Target for improvement: a cluster randomised trial of public involvement in quality-indicator prioritisation (intervention development and study protocol)

<p>Abstract</p> <p>Background</p> <p>Public priorities for improvement often differ from those of clinicians and managers. Public involvement has been proposed as a way to bridge the gap between professional and public clinical care priorities but has not been studied in the context of quality-indicator choice. Our objective is to assess the feasibility and impact of public involvement on quality-indicator choice and agreement with public priorities.</p> <p>Methods</p> <p>We will conduct a cluster randomised controlled trial comparing quality-indicator prioritisation with and without public involvement. In preparation for the trial, we developed a 'menu' of quality indicators, based on a systematic review of existing validated indicator sets. Participants (public representatives, clinicians, and managers) will be recruited from six participating sites. In intervention sites, public representatives will be involved through direct participation (public representatives, clinicians, and managers will deliberate together to agree on quality-indicator choice and use) and consultation (individual public recommendations for improvement will be collected and presented to decision makers). In control sites, only clinicians and managers will take part in the prioritisation process. Data on quality-indicator choice and intended use will be collected. Our primary outcome will compare quality-indicator choice and agreement with public priorities between intervention and control groups. A process evaluation based on direct observation, videorecording, and participants' assessment will be conducted to help explain the study's results. The marginal cost of public involvement will also be assessed.</p> <p>Discussion</p> <p>We identified 801 quality indicators that met our inclusion criteria. An expert panel agreed on a final set of 37 items containing validated quality indicators relevant for chronic disease prevention and management in primary care. We pilot tested our public-involvement intervention with 27 participants (11 public representatives and 16 clinicians and managers) and our study instruments with an additional 21 participants, which demonstrated the feasibility of the intervention and generated important insights and adaptations to engage public representatives more effectively. To our knowledge, this study is the first trial of public involvement in quality-indicator prioritisation, and its results could foster more effective upstream engagement of patients and the public in clinical practice improvement.</p> <p>Trial registration</p> <p><a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2496">NTR2496</a> (Netherlands National Trial Register, <url>http://www.trialregister.nl</url>).</p

Dispositif d'évaluation précoce de la résistance du pommier à la tavelure (Venturia inaequalis)

National audienc

Dispositif d'évaluation des niveaux de sensibilité des variétés de pommier à la tavelure

National audienc

How Did Host Domestication Modify Life History Traits of Its Pathogens?

Understanding evolutionary dynamics of pathogens during domestication of their hosts and rise of agro-ecosystems is essential for durable disease management. Here, we investigated changes in life-history traits of the fungal pathogen Venturia inaequalis during domestication of the apple. Life traits linked to fungal dispersal were compared between 60 strains that were sampled in domestic and wild habitats in Kazakhstan, the center of origin of both host and pathogen. Our two main findings are that transition from wild to agro-ecosystems was associated with an increase of both spore size and sporulation capacity; and that distribution of quantitative traits of the domestic population mostly overlapped with those of the wild population. Our results suggest that apple domestication had a considerable impact on fungal characters linked to its dispersal through selection from standing phenotypic diversity. We showed that pestification of V. inaequalis in orchards led to an enhanced allocation in colonization ability from standing variation in the wild area. This study emphasizes the potential threat that pathogenic fungal populations living in wild environments represent for durability of resistance in agro-ecosystems

Hybridizations between formae speciales of Venturia inaequalis pave the way for a new biocontrol strategy to manage fungal plant pathogens

International audienceHybridization and adaptation to new hosts are important mechanisms of fungal disease emergence. Evaluating the risk of emergence of hybrids with enhanced virulence is then key to develop sustainable crop disease management. We evaluated this risk in Venturia inaequalis, the fungus responsible for the common and serious scab disease on Rosaceae hosts, including apple, pyracantha and loquat. Field isolates from these three hosts and progenies obtained from five crosses between formae speciales isolates collected from pyracantha (f.sp. pyracantha) and apple (f.sp. pomi) were tested for their pathogenicity on the three hosts. We confirmed a strict host specificity between isolates from apple and pyracantha, and showed that most isolates were able to cause disease on loquat. None of the 251 progeny obtained from five crosses between V. inaequalis f.sp. pyracantha and V. inaequalis f. sp. pomi could infect apple. If confirmed on more crosses, the inability of the hybrids to infect apple could lead to a novel biocontrol strategy based on a sexual hijacking of V. inaequalis f.sp. pomi by a massive introduction of V. inaequalis f.sp. pyracantha in apple orchards. This strategy, analogous to the sterile insect approach, could lead to the collapse of the population size of V. inaequalis and dramatically reduce the use of chemicals in orchards

Pairwise correlations between phenotypic traits.

<p>Scatter plots indicating the degree of correlation between traits (below diagonal) and pairwise Pearson's correlation R values (above diagonal). Pearson’s correlation coefficients were calculated from averaged data from each strain for sporulation capacity, spore size and hyphal growth. Statistical significant correlation coefficients are indicated as following: ** P-value < 0.01 and *** P-value < 0.001. Calculations were performed for domestic (A panel) and wild (B panel) populations, respectively.</p

Quantitative distribution of life history trait variables between wild (blue) and domestic population (green).

<p>The horizontal line in boxplots represents the median. A significant difference between populations is observed for the sporulation capacity and spore size. Sporulation average in wild population: 122,400 spores mL^-1; and in domestic population: 199,955 spores mL^-1. Spore size average is 9.2 μm in the wild population and is 9.5 μm in the domestic population.</p

Quantitative distribution of life history trait variables.

<p>Distribution of quantitative variables: hyphal growth 24 days after deposits on agar (cm), germination rate (in logit units), sporulation capacity (in Log₁₀ units), and spore size (μm). Blue histograms correspond to the wild population and green ones correspond to the domestic population.</p

Slow erosion of a quantitative apple resistance to Venturia inaequalis based on an isolate-specific Quantitative Trait Locus

Quantitative plant resistance affects the aggressiveness of pathogens and is usually considered more durable than qualitative resistance. However, the efficiency of a quantitative resistance based on an isolate-specific Quantitative Trait Locus (QTL) is expected to decrease over time due to the selection of isolates with a high level of aggressiveness on resistant plants. To test this hypothesis, we surveyed scab incidence over an eight-year period in an orchard planted with susceptible and quantitatively resistant apple genotypes. We sampled 79 Venturia inaequalis isolates from this orchard at three dates and we tested their level of aggressiveness under controlled conditions. Isolates sampled on resistant genotypes triggered higher lesion density and exhibited a higher sporulation rate on apple carrying the resistance allele of the QTL T1 compared to isolates sampled on susceptible genotypes. Due to this ability to select aggressive isolates, we expected the QTL T1 to be non-durable. However, our results showed that the quantitative resistance based on the QTL T1 remained efficient in orchard over an eight-year period, with only a slow decrease in efficiency and no detectable increase of the aggressiveness of fungal isolates over time. We conclude that knowledge on the specificity of a QTL is not sufficient to evaluate its durability. Deciphering molecular mechanisms associated with resistance QTLs, genetic determinants of aggressiveness and putative trade-offs within pathogen populations is needed to help in understanding the erosion processe

Threat to Asian wild apple trees posed by gene flow from domesticated apple trees and their pestified pathogens

Secondary contact between crops and their wild relatives poses a threat to wild species, not only through gene flow between plants, but also through the dispersal of crop pathogens and genetic exchanges involving these pathogens, particularly those that have become more virulent by indirect selection on resistant crops, a phenomenon known as “pestification”. Joint analyses of wild and domesticated hosts and their pathogens are essential to address this issue, but such analyses remain rare. We used population genetics approaches, demographic inference and pathogenicity tests on host-pathogen pairs of wild or domesticated apple trees from Central Asia and their main fungal pathogen, Venturia inaequalis, which itself has differentiated agricultural and wild-type populations. We confirmed the occurrence of gene flow from cultivated (Malus domestica) to wild (Malus sieversii) apple trees in Asian forests, potentially threatening the persistence of Asian wild apple trees. Pathogenicity tests demonstrated the pestification of V. inaequalis, the agricultural-type population being more virulent on both wild and domesticated trees. SNP markers and the demographic modeling of pathogen populations revealed hybridization following secondary contact between agricultural and wild-type fungal populations, and dispersal of the agricultural-type pathogen population in wild forests, increasing the threat of disease in the wild apple species. We detected a SNP potentially involved in pathogen pestification, generating an early stop codon in a gene encoding a small secreted protein in the agricultural-type fungal population. Our findings, based on joint analyses of paired host and pathogen datasets, highlight the threat posed by cultivating a crop near its center of origin, in terms of pestified pathogen invasions in wild plant populations and introgression in the wild-type pathogen population