Janio Morais Santurio

Hypertonic sabouraud broth as a simple and powerful test for Candida dubliniensis screening

We developed a new screening test for C. dubliniensis based on its inability to grow on Sabouraud dextrose broth with 6.5% NaCl. A total of 266 clinical yeast isolates and 3 reference strains were tested, including 250 C. albicans and 19 C. dubliniensis strains. All C. albicans isolates tested exhibited significant growth on hypertonic Sabouraud broth up to 96 h, while, all C. dubliniensis isolates did not exhibit any visually detectable growth during the same period.

Cutaneous Pythiosis insidiosi in calves from the Pantanal region of Brazil

Two cases of cutaneous Pythiosis insidiosi were diagnosed in cattle from the Pantanal region, Brazil. The lesions were observed in the limbs of two 8-month-old beef calves. Close examination showed local swelling and focal ulceration of the skin. Microscopically, there was multifocal granulomatous dermatitis with intralesional Pythium insidiosum hyphae. The diagnosis was based on the morphological aspects, immunohistochemical findings and culture of the etiologic agent.

Atividade antimicrobiana dos óleos essenciais de orégano, tomilho e canela frente a sorovares de Salmonella enterica de origem avícola

Essential oils from oregano (Origanum vulgare), thyme (Thymus vulgaris) and cinnamom (Cinnamomum zeylanicum) were tested for their inhibitory activity against sixty Salmonella sp. isolates. These microorganisms were distributed in 20 serovars, all of them isolated from broiler chickens. Based on microdilution technique, the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined. The strongest antibacterial activity was obtained for oregano (MIC mean = 529mg ml-1 and MBCmean = 661mg ml-1), followed by a moderate activity for thyme (MICmean=961mg ml-1 and MBCmean=1074mg ml-1) and the lowest obtained activity observed for cinnamon (MICmean= 1335mg ml-1 and MBCmean= 1979mg ml-1). Despite of this activity pattern, the serovars of Salmonella enterica showed significant susceptibility variations. However none of them could be classified as sensitive or resistant to the three essential oils tested. At the moment, when the antibiotics, as growth promoters, are being replaced, the essential oils from spices could be a very reasonable choice and the present results show us two points: the essential oils from oregano and thyme are effective against Salmonella isolates but the variations among the serovars must be considered.

Pitiose eqüina no Pantanal brasileiro: aspectos clínico-patológicos de casos típicos e atípicos

Equine pythiosis is an endemic disease of horses and causes significant economic losses to equine breeding in the Brazilian Pantanal. This article describes 16 cases of subcutaneous pythiosis in horses from that region. The clinical cases were divided in typical (11) and atypical (5), according to the clinical features and duration of the disease. The clinical diagnosis was confirmed by detection of specific antibodies by ELISA, isolation of the agent and histopathology. The duration of the disease varied from 1 to 6 months in the typical cases and was over 12 months in the atypical ones. The lesions in the typical cases were characterized by subcutaneous ulcerated granulomas with abundant serosanguineous secretion and itching. The atypical cases presented subcutaneous lesions characterized by large, circumscribed tumorous masses covered by a dark non ulcerated skin, associated with little or no secretion. These lesions showed a well organized aspect, were sometimes pedunculate and the animals showed a good body condition. Histologically, the typical cases were characterized by granulation tissue with abundant eosinophils; whereas the atypical cases presented pseudo-epitheliomatous hyperplasia of the epidermis and eosinophilic infiltrate. The complete description of the clinical and histopathological features and possible factors responsible for differences between the two clinical forms are presented and discussed.

Three types of immunotherapics against pythiosis insidiosi developed and evaluated

Pythiosis is a granulomatous disease of horses, cattle, dogs, cats and humans identified in tropical and subtropical areas and caused by Pythium insidiosum, a zoosporic fungus. Experimental models of pythiosis in naturally infected species have not yet been reported but, rabbits may be inoculated with zoospores as an experimental model for studying the disease. The present study evaluates the efficacy of three different of immunotherapics in the rabbit model. Approximately 17500 zoospores of oomycete P. insidiosum (CBS 101555 strain) were inoculated in each animal to generate the disease. Immunotherapics were produced from vortexed or sonicated cultures of the same strain. Four groups of five animals were employed: group 1, placebo; group 2, sonicated immunotherapic; group 3, mixed immunotherapic; and group 4, vortexed immunotherapic. All rabbits were inoculated with viable zoospores one month before administration of the immunotherapics. Eight doses of immunotherapic or placebo were used in each animal with a 14 day interval between injections. Rabbits receiving the vortexed immunotherapic were most effectively protected (P<0.05), showing a decrease in the area of coastal nodules due to Pythiosis insidiosum by 71.8% after 26 weeks of evaluation. Moreover, two animals in this group showed complete remission of the infection at the end of the 26 weeks. In contrast to these findings, rabbits given the sonicated immunotherapic did not show any protection and had an increase of 211.8% in the size of lesions. This failure of sonicated immunotherapic may reflect denaturation of protective antigens due to the sonication method.

Micotoxinas e Micotoxicoses na Avicultura

Esta revisao tem como objetivo principal mostrar, baseado em dezenas de pesquisas realizadas, os efeitos toxicos das micotoxinas aflatoxinas, tricotecenos, zealenona e fumonisinas sobre o desempenho das aves. O descobrimento das propriedades hepatotoxicas e hepatocarcinogenicas de algumas linhagens de Aspergillus flavus e A. parasiticus em perus, na Inglaterra, no inicio da decada de 1960, seguida pela elucidacao da estrutura de seus metabolitos toxicos, as aflatoxinas, deu novo enfoque e prioridade para a pesquisa sobre micotoxinas. Analises de aflatoxinas realizadas no Laboratorio de Analises Micotoxicologicas (LAMIC) da Universidade Fedaral de Santa Maria, entre os anos de 1986 e janeiro de 2000, em 15.600 amostras de alimentos destinados principalmente ao consumo animal, demonstram que no milho analisado, 41,9% das amostras estavam contaminadas por aflatoxinas. Em surtos de aflatoxicose no campo, uma das caracteristicas mais marcantes e a ma absorcao que se manifesta como particulas de racao mal digeridas na excreta das aves. Tambem observa-se, em frangos e poedeiras que recebem AFL, extrema palidez das mucosas e pernas. Dietas deficientes em riboflavina ou colecalciferol (vit. D) tornaram frangos sensiveis, nos indices de desenvolvimento corporal, a concentracoes muito baixas de AFL. O efeito aflatoxina nos frangos e maior na fase inicial de crescimento, ou seja, quando as aves ingeriram aflatoxina nos primeiros 21 dias de vida, e quanto maior o nivel de stress do lote, menor a quantidade de AFL para afetar negativamente seu desempenho, seja na producao de carne ou de ovos. As principais micotoxinas do grupo dos tricotecenos sao: toxina T-2; deoxynivalenol (DON); diacetoxyscirpenol (DAS), todas produzidas atraves de diversas especies de fungos do genero Fusarium. Alem dos tricotecenos, o fusarium tambem pode produzir zearalenona e fumonisinas. Dessas fusarium-toxinas, somente toxina T-2 gera patologias serias nas aves, como lesoes orais e imunodepressao. As fumonisinas afetam o desempenho de frangos de corte a partir de uma ingestao de 75 ppm. Ja zearalenona e DON sao inocuas quando ingeridas por aves. Para o controle de contaminacao de micotoxinas nos alimentos, o melhor metodo e prevenir o crescimento de fungos, apertando-se no controle de qualidade da materia prima. Metodos alternativos podem ser usados, utilizando-se antifungicos ou adsorventes na racao. O monitoramento dos graos recebidos ou a receber e o ponto fundamental num programa de controle de micotoxinas. Isso deve ser feito atraves de um programa amostral consistente da massa de graos recebida ou a ser adquirida, com analises periodicas das micotoxinas.

In Vitro Activities of Voriconazole, Itraconazole, and Terbinafine Alone or in Combination against Pythium insidiosum Isolates from Brazil

ABSTRACT We evaluated the in vitro activities of voriconazole, itraconazole, and terbinafine against 30 clinical isolates of Pythium insidiosum using a checkerboard macrodilution method. The combined activity of terbinafine plus itraconazole or plus voriconazole was synergic against 17% of the strains. Antagonism was not observed.

Identification of Pythium insidiosum by nested PCR in cutaneous lesions of Brazilian horses and rabbits.

Pythium insidiosum is a fungus-like organism present in subtropical and tropical areas, such as Brazil, known to infect humans and various animal species. P. insidiosum is the etiological agent of pythiosis, an emerging and granulomatous disease characterized mainly by cutaneous and subcutaneous lesions in horses, the principal species affected. Accurate diagnosis of pythiosis and identification of its causal agent by microbiological and serological tests can be often difficult and inconclusive principally for horses and humans. The aim of this study was to evaluate the application of the previously described P. insidiosum-specific nested polymerase chain reaction (PCR) assay to directly detect P. insidiosum DNA in clinical and experimental lesions. Universal fungal primers (ITS1 and ITS4) were used during the first-round of PCR to amplify ITS1, 5.8s, and ITS2. A second-round of PCR was conducted with P. insidiosum-specific primers (PI1 and PI2) to amplify a variable region within this ITS1. In this study, a total of 21 equine clinical samples (kunkers) and 28 specimens from experimentally infected rabbits were analyzed by nested PCR. The first-round of PCR generated 800-base pair products, and the second-round produced 105-base pair amplicons for each P. insidiosum-specific sample; no amplicons were generated in negative control samples. Our results suggest that nested PCR is an important and efficient tool for diagnosis of both endemic (horse samples) and experimental (rabbit samples) pythiosis.

Candida dubliniensis: Epidemiology and Phenotypic Methods for Identification

Candida dubliniensis is an emerging pathogen first described in 1995, which shares many phenotypic features with Candida albicans and therefore may be misidentified in microbial laboratories. Despite various phenotypic techniques described in the literature to differentiate the two species, the correct identification of C. dubliniensis remains problematic due to phenotypic similarities between these species. Thus, as the differences between both are best characterized at genetic levels, several molecular methods have been proposed to provide a specific and rapid identification of this species. Epidemiological studies have shown that C. dubliniensis is prevalent throughout the world and it is primarily associated with oral carriage and oropharyngeal infections in patients infected with human immunodeficiency virus (HIV). However, data acquired from its isolation from other healthy and immunocompromised patients are variable, and there is still no real consensus on the epidemiological relevance of this species. In this article, we review the various phenotypic methods used in the identification of C. dubliniensis and the epidemiological impact of this new species.

Antifungal Susceptibilities of Sporothrix albicans, S. brasiliensis, and S. luriei of the S. schenckii Complex Identified in Brazil

ABSTRACT We studied 40 strains of the species complex formerly classified as the single species Sporothrix schenckii to identify new species within this complex and evaluate their antifungal susceptibility profiles. Based on phenotypic tests (ability to grow at 37°C, colony diameters, and pigmentation of the colonies, as well as assimilation of sucrose and raffinose) and molecular assays (amplification of a fragment of the calmodulin gene), here we report the identification of S. albicans, S. brasiliensis, S. luriei, and S. schenckii; two isolates of these species were detected as itraconazole-resistant strains.