3D Structure of the Tail Complex of E. coli Bacteriophage DT57C

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Molecular analyses of fecal bacteria and hydrodynamic modeling for microbial risk assessment of a drinking water source

Safe water is a global concern, and methods to accurately monitor quality of water are vital. To assess the risks related to bacterial pathogen load in Lake Vomb that provides drinking water to the southern part of Sweden, this study combined molecular analyses of enterobacteria and bacterial pathogens in water using quantitiative real-time PCR with hydrodynamic modeling and quantitative microbial risk assessment (QMRA). A real-time PCR assay to detect enterobacteria was set up by primers targeting ssrA. Between February 2015 and May 2016, presence of ssrA gene copies as well as Campylobacter spp., Salmonella spp., and EHEC O157 DNA was analyzed by real-time PCR at several locations in the catchment of Lake Vomb and its tributaries Bjorkaan, Borstbacken, and Torpsbacken. Bjorkaan had the highest detected concentrations of the ssrA gene and, according to the results of hydrodynamic modeling, contributed most to the contamination of the water intake in the lake. None of the water samples were positive for genes encoding EHEC O157 and Campylobacter spp., while invA (Salmonella spp.) was present in 11 samples. The QMRA showed that the suggested acceptable risk level (daily probability of infection <2.7 x 10-7) is achieved with a 95% probability, if the Salmonella concentrations in the water intake are below 101 bacteria/100 mL. If a UV-disinfection step is installed, the Salmonella concentration at the water intake should not exceed 106 bacteria/100 mL

Abstract P-45: Structure of the Bacteriophage AR9 Bacillus Subtilis Chaperonin According to Cryo-Electron Microscopy

Background: Chaperonins are a family of molecular chaperones Hsp60 (heat shock proteins 60). GroEL is a bacterial chaperonin. It ensures the correct folding of proteins, using the energy of ATP hydrolysis. Three-dimensional reconstructions of its predicted orthologs were obtained and biochemically characterized in free and nucleotide-bound states for bacteriophages EL Pseudomonas aeruginosa, OBP Pseudomonas fluorescens (Kurochkina, L. P. et al., Journal of virology, 2012; Semenyuk, P. I. et al., Biochemical Journal, 2016; Stanishneva-Konovalova, T. B. et al., Journal of Structural Biology, 2020). Physicochemical studies were carried out for the bacteriophage AR9 Bacillus Subtilis and confirmed that the protein has chaperone activity and does not require co-chaperonin to function (Semenyuk P. I. et al., International Journal of Biological Macromolecules, 2020). Methods: The recombinant chaperonin of the B. subtilis bacterial phage AR9 (gp228) was isolated and purified in a free state and vitrified in Vitrobot Mark IV. Data were collected using a Titan Krios cryo-TEM and processed in Warp, RELION and cryoSPARC software. Results: The final structures of the chaperonin were reconstructed with a C1 and C7 symmetry at the resolution of 4.5 Å and 4.0 Å respectively. Significant heterogeneity of the apical domains was addressed further using 3D classification and symmetry expansion in RELION resulting in a set of classes reflecting the conformational transition of the subunits between different states. At least four different conformational states of the subunit were clearly resolved. Conclusion: Gp228 structure show similarities between bacteriophage chaperonin and also bacterial chaperonin GroEL. It is formed by a single ring consisting of seven identical subunits, each has three domains: equatorial, intermediate, and apical. The subunits of the apo-form chaperonin Gp228 exhibit significant conformational flexibility in the apical and intermediate domains

Opisthorchis felineus infection, risks, and morbidity in rural Western Siberia, Russian Federation

The liver fluke, Opisthorchis felineus, is widely distributed throughout Europe and large parts of the Russian Federation. In Western Siberia, information about opisthorchiasis is lacking although infection may lead to severe liver and bile duct diseases. We aimed to assess the current prevalence of O. felineus infection along with associated risk factors and morbidity in rural Western Siberia.; We conducted a community-based, cross-sectional study in the rural Shegarskiy district, Tomsk Oblast, Russian Federation. All household members (≥ 7 years) present on the survey day were enrolled (n = 600). Two stool samples per person were examined for helminth eggs, using PARASEP (DiaSys Ltd, UK). The number of eggs per gram (EPG) of feces was recorded. Each study participant was interviewed to determine risk factors, using a pre-tested questionnaire. An abdominal ultrasonography examination of liver and bile ducts was performed with a mobile, high resolution ultrasound device. In total, 488 persons completed assessments (two stool samples, completed questionnaires); of those, 436 individuals had an ultrasonography (US) examination.; We observed a prevalence of O. felineus infection of 60.2%. Significant risk factors for infection were the consumption of river fish (odds ratio from adjusted analysis [aOR] 2.4, 95% CI 1.52-3.95, p<0.001), particularly stock fish (OR from multivariable analysis [mOR] 3.2, 95% CI 2.63-3.80, p<0.001), smoked fish (mOR 1.5, 95% CI 1.24-1.72, p<0.001), frozen fish (mOR 1.6, 95% CI 1.29-2.02, p<0.001), and raw fish (mOR 1.4, 95% CI 1.05-1.84, p = 0.02); and fishing activities (mOR 1.2, 95% CI 1.03-1.43, p = 0.019). Women had a higher risk of infection than men. Infection was associated positively with age and negatively with socio-economic status. The respondents' general awareness of opisthorchiasis was quite high (93.2%), but their knowledge about infection transmission and prevention was insufficient. Children aged 7-18 years old had a lower level of awareness compared to adults. The abdominal ultrasonography results demonstrated a strong association between O. felineus infection and gallbladder stones (mOR 2.8, 95% CI 1.33-6.04, p = 0.007) and periductal fibrosis of intrahepatic bile ducts (mOR 1.9, 95% CI 1.08-3.46, p = 0.026).; O. felineus infection is highly prevalent in rural regions of Western Siberia, and associated with severe hepatobiliary pathology. Identified risk factors will be used to develop a comprehensive targeted O. felineus infection control program

Difficulties in diagnosing intestinal T-cell lymphoma. Case report

The article describes a rare diagnosis of monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), due to its veiled by a number of so-called masks of enteropathies. A detailed analysis of all clinical, morphological and immunohistochemical data made it possible to establish the correct diagnosis. The revealed pathology is extremely rare in practice, even among specialists in hematology. The article demonstrates the main stages of both a complex diagnosis and an attempt at therapy for this aggressive form of intestinal lymphoma

Abstract P-41: Contribution of Matrix-bound Vesicles Produced by Mesenchymal Stromal Cells in the Differentiation of Multipotent Stem Cells in vitro

Background: According to the current view on the extracellular matrix (ECM) composition and functions, it includes not only structural proteins and components of cell adhesion, but also various deposited components, including enzymes involved in ECM remodeling, growth factors, and matrix-bound vesicles (MBV). MBV can presumably participate in the formation of a specific microenvironment for stem cells and regulate their differentiation. However, the contribution of MBV to these processes remains poorly understood. In our work, we evaluated the effects of MBV within native ECM produced by mesenchymal stromal cells (MSCs) cultured in cell sheet on multipotent stem cell differentiation. Methods: We isolated MBV from decellularized MSC-produced ECM by treatment with the following enzymes: collagenase, hyaluronidase, or trypsin, and centrifugation on 1000 kDa filters. The nanostructure and relative size in each sample were observed using TEM. The particle size and concentration were also studied with NTA. In addition, the obtained MBV were examined for the presence of key exosome markers using Western blot. Then we investigated the effect of MBV on the formation of capillary-like structures by endothelial cells (in vitro model of angiogenesis) as well as on the differentiation of primary MSCs isolated from human adipose tissue in the adipogenic, osteogenic, and chondrogenic directions. Results: As a result of comparative analysis of isolation protocols, it was shown that all MBV samples had the characteristics of extracellular vesicles (EV), but differed in size and representation of exosomal markers. The MBV isolated from ECM did not stimulate the formation of capillary-like structures by endothelial cells, in contrast to EV secreted by MSCs to the conditioned medium, but maintained the viability of the endothelium. Isolated MBV stimulated osteogenic and adipogenic differentiation of MSCs similar to secreted EV. On the other hand, preincubation of MSCs with MBV leads to reorganization of cell monolayer to spheroid-like structures during chondrogenic differentiation. Conclusion: Here, we developed the protocol of isolation of MBV from ECM that have distinguished characteristics and functional activity

Physical Rehabilitation Needs in the BRICS Nations from 1990 to 2017: Cross-National Analyses Using Data from the Global Burden of Disease Study

Background: This study analyzes the current and evolving physical rehabilitation needs of BRICS nations (Brazil, Russian Federation, India, China, South Africa), a coalition of large emergent economies increasingly important for global health. Methods: Secondary, cross-national analyses of data on Years Lived with Disability (YLDs) were extracted from the Global Burden of Disease Study 2017. Total physical rehabilitation needs, and those stratified per major condition groups are analyzed for the year 2017 (current needs), and for every year since 1990 (evolution over time). ANOVAs are used to detect significant yearly changes. Results: Total physical rehabilitation needs have increased significantly from 1990 to 2017 in each of the BRICS nations, in every metric analyzed (YLD Counts, YLDs per 100,000 people, and percentage of YLDs relevant to physical rehabilitation; all p < 0.01). Musculoskeletal & pain conditions were leading cause of physical rehabilitation needs across the BRICS nations but to varying degrees: from 36% in South Africa to 60% in Brazil. Country-specific trends include: 25% of South African needs were from HIV-related conditions (no other BRICS nation had more than 1%); India had both absolute and relative growths of pediatric rehabilitation needs (p < 0.01); China had an exponential growth in the per-capita needs from neurological and neoplastic conditions (p < 0.01; r2 = 0.97); Brazil had a both absolute and relative growth of needs coming from musculoskeletal & pain conditions (p < 0.01); and the Russian Federation had the highest neurological rehabilitation needs per capita in 2017 (over than three times those of India, South Africa or Brazil). Conclusions: total physical rehabilitation needs have been increasing in each of the BRICS nations, both in absolute and relative values. Apart from the common growing trend, each of the BRICS nations had own patterns for the amount, typology, and evolution of their physical rehabilitation needs, which must be taken into account while planning for health and physical rehabilitation programs, policies and resources

ОЦЕНКА БАКТЕРИОЦИНОГЕННОСТИ ИНДИГЕННЫХ МОЛОЧНОКИСЛЫХ БАКТЕРИЙ, ПОЛУЧЕННЫХ С ТУШ КРУПНОГО РОГАТОГО СКОТА

Cattle carcasses of ritual slaughter (Halal) from the lateral and medial side were investigated in order to identify the indigenous strains of lactic acid microorganisms capable of producing bacteriocins. Only 14 strains, from 36 strains of microorganisms isolated from washings taken from carcasses, were used for further research and identified as lactabacilus. In the study of their bacteriocinogenicity by the method of two-layer agars of modified composition, high inhibitory efficiency was proved with respect to the growth of the pathogen Salmonella typhimurium, only 6 isolated strains of lactabacilus. The use of this method of evaluation will not only reveal the presence of the ability of the lactabacilus to produce bacteriocins, but also to study their antagonistic activity against many of the studied microorganisms, which are indicators of compliance with various modes of technological processes. The presence of such microorganisms in the meat will increase the shelf life of meat, due to the suppression of the growth of closely related lactabacilus, some of which are spoilage microorganisms, as well as the growth of opportunistic and pathogenic microflora. In addition, the use of lactabacilus with bacteriocinogenicity in the production technology of raw sausages will reduce the risk of production of unsafe products. Thus, the presence of indigenous lactabacilus in meat is an additional factor that ensures the flow of desired biochemical processes and the safety of raw smoked sausages.ContributionAll authors bear responsibility for the work and presented data. All authors made an equal contribution to the work. Dagmara S. Bataeva developed scientific and methodological approaches to work, determined the scope of research, analyzed the data obtained, performed the narrative and corrected it after submitting to the editorial office. Olga V. Sokolova conducted a review and analysis of the literature, carried out the descriptive part Elena V. Zaiko selected research objects, carried out microbiological analysis. Victoria V. Pashkova carried out preparatory work and microbiological analysis. The authors were equally involved in writing the manuscript and bear the equal responsibility for plagiarism.Conflict of interestThe authors declare no conflict of interest.Исследованы туши крупного рогатого скота ритуального убоя (халяль) с латеральной и медиальной стороны с целью выявления индигенных штаммов молочнокислых микроорганизмов, способных продуцировать бактериоцины. Из 36 штаммов микроорганизмов, выделенных из смывов, отобранных с туш, только 14 были использованы для дальнейшего исследования и идентифицированы как молочнокислые бактерии (МКБ). При изучении их бактериоциногенности по методике двухслойных агаров модифицированного состава, была доказана высокая ингибирующая эффективность в отношении роста патогенного микроорганизма Salmonella typhimurium, только 6 выделенных штаммов молочнокислых бактерий. Использование данного метода оценки позволит не только выявить наличие способности МКБ продуцировать бактериоцины, но и изучить их антагонистическую активность в отношении многих изучаемых микроорганизмов, которые являются индикаторами соблюдения различных режимов технологических процессов. Наличие таких микроорганизмов в мясе позволит увеличить срок хранения мяса, за счет подавления роста близкородственных лактобацилл, некоторые из которых являются микроорганизмами порчи, а также рост условно-патогенной и патогенной микрофлоры. Кроме этого, применение молочнокислых бактерий, обладающих бактериоциногенностью, в технологии производства сырокопченых колбас позволит снизить риск производства небезопасной продукции. Таким образом, наличие в мясе индигенных МКБ является дополнительным фактором, обеспечивающим протекание желательных биохимических процессов и безопасность сырокопченых колбас.Критерии авторстваОтветственность за работу и  предоставленные сведения несут все авторы. Все авторы в равной степени участвовали в этой работе. Батаева Д.С. разрабатывала научно-методические подходы к проведению работ, определяла объем исследований, анализировала полученные данные, выполняла описательную часть статьи и корректировала после подачи в редакцию Соколова О.В. проводила обзор и анализ литературы, выполняла описательную часть Зайко Е.В. отбирала объекты исследования, выполняла микробиологический анализ. Пашкова В.В. выполняла подготовительные работы, микробиологические исследования. Авторы в равных долях имеют отношение к написанию рукописи и одинаково несут ответственность за плагиат.Конфликт интересовАвторы заявляют об отсутствии конфликта интересов

Novel inter-subunit contacts in Barley Stripe Mosaic Virus revealed by Cryo-Electron Microscopy

Barley stripe mosaic virus (BSMV, genus Hordeivirus) is a rod-shaped single-stranded RNA virus similar to viruses of the structurally characterized and well-studied genus Tobamovirus. Here we report the first high-resolution structure of BSMV at 4.1 Å obtained by cryo-electron microscopy. We discovered that BSMV forms two types of virion that differ in the number of coat protein (CP) subunits per turn and interactions between the CP subunits. While BSMV and tobacco mosaic virus CP subunits have a similar fold and interact with RNA using conserved residues, the axial contacts between the CP of these two viral groups are considerably different. BSMV CP subunits lack substantial axial contacts and are held together by a previously unobserved lateral contact formed at the virion surface via an interacting loop, which protrudes from the CP hydrophobic core to the adjacent CP subunit. These data provide an insight into diversity in structural organization of helical viruses