Репозиторий Университета

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. In the context of a post-antibiotic era, the phenomenon of microbial allolysis, which is defined as the partial killing of bacterial population induced by other cells of the same species, may take on greater significance. This phenomenon was revealed in some bacterial species such as Streptococcus pneumoniae and Bacillus subtilis, and has been suspected to occur in some other species or genera, such as enterococci. The mechanisms of this phenomenon, as well as its role in the life of microbial populations still form part of ongoing research. Herein, we describe recent developments in allolysis in the context of its practical benefits as a form of cell death that may give rise to developing new strategies for manipulating the life and death of bacterial communities. We highlight how such findings may be viewed with importance and potential within the fields of medicine, biotechnology, and pharmacology.

© 2018. Conjugates of Streptococcus pneumoniae type 9N capsular polysaccharide with tetanus toxoid have been prepared. Their interactions with specific antibodies to tetanus toxoid and polysaccharide 9N were assessed, which permitted to select a conjugate with the optimal ratio of the polysaccharide and carrier protein (3:4). The parameters of the efficient adsorption of tetanus toxoid and polysaccharide on aluminum hydroxide for the following in vivo experiments were determined using the quantitative ELISA; in particular, the optimum ratio of the conjugate and adjuvant was proved be ≤ 1:1 (w/w). The repetitive immunization with the selected conjugate adsorbed on aluminum hydroxide increased the anti-PS antibody titers up to 70400 (p < 0,001) which is 140-fold higher as compared to the antigen unconjugated form. The investigation of the antibody protection from Streptococcus pneumoniae 9N after the intranasal challenge of wild-type mice revealed that the titer of the bacterial contamination in the immunized mouse lung tissue was 10-fold lower than that in non-immune mice 72 h after the contamination (p > 0,05).

© 2018 Tomsk National Research Medical Center of the Russian Academy of Sciences. All rights reserved. The purpose of the study was to present data on polymixin-based antibiotics with activity against infections caused by multidrug-resistant Gram-negative bacteria, such as Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Material and methods. The review includes data from clinical as well as in vitro studies for the period 1998–2017. The search for relevant sources was carried out in the Medline, Cochrane Library, Elibrary and other databases. Results. The analysis of the data showed the presence of synergism and additive activity of polymyxin in combination with carbapenems, rifampicin and azithromycin. However, experimental data showed no direct positive correlation between combination of polymyxim and azithromycin/ rifampicin. In clinical studies, in hospital-acquired pneumonia, including ventilator-associated pneumonia, the clinical response rate of polymyxin B combined with other antibiotics ranged from 38 % to 88 %. High nephro- and neurotoxicity of polymyxin observed in previous studies can be explained by a lack of understanding of its toxicodynamics or the use of an incorrect dose. Conclusion. Polymyxin B in combination with other antibiotics is a promising treatment against infectious complications caused by multidrug resistant Gram-negative bacteria.

© 2018, SPb RAACI. The aim of this work was to study features of gene expression TLR2, TLR4, and TLR9 in the course of acute respiratory infection, depending on the time elapsing since the contamination, and dose of infection. The studies of in vivo models of acute respiratory infections caused by Gram-negative Klebsiella pneumoniae showed that, at infection dose of 104 CFU/ml, the TLR4 gene expression levels in epithelium of upper respiratory tract at 1, 3, 10 days were increased 30 times and more, complete elimination of the pathogen was observed at 3 days. At the dose of infection of 107 CFU/ml, persistence of the pathogen in upper respiratory tract was observed within a few days, accompanied by a significant increase in the level of TLR9 expression in epithelium of upper respiratory tract, and TLR4 levels in the lungs 1 day after infection, in parallel to elimination of the pathogen from the lower respiratory tract. Thus, the characteristic features of TLR4 and TLR9 gene expression in the upper respiratory tract may be considered a potential diagnostic and prognostic factors in evaluation of the course of acute respiratory infections caused by Klebsiella pneumoniae.