162 research outputs found

    Characterisation and comparison of bacterial communities on reverse osmosis membranes of a full-scale desalination plant by bacterial 16S rRNA gene metabarcoding

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    Microbiomes of full-scale seawater reverse osmosis membranes are complex and subject to variation within and between membrane units. The pre-existing bacterial communities of unused membranes before operation have been largely ignored in biofouling studies. This study is novel as unused membranes were used as a critical benchmark for comparison. Fouled seawater reverse osmosis membrane biofilm communities from an array of autopsied membrane samples, following a 7-year operational life-span in a full-scale desalination plant in Western Australia, were characterised by 16S rRNA gene metabarcoding using the bacterial primers 515F and 806R. Communities were then compared based on fouling severity and sampling location. Microbiomes of proteobacterial predominance were detected on control unused membranes. However, fouled membrane communities differed significantly from those on unused membranes, reflecting that operational conditions select specific bacteria on the membrane surface. On fouled membranes, Proteobacteria were also predominant but families differed from those on unused membranes, followed by Bacteriodetes and Firmicutes. Betaproteobacteria correlated with stable, mature and thick biofilms such as those in severely fouled membranes or samples from the feed end of the membrane unit, while Alpha and Gammaproteobacteria were predominantly found in biofilms on fouled but visually clean, and moderately fouled samples or those from reject ends of membrane units. Gammaproteobacteria predominated the thin, compact biofilms at the mid-feed end of membrane units. The study also supported the importance of Caulobacterales and glycosphingolipid-producing bacteria, namely Sphingomonadales, Rhizobiales and Sphingobacteriia, in primary attachment and biofilm recalcitrance. Nitrate-and-nitrite-reducing bacteria such as Rhizobiales, Burkholderiales and some Pseudomonadales were also prevalent across all fouled membranes and appeared to be critical for ecological balance and biofilm maturation

    Molecular investigation into the presence of a Coxiella sp. in Rhipicephalus sanguineus ticks in Australia

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    Q fever is an infectious disease with a global distribution caused by the intracellular bacterium, Coxiella burnetii, which has been detected in a large number of tick species worldwide, including the brown dog tick, Rhipicephalus sanguineus. Recent reports of a high seroprevalance of C. burnetii in Australian dogs, along with the identification of additional Coxiella species within R. sanguineus ticks, has prompted an investigation into the presence and identification of Coxiella species in R. sanguineus ticks in Australia. Using a combination of C. burnetii species-specific IS1111a transposase gene and Coxiella genus-specific 16S rRNA PCR assays, a Coxiella sp. was identified in 100% (n = 199) of R. sanguineus ticks analysed, and C. burnetii was not detected in any R. sanguineus ticks studied. Phylogenetic analysis of the 16S rRNA gene revealed the Coxiella sequences were closely related to Coxiella sp. identified previously in R. sanguineus and R. turanicus ticks overseas. This study illustrates the value of using genus specific PCR assays to detect previously unreported bacterial species. Furthermore, the presence of an additional Coxiella sp. in Australia requires further investigation into its potential for contributing to serological cross-reactions during Q fever testing

    Next generation sequencing reveals widespread trypanosome diversity and polyparasitism in marsupials from Western Australia

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    In Western Australia a number of indigenous Trypanosoma spp. infect susceptible native marsupials, such as the woylie (Bettongia penicillata), brushtail possum (Trichosurus vulpecula), and chuditch (Dasyurus geoffroii). Two genotypes of Trypanosoma copemani (identified as G1 and G2) have been found in the woylie, and G2 has been implicated in the decline of this host species, making its presence of particular interest. Here we used targeted amplicon next generation sequencing (NGS) of the Trypanosoma 18S rDNA loci on 70 Trypanosoma-positive marsupial blood samples, to identify T. copemani genotypes and multiple Trypanosoma infections (polyparasitism) in woylies and cohabiting species in Western Australia. Polyparasitism with Trypanosoma spp. was found in 50% of the wildlife sampled, and within species diversity was high, with 85 zero-radius operational taxonomic units (ZOTUs) identified in nine putative parasite species. Trypanosoma copemani was assigned 17 ZOTUs and was identified in 80% of samples. The most abundant ZOTU isolated (63%) differed slightly from the published genotype of G1, and G2 was the second most abundant ZOTU (14%). Trypanosome diversity was significantly greater in woylies than in brushtail possums, and parasite community composition also differed significantly between these host species. One novel Trypanosoma spp. genotype (Trypanosoma sp. ANU2) was found in 20% of samples. A species of Crithidia was detected in a woylie, and two avian trypanosomes (Trypanosoma avium and Trypanosoma sp. AAT) were identified in woylies for the first time

    The Consumption, Production and Regulation of Alcohol in the UK: The Relevance of the Ambivalence of the Carnivalesque

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    Alcohol consumption in 21st-century Britain is of significant interest to government, media and academics. Some have referred to a ‘new culture of intoxication’ or ‘calculated hedonism’, fostered by the drinks industry, and enabled by a neoliberal policymaking context. This article argues that the ‘carnivalesque’ is a better concept through which to understand alcohol’s place in British society today. The concept of the carnivalesque conveys an earthy yet extraordinary culture of drinking, as well as ritual elements with a lack of comfort and security that characterise the night-time economy for many people. This night-time carnival, as well as being something experienced by participants, is also a spectacle, with gendered and classed dynamics. It is suggested that this concept is helpful in making sense of common understandings of alcohol that run through the spheres not only of alcohol consumption but also production and regulation

    Understanding English alcohol policy as a neoliberal condemnation of the carnivalesque

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    Much academic work has argued that alcohol policy in England over the past 25 years can be characterised as neoliberal, particularly in regard to the night-time economy and attempts to address “binge” drinking. Understanding neoliberalism as a particular “mentality of government” that circumscribes the range of policy options considered appropriate and practical for a government to take, this article notes how the particular application of policy can vary by local context. This article argues that the approach of successive governments in relation to alcohol should be seen as based on a fear and condemnation of the carnivalesque, understood as a time when everyday norms and conventions are set aside, and the world is – for a limited period only – turned inside out. This analysis is contrasted with previous interpretations that have characterised government as condemning intoxication and particular forms of pleasure taken in drinking. Although these concepts are useful in such analysis, this article suggests that government concerns are broader and relate to wider cultures surrounding drunkenness. Moreover, there is an ambivalence to policy in relation to alcohol that is better conveyed by the concept of the carnivalesque than imagining simply a condemnation of pleasure or intoxication

    International consensus recommendations for management of new onset refractory status epilepticus including febrile infection-related epilepsy syndrome: Statements and supporting evidence

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    Objective: This study was undertaken to develop consensus-based recommendations for the management of adult and pediatric patients with new onset refractory status epilepticus (NORSE)/febrile infection-related epilepsy syndrome (FIRES) based on best evidence and experience. Methods: The Delphi methodology was followed. A facilitator group of nine experts was established, who defined the scope, users, and suggestions for recommendations. Following a review of the current literature, recommendation statements concerning diagnosis, treatment, and research directions were generated, which were then rated on a scale of 1 (strongly disagree) to 9 (strongly agree) by a panel of 48 experts in the field. Consensus that a statement was appropriate was reached if the median score was ≥7 and inappropriate if the median score was ≤3. The analysis of evidence was mapped to the results of each statement included in the Delphi survey. Results: Overall, 85 recommendation statements achieved consensus. The recommendations are divided into five sections: (1) disease characteristics; (2) diagnostic testing and sampling; (3) acute treatment; (4) treatment in the postacute phase; and (5) research, registries, and future directions in NORSE/FIRES. The detailed results and discussion of all 85 statements are outlined herein. A corresponding summary of findings and practical flowsheets are presented in a companion article. Significance: This detailed analysis offers insight into the supporting evidence and the current gaps in the literature that are associated with expert consensus statements related to NORSE/FIRES. The recommendations generated by this consensus can be used as a guide for the diagnosis, evaluation, and management of patients with NORSE/FIRES, and for planning of future research
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