Browsing by Author "Marshall J"

Now showing 1 - 5 of 5
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    Dairy Cattle Density and Temporal Patterns of Human Campylobacteriosis and Cryptosporidiosis in New Zealand
    (Springer Nature Switzerland AG on behalf of the EcoHealth Alliance, 2022-06-10) Grout L; Marshall J; Hales S; Baker MG; French N
    Public health risks associated with the intensification of dairy farming are an emerging concern. Dairy cattle are a reservoir for a number of pathogens that can cause human illness. This study examined the spatial distribution of dairy cattle density and explored temporal patterns of human campylobacteriosis and cryptosporidiosis notifications in New Zealand from 1997 to 2015. Maps of dairy cattle density were produced, and temporal patterns of disease rates were assessed for urban versus rural areas and for areas with different dairy cattle densities using descriptive temporal analyses. Campylobacteriosis and cryptosporidiosis rates displayed strong seasonal patterns, with highest rates in spring in rural areas and, for campylobacteriosis, summer in urban areas. Increases in rural cases often preceded increases in urban cases. Furthermore, disease rates in areas with higher dairy cattle densities tended to peak before areas with low densities or no dairy cattle. Infected dairy calves may be a direct or indirect source of campylobacteriosis or cryptosporidiosis infection in humans through environmental or occupational exposure routes, including contact with animals or feces, recreational contact with contaminated waterways, and consumption of untreated drinking water. These results have public health implications for populations living, working, or recreating in proximity to dairy farms.
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    Development of a multiplex droplet digital PCR assay for simultaneous detection and quantification of Escherichia coli, E. marmotae, and E. Ruysiae in water samples
    (Elsevier BV, 2024-03-01) Moinet M; Collis RM; Rogers L; Devane ML; Biggs PJ; Stott R; Marshall J; Muirhead R; Cookson AL
    Escherichia coli are widely used by water quality managers as Fecal Indicator Bacteria, but current quantification methods do not differentiate them from benign, environmental Escherichia species such as E. marmotae (formerly named cryptic clade V) or E. ruysiae (cryptic clades III and IV). Reliable and specific techniques for their identification are required to avoid confounding microbial water quality assessments. To address this, a multiplex droplet digital PCR (ddPCR) assay targeting lipB (E. coli and E. ruysiae) and bglC (E. marmotae) was designed. The ddPCR performance was assessed using in silico analysis; genomic DNA from 40 local, international, and reference strains of target and non-target coliforms; and spiked water samples in a range relevant to water quality managers (1 to 1000 cells/100 mL). Results were compared to an analogous quantitative PCR (qPCR) and the Colilert method. Both PCR assays showed excellent sensitivity with a limit of detection of 0.05 pg/μL and 0.005 pg/μl for ddPCR and qPCR respectively, and of quantification of 0.5 pg/μL of genomic DNA. The ddPCR allowed differentiation and quantification of three Escherichia species per run by amplitude multiplexing and showed a high concordance with concentrations measured by Colilert once proportional bias was accounted for. In silico specificity testing underlined the possibility to further detect and distinguish Escherichia cryptic clade VI. Finally, the applicability of the ddPCR was successfully tested on environmental water samples where E. marmotae and E. ruysiae potentially confound E. coli counts based on the Most Probable Number method, highlighting the utility of this novel ddPCR as an efficient and rapid discriminatory test to improve water quality assessments.
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    Dysphagia management in community/home settings: A scoping review investigating practices in Africa.
    (Taylor & Francis Group, 2024-02-21) Jayes M; Madima V; Marshall J; Pillay M
    PURPOSE: Little is known about how people living with dysphagia in rural, socioeconomically impoverished contexts in Africa are supported and manage their disability. This scoping review sought to map and synthesise evidence relating to the management of dysphagia in adults in community/home settings in Africa as a starting point for a broader study on this topic. METHOD: A multifaceted search strategy involved searches of electronic databases and grey literature, hand searches, ancestry searches, and consultation with expert advisors. Records were screened by two blinded researchers. Characteristics of included studies were summarised, and their findings synthesised using the Framework approach. RESULT: Six studies were included, relating to services for people with dysphagia secondary to various aetiologies. No grey literature was identified that provided service delivery descriptions or practice guidance. This limited evidence suggests little professional support is available to people living with dysphagia in the community. Individuals and carers use a range of strategies, including choosing different food and drink items and modifying how food is chewed and swallowed. CONCLUSION: Further research is required to understand current practice in managing dysphagia in the community in Africa, and the needs and priorities of community members who experience dysphagia and their carers.
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    High-resolution genomic analysis to investigate the impact of the invasive brushtail possum (Trichosurus vulpecula) and other wildlife on microbial water quality assessments.
    (Public Library of Science (PLoS), 2024-01-18) Moinet M; Rogers L; Biggs P; Marshall J; Muirhead R; Devane M; Stott R; Cookson A; Adenyo C
    Escherichia coli are routine indicators of fecal contamination in water quality assessments. Contrary to livestock and human activities, brushtail possums (Trichosurus vulpecula), common invasive marsupials in Aotearoa/New Zealand, have not been thoroughly studied as a source of fecal contamination in freshwater. To investigate their potential role, Escherichia spp. isolates (n = 420) were recovered from possum gut contents and feces and were compared to those from water, soil, sediment, and periphyton samples, and from birds and other introduced mammals collected within the Mākirikiri Reserve, Dannevirke. Isolates were characterized using E. coli-specific real-time PCR targeting the uidA gene, Sanger sequencing of a partial gnd PCR product to generate a gnd sequence type (gST), and for 101 isolates, whole genome sequencing. Escherichia populations from 106 animal and environmental sample enrichments were analyzed using gnd metabarcoding. The alpha diversity of Escherichia gSTs was significantly lower in possums and animals compared with aquatic environmental samples, and some gSTs were shared between sample types, e.g., gST535 (in 85% of samples) and gST258 (71%). Forty percent of isolates gnd-typed and 75% of reads obtained by metabarcoding had gSTs shared between possums, other animals, and the environment. Core-genome single nucleotide polymorphism (SNP) analysis showed limited variation between several animal and environmental isolates (<10 SNPs). Our data show at an unprecedented scale that Escherichia clones are shared between possums, other wildlife, water, and the wider environment. These findings support the potential role of possums as contributors to fecal contamination in Aotearoa/New Zealand freshwater. Our study deepens the current knowledge of Escherichia populations in under-sampled wildlife. It presents a successful application of high-resolution genomic methods for fecal source tracking, thereby broadening the analytical toolbox available to water quality managers. Phylogenetic analysis of isolates and profiling of Escherichia populations provided useful information on the source(s) of fecal contamination and suggest that comprehensive invasive species management strategies may assist in restoring not only ecosystem health but also water health where microbial water quality is compromised.
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    Stitching a new garment: Considering the future of the speech–language therapy profession globally
    (AOSIS, 2022-11-21) Staley B; Fernandes M; Hickey E; Barrett H; Wylie K; Marshall J; Pillay M; Kathard H; Sowden R; Rochus D; Westby CE; Roman TR; Hartley SD
    Providing equitable support for people experiencing communication disability (CD) globally is a historical and contemporary challenge for the speech–language therapy profession. A group of speech–language therapists (SLTs) with ongoing and sustained experiences in Majority and Minority World contexts participated in five virtual meetings in 2021. The aim of these meetings was to develop provocative statements that might spur a global discussion among individuals and organisations that support people experiencing CD. The following questions were discussed: What is our vision for the future of the profession globally? What are the global challenges around access to speech–language therapy services? Four main themes emerged: (1) the need to centre people experiencing CD as the focal point of services, (2) participation, (3) equity and (4) community. The themes relate to the need for a process of de-imperialism in the profession. Suggestions were made to develop more suitable terminology and to establish a global framework that promotes more equitable access to communication services. We seek the adoption of approaches that focus on reciprocal global engagement for capacity strengthening. Alternative models of culturally sustaining and equitable service delivery are needed to create impact for people experiencing CD, and their families worldwide. Contribution: Provocative statements were developed to prompt global conversations among speech–language therapy professionals and associations. We encourage readers to consider the questions posed, share their viewpoints and initiate positive change towards a global strategy.