Молекулярно -эпидемиологическая характеристика стрептококков, выделенных у детей младшего школьного возраста во Вьетнаме

Objectives. The goal of the study was to isolate group A, С, and G streptococci from children and characterize them by the methods of molecular epidemiology.Materials and methods. Group A, С, and G streptococci were isolated from tonsils and back wall of pharynx of Vietnamese children during 2012–2014. сpn60 gene based PCR approach and rnpB gene sequencing were used to identify streptococcal species belonging to group С and G streptococci. The presence of scpA, lmb, nga, slo virulence genes was analyzed in S. anginosus and S. dysgalactiae subsp. equisimilis strainS. emm-typing of S. pyogenes was done as published (http://www.cdc.gov/ncidod/biotech/strep/MProteinGene_typing.htm). Antibiotic resistance of the strains was tested by the disk diffusion method.Results. A total of 1359 children were examined. Group A streptococci (S. pyogenes) were isolated from 49 children, group C streptococci – from 8 children (4 stains – S. anginosus, 1 strain – S. dysgalactiae subsp. equisimilis, 1 strain – S. parasanguinis, 1 strain – S. gordonii, 1 strain – S. constellatus), and group G streptococci – from 75 children (55 stains – S. anginosus, 8 stains – S. dysgalactiae subsp. equisimilis, 4 stains – S. sanguinis, 3 stains – S. parasanguinis, 2 stains – S. australis, 2 stains – S. constellatus, 1 stain – S. mitis). emm-typing of 47 S. pyogenes strains revealed 15 different emm-subtypes belonging to 11 different emm-typeS. The subtypes emm104.0 and emm109.1 were found to be predominant. S. anginosus strains under study were genetically heterogeneous for the presence of virulence genes. All tested strains were susceptible to cephalosporins and vancomycin, and resistant to amikacine. A total of 70% and 52,5% of S. pyogenes were resistant to tetracycline and erythromycin, respectively.Цель. Выделение стрептококков групп А, С, G у детей младшего школьного возраста и их характеристика с использованием методов молекулярной эпидемиологии.Материалы и методы. Изоляты стрептококков групп А, С и G выделяли с поверхности миндалин и задней стенки глотки у 1359 детей младшего школьного возраста во Вьетнаме в 2012–2014 гг. Видовую принадлежность стрептококков групп С и G выявляли с помощью экспресс-метода дифференциальной ПЦР-диагностики и секвенирования гена rnpB. Наличие генов вирулентности scpA, lmb, nga, slo у штаммов S. anginosus и S. dysgalactiae subsp. equisimilis анализировали с использованием ПЦР. emm-типирование штаммов S. pyogenes проводили согласно методике, опубликованной на сайте Centers for Disease Control and Prevention (http://www.cdc.gov/ncidod/biotech/strep/M-ProteinGene_typing. htm). Спектр антибиотикорезистентности штаммов определяли диско-диффузионным методом.Результаты. В результате микробиологического исследования материала с миндалин и задней стенки глотки были выделены и идентифицированы 49 штаммов стрептококков группы А (S. pyogenes), 8 штаммов стрептококков группы С (4 штамма – S. anginosus, по 1 штамму – S. dysgalactiae subsp. equisimilis, S. parasanguinis, S. gordonii, S. constellatus) и 75 штаммов стрептококков группы G (55 штаммов – S. anginosus, 8 штаммов – S. dysgalactiae subsp. equisimilis, 4 штамма – S. sanguinis, 3 штамма – S. parasanguinis, 2 – штамма S. australis, 2 штамма – S. constellatus, 1 штамм – S. mitis). Среди 47 штаммов S. pyogenes было выявлено 15 emm-подтипов, относящихся к 11 emm-типам. Доминирующими оказались редко встречающиеся генотипы emm104.0 и emm109.1. Выявлен геномный полиморфизм штаммов S. anginosus по наличию генов вирулентности. Все исследованные штаммы были чувствительны к цефалоспоринам и ванкомицину и устойчивы к амикацину. 70% штаммов S. pyogenes были устойчивы к тетрациклину и 52,5% – к эритромицину

Adducts of the Zinc Salt of Dinitramic Acid

Herein, we describe the synthesis of coordination compounds starting from carbohydrazide ((H2NHN)2C=O (CHZ)) and the Zn2+ salt of dinitramic acid (HDN), which are high-nitrogen substances that exhibit properties similar to those of a burning-rate inhibitor of pyrotechnic compositions. This study demonstrates that these compounds react with glyoxal to furnish adducts of metal–organic macrocyclic cages bearing the elements of carbohydrazide, complexing metals and the HDN anion, depending on the ratio of the starting reactants. The assembled macrocyclic cage has “host–guest” properties and is a safe container for the storage of HDN salts. X-ray crystallographic analysis of the resultant coordination compound, [Zn(chz)3(N(NO2)2)2]), indicated that the metal–ligand association occurs via the N and O atoms of carbohydrazide. The zinc salt of dinitramic acid, which is enclosed into adducts with a macrocycle, is thermally stable and insensitive to mechanical impacts. The complex zinc salt of dinitramide was shown herein to exhibit inhibitory activity towards the burning rate of pyrotechnic compositions

A New Approach for the Synthesis of 2,3,4а,6,7,8а,9,10-Octaaza-4,8-dioxo-3,4,4a,7,8,8а,9,9a,10,10а-decahydroanthracene and High-Energy Performance Characterization of Its Dinitramide Salt

A simple, one-pot regioselective method for the synthesis of a high-nitrogen tricycle, 2,3,4а,6,7,8а,9,10-octaaza-4,8-dioxo-3,4,4a,7,8,8а,9,9a,10,10а-decahydroanthracene, with a yield of 27% was developed on a starting urea basis as a result of studies focused on finding new, more efficient approaches to the synthesis of high-energy derivatives of dinitramic acid (DNA). This tricycle was further treated to furnish 2,3,4а,6,7,8а,9,10-octaaza-4,8-dioxo-3,4,4a,7,8,8а,9a,10а-octohydroanthracene-9,10-ion-bis(dinitramide). The resultant salt of dinitramic acid exhibited inhibitory properties towards the burning rate of pyrotechnic compositions, reducing it by 30%, and possessed good thermal stability due to a high decomposition temperature above 260 °C and a low sensitivity to mechanical stimuli. The structural features of the new tricycle-based dinitramide salt were characterized via 2D NMR spectroscopy and double-focusing sector mass spectrometry (DFS)

The molecular epidemiological characteristics of streptococci isolated from primary school children in Vietnam

Objectives. The goal of the study was to isolate group A, С, and G streptococci from children and characterize them by the methods of molecular epidemiology.Materials and methods. Group A, С, and G streptococci were isolated from tonsils and back wall of pharynx of Vietnamese children during 2012–2014. сpn60 gene based PCR approach and rnpB gene sequencing were used to identify streptococcal species belonging to group С and G streptococci. The presence of scpA, lmb, nga, slo virulence genes was analyzed in S. anginosus and S. dysgalactiae subsp. equisimilis strainS. emm-typing of S. pyogenes was done as published (http://www.cdc.gov/ncidod/biotech/strep/MProteinGene_typing.htm). Antibiotic resistance of the strains was tested by the disk diffusion method.Results. A total of 1359 children were examined. Group A streptococci (S. pyogenes) were isolated from 49 children, group C streptococci – from 8 children (4 stains – S. anginosus, 1 strain – S. dysgalactiae subsp. equisimilis, 1 strain – S. parasanguinis, 1 strain – S. gordonii, 1 strain – S. constellatus), and group G streptococci – from 75 children (55 stains – S. anginosus, 8 stains – S. dysgalactiae subsp. equisimilis, 4 stains – S. sanguinis, 3 stains – S. parasanguinis, 2 stains – S. australis, 2 stains – S. constellatus, 1 stain – S. mitis). emm-typing of 47 S. pyogenes strains revealed 15 different emm-subtypes belonging to 11 different emm-typeS. The subtypes emm104.0 and emm109.1 were found to be predominant. S. anginosus strains under study were genetically heterogeneous for the presence of virulence genes. All tested strains were susceptible to cephalosporins and vancomycin, and resistant to amikacine. A total of 70% and 52,5% of S. pyogenes were resistant to tetracycline and erythromycin, respectively

Synthesis of Nitro- and Acetyl Derivatives of 3,7,10-Trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane

Here, we report the study results of the nitration of 3,7,10-trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane (THAP) by different nitrating agents such as nitric acid, mixed nitric/sulfuric acids, nitric anhydride, and mixed concentrated nitric acid/acetic anhydride to furnish 3,7,10-trioxo-2-nitro-2,4,6,8,9,11-hexaaza[3.3.3]propellane and 3,7,10-trioxo-2,8-dinitro-2,4,6,8,9,11-hexaaza[3.3.3]propellane, whereas a lactam–lactim rearrangement was found to take place upon vigorous cooling to give 10-hydroxy-2,4,6,8,9,11-hexaazatricyclo[3.3.3.01,5]undec-9-ene-3,7-dione. The two competing reactions, lactam–lactim rearrangement, and nitration were found to take place. The acylation of 3,7,10-trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane was examined and the formation conditions of 2,6-di- and 2,6,9-triacetyl-substituted and 3,7,10-trioxo-2,4,6,8,9,11-hexaacetyl-2,4,6,8,9,11-hexaaza[3.3.3]propellane were established. The acetyl derivatives were found to be instable in an acidic medium and to undergo deacylation. The obtained findings correlate well with the quantum-chemical calculations