To determine whether incorporation of peptides into diets can improve larval development, sea bass (Dicentrarchus labrax) larvae were fed for 21 d one of three isonitrogenous, isoenergetic semipurified diets in which enzymatic hydrolysate (75% di- and tripeptides) of fish meal proteins was substituted for 0, 20 or 40% of native fish meal proteins. Growth and survival were significantly greater (P < 0.05) in larvae fed peptide diets compared to those fed only native protein, with the best performance exhibited by those fed the 20% level of peptides. Chymotrypsin activity was much higher in groups fed peptide diets compared to that fed all native protein (P < 0.001), indicating a greater proteolytic capacity of the pancreas. At the intestinal level, activities of the brush border enzymes, aminopeptidase, maltase and gamma-glutamyl transpeptidase, increased with age while the cytosolic enzyme, leu-ala peptidase, decreased with age (P < 0.001). These changes in enzymatic activities correspond to the normal development of intestinal digestion. This development occurred earlier in the group fed 20% peptide-substituted diet than in the two other groups. The better larval performances observed in groups fed diets containing peptides can be related to the enhanced proteolytic capacity of the pancreas and the earlier development of intestinal digestion.

The acute inflammatory response to interval exercise is intensity-dependent. Although obesity influences the basal concentrations of several cytokines, only HIIE induced important alterations in IL-8 and IL-10 levels, which may have important implications in the control of chronic low-grade inflammation in obesity.

A deep-sea, aerobic, mesophilic and heterotrophic new bacterium was isolated from a sample of fluid collected among a dense population of Riftia pachyptila, in the vicinity of an active hydrothermal vent of the Southern depression of the Guaymas basin (Gulf of California). On the basis of phenotypic and phylogenetic analyses and DNA/DNA relatedness, the strain GY785 was recognized as a new species of the genus Alteromonas and the name of Alteromonas infernus is proposed. During the stationary phase in batch cultures in the presence of glucose, this bacterium secreted two unusual polysaccharides. The water-soluble exopolysaccharide-1 produced contained glucose, galactose, galacturonic and glucuronic acids as monosaccharides. The gel-forming exopolysaccharide-2 was separated from the bacterial cells by dialysis against distilled water and partially characterized.

Despite the high number of victims of COVID-19, tuberculosis (TB) remains as the leading cause of death among infectious diseases worldwide. Since the beginning of the pandemic, there is an increasing number of studies trying to elucidate the interactions between Mycobacterium tuberculosis and SARS-CoV-2. The first case reports point to a worsening of respiratory symptoms in co-infected TB/COVID-19 individuals. However, data from the cohort studies has shown some conflicting results. This study proposes to conduct a systematic review on the current literature on TB/COVID-19 co-infection cohorts, evaluating clinical and epidemiological data, focusing on its implications to the immune system. From an immunological perspective, the TB/COVID-19 co-infection has the potential to generate a "perfect storm". The disorders induced by each pathogen to the immune modulation tend to induce an unbalanced inflammatory response, which can promote the progression and worsening of both diseases. Understanding the nature of the interactions between M. tuberculosis and SARS-CoV-2 will be crucial for the development of therapeutic strategies against co-infection.

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