The induction of natural competence adapts staphylococcal metabolism to infection.

A central question concerning natural competence is why orthologs of competence genes are conserved in non-competent bacterial species, suggesting they have a role other than in transformation. Here we show that competence induction in the human pathogen Staphylococcus aureus occurs in response to ROS and host defenses that compromise bacterial respiration during infection. Bacteria cope with reduced respiration by obtaining energy through fermentation instead. Since fermentation is energetically less efficient than respiration, the energy supply must be assured by increasing the glycolytic flux. The induction of natural competence increases the rate of glycolysis in bacteria that are unable to respire via upregulation of DNA- and glucose-uptake systems. A competent-defective mutant showed no such increase in glycolysis, which negatively affects its survival in both mouse and Galleria infection models. Natural competence foster genetic variability and provides S. aureus with additional nutritional and metabolic possibilities, allowing it to proliferate during infection.

Enhanced immunological response by dendritic cells in male hypogonadism.

BACKGROUND: The effect of male hypogonadism on the immune response is poorly understood, even though testosterone has both immunosuppressive and anti-inflammatory effects in men. DESIGN: In this study, we compared the distribution and functional status of peripheral blood (PB) monocytes, dendritic cells (DCs) [CD16(+) (monocytoid), CD33(+) (myeloid) and CD33(-) (plasmacytoid)] and CD4(+) CD25(+)CD127(-/lo) regulatory T cells from hypogonadic men and control subjects. Immunophenotypic studies were performed both on resting and in vitro-stimulated cells. RESULTS: Overall, no significant differences were detected on the number of monocytes, DCs and CD4(+) CD25(+) CD127(-/lo) regulatory T cells between both groups of subjects. However, hypogonadic men showed slightly higher numbers of circulating CD16(+) cells expressing the CD107b activation/degranulation-associated marker than controls, such differences reaching statistical significance after in vitro stimulation with CpG oligodeoxynucleotides. Interestingly, antigen-stimulated expression of CD107b on CD16(+) cells inversely correlated with the serum concentrations of total testosterone (r(2)=-0.45; P=0.01), free testosterone (r(2)=-0.48; P=0.005), calculated free testosterone (r(2)=-0.44; P=0.01) and bioavailable testosterone (r(2)=-0.46; P=0.008) among all cases studied, as well as with both the LH (r(2)=-0.53, P=0.04) and FSH (r(2)=-0.54, P=0.04) serum levels among hypogonadic men. CONCLUSIONS: These findings show an enhanced immunological response of circulating (activated) CD16(+) DCs to antigen stimulation, which was inversely related to testosterone and gonadotropin serum levels. Such findings suggest a modulation by the hypothalamic-hypophyseal-gonadal axis of the immune response and may have clinical implications for hypogonadic men, as regards susceptibility to autoimmune diseases and increased responses to antigenic stimuli.

[Trends in semen quality in a non-industrialized population from the Salamanca area, Spain, during the last 30 years]. / Evolución de la calidad seminal en una población no industrializada procedente de Salamanca durante los últimos treinta años.

BACKGROUND AND OBJECTIVE: The objective was to analyze the secular trend in semen quality over the past 30 years (1978-2007) in a population-based study in Salamanca, Western Spain. Information about this issue in non-industrialized areas of Southern Europe is lacking. SUBJECTS AND METHODS: We analyzed semen quality in 612 consecutive healthy normospermic subjects derived to our unit for andrologic evaluation. The study was performed at a single Centre and a single highly experienced technician made all analyses at the same laboratory. RESULTS: The age of the subjects at diagnosis increased, while the time interval of childless relationships before consultation decreased over time. Semen volume and sperm counts decreased while sperm motility increased over this period. Motile density per ejaculate showed a clearly decreasing trend. CONCLUSIONS: Our results demonstrate a decrease in semen quality over the last 30 years in the area of Salamanca in western Spain, suggesting that non-industrial-related factors may be involved in decreasing semen quality.

[Study of AZF regions of Y chromosome in males with idiopathic infertility. Analysis of two methods of molecular diagnosis]. / Estudio de las regiones AZF del cromosoma Y en varones con infertilidad idiopática. Comparación de dos métodos de diagnóstico molecular.

BACKGROUND AND OBJECTIVE: It is well known that both azoospermia and oligozoospermia are associated to microdeletions of single tagged sites (STS) in the long arm of the Y chromosome. Characterization of deletions is carried out by polymerase chain reaction, although the number and regions included in the analysis varies between laboratories. The aim of this study was to analyze the presence of chromosome Y microdeletions using 2 different sets of STSs. PATIENTS AND METHOD: We analysed the presence of microdeletions in the Yq chromosome in 30 patients with idiopathic male infertility, using 2 sets of STSs, those proposed by the European Molecular Genetics Quality Network (EMQN) as first choice and those of the Y Chromosome Deletion Detection System (Promega). RESULTS: AZF microdeletions were detected in 4 patients (13%). Only one case was detected simultaneously with both sets. CONCLUSION: In patients with idiopathic male infertility detection of AZF microdeletion in Y chromosome has important methodological problems. Further studies are needed to achieve a more reliable method to be used by clinical laboratories.