Safety, beneficial and technological properties of Enterococcus faecium isolated from Brazilian cheeses

This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens. Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results.

Potential Correlation between Carboxylic Acid Metabolites in Biomphalaria alexandrina Snails after Exposure to Schistosoma mansoni Infection

Carboxylic acids play an important role in both aerobic and anaerobic metabolic pathways of both the snail and the parasite. Monitoring the effects of infection by schistosome on Biomphalaria alexandrina carboxylic acids metabolic profiles represents a promising additional source of information about the state of metabolic system. We separated and quantified pyruvic, fumaric, malic, oxalic, and acetic acids using ion-suppression reversed-phase high performance liquid chromatography (HPLC) to detect correlations between these acids in both hemolymph and digestive gland gonad complex (DGG's) samples in a total of 300 B. alexandrina snails (150 infected and 150 controls) at different stages of infection. The results showed that the majority of metabolite pairs did not show significant correlations. However, some high correlations were found between the studied acids within the control group but not in other groups. More striking was the existence of reversed correlations between the same acids at different stages of infection. Some possible explanations of the underlying mechanisms were discussed. Ultimately, however, further data are required for resolving the responsible regulatory events. These findings highlight the potential of metabolomics as a novel approach for fundamental investigations of host-pathogen interactions as well as disease surveillance and control.

Morphology, histology and histochemistry of the digestive system of South American Catfish (Rhamdia quelen) / Morfología, histología e histoquímica del tubo digestivo del Bagre Sudamericano (Rhamdia quelen)

The purpose of the present work was the anatomical, histo logical and histochemical description oí Rhamdia quelen juvenile digestive system. Samples of gut were fixed, dehydrated and included in paraffin and then stained with haematoxylin and eosin. For the identification and differentiation of mucosubstances the preparations were treated with Periodic Acid Schiff, Alcian Blue pH 0,4 and 2,5 andPAS/AB pH 2,5. Anatomical details of the oesophagus were like a short tube with primary and secondary mucous folds. The stratified epithelium is composed of three cellular types: small cells, abundant goblet cells with acid and neutral mucosubstances (MS) and large acid cells. The stomach is J-shaped and its mucosa presents broad and deep folds in relaxing state. Histologically, the stomach shows three different regions: cardiac, fundic and pyloric region. The luminal surface of the epithelium consists of a layer of secretory columnar cells of neutral MS. Tubuloacinar glands were surrounded by connective and muscular smooth fibers bundle. The intestine extends from the stomach until the anus, and four different sections can be distinguished: ascending, descending, convoluta and terminal straight. It was identified a simple columnar epithelium mainly composed by two cellular types: absorptive cell and goblet cell neutral MS secretory. On the basis of the anatomical and histo logical study carried out, we conclude that R. quelen presents an alimentary canal compatible with species that possess omnivorous nutritious habits.

El propósito del presente trabajo fue realizar las descripciones anatómica, histológica e histoqufmica del sistema digestivo de Rhamdia quelen jóvenes. Las muestras de intestino fueron fijadas, deshidratadas e incluidas en parafina y posteriormente teñidas con hematoxilina y eosina. Para la identificación y diferenciación de muco substancias los preparados fueron tratados con ácido periódico de Schiff, Azul Alcian pH 0,4 y 2,5 y PAS/AB pH 2,5. Los detalles anatómicos del esófago mostraron un pequeño tubo con pliegues mucosos primarios y secundarios. El epitelio estratificado presentaba tres tipos celulares: células pequeñas, abundantes células caliciformes con muco substancia (MS) acida y neutra y células grandes acidas. El estómago tenía forma de J y su mucosa presenta pliegues amplios y profundos en estado de relajación. Histológicamente, el estómago mostraba tres diferentes regiones: cardiaca, fúndica y pilórica. La superficie luminal del epitelio constaba de una capa de células columnares secretoras de MS neutro. Glándulas tubuloacinares estaban rodeadas por tejido conjuntivo y fibras musculares lisas. El intestino se extendía desde el estómago hasta el ano, y cuatro diferentes secciones era posible distinguir: ascendente, descendente, convoluta y terminal recta. Se identificó un epitelio columnar simple, compuesto principalmente por dos tipos celulares: células de absorción y células caliciformes secretoras de MS neutra. Sobre la base de los estudios anatómico e histológico realizados, se concluye que R. quelen presenta un canal alimentario compatible con las especies que poseen hábitos nutritivos omnívoros.