Streptococcus agalactiae (Group B Streptococcus, GBS) is a commensal of the digestive and genitourinary tracts of humans that emerged as the leading cause of bacterial neonatal infections in Europe and North America during the 1960s. Due to the lack of epidemiological and genomic data, the reasons for this emergence are unknown. Here we show by comparative genome analysis and phylogenetic reconstruction of 229 isolates that the rise of human GBS infections corresponds to the selection and worldwide dissemination of only a few clones. The parallel expansion of the clones is preceded by the insertion of integrative and conjugative elements conferring tetracycline resistance (TcR). Thus, we propose that the use of tetracycline from 1948 onwards led in humans to the complete replacement of a diverse GBS population by only few TcR clones particularly well adapted to their host, causing the observed emergence of GBS diseases in neonates.

(1) Background: Biomarkers of efficacy for subcutaneous immunotherapy (SCIT) on allergic rhinitis have not been evaluated in details. The present study aims to assess the relevance of measuring of sIgE, sIgG4 and IgE/IgG4 ratio during SCIT in patients with allergic rhinitis; (2) Methods: 20 patients, 13 men and 7 women aged 19 to 58 years, with clinically manifested seasonal and perennial allergic rhinitis were studied. At the initiation and in the end of the three-year course of SCIT serum allergen-specific IgE and IgG4 were measured with ImmunoCAP system. The sIgE/sIgG4 ratio was calculated as a biomarker for immunologic effectiveness; (3) Results: There was a significant increase of sIgG4 antibodies (p < 0.05), while at the end of SCIT for the sIgE levels no significant changes were seen (p > 0.05). Moreover, 90% of patients showed a decrease of the IgE/IgG4 ratio; (4) Conclusions: In most of treated patients with AR, SCIT with Bulgarian allergen products leads to clear immunological changes. After a 3-year of SCIT there is a significant increase in allergen specific IgG4 levels and both decrease of sIgE and IgE/IgG4 ratio. sIgE, sIgG4 and IgE/IgG4 ratio can be used as a substantial biomarker for predicting immunological effectiveness of SCIT.

Medical practice faces serious problems due to the constantly increasing bacterial poly-resistance to antibiotics, and the side effects of the latter, often including allergic and immunosuppressive reactions. One way to resolve this problem is the application of immunomodulators that increase resistance to bacterial and viral infections by stimulating non-specific immunity mechanisms. In the course of more than 20 years a number of oral immunomodulators have been developed and investigated in the NCIPD, Sofia: Respivax, Urostim and Dentavax which are widely and successfully applied in clinical practice for immunotherapy and immunomodulation. Data about the effects of polybacterial immunomodulators demonstrate a pronounced stimulation of phagocytosis, synthesis of secretory IgA, surfactant, interferon and a number of Th1 type of cytokines. Numerous investigations, including double-blind studies, have proved their efficacy in the prevention and treatment of non-specific respiratory, uro-genital and periodontal infections as well as in the complex therapy of AIDS. Based on this, polybacterial immunostimulators seem a very promising tool for immunotherapy and immunoprevention, allowing the modulation of immune responses in a most beneficial way.