Maria Jiménez-Valera | PubMed Health

PubMed2006

A selective differential medium for Lactobacillus plantarum.

The quantification of exogenous lactobacilli in faecal samples is frequently required for the evaluation of the intestinal colonization by probiotic bacteria. In this study, a selective and differential medium, designated LPSM, was developed for the culture of exogenous Lactobacillus plantarum. In quantitative assays, LPSM showed a sensitivity similar to those of enriched and Lactobacillus-adapted media. The presence of ciprofloxacin made LPSM inhibitory to most intestinal bacteria, including endogenous acid lactic bacteria, whereas exogenous L. plantarum strains grew producing a yellow color caused by acid production from sorbitol in the presence of bromocresol purple. The results showed that LPSM is suitable for detection and enumeration of L. plantarum in faecal samples.

Animals↗

PubMed2004

Lack of apoptosis in Listeria monocytogenes-infected thymocytes from mice fed with dietary lipids.

The potential action of certain fatty acids has been studied since the early 1970s. Numerous effects on immune system functions have been related to dietary lipid administration; therefore, several of them have been applied in the treatment of inflammatory disorders. Nevertheless, n-3 polyunsaturated fatty acids may affect host resistance to infectious diseases. In addition, several studies have demonstrated that certain fatty acids are involved in apoptosis induction. Here, we have examined the action of different dietary lipids on the promotion of apoptosis in thymocytes from mice fed with dietary lipids and infected with Listeria monocytogenes. Thus, L. monocytogenes promoted an important cytotoxic effect in all of the groups, but it did not increase the percentage of DNA fragmentation. Similarly, an important increase of caspase-3 activity was demonstrated in OO and FO groups, but infection with L. monocytogenes exerted an inhibitory effect. Finally, L. monocytogenes did not modify proteasome activity among groups fed with dietary lipids. On the basis of this preliminary study, we can state that the infection of thymocytes from mice fed with dietary lipids does not promote a synergistic effect in the induction of apoptosis. Hence, these results may partially serve to elucidate the immune mechanisms involved in cells from mice fed with dietary lipids in an infectious process.

Animals↗