404 resultados para Thermotolerant yeasts
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Aims: The aim of this study was to identify and determine the diversity, occurrence and distribution of fungi in water used at a haemodialysis centre.Methods and Results: Samples in the hydraulic circuit for the distribution of the water, dialysate samples and samples of sterilization solution from dialysers were collected over a 3-month period, and 500 ml of each sample was filtered through membranes. All together 116 isolates of fungi were recovered from 89% of all water samples collected inside the haemodialysis unit, with prevalence of moulds in tap water samples and of yeasts in dialysate samples. Fusarium spp. was the most abundant genus found, whereas Candida parapsilosis was the predominant yeast species.Conclusions: This study demonstrated that various fungi were present in the water system. These data suggest the inclusion of the detection and quantification of fungi in the water of haemodialysis.Significance and Impact of the Study: The recovery of fungi from aqueous haemodialysis environments implies a potential risk for haemodialysis patients and indicates the need for continuous maintenance and monitoring. Further studies on fungi in haemodialysis water systems are required to investigate the organism ability to persist, their role in biofilm formation and their clinical significance.
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In this study, water and eight sanitizing solutions (vinegar at 6, 25, and 50%; acetic acid at 2 and 4%; peracetic acid at 80 ppm, sodium hypochlorite at 200 ppm, and sodium dichloroisocyanurate at 200 ppm) were compared in terms of their effectiveness against the natural microbiota of lettuce. All of the samples were kept in contact with the sanitizing solutions for 15 min, and the effectiveness of a sanitizing agent was evaluated on the basis of the number of decimal reductions of the total aerobic mesophilic count, the mold and yeast count, the total coliform count, and the Escherichia coli count. The average initial levels of these organisms in the samples were 6.94 log(10) CFU/g for aerobic mesophilic microorganisms, 5.62 log(10) CFU/g for molds and yeasts, and 3.25 log(10) CFU/g for total coliforms. of 10 samples analyzed, only 4 contained E. coli, and the average initial level of this microorganism in these 4 samples was 1.64 log(10) CFU/g. Salmonella was not detected in any of the samples tested. The decimal reductions of the populations of aerobic mesophilic microorganisms, molds and yeasts, total coliforms, and E. coli were 0.78, 0.87, 0.82, and >0.14 log(10) CFU/g, respectively, in water; 2.89, >3.41, >2.21, and >0.26 log(10) CFU/g, respectively, in 50% vinegar; 2.42, >3.20, >1.99, and >0.26 log(10) CFU/g, respectively, in 25% vinegar; 1.83, 2.57, 1.58, and >0.26 log(10) CFU/g, respectively, in 6% vinegar; 3.91, >3.58, >2.25, and >0.26 log(10) CFU/g, respectively, in 4% acetic acid; 3.37, >3.53, >2.25, and >0.26 log(10) CFU/g, respectively, in 2% acetic acid; 1.85, 2,32, 1.44, and >0.20 log(10) CFU/g, respectively, in 80 ppm of peracetic acid; 2.63, 2.75, 1.91, and >0.26 log(10) CFU/g, respectively, in 200 ppm of sodium hypochlorite; and 3.23, >3.08, >1.95, and >0.26 log(10) CFU/g, respectively, in 200 ppm of sodium dichloroisocyanurate. Statistical analysis of the results showed that the effectiveness levels for all of the sanitizing agents tested were equivalent to or higher than that for sodium hypochlorite at 200 ppm.
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Paracoccidioides brasiliensis is a dimorphic fungus known to produce invasive systemic disease in humans. The 43-kDa glycoprotein of P, brasiliensis is the major diagnostic antigen of paracoccidioidomycosis and may act as a virulence factor, since it is a receptor for laminin. Very little is known about early interact-ions between this fungus and the host cells, so we developed in vitro a model system employing cultured mammalian cells (Vero cells), in order to investigate the factors and virulence mechanisms of P. brasiliensis related to the adhesion and invasion process. We found that there is a permanent interaction after 30 min of contact between the fungus and the cells. The yeasts multiply in the cells for between 5 and 24 h. Different strains of P, brasiliensis were compared, and strain 18 thigh virulence) was the most strongly adherent, followed by strain 113 (virulent), 265 (considered of low virulence) and 113M(mutant obtained by ultraviolet radiation, deficient in gp43). P. brasiliensis adhered to the epithelial cells by a narrow tube, while depressions were noticed in the cell surface, suggesting an active cavitation process. An inhibition assay was performed and it was verified that anti-gp43 serum and a pool of sera from individuals with paracoccidioidomycosis were able to inhibit the adhesion of P. brasiliensis to the Vero cells. Glycoprotein 43 (gp43) antiserum abolished 85 % of the binding activity of P. brasiliensis. This fungus can also invade the Vero cells, and intraepithelial parasitism could be an escape mechanism in paracoccidioidomycosis. (C) 2000 Editions scientifiques et medicales Elsevier SAS.
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The aim of this study is to describe the degree of yeast-colonization in diabetic and hemodialysed-users of dental prostheses. Individuals (306) were examined using an oral rinse technique in order to evaluate the incidence of yeast-carriage, and genotype of C. albicans. Yeasts were isolated from 68.4% (91/133) individual's dental prostheses users. Dental prostheses were found to be a significant factor for the yeast colonization (P < 0.05). Overall, the intensity of carriage was higher in diabetic patients as compared with health and hemodialysed individuals (P < 0.05). The isolation rates were: C. albicans (51.7%), C. parapsilosis (20.9%), C. tropicalis (14.3%), C. glabrata (6.6%), C. krusei (3.3%), C. rugosa (1.1%), and Pichia (Pichia ohmeri, 2.2%). Ready-To-Go RAPD Analysis Beads were used and primer OPJ 6 distinguished the C. albicans isolates found in prostheses users. All the isolates were grouped into 11 RAPD profiles in four main clusters and, the average S (AB) for the entire collection of 47 C. albicans isolates were 0.779 +/- 0.178. Over 85% of isolates had a similarity level higher than or equal to 0.8 reinforcing the idea that the use of dental prostheses, independently of the host's clinical condition, probably provides the necessary conditions for these strains to gain a growth-specific advantage over others.
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The aim of this study was to investigate oral yeast colonization, antifungal susceptibility and strain diversity in insulin-dependent diabetes mellitus patients (175), as well as to evaluate the influence of dental prostheses. Oral rinse samples were cultured on selective media, in order to isolate, count and identify the yeasts recovered. More than half of the diabetic subjects (53%) carried significant amounts of Candida cells in the buccal cavity and these organisms were recovered at higher densities in diabetics wearing dentures. A total of 93 yeast strains were isolated from these patients, including: Candida spp. (n = 89); Pichia (n = 02); Trichosporon (n = 1), and Geotrichum (n = 1). C. albicans represented 56% of these strains, non-albicans Candida 39.8%, and other genera of yeast 4.3%. C. albicans was prevalent, followed by C. parapsilosis, C. tropicalis, C. glabrata, C. krusei, C. rugosa and C. guilliermondii. Agar disk-diffusion tests of the susceptibility of non-albicans Candida and other genera of yeast to fluconazole showed resistance in 21.9%, mainly in C. rugosa (100%), C. glabrata (57%) and C. krusei (50%). Local oral factors, such as the presence of dentures, in association with diabetes, seemed to have the effect of increasing the amount and variety of Candida species in the oral cavities, mainly those with lower drug susceptibilities.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Yeasts are becoming a common cause of nosocomial fungal infections that affect immunocompromised patients. Such infections can evolve into sepsis, whose mortality rate is high. This study aimed to evaluate the viability of Candida species identification by the automated system Vitek-Biomerieux (Durham, USA). Ninety-eight medical charts referencing the Candida spp. samples available for the study were retrospectively analyzed. The system Vitek-Biomerieux with Candida identification card is recommended for laboratory routine use and presents 80.6% agreement with the reference method. By separate analysis of species, 13.5% of C. parapsilosis samples differed from the reference method, while the Vitek system wrongly identified them as C. tropicalis, C. lusitaneae or as Candida albicans. C. glabrata presented a discrepancy of only one sample (25%), and was identified by Vitek as C. parapsilosis. C. guilliermondii also differed in only one sample (33.3%), being identified as Candida spp. All C. albicans, C. tropicalis and C. lusitaneae samples were identified correctly.
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Paracoccidioidomycosis (PCM) is a severe systemic mycosis, endemic in Latin America and highly prevalent in Brazil, where it ranks eighth as a mortality cause among infectious and parasitic diseases in humans. The disease in animals has been little explored. It is observed that armadillos can harbor the fungus at high frequencies, although the active disease has not been well documented in this wild mammal. Dogs are susceptible to experimental infection, and the naturally acquired PCM-disease was reported only recently in a dog from Brazil. The present work reports the second case of naturally acquired PCM in a 6-year-old female dog that presented emaciation, lymphadenomegaly, and hepatosplenomegaly. Biochemical and pulmonary radiographic evaluation did not reveal any abnormalities. PCM was diagnosed by clinical findings, culturing, immunohistochemistry, and histopathology of popliteal lymph node. The fungus was recovered from popliteal lymph node, and the molecular analysis showed respective sequencing similarities of 99 and 100% for 803 nucleotides of the Gp43 gene and 592 nucleotides from the ITS-5.8S region of Paracoccidioides brasiliensis. Immunohistochemistry revealed severe lymphadenitis and presented numerous yeasts, which reacted against the gp43 antibody. Histopathology revealed a severe granulomatous lymphadenitis associated with numerous single or multiple budding yeasts. After diagnosis, the dog was successfully treated with itraconazol for 2 years. Veterinarians should be aware of the importance of considering PCM for differential diagnosis, especially in dogs from PCM-endemic areas, whose monophagocytic system involvement is evident.
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Infantile botulism was recognized in 1976 as a paralyzing disease caused by the ingestion of viable spores that would germinate and colonize the intestinal tract of infants, with local production and absorption of Clostridium botulinum toxin. The possible origins of botulinic spores are dust and honey, which has been identified as a dietary risk factor for infantile botulism. The objectives of the present study were to investigate 100 honey samples obtained in the state of São Paulo (Brazil) in terms of incidence of botulinic spores and of microbiologic quality, in agreement with Decree 367/9. All 100 samples analysed were negative for the presence of Salmonella, Shigella, total coliforms. C botulinum spores were present in 3 samples (3%) and molds and yeasts, in 64 samples (64%), but only 25 (25%) exceeded established criteria, with counts ranging from zero to 1.5 x 10(5) CFU/g. The presence of small sporogenic Gram-positive rods was observed in 42 (42%) of the 100 samples tested but these bacteria were not identified. (C) 2003 Elsevier Ltd. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to evaluate the effects of feeding cattle with isoprotein and isoenergetic diets, with and without the addition of polyclonal antibody preparation (PAP), yeasts (YST) or monensin sodium (MON) on performance, carcass characteristics and gain cost in feedlot. Ninety-five 20-month old bullocks (323.3±21.8 kg) were distributed in 25 pens. The completely randomized experimental design had a 2 × 2 + 1 factorial arrangement and the treatments were replicated 5 times. There was no effect of MON for DMI throughout the feedlot period; however, MON reduced the dry matter intake (DMI) in g/kg of BW in the first 28 days when compared with the other treatments. The gain cost decreased with MON addition in relation to the other treatments. Inclusion of YST decreased average daily gain (ADG), final body weight, hot carcass weight, carcass weight, gain to feed ratio and DMI in g/kg body weight, worsening feed conversion and increasing the gain cost in the feeding periods. Inclusion of PAP increased ADG and decreased the gain cost, besides improving feed conversion. For MON and PAP, a difference was found for kidney-pelvic fat and kidney-pelvic fat per 100 kg of hot carcass weight. For MON and YST, there was a difference in ADG, feed conversion, gain cost and carcass yield and kidney-pelvic fat per 100 kg of hot carcass. Treatment YST worsened performance in relation to the non-supplemented treatments. Feeding PAP to animals did not influence performance and carcass characteristics of bullocks in feedlot negatively. Thus, PAP shows potential to substitute MON in cattle feeding using isoprotein and isoenergetic diets.
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Heat stress has negative effects on pregnancy rates of lactating dairy cattle. There are genetic differences in tolerance to heat stress; Bos taurus indicus (B. t. indicus) cattle and embryos are more thermotolerant than Bos taurus taurus (B. t. taurus). In the present study, the effects of sire and sire breed on conception and embryonic/fetal loss rates of lactating Holstein cows during the Brazilian summer were determined. In Experiment 1, cows (n = 302) were AI after estrus detection or at a fixed-time with semen from one Gyr (B. t. indicus) or one Holstein sire (B. t. taurus). Pregnancy was diagnosed 80 days after AI. In Experiment 2, cows (n = 811) were AI with semen from three Gyr and two Holstein sires. Pregnancy was diagnosed at 30-40 and at 60-80 days after AI. Cows diagnosed pregnant at the first examination but non-pregnant at the second were considered as having lost their embryo or fetus. Data were analyzed by logistic regression. The model considered the effect of sire within breed, sire breed, days postpartum, period of lactation, and AI type (AI after estrus versus fixed-time). There was no effect of the AI type, days postpartum or milk production on conception or embryonic loss rates. The use of Gyr bulls increased pregnancy rate when compared to Holstein bulls [9.1% (60/657) versus 5.0% (23/456), respectively, P = 0.008; data from Experiments 1 and 2 combined]. Additionally, in Experiment 2, cows inseminated using semen from sire #4 (Gyr) had lower embryonic loss (10%) when compared with other B. t. indicus (35.3% and 40%) or B. t. taurus sires (18.2% and 38.5%, P = 0.03). In conclusion, the use of B. t. indicus sires may result in higher conception rates in lactating Holstein cows during summer heat stress. Moreover, sire can affect embryonic loss and selection of bulls according to this criterion may result in higher parturition rates in lactating Holstein cows. (c) 2006 Elsevier B.V. All rights reserved.
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Heat stress has negative effects on bovine reproduction, particularly for European breeds (Bos taurus taurus) that are less thermotolerant than zebu cattle (Bos taurus indicus). Here, the evidence that spermatozoa and oocyte both contribute to early embryonic resistance to heat shock is demonstrated. In addition, the use of reproductive biotechnologies to improve bovine thermotolerance, are outlined by comparing data from taurus, indicus and crossbred genotypes. (c) 2005 Published by Elsevier B.V.
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O objetivo deste trabalho foi analisar quantitativamente os microrganismos, Streptococcus do grupo mutans e Candida sp, da cavidade bucal de pacientes com carcinoma de orofaringe antes, durante e após o tratamento com radioterapia e correlacionar fatores salivares como pH, capacidade tampão (CT) e fluxo salivar (FS). Amostras de saliva foram coletadas, diluídas e inoculadas em ágar SB-20 e ágar Sabouraud, respectivamente para Streptococcus do grupo mutans e Candida sp. Previamente à diluição, a saliva concentrada foi analisada, determinando-se os fatores salivares. Após crescimento das colônias, o número de microrganismos foi determinado em UFC/ml. A análise dos resultados permitiu concluir que houve correlação positiva entre os fatores salivares e a presença de microrganismos ilustrada pelo aumento no número de UFC/ml dos microrganismos analisados concomitantemente com a diminuição do fluxo salivar. Os efeitos da radiação comprometeram a homeostasia salivar e favoreceram o aumento das infecções por leveduras e bactérias durante o tratamento radioterápico.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)