Search results

Temperature and nutrient limitations decrease transfer of conjugative IncP-1 plasmid pKJK5 to wild Escherichia coli strains

Plasmid-mediated dissemination of antibiotic resistance among fecal Enterobacteriaceae in natural ecosystems may contribute to the persistence of antibiotic resistance genes in anthropogenically impacted environments. Plasmid transfer frequencies measured under laboratory conditions might lead to overestimation of plasmid transfer potential in natural ecosystems. This study assessed differences in the conjugative transfer of an IncP-1 (pKJK5) plasmid to three natural Escherichia coli strains carrying extended-spectrum beta-lactamases, by filter mating. Matings were performed under optimal laboratory conditions (rich LB medium and 37°C) and environmentally relevant temperatures (25, 15 and 9°C) or nutrient regimes mimicking environmental conditions and limitations (synthetic wastewater and soil extract). Under optimal nutrient conditions and temperature, two recipients yielded high transfer frequencies (5 × 10–1) while the conjugation frequency of the third strain was 1000-fold lower. Decreasing mating temperatures to psychrophilic ranges led to lower transfer frequencies, albeit all three strains conjugated under all the tested temperatures. Low nutritive media caused significant decreases in transconjugants (−3 logs for synthetic wastewater; −6 logs for soil extract), where only one of the strains was able to produce detectable transconjugants. Collectively, this study highlights that despite less-than-optimal conditions, fecal organisms may transfer plasmids in the environment, but the transfer of pKJK5 between microorganisms is limited mainly by low nutrient conditions.

Revealing new leads for the impact of galacto-oligosaccharides on gut commensals and gut health benefits through text mining

Minerals and Sarcopenia in Older Adults: An Updated Systematic Review

ObjectiveThis systematic review aims to reevaluate the role of minerals on muscle mass, muscle strength, physical performance, and the prevalence of sarcopenia in community-dwelling and institutionalized older adults.DesignSystematic review.Setting and ParticipantsIn March 2022, a systematic search was performed in PubMed, Scopus, and Web of Sciences using predefined search terms. Original studies on dietary mineral intake or mineral serum blood concentrations on muscle mass, muscle strength, and physical performance or the prevalence of sarcopenia in older adults (average age ≥65 years) were included.MethodsEligibility screening and data extraction was performed by 2 independent reviewers. Quality assessment was performed with the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies. Risk of bias was evaluated using the Risk Of Bias In Non-randomized Studies-of Exposure (ROBINS-E) tool.ResultsFrom the 15,622 identified articles, a total of 45 studies were included in the review, mainly being cross-sectional and observational studies. Moderate quality of evidence showed that selenium (n = 8) and magnesium (n = 7) were significantly associated with muscle mass, strength, and physical performance as well as the prevalence of sarcopenia. For calcium and zinc, no association could be found. For potassium, iron, sodium, and phosphorus, the association with sarcopenic outcomes remains unclear as not enough studies could be included or were nonconclusive (low quality of evidence).Conclusions and ImplicationsThis systematic review shows a potential role for selenium and magnesium on the prevention and treatment of sarcopenia in older adults. More randomized controlled trials are warranted to determine the impact of minerals on sarcopenia in older adults.

Enhancing citizens’ participation in the community to promote health and wellbeing

BackgroundIn 2015, Amsterdam became part of the WHO Age Friendly City community, thereby accepting the responsibility to work towards a more age friendly Amsterdam. To study senior citizens’ needs and wishes concerning the age friendliness of their neighbourhood, the municipality asked the Amsterdam University of Applied Science to set up two pilot projects in two neighbourhoods. Aim was to 1) gain insight in seniors’ views and wishes regarding an age friendly city, and 2) reflect on the experiences with working with senior co-researchers. MethodologyThe study followed a Participatory Action Research approach with research teams consisting of seniors as co-researchers and professional researchers. We chose two neighbourhoods with distinct characteristics: the Indische Buurt which is centrally located, vibrant, multicultural, and strongly gentrifying, and Buitenveldert, a suburban and spacious neighbourhood, with less facilities and a dominance of well-to-do senior citizens. In both areas, we recruited senior co-researchers to form the research teams. They generally lived in, or close to, the pilot neighbourhood, and varied in age and ethnical background. The aim was to put the co-researchers in the lead during the entire research process. However, it differed between the neighbourhoods which type of researcher was in the lead. As a team, they formulated the main research question, constructed a topic list for interviews with older citizens, convened the interviews, analysed the data, wrote the report, and presented the results. During the entire process, they were supported by professional researchers.Both research teams interviewed 40 senior citizens, who were recruited through the co-researchers’ networks, professional care organisations, neighbourhood communities, and local media. We intended to gather a sample representative for the neighbourhood population. In the Indische Buurt, this proved to be difficult, since the relatively large Turkish and Moroccan communities were difficult to get into contact with, and it was hard to find co-researchers from those communities who could have provided a way in. Process and outcomesWe will share some of the results, but we will mainly reflect on the research process. ProcessRegarding the process, we found some differences between the two neighbourhoods. In the Indische Buurt, it took much effort to find co-researchers, since the seniors we encountered said to be too busy with other neighbourhood activities. We did recruit a small group of four co-researchers of different ethnical background, but sadly lacking Turkish and Moroccan seniors. They started with a very limited research experience and experienced ownership, which greatly increased during the process. At the finalisation of the project, the group ceased to be, but the outcomes were followed up by existing groups and organisations in the neighbourhood.In Buitenveldert, a large group of co-researchers was recruited in no-time, bearing more resemblance to an action group than a research group. They were generally highly educated and some already had research experience. The group proved to be pro-active, had a strong feeling of ownership, and worked in constant collaboration with the ‘professional’ researchers, respecting each other’s knowledge and skills. At the finalisation of the project, the group remained active as partner of the local government. OutcomesConcerning the content of the outcomes, we found some expected differences and unexpected similarities. For instance, we expected to find different outcomes concerning housing and facilities between the neighbourhoods. Indeed, in Buitenveldert, housing was already age friendly whereas facilities were scarce and geographically far apart. Yet, in the Indische Buurt, housing was poorly equipped for physically impaired seniors, but facilities were abundant and close by.We also found that, in both neighbourhoods, senior citizens were reluctant to share their limitations and ask for support, despite differences in neighbourhood, ethnicity, age etc. Of course, this can be expected of seniors from the ‘silent generation’. However, they seemingly shared these emotions more easily with their peers than with professional researchers. ConclusionThe social-cultural context of the neighbourhood impacts the research process. Overall, co-research appears to be a fruitful method to involve senior citizens in decisions concerning the improvement of their neighbourhood. Aims and content of the workshopWe aim to:• present our reflections on the participative process of working with senior co-researchers in Amsterdam• exchange and discuss with the participants of the workshop the lessons learned on how to facilitate citizens’ participation in the community• discuss similar and future projects and possibilities for collaboration among the participants of the workshopContent of the workshop• Presentation• Exchange and discussion in small groups • Plenary discussion on possible collaboration projects aiming to enhance citizens’ participation in the community

Use of and satisfaction with ankle foot orthoses

Objective: The aim of this study was to obtain insight in specific elements influencing the use, non-use, satisfaction, and dissatisfaction of ankle foot orthoses (AFOs) and the presence of underexposed problems with respect to AFOs. Methods: A questionnaire was composed to obtain information from AFO users to investigate the variables associated with satisfaction and the relation between these variables. A specific feature of this study was the systematic analysis of the remarks made by the respondents about their AFO. Quantitative data analyses were used for analysing the satisfaction and qualitative analyses were used analysing the remarks of the respondents. A total of 211 users completed the questionnaire. Results: Our survey showed that 1 out of 15 AFOs were not used at all. About three quarters of the AFO users were satisfied and about one quarter was dissatisfied. Females and users living alone reported relatively high levels of dissatisfaction, especially in the field of dimensions, comfort, weight, safety and effectiveness. Dissatisfaction with respect to off-the-shelf AFOs for the item durability was higher than that for custom-made AFOs. In the delivery and maintenance process the items ‘maintenance’, ‘professionalism’ and ‘delivery follow-up’ were judged to be unsatisfactory. A large number of comments were made by the respondents to improve the device or process, mainly by the satisfied AFO users. These comments show that even satisfied users experience many problems and that a lot of problems of AFO users are ‘underexposed’. Conclusion: To improve user satisfaction, the user practice has to be identified as an important sub-process of the whole orthopaedic chain especially in the diagnosis and prescription, delivery tuning and maintenance, and evaluation phase.

Transient repression of the synthesis of OmpF and aspartate transcarbamoylase in Escherichia K12 as a response to pollutant stress

The synthesis of total cellular proteins in Escherichia coli K12 was studied in batch culture following exposure of cells to low concentrations of monochlorophenol, pentachlorophenol and cadmium chloride. Changes in protein patterns were identified after pulse-chase labelling of proteins with [35S]methionine and subsequent two-dimensional gel electrophoresis (2D-PAGE). We demonstrated that besides the induction of some stress proteins, also a transient decrease in the rate of synthesis of other proteins occurred. Two of these proteins were identified as OmpF and aspartate transcarbamoylase (ATCase). Their transient repression appeared to be a general response to stress elicited by different pollutants and may therefore be used as a general and sensitive early warning system for pollutant stress.