Изучение видового разнообразия бактерий рода Bifidobacterium кишечной микрофлоры с использованием метода MALDI-TOF масс-спектрометрии

Background: The members of genus Bifidobacterium represent a significant part of intestinal microbiota in adults and predominate in infants. Species repertoire of the intestinal bifidobacteria is known to be subjected to major changes with age; however, many details of this process are still to be elucidated.Objective: Our aim was to study the diversity of intestinal bifidobacteria and changes of their qualitative and quantitative composition characteristics during the process of growing up using MALDI-TOF mass-spectrometric analysis of pure bacterial cultures.Methods: A cross-sectional study of bifidobacteria in the intestinal microbiota was performed in 93 healthy people of the ages from 1 month to 57 years. Strains were identified using Microflex LT MALDI-TOF MS, the confirmation was performed by 16S rRNA gene fragment sequencing.Results: 93% of isolated bifidobacterial strains were successfully identified using MALDI-TOF mass-spectrometry. At least two of the strains from each species were additionally identified by 16S rRNA gene fragment sequencing, in all of the cases the results were the same. It was shown that the total concentration of bifidobacteria decreases with age (p 0.001) as well as the frequency of isolation of Bifidobacterium bifidum (p =0.020) and Bifidobacterium breve (p 0.001), and the frequency of isolation of Bifidobacterium adolescentis, increases (p 0.001), representing the continuous process of transformation of microbiota.Conclusion: The method of MALDI-TOF mass spectrometry demonstrated the ability to perform rapid and reliable identification of bifidobacteria that allowed the study of changes in the quantitative and qualitative characteristics of human microbiota in the process of growing up.Представители рода Bifidobacterium представляют значительную часть микрофлоры кишечника взрослых людей и численно доминируют в микрофлоре младенцев. Известно, что видовой состав кишечных бифидобактерий подвергается сильным изменениям с возрастом, однако многие детали этого процесса остаются неясными.Цель исследования: изучить видовое разнообразие бифидобактерий кишечника и изменения их качественного и количественного состава в процессе взросления человека при помощи технологии MALDI-TOF масс-спектрометрического анализа белковых профилей чистых культур.Методы: кросс-секционное исследование разнообразия бифидобактерий в составе нормальной микрофлоры кишечника проведено у 93 человек в возрасте от 1 мес до 57 лет. Осуществляли выделе- ние чистых культур и их идентификацию на приборе Microflex LT MALDI-TOF MS (Bruker Daltonics, Германия), подтверждение реализовывали с использованием секвенирования фрагмента гена 16S рРНК.Результаты: с применением MALDI-TOF масс-спектрометрии было успешно идентифицировано 93% выделенных штаммов бифидобактерий. Минимум по 2 представителя от каждого из видов были дополнительно определены методом секвенирования фрагмента гена 16SрРНК; во всех случаях результаты методов совпали. Показано, что с возрастом происходит снижение общей концентрации бифидобактерий (p 0,001), уменьшается встречаемость видов Bifidobacterium bifidum (p =0,020) и Bifidobacterium breve (p 0,001), а встречаемость вида Bifidobacterium adolescentis увеличивается (p 0,001), отражая постепенные процессы перестройки микрофлоры.Заключение: метод MALDI-TOF масс-спектрометрии показал возможность быстрой и надежной идентификации бифидобактерий, позволившей провести исследование изменений количественных и качественных показателей микрофлоры человека в процессе взрослени

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Noncontiguous finished genome sequence of Megasphaera sp. ASD88, isolated from faeces of a child with autism spectrum disorder

We report here a draft genome sequence of Megasphaera sp. ASD88, a strain from the intestinal microbiota of a child with autism spectrum disorder, representing a previously undescribed species of the genus Megasphaera. The assembled sequence consists of 88 scaffolds, and the total size is 2.59 Mb. Keywords: Autism spectrum disorder, Gut microbiota, Megasphaera, Negativicutes, Novel species, Taxonogenomic

Prevotella rara sp. nov., isolated from human faeces

A strain of obligately anaerobic, Gram-stain-negative rods was isolated from human faeces and characterized both phenotypically and genotypically. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences revealed the strain to represent a member of the genus Prevotella, distant from the species with validly published names, with the closest relationship to Prevotella oryzae. The strain was moderately saccharolytic and proteolytic. The predominant menaquinones were MK-13 and MK-12. The major cellular long-chain fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The genomic DNA G+C content was 45.7 mol%. On the basis of chemotaxonomic and genotypic properties, it was concluded that the strain represent a novel species within the genus Prevotella, for which the name Prevotellarara sp. nov. is proposed. The type strain of Prevotellarara is 109T (=VKM B-2992T=DSM 105141T)

Diplocloster agilis gen. nov., sp. nov. and Diplocloster modestus sp. nov., two novel anaerobic fermentative members of Lachnospiraceae isolated from human faeces

Three novel strains of Gram-stain-negative, obligately anaerobic, spore-forming straight or slightly curved rods with pointed ends occurring singly or in pairs were isolated from the faeces of healthy human children. The strains were characterized by mesophilic fermentative metabolism and production of acetate, ethanol and H2 as the end metabolic products. Strains ASD3451 and ASD5720T were motile, fermented lactose and raffinose, and weakly fermented maltose. Strain ASD4241T was non-motile and did not ferment the carbohydrates listed above but fermented starch. Strains ASD3451 and ASD5720T shared average nucleotide identity higher than 98.5% with each other, while ASD4241T had only 88.5-89% identity to them. Based on phylogenetic and chemotaxonomic analyses, we propose Diplocloster agilis gen. nov., sp. nov. (ASD5720T=JCM 34353T=VKM B-3497T) and Diplocloster modestus sp. nov. (ASD4241T=JCM 34351T=VKM B-3498T) within the family Lachnospiraceae. © 2022 The Authors

An idealised experimental model of ocean surface wave transmission by an ice floe

An experimental model of transmission of ocean waves by an ice floe is presented. Thin plastic plates with different material properties and thicknesses are used to model the floe. Regular incident waves with different periods and steepnesses are used, ranging from gently-sloping to storm-like conditions. A wave gauge is used to measure the water surface elevation in the lee of the floe. The depth of wave overwash on the floe is measured by a gauge in the centre of the floe's upper surface. Results show transmitted waves are regular for gently-sloping incident waves but irregular for storm-like incident waves. The proportion of the incident wave transmitted is shown to decrease as incident wave steepness increases, and to be at its minimum for an incident wavelength equal to the floe length. Further, a trend is noted for transmission to decrease as the mean wave height in the overwash region increases