Streptococcus suis

Streptococcus suis is an important pathogen causing economic problems in the pig industry. Moreover, it is a zoonotic agent causing severe infections to people in close contact with infected pigs or pork-derived products. Although considered sporadic in the past, human S. suis infections have been reported during the last 45 years, with two large outbreaks recorded in China. In fact, the number of reported human cases has significantly increased in recent years. In this review, we present the worldwide distribution of serotypes and sequence types (STs), as determined by multilocus sequence typing, for pigs (between 2002 and 2013) and humans (between 1968 and 2013). The methods employed for S. suis identification and typing, the current epidemiological knowledge regarding serotypes and STs and the zoonotic potential of S. suis are discussed. Increased awareness of S. suis in both human and veterinary diagnostic laboratories and further establishment of typing methods will contribute to our knowledge of this pathogen, especially in regions where complete and/or recent data is lacking. More research is required to understand differences in virulence that occur among S. suis strains and if these differences can be associated with specific serotypes or STs

Insulin analogs: Assessment of insulin mitogenicity and IGF-I activity.

The metabolic activity of insulin has been studied extensively in vitro and in vivo, based on the initial assessment of insulin receptor affinity, followed by methods to estimate the metabolic activity in vitro. These estimates provide some guidance about the biological activity which will be found in vivo; they need to be confirmed and supplemented by testing the glucose-lowering activity in animals (mice, rats, dogs, pigs). The biological effects (hypoglycemic activity) are related to the direct activation of the insulin receptor and subsequent signaling through intracellular mechanisms. The second group of biological effects is related to cell proliferation (mitogenic activity), which may be mediated by the insulin receptor, by the IGF-I receptor, and by hybrids of the two receptors. The evaluation of the relevance of mitogenicity estimates may be performed in in vitro and in vivo. One approach is cell proliferation in benign and malignant cell lines, for example, on mammary epithelial cell lines MCF-10 and MCF-7 (Milazzo et al. 1997)