98 research outputs found

    Результаты изучения палеодегазации неогена и перспективы нефтегазоносности Юго-Западного Крыма

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    Склад флюїдів з Гераклітiв принципово не відрізняється від складу газів із сучасних зон струминного виділення в Чорному морі, що є підтвердженням їх генетичного споріднення. Дані аналізів вказують на різкі коливання змістів і непостійний склад газових флюїдів палеодегазаціі в неогені. Наявність газів вуглеводнів та слідів нафти в Гераклітах, тектонічна будова регіону дозволяють зробити висновок про високі перспективи знаходження родовищ нафти і газу в Південно-Західному Криму.The composition of fluids from Heraclitus has no fundamental differences from the gas composition from the modern jet ejections zones in the Black Sea, which is a confirmation of their genetic relatedness. Data of analysis show sharp fluctuations of the contents and unstable structure of gas fluids paleo degassing of Neogene. The presence of hydrocarbon gases and traces of oil in Heraclitus, the tectonic structure of the region allow to conclude high prospects of finding oil and gas in the South-West Crimea

    Distinguishing blaKPC -gene-containing IncF plasmids from epidemiologically related and unrelated Enterobacteriaceae based on short- and long-read sequence data

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    BACKGROUND: Limited information is available on whether blaKPC -containing plasmids from isolates in a hospital outbreak can be differentiated from epidemiologically unrelated blaKPC-containing plasmids based on sequence data. This study aimed to evaluate the performance of three approaches to distinguish epidemiologically related from unrelated blaKPC-containing pKpQiL-like IncFII(k2)-IncFIB(pQiL) plasmids. METHOD: Epidemiologically related isolates, were short- and long-read whole genome sequenced. A hybrid assembly was performed and plasmid sequences were extracted from the assembly graph. Epidemiologically unrelated plasmid sequences were extracted from the GenBank. Pairwise comparisons were performed of epidemiologically related and unrelated plasmids based on SNP differences using snippy, phylogenetic distance using Roary and using a similarity index that penalizes size differences between plasmids (Stoesser-index). The percentage of pairwise comparisons misclassified as genetically related or as clonally unrelated was determined using different genetic thresholds for genetic relatedness. RESULTS: The ranges in number of SNP differences, Roary phylogenetic distance, and Stoesser-index overlapped between the epidemiologically related and unrelated plasmids. When using a genetic similarity threshold that classified 100% of epidemiologically related plasmid pairs as genetically related, the percentages of plasmids misclassified as epidemiologically related ranged from 6.7% (Roary) to 20.8% (Stoesser-index). DISCUSSION: Although epidemiologically related plasmids can be distinguished from unrelated plasmids based on genetic differences, blaKPC-containing pKpQiL-like IncFII(k2)-IncFIB(pQiL) plasmids show a high degree of sequence similarity. The phylogenetic distance as determined using Roary showed the highest degree of discriminatory power between the epidemiologically related and unrelated plasmids

    Development of amoxicillin resistance in Escherichia coli after exposure to remnants of a non-related phagemid-containing E. coli:an exploratory study

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    OBJECTIVE: To determine the effect of exposure to remnants of a phagemid-containing E. coli, killed by treatment with a propanol-based hand rub, on antimicrobial resistance in E. coli isolates. METHODS: An in vitro model was developed in which a clinical E. coli isolate (EUR1) was exposed to remnants of an E. coli K-12 strain containing a phagemid (pBS-E12) strain treated with Sterillium®. A series of 200 experiments was performed using this in vitro model. As a control, a series of 400 experiments was performed where the EUR1 was exposed either to the remnants of an E. coli K-12 strain (not containing a phagemid) (E12) treated with Sterillium® (n = 200) or to dried Sterillium® only (n = 200). The number of experiments that showed growth of an amoxicillin-resistant EUR1 isolate was evaluated in all three groups. An additional 48 experiments were performed in which a different clinical E. coli isolate (EUR2) was exposed to remnants of the pBS-E12 treated with Sterillium®. Whole-genome sequencing and phenotypic testing for AmpC beta-lactamase production was performed to investigate the mechanism behind this resistance development. RESULTS: In 22 (11.0%) of 200 experiments in which the EUR1 isolate was exposed to remnants of a pBS-E12 an amoxicillin-resistant mutant isolate was obtained, as opposed to only 2 (1.0%) of 200 experiments involving the exposure of the EUR1 to Sterillium® only (risk difference: 10.0%; 95% CI 5.4-14.6%)) and 1 (0.5%) of 200 experiments involving the exposure of the EUR1 isolate to the remnants of the phagemid-free E12 (risk difference: 10.5%; 95% CI 6.1-14.9%). In 1 (2.1%) of the 48 experiments in which the EUR2 isolate was exposed to remnants of a pBS-E12 an amoxicillin-resistant mutant isolate was obtained. The development of resistance in all experiments was due to mutations in the promoter/attenuator region of the chromosomal AmpC beta-lactamase (cAmpC) gene leading to cAmpC hyperproduction. CONCLUSION: Exposure of an E. coli isolate to another phagemid-containing E. coli that was treated with propanol-based hand rub increased the development of amoxicillin resistance. Although phagemids are cloning vectors that are not present in clinical isolates, this finding may have implications for hand disinfection practices in healthcare facilities

    Detection of extended-spectrum beta-lactamase (ESBL) genes and plasmid replicons in Enterobacteriaceae using PlasmidSPAdes assembly of short-read sequence data

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    Knowledge of the epidemiology of plasmids is essential for understanding the evolution and spread of antimicrobial resistance. PlasmidSPAdes attempts to reconstruct plasmids using short-read sequence data. Accurate detection of extended-spectrum beta-lactamase (ESBL) genes and plasmid replicon genes is a prerequisite for the use of plasmid assembly tools to investigate the role of plasmids in the spread and evolution of ESBL production in Enterobacteriaceae. This study evaluated the performance of PlasmidSPAdes plasmid assembly for Enterobacteriaceae in terms of detection of ESBL-encoding genes, plasmid replicons and chromosomal wgMLST genes, and assessed the effect of k-mer size. Short-read sequence data for 59 ESBL-producing Enterobacteriaceae were assembled with PlasmidSPAdes using different k-mer sizes (21, 33, 55, 77, 99 and 127). For every k-mer size, the presence of ESBL genes, plasmid replicons and a selection of chromosomal wgMLST genes in the plasmid assembly was determined. Out of 241 plasmid replicons and 66 ESBL genes detected by whole-genome assembly, 213 plasmid replicons [88 %; 95 % confidence interval (CI): 83.9-91.9] and 43 ESBL genes (65 %; 95 % CI: 53.1-75.6) were detected in the plasmid assemblies obtained by PlasmidSPAdes. For most ESBL genes (83.3 %) and plasmid replicons (72.0 %), detection results did not differ between the k-mer sizes used in the plasmid assembly. No optimal k-mer size could be defined for the number of ESBL genes and plasmid replicons detected. For most isolates, the number of chromosomal wgMLST genes detected in the plasmid assemblies decreased with increasing k-mer size. Based on our findings, PlasmidSPAdes is not a suitable plasmid assembly tool for short-read sequence data for ESBL-encoding plasmids of Enterobacteriaceae

    Исследования гидравлических сопротивлений при движении в трубах золошлаковых тампонажно- закладочных суспензий

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    Експериментально досліджено залежність гідравлічного опору від швидкості руху та концентрації золошлакових суспензій при течії по трубах. Встановлена критична швидкість руху концентрованих гідросумішей.Dependence of hydraulic resistance is experimentally set from the rate of movement of ash-slag suspensions at a flow on pipes. The critical speed of motion of the concentrated slurries is set

    Гибридная интегральная схема для обработки звукового сигнала

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    Разработана гибридная интегральная схема с номинальным напряжением питания 1,4 В, током потребления 0,7 мА и габаритными размерами 8x4x3 мм для обработки звукового сигнала в автономной аппаратуре.Розроблена гібридна інтегральна схема з номінальною напругою живлення 1,4 В, струмом споживання 0,7 мА і габаритними розмірами 8x4x3 мм забезпечує багатофункціональну обробку звуковою сигналу в аналоговій мікроелектронній апаратурі. Наведено її конструкторсько-технологічні та електричні параметри.Developed hybrid integrated circuit with rated supply voltage of 1,4 V, current consumption 0,7 mA and overall dimensions 8x4x3 mm provides soft processing of the audio signal in analog microelectronic equipment. Given its design, technological and electrical parameters

    Prevention of severe infectious complications after colorectal surgery using preoperative orally administered antibiotic prophylaxis (PreCaution):Study protocol for a randomized controlled trial

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    BACKGROUND: Colorectal surgery is frequently complicated by surgical site infections (SSIs). The most important consequences of SSIs are prolonged hospitalization, an increased risk of surgical reintervention and an increase in mortality. Perioperative intravenously administered antibiotic prophylaxis is the standard of care to reduce the risk of SSIs. In the last few decades, preoperative orally administered antibiotics have been suggested as additional prophylaxis to further reduce the risk of infection, but are currently not part of routine practice in most hospitals. The objective of this study is to evaluate the efficacy of a preoperative orally administered antibiotic prophylaxis (Pre-OP) in addition to intravenously administered perioperative antibiotic prophylaxis to reduce the incidence of deep SSIs and/or mortality after elective colorectal surgery. METHODS/DESIGN: The PreCaution trial is designed as a multicenter, double-blind, randomized, placebo-controlled clinical trial that will be carried out in The Netherlands. Adult patients who are scheduled for elective colorectal surgery are eligible to participate. In total, 966 patients will be randomized to receive the study medication. This will either be Pre-OP, a solution that consists of tobramycin and colistin sulphate, or a placebo solution. The study medication will be administered four times daily during the 3 days prior to surgery. Perioperative intravenously administered antibiotic prophylaxis will be administered to all patients in accordance with national infection control guidelines. The primary endpoint of the study is the cumulative incidence of deep SSIs and/or mortality within 30 days after surgery. Secondary endpoints include both infectious and non-infectious complications of colorectal surgery, and will be evaluated 30 days and/or 6 months after surgery. DISCUSSION: To date, conclusive evidence on the added value of preoperative orally administered antibiotic prophylaxis in colorectal surgery is lacking. The PreCaution trial should determine the effects of orally administered antibiotics in preventing infectious complications in elective colorectal surgery. TRIAL REGISTRATION: Netherlands Trial Register, ID: NTR6113 . Registered on 11 October 2016; EudraCT 2015-005736-17

    Prevention of severe infectious complications after colorectal surgery using oral non-absorbable antimicrobial prophylaxis:results of a multicenter randomized placebo-controlled clinical trial

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    BACKGROUND: Surgical site infections (SSIs) are common complications after colorectal surgery. Oral non-absorbable antibiotic prophylaxis (OAP) can be administered preoperatively to reduce the risk of SSIs. Its efficacy without simultaneous mechanical cleaning is unknown. METHODS: The Precaution trial was a double-blind, placebo-controlled randomized clinical trial conducted in six Dutch hospitals. Adult patients who underwent elective colorectal surgery were randomized to receive either a three-day course of preoperative OAP with tobramycin and colistin or placebo. The primary composite endpoint was the incidence of deep SSI or mortality within 30 days after surgery. Secondary endpoints included both infectious and non-infectious complications at 30 days and six months after surgery. RESULTS: The study was prematurely ended due to the loss of clinical equipoise. At that time, 39 patients had been randomized to active OAP and 39 to placebo, which reflected 8.1% of the initially pursued sample size. Nine (11.5%) patients developed the primary outcome, of whom four had been randomized to OAP (4/39; 10.3%) and five to placebo (5/39; 12.8%). This corresponds to a risk ratio in the intention-to-treat analysis of 0.80 (95% confidence interval (CI) 0.23-2.78). In the per-protocol analysis, the relative risk was 0.64 (95% CI 0.12-3.46). CONCLUSIONS: Observational data emerging during the study provided new evidence for the effectiveness of OAP that changed both the clinical and medical ethical landscape for infection prevention in colorectal surgery. We therefore consider it unethical to continue randomizing patients to placebo. We recommend the implementation of OAP in clinical practice and continuing monitoring of infection rates and antibiotic susceptibilities. TRIAL REGISTRATION: The PreCaution trial is registered in the Netherlands Trial Register under NL5932 (previously: NTR6113) as well as in the EudraCT register under 2015-005736-17

    Seroprevalence of SARS-CoV-2 antibodies among healthcare workers in Dutch hospitals after the 2020 first wave:a multicentre cross-sectional study with prospective follow-up

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    BACKGROUND: We aimed to estimate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence and describe its determinants and associated symptoms among unvaccinated healthcare workers (HCWs) after the first wave of the pandemic.METHODS: HCWs from 13 Dutch hospitals were screened for antibodies against the spike protein of SARS-CoV-2 in June-July 2020 and after three months. Participants completed a retrospective questionnaire on determinants for occupational and community exposure to SARS-CoV-2 and symptoms suggestive of COVID-19 experienced since January 2020. The seroprevalence was calculated per baseline characteristic and symptom at baseline and after follow-up. Adjusted odds ratios (aOR) for seropositivity were determined using logistic regression.RESULTS: Among 2328 HCWs, 323 (13.9%) were seropositive at enrolment, 49 of whom (15%) reported no previous symptoms suggestive of COVID-19. During follow-up, only 1% of the tested participants seroconverted. Seroprevalence was higher in younger HCWs compared to the mid-age category (aOR 1.53, 95% CI 1.07-2.18). Nurses (aOR 2.21, 95% CI 1.34-3.64) and administrative staff (aOR 1.87, 95% CI 1.02-3.43) had a higher seroprevalence than physicians. The highest seroprevalence was observed in HCWs in the emergency department (ED) (aOR 1.79, 95% CI 1.10-2.91), the lowest in HCWs in the intensive, high, or medium care units (aOR 0.47, 95% CI 0.31-0.71). Chronic respiratory disease, smoking, and having a dog were independently associated with a lower seroprevalence, while HCWs with diabetes mellitus had a higher seroprevalence. In a multivariable model containing all self-reported symptoms since January 2020, altered smell and taste, fever, general malaise/fatigue, and muscle aches were positively associated with developing antibodies, while sore throat and chills were negatively associated.CONCLUSIONS: The SARS-CoV-2 seroprevalence in unvaccinated HCWs of 13 Dutch hospitals was 14% in June-July 2020 and remained stable after three months. A higher seroprevalence was observed in the ED and among nurses, administrative and young staff, and those with diabetes mellitus, while a lower seroprevalence was found in HCWs in intensive, high, or medium care, and those with self-reported lung disease, smokers, and dog owners. A history of altered smell or taste, fever, muscle aches and fatigue were independently associated with the presence of SARS-CoV-2 antibodies in unvaccinated HCWs.</p

    COVID-19 in health-care workers in three hospitals in the south of the Netherlands:A cross-sectional study

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    Background: 10 days after the first reported case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the Netherlands (on Feb 27, 2020), 55 (4%) of 1497 health-care workers in nine hospitals located in the south of the Netherlands had tested positive for SARS-CoV-2 RNA. We aimed to gain insight in possible sources of infection in health-care workers. Methods: We did a cross-sectional study at three of the nine hospitals located in the south of the Netherlands. We screened health-care workers at the participating hospitals for SARS-CoV-2 infection, based on clinical symptoms (fever or mild respiratory symptoms) in the 10 days before screening. We obtained epidemiological data through structured interviews with health-care workers and combined this information with data from whole-genome sequencing of SARS-CoV-2 in clinical samples taken from health-care workers and patients. We did an in-depth analysis of sources and modes of transmission of SARS-CoV-2 in health-care workers and patients. Findings: Between March 2 and March 12, 2020, 1796 (15%) of 12 022 health-care workers were screened, of whom 96 (5%) tested positive for SARS-CoV-2. We obtained complete and near-complete genome sequences from 50 health-care workers and ten patients. Most sequences were grouped in three clusters, with two clusters showing local circulation within the region. The noted patterns were consistent with multiple introductions into the hospitals through community-acquired infections and local amplification in the community. Interpretation: Although direct transmission in the hospitals cannot be ruled out, our data do not support widespread nosocomial transmission as the source of infection in patients or health-care workers. Funding: EU Horizon 2020 (RECoVer, VEO, and the European Joint Programme One Health METASTAVA), and the National Institute of Allergy and Infectious Diseases, National Institutes of Health
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