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Abstract Background Epidemiological studies worldwide have shown that A. fumigatus exhibits important phenotypic and genotypic diversity, and these findings have been of great importance in improving the diagnosis and treatment of diseases caused by this fungus. However, few studies have been carried out related to the epidemiology of this fungus in Latin America. This study´s aim is to report on the epidemiology of the fungus by analyzing the phenotypic variability of Aspergillus section Fumigati isolates from different Latin American countries and the relationship between this variability, the geographical origin and genotypic characteristics. Methods We analyzed the phenotypic characteristics (macro- and micromorphology, conidial size, vesicles size, antifungal susceptibility and thermotolerance at 28, 37 and 48°C) of A. section Fumigati isolates from Mexico (MX), Argentina (AR), Peru (PE) and France (FR). The results were analyzed using analysis of variance (ANOVA) and Tukey's multiple comparison test to detect significant differences. Two dendrograms among isolates were obtained with UPGMA using the Euclidean distance index. One was drawn for phenotypic data, and the other for phenotypic and genotypic data. A PCoA was done for shown isolates in a space of reduced dimensionality. In order to determine the degree of association between the phenotypic and genotypic characteristics AFLP, we calculated the correlation between parwise Euclidean distance matrices of both data sets with the nonparametric Mantel test. Results No variability was found in the macromorphology of the studied isolates; however, the micromorphology and growth rate showed that the PE isolates grew at a faster rate and exhibited the widest vesicles in comparison to the isolates from MX, AR and FR. The dendrogram constructed with phenotypic data showed three distinct groups. The group I and II were formed with isolates from PE and FR, respectively, while group III was formed with isolates from MX and AR. The dendrogram with phenotypic and genotypic data showed the same cluster, except for an isolate from FR that formed a separate cluster. This cluster was confirmed using PCoA. The correlation between the phenotypic and genotypic data of the isolates revealed a statistically significant association between these characteristics. Conclusions The PE isolates showed specific phenotypic characteristics that clearly differentiate them from the rest of the isolates, which matches the genotypic data. The correlation between the phenotypic and genotypic characteristics showed a statistically significant association. In conclusion, phenotypic and genotypic methods together increase the power of correlation between isolates.

To assess what defence mechanisms are triggered by Cd2+ stress in Methanosarcina acetivorans, cells were cultured at different cadmium concentrations. In the presence of 100 μM CdCl2, the intracellular contents of cysteine, sulfide and coenzyme M increased, respectively, 8, 27 and 7 times versus control. Cells incubated for 24 h in medium with less cysteine and sulfide removed up to 80% of Cd2+ added, whereas their cysteine and coenzyme M contents increased 160 and 84 times respectively. Cadmium accumulation (5.2 μmol/10-15 mg protein) resulted in an increase in methane synthesis of 4.5 times in cells grown on acetate. Total phosphate also increased under high (0.5 mM) Cd2+ stress. On the other hand, cells preadapted to 54 μM CdCl2 and further exposed to > 0.63 mM CdCl2 developed the formation of a biofilm with an extracellular matrix constituted by carbohydrates, DNA and proteins. Biofilm cells were able to synthesize methane. The data suggested that increased intracellular contents of thiol molecules and total phosphate, and biofilm formation, are all involved in the cadmium resistance mechanisms in this marine archaeon. [ABSTRACT FROM AUTHOR]

Background: Epidemiological studies worldwide have shown that A. fumigatus exhibits important phenotypic and genotypic diversity, and these findings have been of great importance in improving the diagnosis and treatment of diseases caused by this fungus. However, few studies have been carried out related to the epidemiology of this fungus in Latin America. This study's aim is to report on the epidemiology of the fungus by analyzing the phenotypic variability of Aspergillus section Fumigati isolates from different Latin American countries and the relationship between this variability, the geographical origin and genotypic characteristics. Methods: We analyzed the phenotypic characteristics (macro- and micromorphology, conidial size, vesicles size, antifungal susceptibility and thermotolerance at 28, 37 and 48°C) of A. section Fumigati isolates from Mexico (MX), Argentina (AR), Peru (PE) and France (FR). The results were analyzed using analysis of variance (ANOVA) and Tukey's multiple comparison test to detect significant differences. Two dendrograms among isolates were obtained with UPGMA using the Euclidean distance index. One was drawn for phenotypic data, and the other for phenotypic and genotypic data. A PCoA was done for shown isolates in a space of reduced dimensionality. In order to determine the degree of association between the phenotypic and genotypic characteristics AFLP, we calculated the correlation between parwise Euclidean distance matrices of both data sets with the nonparametric Mantel test. Results: No variability was found in the macromorphology of the studied isolates; however, the micromorphology and growth rate showed that the PE isolates grew at a faster rate and exhibited the widest vesicles in comparison to the isolates from MX, AR and FR. The dendrogram constructed with phenotypic data showed three distinct groups. The group I and II were formed with isolates from PE and FR, respectively, while group III was formed with isolates from MX and AR. The dendrogram with phenotypic and genotypic data showed the same cluster, except for an isolate from FR that formed a separate cluster. This cluster was confirmed using PCoA. The correlation between the phenotypic and genotypic data of the isolates revealed a statistically significant association between these characteristics. Conclusions: The PE isolates showed specific phenotypic characteristics that clearly differentiate them from the rest of the isolates, which matches the genotypic data. The correlation between the phenotypic and genotypic characteristics showed a statistically significant association. In conclusion, phenotypic and genotypic methods together increase the power of correlation between isolates. [ABSTRACT FROM AUTHOR]

The indiscriminate use of herbal products is increasingly growing worldwide; nonetheless consumers are not warned about the potential health risks that these products may cause. Hintonia latiflora (Hl) is a tree native to the American continent belonging to the Rubiaceae family and its stem bark is empirically used mainly to treat diabetes and malaria; supplements containing Hl are sold in America and Europe without medical prescription, thus scientific information regarding its toxicity as a consequence of a regular consumption is needed. In the present study, the histopathological effect of 200 and 1000 mg/kg of HI methanolic stem bark extract (HlMeOHe) was evaluated in the small bowel, liver, pancreas, kidneys and brain of CD-1 male mice after oral sub-acute treatment for 28 days. No histopathological alterations were observed in the brain and small bowel of the treated animals; however, mice presented diarrhea from day 2 of treatment with both doses. No histological changes were observed in the tissues collected from the animals treated with 200 mg/kg, except for the liver that depicted periportal hepatitis. Animals treated with the higher dose showed in the liver sections hydropic degeneration, hepatitis and necrosis, kidney sections depicted tubular necrosis and in pancreas sections, hydropic degeneration of the pancreatic islets was observed. In conclusion, HlMeOHe damaged the liver with an oral dose of 200 mg/kg, and at 1000 mg/kg injured the kidneys and pancreas of the CD-1 male mice.

Malaria continues to be a major global health problem, and over 40% of the world's population is at risk. Severe or complicated malaria is defined by clinical or laboratory evidence of vital organ dysfunction, including dysfunction of the central nervous system (CNS). The pathogenesis of complicated malaria has not been completely elucidated; however, the development of the multiorgan affection seems to play an important role in the disruption of the blood brain barrier (BBB) that protects the CNS against chemical insults. Historically, the BBB has received more attention in the pathogenesis of malaria than have the cerebrospinal fluid-brain barrier (CSFBB) and ependymal cells. This perspective may be misguided because, in the context of disease or toxicity, the CSFBB is more vulnerable to many foreign invaders than are the capillaries. Given the lack on studies of the damage to the CSFBB and ependymal epithelium in experimental murine malaria, the present study evaluated morphological changes in the ependymal cells of CD-1 male mice infected with lethal Plasmodium yoelii yoelii (Pyy) via histopathology and scanning electron microscopy (SEM). Samples were taken two, four and six days post-infection (PI). No lesions were observed upon the initial infection. By the fourth day PI, fourth ventricle ependymal samples exhibited disruptions and roughened epithelia. More severe injuries were observed at six days PI and included thickened cilia and deep separations between the ependymal intercellular spaces. In some of the analyzed areas, the absence of microvilli and cell layer detachment were observed, and some areas exhibited blebbing surfaces. The ependymal cell lesions observed in the CD1 male mice infected with lethal Pyy seemed to facilitate the paracellular permeability of the CSFBB and consequently promote the access of inflammatory mediators and toxic molecules through the barrier, which resulted in damage to the brain tissue. Understanding the mechanism of ependymal disruption during lethal murine malaria could help to elucidate the local and systemic factors that are involved in the pathogenesis of the disease and may provide essential clues for the prevention and treatment of complicated human malaria.