Hepatotoxicidad por Amanita lilloi, reporte de primeros casos / Amanita lilloi hepatotoxicity, first cases report

Se presentan dos casos clínicos de intoxicación por A. lilloi, hongos silvestres, que fueron recolectados por quienes los consumieron. Ambas pacientes desarrollaron sintomatología digestiva y evolucionaron a la falla hepática. La consulta tardía retrasó el diagnóstico y el tratamiento, pero igualmente la evolución de ambas pacientes fue favorable.

Two clinical cases of poisoning A. lilloi, wild mushrooms, which were collected by those who consumed themdebe, are presented. Both patients developed gastrointestinal symptoms and progressed to liver failure. The late consultation delayed diagnosis and treatment, but nevertheless the evolution of both patients was favorable.

Mycotoxicological and palynological profiles of commercial brands of dried bee pollen

Abstract Pollen is used in the human diet as a food supplement because of its high nutritional value; however, this product is prone to fungal contamination that could potentially generate toxins that are harmful to human health. This study aimed to verify the floral diversity of commercial brands of bee pollen and their mycotoxicological safety for human consumption. A total of 27 bee pollen samples were analyzed; these samples represented commercial brands, either showing an inspection seal or not, marketed in the State of Rio de Janeiro. The analyzed parameters included floral diversity through palynological analysis, water activity, fungal counts, identification and toxigenic profiles. The palynological analysis identified nine plant families, of which the Asteraceae was predominant. Analysis of hygienic quality based on fungal load showed that 92% of samples were reproved according to the commercial, sanitary, and food safety quality indicators. Aspergillus, Cladosporium and Penicillium were the most common genera. Toxigenic evaluation showed that 25% of the A. flavus strains produced aflatoxins. The high rate of contamination of products bearing an inspection seal emphasizes the need to monitor the entire procedure of bee pollen production, as well as to revise the current legislation to ensure safe commercialization of this product.

Mechanism of sterigmatocystin biosynthesis regulation by pH in Aspergillus nidulans

External pH constitutes one of the most important environmental factors that control growth, metabolism and differentiation in microorganisms, including fungi. We have analyzed the effect of external pH on sterigmatocystin biosynthesis in Aspergillus nidulans. It was observed in repeated experiments that alkaline pH, in opposition to acid pH, increased sterigmatocystin production and the transcript levels of aflR, the master gene that regulates expression of the sterigmatocystin cluster in A. nidulans. It is known that pH effects in fungi operate mostly through the Pal/Pac signaling pathway, originally described in Aspergillus nidulans. Accordingly, we studied the role of this signaling pathway in ST biosynthesis. It was observed that aflR transcript levels were increased in the "alkalinity mimicking" mutant pacCc14 and were minimal in the "acidity mimicking" mutant palA1. No sterigmatocystin was produced by palA1 or pacC- mutants at neither acid or alkaline pH of incubation. Finally, fluG and flbA, genes known to regulate both conidiation and sterigmatocystin synthesis upstream in the regulatory cascade, were up-regulated at alkaline pH.

Culture filtrate of Lasiodiplodia theobromae restricts the development of natural resistance in Brassica nigra plants.

Culture filtrate of Lasiodiplodia theobromae increased respiration rate, phenylalanine ammonia lyase activity, and levels of hydrogen peroxide, lipid peroxides and salicylic acid in B. nigra plants. Salicylic acid (SA) level increased for 1 hr of interaction and reduced later. Development of systemic acquired resistance (SAR) was found restricted in plants infected with L. theobromae due to deficiency of SA, which is a major signal for development of SAR. Exogenously supplied SA did develop resistance and plant death was delayed. It was hypothesized that deficiency of SA could be due to jasmonic acid produced by fungus that inhibits SA biosynthesis.

Killer toxin of Saccharomyces cerevisae Y500-4L active against fleischmann and Itaiquara commercial brands of yeast

The strain Saccharomyces cerevisae Y500-4L, previously selected from the must of alcohol producing plants and showing high fermentative and killer capacities, was characterized according to the interactions between the yeasts and examined for curing and detection of dsRNA plasmids, which code for the killer character. The killer yeast S. cerevisae Y500-4L showed considerable killer activity against the Fleischmann and Itaiquara commercial brands of yeast and also against the standard killer yeast K2 (S. diastaticus NCYC 713), K4 (Candida glabrata NCYC 388) and K11(Torulopsis glabrata ATCC 15126). However S. cerevisae Y500-4L showed sensitivity to the killer toxin produced by the standard killer yeasts K8 (Hansenula anomala NCYC 435), K9(Hansenula mrakii NCYC500), K10(Kluyveromyces drosophilarum NCYC575) and K11(Torulopsis glabrata ATCC 15126). No M-dsRNA plasmid was detected in the S. cerevisae Y500-4L strain and these results suggest that the genetic basis for toxin production is encoded by chromosoma DNA. The strain S.cerevisae Y500-4L was more resistant to the loss of the phenotype killer with cycloheximide and incubation at elevated temperatures (40§C) than the standard killer yeast S. cerevisae K1.

Identificación fisicoquímica de algunos aluminosilicatos y de su actividad adsorbente sobre aflatoxina B1 in vitro / In vitro physico-chemical identification and adsorbent efficacy of some commercial aluminosilicates on aflatoxin B1 in Mexico

Se tomaron muestras de 6 aluminosilicatos comerciales distribuidos en México. A cada muestra se la practicaron los siguientes análisis: contenido de potasio (K), calcio (Ca), sodio (Na), aluminio (Al) y silicio (Si), por medio de espectrofotometría de absorción atómica; el contenido de K en las muestras analizadas varía de 0 a 0.89 por ciento, el Ca de 0 a 0.76 por ciento, el Na de 0.42 a 1.68 por ciento, el AI de 0.90 a 8.15 por ciento y el de Si de 13.29 a 62.71 por ciento. Resalta la muestra de Fusox en cuento a contenido de Si (62.7 por ciento). La proporción de A1/Si en las muestras analizadas fue la siguiente: Milbond, 0.416; trisil, 0.356; Quibenzil, 0.13; Rekasil, 0.276; Boldclay, 0.337; Fusox, 0.14. Se midió el tamaño de las partículas por microscopía electrónica de barrido y se encontró que Milbond, Trisil, Quibensil y Rekasil según el tamaño de sus partículas corresponden a una zeolita, a diferencia de Boldclay, con 72.62µ. Los resultados obtenidos en la confrontación in vitro, de los 6 aluminosilicatos comerciales, mostraron que sólo dos de ellos presentaron actividad adsorbente de aflatoxina B1. El porcentaje de esta actividad fue de 97.5 en Milbond y de 90 en Fusox. Después de la medición del pH se encontró que no existe relación entre la capacidad adsorbente de aflatoxina B1 y el pH del aluminosilicato