A peptide factor secreted by Staphylococcus pseudintermedius exhibits properties of both bacteriocins and virulence factors.

Staphylococcus pseudintermedius is a common commensal bacterium colonizing the skin and mucosal surfaces of household animals. However, it has recently emerged as a dangerous opportunistic pathogen, comparable to S. aureus for humans. The epidemiological situation is further complicated by the increasing number of methicillin-resistant S. pseudintermedius infections and evidence of gene transmission driving antibiotic resistance between staphylococci colonizing human and zoonotic hosts. In the present study, we describe a unique peptide, BacSp222, that possesses features characteristic of both bacteriocins and virulence factors. BacSp222 is secreted in high quantities by S. pseudintermedius strain 222 isolated from dog skin lesions. This linear, fifty-amino-acid highly cationic peptide is plasmid-encoded and does not exhibit significant sequence similarities to any other known peptides or proteins. BacSp222 kills gram-positive bacteria (at doses ranging from 0.1 to several micromol/l) but also demonstrates significant cytotoxic activities towards eukaryotic cells at slightly higher concentrations. Moreover, at nanomolar concentrations, the peptide also possesses modulatory properties, efficiently enhancing interferon gamma-induced nitric oxide release in murine macrophage-like cell lines. BacSp222 appears to be one of the first examples of multifunctional peptides that breaks the convention of splitting bacteriocins and virulence factors into two unrelated groups.

Effects of exposure to dietary chromium on tissue mineral contents in rats fed diets with fiber.

This study evaluated the effects of diets with fiber (cellulose and/or pectin) supplemented with chromium(III) on homeostasis of selected minerals in femurs, thigh muscles, livers, and kidneys of rats. For 6 weeks, male rats were fed experimental diets: a fiber-free diet (FF), a diet containing 5% cellulose (CEL), 5% pectin (PEC), or 2.5% cellulose and 2.5% pectin (CEL+PEC). These diets had 2.53 or 0.164 mg Cr/kg diet. The tissue levels of Ca, Mg, Zn, Fe, and Cr were determined by using atomic absorption spectrometry. Supplementing diets with Cr resulted in significantly higher Cr levels in the femurs of rats fed the CEL diet and significantly higher Cr and Fe levels in the rats fed the CEL+PEC diet compared to the rats fed FF diet. Muscle Ca content was significantly lower in the rats fed the CEL+PEC+Cr diet compared to the rats fed FF+Cr diet. The rats consuming the PEC+Cr diet had the highest liver Cr content. The highest kidney Zn content was observed in the rats fed diets containing Cr and one type of fiber. These results indicate that diets containing chromium at elevated dose and fiber have a significant effect on the mineral balance in rat tissues.

Effect of cellulose, pectin and chromium(III) on lipid and carbohydrate metabolism in rats.

The effects of cellulose, pectin and chromium(III) on lipid and carbohydrate metabolism were investigated in rats. Eighty male Buffalo rats (n=10/group, 4 weeks old) were fed experimental diets for 6 weeks. The two control groups received a fiber free diet (FF) or a fiber free diet plus chromium (FF+Cr) (2.53 mg Cr/kg diet). The other groups were fed diets containing 5% of cellulose (CEL), 5% of pectin (PEC) or 2.5% of cellulose plus 2.5% of pectin (CEL+PEC) with or without chromium. The daily food intake and body weight of the rats were not affected by the experimental diets. Total cholesterol level in plasma was significantly lower (p≤0.05) in the PEC group than the rats fed the FF diet. Feeding of rats with the PEC+Cr diet resulted in a significantly higher concentration of plasma HDL cholesterol (p≤0.05) when compared with the CEL+Cr group. No statistically significant differences in the concentrations of plasma triglycerides (TG) and non-esterified fatty acids (NEFA) between the groups were observed. Rats fed the CEL+Cr diet had a significantly lower content of cholesterol and rats fed the CEL+Cr diet lower contents of cholesterol and TG in the liver (p≤0.05) when compared with other groups. The concentration of HbA1c was significantly lower (p≤0.05) in rats fed the CEL and CEL+Cr diets than in other groups. A significantly lower concentration of plasma glucose (p≤0.05) was observed in rats receiving the CEL+PEC diet in comparison with the FF group. A significant effect of fiber and chromium combination was shown only in the case of triglyceride content in the liver of rats (p≤0.05). In conclusion, our results suggest that a diet containing fiber (PEC) and chromium or their supplements may be beneficial for correcting some disturbances of lipid metabolism, and a diet containing cellulose or its supplements may be used to improve glycemic control.

[The influence of deficient and excessive dietary energy supply on immune system functioning]. / Wplyw niedoborowej lub nadmiernej podazy energii z pozywieniem na funkcjonowanie ukladu odpornosciowego.

There is direct dependence between immune system functioning and nutritional value of food. Balanced diet satisfies energetic demand of body cells, including immune system cells which constitute nonspecific barrier and a specific defense against infection. Both too low and excessive energy supply in food have negative influence on cell-mediated and humoral immunity of the organism. The article deals with the influence of protein-energy malnutrition on immunity mechanisms mobility and immunity consequences of excessive dietary energy supply concurrent with obesity taking into consideration patient age groups.