Efforts to describe toxins from the two major families of venomous snakes (Viperidae and Elapidae) usually reveal proteins belonging to few structural types, particular of each family. Here we carried on an effort to determine uncommon cDNAs that represent possible new toxins from Lachesis muta (Viperidae). In addition to nine classes of typical toxins, atypical molecules never observed in the hundreds of Viperidae snakes studied so far are highly expressed: a diverging C-type lectin that is related to Viperidae toxins but appears to be independently originated; an ohanin-like toxin, which would be the third member of the most recently described class of Elapidae toxins, related to human butyrophilin and B30.2 proteins; and a 3FTx-like toxin, a new member of the widely studied three-finger family of proteins, which includes major Elapidae neurotoxins and CD59 antigen. The presence of these common and uncommon molecules suggests that the repertoire of toxins could be more conserved between families than has been considered, and their features indicate a dynamic process of venom evolution through molecular mechanisms, such as multiple recruitments of important scaffolds and domain exchange between paralogs, always keeping a minimalist nature in most toxin structures in opposition to their nontoxin counterparts.

Streptococcus pneumoniae remains an important cause of disease with high mortality and morbidity, especially in children and in the elderly. The widespread use of the polysaccharide conjugate vaccines in some countries has led to a significant decrease in invasive disease caused by vaccine serotypes, but an increase in disease caused by non-vaccine serotypes has impacted on the overall efficacy of these vaccines on pneumococcal disease. The obvious solution to overcome such shortcomings would be the development of new formulations that provide serotype-independent immunity. This review focuses on the most promising approaches, including protein antigens, whole cell pneumococcal vaccines, and recombinant bacteria expressing pneumococcal antigens. The protective capacity of these vaccine candidates against the different stages of pneumococcal infection, including colonization, mucosal disease, and invasive disease in animal models is reviewed. Some of the human trials that have already been performed or that are currently ongoing are presented. Finally, the feasibility and the possible shortcomings of these candidates in relation to an ideal vaccine against pneumococcal infections are discussed.

a b s t r a c tThe role of TlyA, TlyB and TlyC proteins in the biology of Leptospira is still uncertain. Although these proteins have been considered as putative hemolysins, we demonstrate that leptospiral recombinant TlyB and TlyC do not possess hemolytic activity. However, further experiments showed that TlyC is a surface-exposed protein that seems to bind to laminin, collagen IV and fibronectin. The expression of both proteins was detected both in vitro and in vivo. Our findings suggest that TlyB and TlyC are not directly involved in hemolysis, and that TlyC may contribute to Leptospira binding to extracellular matrix (ECM) during host infection.