6 research outputs found
Determination of Influence of the oil production factor on the Russian economy
The article describes the results of statistical analysis and forecasting of the oil market of the Russian Federation. An analysis of the dependence of monetary aggregates on factors of oil production, export and the price of oil has been conducted using three-factor mode
Natural antimicrobial peptide complexes in the fighting of antibiotic resistant biofilms: Calliphora vicina medicinal maggots
Biofilms, sedimented microbial communities embedded in a biopolymer matrix cause vast
majority of human bacterial infections and many severe complications such as chronic
inflammatory diseases and cancer. Biofilms' resistance to the host immunity and antibiotics
makes this kind of infection particularly intractable. Antimicrobial peptides (AMPs) are a ubiquitous
facet of innate immunity in animals. However, AMPs activity was studied mainly on
planktonic bacteria and little is known about their effects on biofilms. We studied structure
and anti-biofilm activity of AMP complex produced by the maggots of blowfly Calliphora
vicina living in environments extremely contaminated by biofilm-forming germs. The complex
exhibits strong cell killing and matrix destroying activity against human pathogenic antibiotic
resistant Escherichia coli, Staphylococcus aureus and Acinetobacter baumannii biofilms as
well as non-toxicity to human immune cells. The complex was found to contain AMPs from
defensin, cecropin, diptericin and proline-rich peptide families simultaneously expressed in
response to bacterial infection and encoded by hundreds mRNA isoforms. All the families
combine cell killing and matrix destruction mechanisms, but the ratio of these effects and
antibacterial activity spectrum are specific to each family. These molecules dramatically
extend the list of known anti-biofilm AMPs. However, pharmacological development of the
complex as a whole can provide significant advantages compared with a conventional onecomponent
approach. In particular, a similar level of activity against biofilm and planktonic
bacteria (MBEC/MIC ratio) provides the complex advantage over conventional antibiotics.
Available methods of the complex in situ and in vitro biosynthesis make this idea practicable.Russian Science Foundation, grant № 16-14-0004
Biofilm infections between Scylla and Charybdis: interplay of host antimicrobial peptides and antibiotics
Sergey Chernysh,* Natalia Gordya,* Dmitry Tulin, Andrey Yakovlev Laboratory of Insect Biopharmacology and Immunology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia *These authors contributed equally to this work Purpose: The aim of this study is to improve the anti-biofilm activity of antibiotics. We hypothesized that the antimicrobial peptide (AMP) complex of the host’s immune system can be used for this purpose and examined the assumption on model biofilms. Methods: FLIP7, the AMP complex of the blowfly Calliphora vicina containing a combination of defensins, cecropins, diptericins and proline-rich peptides was isolated from the hemolymph of bacteria-challenged maggots. The complex interaction with antibiotics of various classes was studied in biofilm and planktonic cultures of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii by the checkerboard method using trimethyl tetrazolium chloride cell viability and crystal violet biofilm eradication assays supplemented with microscopic analysis. Results: We found that FLIP7 demonstrated: high synergy (fractional inhibitory concentration index <0.25) with meropenem, amikacin, kanamycin, ampicillin, vancomycin and cefotaxime; synergy with clindamycin, erythromycin and chloramphenicol; additive interaction with oxacillin, tetracycline, ciprofloxacin and gentamicin; and no interaction with polymyxin B. The interaction in planktonic cell models was significantly weaker than in biofilms of the same strains. The analysis of the dose–effect curves pointed to persister cells as a likely target of FLIP7 synergistic effect. The biofilm eradication assay showed that the effect also caused total destruction of S. aureus and E. coli biofilm materials. The effect allowed reducing the effective anti-biofilm concentration of the antibiotic to a level well below the one clinically achievable (2–3 orders of magnitude in the case of meropenem, ampicillin, cefotaxime and oxacillin). Conclusion: FLIP7 is a highly efficient host antimicrobial system helping antibiotics to overcome biofilm barriers through persisters’ sensitization and biofilm material destruction. It is promising for the treatment of biofilm infections as an adjuvant of various small-molecule antibiotics. Keywords: insect antimicrobial peptides, antibiotics, synergy, biofilms, persisters, Calliphora vicin
Trends and patterns of the banking sector digitalization process
The article considers the experience of the leaders in the field of digital banking in the Russian Federation - Sberbank, Tinkoff Bank, and VTB Ban