The production of geothermal fluids can be adversely affected by the formation of free gas bubbles (degassing). Decreasing pressures can cause dissolved gas to exsolve, which can reduce water ...production. This study aims to improve the understanding of the conditions under which free gas nucleates in geothermal reservoirs. The focus is on CO2 degassing from brines with varying salinity. We report a series of depressurisation experiments at high pressure and temperature using a cell that allows for visual monitoring of the degassing process using a high-speed camera along with pressure and temperature logging. A geochemical model was created for simulating the degassing behaviour at the same conditions as those used in the experiments, thus allowing for direct comparison.
The efficiency and feasibility of geothermal utilisation depends strongly on the characteristics and behaviour of the fluids that transfer heat between the geosphere and the engineered components of ...a power plant. Chemical and physical processes such as precipitation, corrosion, or degassing are induced by pressure and temperature changes, with potentially serious consequences for power plant operation and project economics. The EU Horizon 2020-funded project REFLECT aims to avoid such problems by collecting high-quality chemical, physical, and microbiological data at extreme salinities, pressures or temperatures and improving the understanding of kinetic processes through laboratory experiments. These data are presented in a European geothermal fluid atlas and implemented in predictive models in order to provide recommendations on how to best operate geothermal systems for a sustainable future.
On June 13, 2019, the US Food and Drug Administration issued a warning after transfer of faeces containing an extended-spectrum β-lactamase (ESBL)-producing Escherichia coli by faecal microbiota ...transplantation led to bacteraemia in two immunocompromised patients. Consequently, we evaluated the effectiveness of the faeces donor-screening protocol of the Netherlands Donor Faeces Bank, which consists of screening of donors for multidrug-resistant organisms every 3 months, combined with additional screening on indication (eg, after travelling abroad) and application of a quarantine period for all faecal suspensions delivered within those 3 months.
We did a retrospective cohort study of data collected between Jan 1, 2015, and Oct 14, 2019, on the multidrug-resistant organism testing results of donor faeces. Additionally, we tested previously quarantined faecal suspensions approved for faecal microbiota transplantation between Dec 12, 2016, and May 1, 2019, for the presence of multidrug-resistant organisms using both aselective and selective broth enrichment media. Whole-genome sequencing with core-genome multilocus sequence typing (cgMLST) was done on all multidrug-resistant isolates.
Among initial screenings, six (9%) of 66 tested individuals were positive for multidrug-resistant organisms and 11 (17%) of 66 tested individuals were positive for multidrug-resistant organisms at any timepoint. Multidrug-resistant organisms were detected in four (25%) of 16 active donors, who had a median donation duration of 268 days (IQR 92 to 366). Among all screening results, 14 (74%) of 19 detected multidrug-resistant organisms were ESBL-producing E coli. 170 (49%) of 344 approved faecal suspensions had corresponding research faeces aliquots available and were tested (from 11 active donors with a median of eight IQR five to 26 suspensions per donor). No multidrug-resistant organisms were detected in the 170 approved faecal suspensions (one-sided 95% CI 0 to 1·7). cgMLST revealed that all multidrug-resistant organisms were genetically different.
Healthy faeces donors can become colonised with multidrug-resistant organisms during donation activities. Our screening protocol did not result in approval of multidrug-resistant organism-positive faecal suspensions for microbiota transplantation.
None.
Background
The Netherlands Donor Feces Bank provides standardized ready-to-use donor faecal suspensions for faecal microbiota transplantation treatment of patients with recurrent Clostridioides ...difficile infection.
Objective
The purpose of this study was evaluation of safety, feasibility and outcome of faecal microbiota transplantation facilitated by a national stool bank.
Methods
The methods used included: observational cohort study of donors and recipients of faecal suspensions; assessment of donor screening and patient selection performed by an expert panel of medical microbiologists, gastroenterologists and infectious disease specialists; and patient outcome evaluated at different timepoints after faecal microbiota transplantation.
Results
Of 871 volunteers who registered as a potential faeces donor, 16 (2%) became active donors. Nine donors stopped or were excluded after a mean donation period of 5.7 months. In 2016–2019, 47 (27%) of 176 requests for faecal microbiota transplantations were deemed not indicated by the expert panel. In total, 129 patients with recurrent C. difficile infection were treated with 143 faecal suspensions in 40 different hospitals. The cure rate at two months after a single infusion was 89% (107/120). Of 84 patients, long-term follow-up (median 42 weeks) was available and sustained cure was achieved in 61 (73%). Early C. difficile infection relapses (within two months after faecal microbiota transplantation) and late recurrences (after more than two months) occurred more frequently in patients who received non-C. difficile antibiotics within three weeks after faecal microbiota transplantation and in moderately to severely immunocompromised patients. Of 21 patients with C. difficile infection after faecal microbiota transplantation, 14 were cured with anti-C. difficile antibiotics and seven with a second transplantation. No faecal microbiota transplantation-related serious adverse events were observed, but gastro-intestinal complaints (nausea, abdominal pain or diarrhoea) persisted in 32% of the treated patients at long-term follow-up.
Conclusion
Faecal suspensions provided by a centralized stool bank, supported by a multidisciplinary expert team, resulted in effective, appropriate and safe application of faecal microbiota transplantation for recurrent C. difficile infection.
Level of evidence
Level II, prospective cohort study
Abstract
Background
Patients with multiple recurrent Clostridioides difficile infections (rCDI) are treated with fecal microbiota transplantation (FMT), using feces provided by healthy donors. ...Blastocystis colonization of donors is considered an exclusion criterion, whereas its pathogenicity is still under debate.
Methods
The introduction of molecular screening for Blastocystis sp. at our stool bank identified 2 donors with prior negative microscopies but positive polymerase chain reactions (PCRs). Potential transmission of Blastocystis sp. to patients was assessed on 16 fecal patient samples, pre- and post-FMT, by PCR and subtype (ST) analyses. In addition, clinical outcomes for the treatment of rCDI (n = 31), as well as the development of gastrointestinal symptoms, were assessed.
Results
There was 1 donor who carried Blastocystis ST1, and the other contained ST3. All patients tested negative for Blastocystis prior to FMT. With a median diagnosis at 20.5 days after FMT, 8 of 16 (50%) patients developed intestinal colonization with Blastocystis, with identical ST sequences as their respective donors. Blastocystis-containing fecal suspensions were used to treat 31 rCDI patients, with an FMT success rate of 84%. This success rate was not statistically different from patients transferred with Blastocystis sp.–negative donor feces (93%, 76/82). Patients transferred with Blastocystis sp.–positive donor feces did not report any significant differences in bowel complaints in the first week, after 3 weeks, or in the months following FMT.
Conclusions
We demonstrated the first transmission of Blastocystis ST1 and ST3 from donors to patients by FMT. This did not result in gastrointestinal symptomatology or have any significant effect on rCDI treatment outcomes.
Transmission of Blastocystis by fecal microbiota transplantation (FMT) from colonized donors occurred in 50% of patients. Transfer did not result in development of gastrointestinal symptoms or affect the outcome of the FMT treatment in patients with recurrent Clostridioides difficile infections.
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