1,720,961 research outputs found
Evaluating The environmental microbiota across four national health service hospitals within England
No full textHospital surfaces contaminated with microbial soiling, such as dry surface biofilms (DSBs), can act as a reservoir for pathogenic micro-organisms, and inhibit their detection and removal during routine cleaning. Studies have recognized that such increases in bioburden can hinder the impact of disinfectants and mask the detection of potential pathogens. Cleanliness within healthcare settings is often determined through routine culture-based analysis, whereby surfaces that exhibit >2.5 colony-forming units (CFU) per cm
2 pose a risk to patient health; therefore, any underestimation could have detrimental effects. This study quantified microbial growth on high-touch surfaces in four hospitals in England over 19 months. This was achieved using environmental swabs to sample a variety of surfaces within close proximity of the patient, and plating these on to non-specific low nutrient detection agar. The presence of DSBs on surfaces physically removed from the environment was confirmed using real-time imaging through episcopic differential interference contrast microscopy combined with epifluorescence. Approximately two-thirds of surfaces tested exceeded the limit for cleanliness (median 2230 CFU/cm
2), whilst 83% of surfaces imaged with BacLight LIVE/DEAD staining confirmed traces of biofilm. Differences in infection control methods, such as choice of surface disinfectants and cleaning personnel, were not reflected in the microbial variation observed and resulting risk to patients. This highlights a potential limitation in the effectiveness of the current standards for all hospital cleaning, and further development using representative clinical data is required to overcome this limitation.
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Efficiency and novelty of using environmental swabs for dry-surface biofilm recovery
No full textStudies on the epidemiology of dry-surface biofilms (DSBs) within healthcare settings have shown an almost universal distribution across frequently touched items. Despite a growing body of evidence for DSBs in hospitals, little attention has been paid to the recovery capacity of techniques used to detect these microbial communities. Biofilms are inherently difficult to remove from surfaces due to adhesive substances within their matrix and may act as sources of infection, but to what extent is largely unknown. In this study, we evaluate the recovery efficiencies of commonly used environmental swabs against DSBs containing 7.24 log10 Acinetobacter baumannii cm−2, using a drip flow reactor and desiccation cycle. Biofilm presence was visually confirmed using episcopic differential interference contrast microscopy combined with epifluorescence and quantified using soni-cated viable plate counts. The swab materials used comprised foam, viscose and cotton, all of which were pre-moistened using a buffer solution. The surfaces were vigorously swabbed by each material type and the resultant microbe populations for both swabs and remaining DSBs were quantified. Our results found foam-tipped swabs to be superior, detecting on average 30 % of the original DSB contamination; followed by viscose (6 %) and cotton (3 %). However, no distinct difference was revealed in the concentration of microbes remaining on the surface after swabbing for each swab type, suggesting there is variation in the capacity for each swab to release biofilm-associated micro-organisms. We conclude whilst environmental swabs do possess the ability to detect biofilms on dry surfaces, the reduced efficiencies are likely to cause an underestimation of the microbes present and should be considered during clinical application.</p
Underestimating the levels of microbiological contamination on environmental surfaces within NHS hospitals
No full textAn automated contact model for transmission of dry surface biofilms of Acinetobacter baumannii in healthcare
No full textDry surface biofilms have been recognised across environmental and equipment surfaces in hospitals and could explain how microbial contamination can survive for an extended period and may play a key role in the transmission of hospital-acquired infections. Despite little being known on how they form and proliferate in clinical settings, DSB models for disinfectant efficacy testing exist. In this study we develop a novel biofilm model to represent formation within hospitals, by emulating patient to surface interactions. The model generates a DSB through the transmission of artificial human sweat (AHS) and clinically relevant pathogens using a synthetic thumb capable of emulating human contact. The DNA, glycoconjugates and protein composition of the model biofilm, along with structural features of the microcolonies was determined using fluorescent stains visualised by epifluorescence microscopy and compared with published clinical data. The model repeatably transferred trace amounts of microorganisms and AHS, every 5 minutes for up to 120 hours onto stainless steel coupons to generate a biofilm model averaging 1.16 x 103 CFU/cm2 falling within the reported range for clinical DSB (4.20 x 102 to 1.60 x 107 bacteria/cm2). Micrographs revealed the heterogeneity of the biofilm across the surface; and reveal protein as the principal component within the matrix, followed by glycoconjugates and DNA. Our in vitro DSB model exhibits many phenotypical characteristics and traits to those reported in situ. The model highlights key features often overlooked and the potential for downstream applications such as antibiofilm claims using more realistic microbial challenges.</p
Corporate food retailers, meat supply chains, and the responsibilities of tackling antimicrobial resistance: Stakeholder report 2018
No full textThis report provides the key findings and recommendations of a study funded by the Economic and Social Research Council (ESRC) as part of a UK Research and Innovation (UKRI) Cross Council Initiative on ‘Tackling Antimicrobial Resistance (AMR)’. Our project is a Pump Priming study funded as part of Theme 4: ‘Tackling AMR beyond the Healthcare Setting’. The aim of the project is to address the responsibility of retailers in tackling the AMR challenge in the context of their chicken and pork supply chains, and to investigate this evolving role and how it might be shaped in the future, both in the UK and also extending to the global scale. This research is significant in light of the O’Neill (2016) report on Tackling Drug-Resistant Infections Globally, the Government Response to the Review of Antimicrobial Resistance (HM Government, 2016) and subsequent roles played by the Department for Environment, Food and Rural Affairs (DEFRA) and the Food Standards Agency (FSA) in taking forward their recommendations regarding the setting of targets for the reduction of antibiotic use, support for antimicrobial stewardship in the food system and the development of codes and standards for addressing AMR in the food system at both national and global levels. The O’Neill Report (2016: 29) calls for “producers, retailers and regulators to agree standards for ‘responsible use’. These standards could then be developed and implemented as an internationally recognised label, or used by existing certification bodies.
Residual protein contamination and prion infectivity after decontamination of spiked surgical surfaces using a cold atmospheric plasma jet
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Legionella pneumophila proliferation is not dependent on intracellular replication
No full textThe complexities of the relationship between Legionella pneumophila and other microorganisms for the growth and survival of legionellae in the environment is still not fully understood, though it is generally believed that amoebae play an important role in the natural environment. Although strains of varying virulence are isolated from environmental sources, it is still generally accepted that intracellular replication is important for the ability of L. pneumophila to proliferate in the natural environment. The model water system allowed the development of reproducible biofilms. A diverse but fairly constant consortium of aquatic microorganisms including fungi, bacteria, and protozoa could be maintained in this system. To investigate if legionellae could have the potential to replicate without multiplication within a protozoal host, an avirulent strain of L. pneumophila serogroup 1 Pontiac (Corby Strain) (CAC) was added to the system. If intracellular multiplication is essential for the proliferation of L. pneumophila in aquatic systems, then elimination of trophozoites in the model system would prevent any further growth of legionellae, and consequently numbers would decrease due to dilution by the continuous culture medium
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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