manifestations, Brazil

We investigated the prevalence of dengue in patients with suspected viral meningitis/meningoencephalitis in a dengue-endemic area. Cerebrospinal fluid analysis showed positive results and a 6.74× greater likelihood of identifying positive fluid in patients who died. Our findings support testing patients with neurologic manifestations for the virus in dengue-endemic areas.

Detection of the dengue non-structural 1 antigen in cerebral spinal fluid samples using a commercially available enzyme-linked immunosorbent assay

The involvement of the central nervous system in dengue infections has been reported in countries where the disease in endemic. The purpose of this study was to determine whether an enzyme-linked immunosorbent assay kit designed to detect the dengue NS1 antigen in serum was able to detect this antigen in cerebral spinal fluid (CSF) samples from patients with fatal outcomes. To evaluate the sensitivity of the kit, 26 dengue-positive CSF samples were used. The Pan-E Dengue Early kit was able to detect the NS1 antigen in 13 of 26 dengue-positive CSF samples, resulting in a sensitivity of 50% (95% confidence interval, 29.9-70.1%) and specificity of 100% (95% confidence interval, 75.3-100%). The kit was able to detect the NS1 antigen in CSF of individuals who had died of dengue. When used in combination with IgM, the detection rate rose to 92.3%. This study reports a method for rapidly detecting the dengue virus in CSF, thereby increasing the diagnosis of dengue fever cases with unusual neurological manifestations.

Yeasts from Macrobrachium amazonicum: a focus on antifungal susceptibility and virulence factors of Candida spp.

In the present study, it was sought to compare yeast microbiota of wild and captive Macrobrachium amazonicum and evaluate the antifungal susceptibility and production of virulence factors by the recovered isolates of Candida spp. Additionally, cultivation water was monitored for the presence of fungi. Overall, 26 yeast isolates belonging to three genera and seven species were obtained, out of which 24 were Candida spp., with Candida famata as the most prevalent species for both wild and captive prawns. From cultivation water, 28 isolates of filamentous fungi were obtained, with Penicillium spp., Cladosporium spp. and Aspergillus spp. as the most frequent genera. Eight out of 24 Candida spp. isolates were resistant to azole derivatives, out of which four were recovered from wild-harvested prawns. As for production of virulence factors, three (12.5%) and eight (33.3%) isolates presented phospholipase and protease activity, respectively. This is the first comparative study between wild and captive prawns and the first report on yeast microbiota of M. amazonicum. The most relevant finding was the high percentage of resistant Candida spp., including from wild individuals, which suggests the occurrence of an environmental imbalance in the area where these prawns were captured.