Pairwise interactions in food webs, including those between predator and prey are often modulated by a third species. Such higher-order interactions are important structural components of natural food webs that can increase the stability of communities against perturbations and ensure continued ecosystem functioning. Particularly the flux of rare organic and inorganic compounds that are essential to species in the community can create higher-order interactions. Even though many such compounds exist, their effect on structuring communities is little understood. In this study, I perform invasion analyses on a general food web model that depicts apparent and exploitative competition. Introducing the provision of essential resources by a prey species to either its competitor or its predator as a higher-order interaction, I find that this mechanism can ensure the focal prey’s persistence. Larger dietary essentiality, i.e. a stronger dependence of the predator or the competitor on the essential resource can increase the invasion growth rate of the focal prey to positive values, thus promoting its persistence when it would go extinct for low essentiality. This research shows that essential resources and the higher-order interactions created by them should be considered in community ecology.
{"title":"Provision of essential resources as a persistence strategy in food webs","authors":"Michael Raatz","doi":"10.24072/pcjournal.315","DOIUrl":"https://doi.org/10.24072/pcjournal.315","url":null,"abstract":"Pairwise interactions in food webs, including those between predator and prey are often modulated by a third species. Such higher-order interactions are important structural components of natural food webs that can increase the stability of communities against perturbations and ensure continued ecosystem functioning. Particularly the flux of rare organic and inorganic compounds that are essential to species in the community can create higher-order interactions. Even though many such compounds exist, their effect on structuring communities is little understood. In this study, I perform invasion analyses on a general food web model that depicts apparent and exploitative competition. Introducing the provision of essential resources by a prey species to either its competitor or its predator as a higher-order interaction, I find that this mechanism can ensure the focal prey’s persistence. Larger dietary essentiality, i.e. a stronger dependence of the predator or the competitor on the essential resource can increase the invasion growth rate of the focal prey to positive values, thus promoting its persistence when it would go extinct for low essentiality. This research shows that essential resources and the higher-order interactions created by them should be considered in community ecology.","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135827574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Veli-Matti Karhulahti, Miia Siutila, Jukka Vahlo, Raine Koskimaa
The academic debates regarding the psychiatric relevance of gaming disorder continue largely because the lived experiences of treatment-seekers remain mostly unstudied. This registered report addresses the above research gap with a longitudinal design that pursues a comparative descriptive understanding of how intensive gaming experiences evolve in both clinical and non-clinical life situations. Accompanied by a rich health survey, interpretative phenomenological analysis was adapted to understand in-depth interview data from treatment-seeking (n=5) and esports-playing (n=4) participants, the latter of which did not experience any gaming-related health problems. The interviews were carried out as a 1-year follow-up. The study finds intensive relationships with gaming to be experienced through
{"title":"Life Thinning and Gaming Disorder: A Longitudinal Qualitative Registered Report","authors":"Veli-Matti Karhulahti, Miia Siutila, Jukka Vahlo, Raine Koskimaa","doi":"10.24072/pcjournal.313","DOIUrl":"https://doi.org/10.24072/pcjournal.313","url":null,"abstract":"The academic debates regarding the psychiatric relevance of gaming disorder continue largely because the lived experiences of treatment-seekers remain mostly unstudied. This registered report addresses the above research gap with a longitudinal design that pursues a comparative descriptive understanding of how intensive gaming experiences evolve in both clinical and non-clinical life situations. Accompanied by a rich health survey, interpretative phenomenological analysis was adapted to understand in-depth interview data from treatment-seeking (n=5) and esports-playing (n=4) participants, the latter of which did not experience any gaming-related health problems. The interviews were carried out as a 1-year follow-up. The study finds intensive relationships with gaming to be experienced through","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135884194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Grégoire Perez, Laure Bournez, Nathalie Boulanger, Johanna Fite, Barbara Livoreil, Karen D. McCoy, Elsa Quillery, Magalie René-Martellet, Sarah I. Bonnet
The tick Ixodes ricinus is the most important vector species of infectious diseases in European France. Understanding its distribution, phenology, and host species use, along with the distribution and prevalence of associated pathogens at a national scale is essential for developing prevention strategies. The aim of this paper is to provide a systematic map and narrative review of the existing knowledge on the eco-epidemiology of I. ricinus in France. Using literature published up to 2020, the present paper provides a distribution map for the species and a summary of environmental factors explaining observed geographical differences in phenology and temporal differences in abundance. The diversity of vertebrate host species used by this tick, along with their degree of infestation when available, are presented and discussed with respect to their potential contribution to the population dynamics of I. ricinus and the circulation of tick-borne zoonotic pathogens. Prevalence data of detected pathogens are summarised in different maps. Results from 187 identified references show that the species is present in most departments, but scarce under Mediterranean climates and in coastal habitats. Its phenology is generally bimodal with climate-associated variations. Abundance seems positively influenced by forest cover and host abundance. Rodents and ruminants are the most studied species groups, but the diversity of sampling protocols (e.g., location, season, exhaustivity of inspection) precluded direct comparisons between groups. Data on pathogens are patchy, with most studies conducted near research laboratories. Among pathogens, Borrelia burgdorferi sensu lato is the most examined and seems most prevalent in north-eastern and central France. The review highlights the gaps in our knowledge of tick-host-pathogen interactions, their ecologies and their distributions, and demonstrates the need to address these gaps in order to optimize tick and tick-borne diseases prevention and control.
蓖麻蜱是欧洲法国最重要的传染病媒介物种。了解其分布、物候和寄主物种利用，以及相关病原体在全国范围内的分布和流行情况，对于制定预防策略至关重要。本文的目的是提供一个系统的地图和叙述综述现有知识的蓖麻毒素在法国的生态流行病学。本文利用截至2020年发表的文献，绘制了该物种的分布图，并总结了解释观测到的物候地理差异和丰度时间差异的环境因素。本文介绍并讨论了该蜱所使用的脊椎动物宿主物种的多样性，以及它们在可用时的侵袭程度，以及它们对蓖麻蜱种群动态和蜱传人畜共患病病原体传播的潜在贡献。在不同的地图中汇总了检测到的病原体的流行率数据。来自187个已确定参考文献的结果表明，该物种存在于大多数省，但在地中海气候和沿海生境中很少。它的物候通常是与气候相关的双峰变化。丰度似乎受到森林覆盖和寄主丰度的积极影响。啮齿类动物和反刍动物是研究最多的物种组，但采样方案的多样性(例如，地点、季节、检查的穷尽性)妨碍了组间的直接比较。关于病原体的数据不完整，大多数研究都是在研究实验室附近进行的。在病原体中，伯氏疏螺旋体(Borrelia burgdorferi sensu lato)是检测最多的，似乎在法国东北部和中部最流行。这篇综述强调了我们在蜱-宿主-病原体相互作用、它们的生态学和分布方面的知识差距，并表明有必要解决这些差距，以优化蜱和蜱传疾病的预防和控制。
{"title":"The distribution, phenology, host range and pathogen prevalence of Ixodes ricinus in France: a systematic map and narrative review","authors":"Grégoire Perez, Laure Bournez, Nathalie Boulanger, Johanna Fite, Barbara Livoreil, Karen D. McCoy, Elsa Quillery, Magalie René-Martellet, Sarah I. Bonnet","doi":"10.24072/pcjournal.291","DOIUrl":"https://doi.org/10.24072/pcjournal.291","url":null,"abstract":"The tick Ixodes ricinus is the most important vector species of infectious diseases in European France. Understanding its distribution, phenology, and host species use, along with the distribution and prevalence of associated pathogens at a national scale is essential for developing prevention strategies. The aim of this paper is to provide a systematic map and narrative review of the existing knowledge on the eco-epidemiology of I. ricinus in France. Using literature published up to 2020, the present paper provides a distribution map for the species and a summary of environmental factors explaining observed geographical differences in phenology and temporal differences in abundance. The diversity of vertebrate host species used by this tick, along with their degree of infestation when available, are presented and discussed with respect to their potential contribution to the population dynamics of I. ricinus and the circulation of tick-borne zoonotic pathogens. Prevalence data of detected pathogens are summarised in different maps. Results from 187 identified references show that the species is present in most departments, but scarce under Mediterranean climates and in coastal habitats. Its phenology is generally bimodal with climate-associated variations. Abundance seems positively influenced by forest cover and host abundance. Rodents and ruminants are the most studied species groups, but the diversity of sampling protocols (e.g., location, season, exhaustivity of inspection) precluded direct comparisons between groups. Data on pathogens are patchy, with most studies conducted near research laboratories. Among pathogens, Borrelia burgdorferi sensu lato is the most examined and seems most prevalent in north-eastern and central France. The review highlights the gaps in our knowledge of tick-host-pathogen interactions, their ecologies and their distributions, and demonstrates the need to address these gaps in order to optimize tick and tick-borne diseases prevention and control.","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136362808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional analyses of projectile points often use visual identification, the presence or absence of discrete characteristics, or linear measurements and angles to classify points into distinct types. Geometric morphometrics provides additional tools for analyzing, visualizing
{"title":"Geometric morphometric analysis of projectile points from the Southwest United States","authors":"Robert J. Bischoff","doi":"10.24072/pcjournal.312","DOIUrl":"https://doi.org/10.24072/pcjournal.312","url":null,"abstract":"Traditional analyses of projectile points often use visual identification, the presence or absence of discrete characteristics, or linear measurements and angles to classify points into distinct types. Geometric morphometrics provides additional tools for analyzing, visualizing","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45251079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Several studies have highlighted the presence of contaminated entries in public sequence repositories, calling for special attention to the associated metadata. Here, we propose and evaluate a fast and efficient k–mer-based approach to assess the degree of mislabeling or contamination. We applied it to high-throughput whole-genome raw sequence data for 236 Ind-Seq and 22 Pool-Seq samples of the invasive species Drosophila suzukii. We first used Clark software to build a dictionary of species-discriminating k–mers from the curated assemblies of 29 target drosophilid species (including D. melanogaster, D. simulans, D. subpulchrella, or D. biarmipes) and 12 common drosophila pathogens and commensals (including Wolbachia). Counting the number of k–mers composing each query sample sequence that matched a discriminating k–mer from the dictionary provided a simple criterion for assignment to target species and evaluation of the entire sample. Analyses of a wide range of samples, representative of both target and other drosophilid species, demonstrated very good performance of the proposed approach, both in terms of run time and accuracy of sequence assignment. Of the 236 D. suzukii individuals, five were reassigned to D. simulans and eleven to D. subpulchrella. Another four showed moderate to substantial microbial contamination. Similarly, among the 22 Pool-Seq samples analyzed, two from the native range were found to be contaminated with 1 and 7 D. subpulchrella individuals, respectively (out of 50), and one from Europe was found to be contaminated with 5 to 6 D. immigrans individuals (out of 100). Overall, the present analysis allowed the definition of a large curated dataset consisting of > 60 population samples representative of the worldwide genetic diversity, which may be valuable for further population genetics studies on D. suzukii. More generally, while we advocate careful sample identification and verification prior to sequencing, the proposed framework is simple and computationally efficient enough to be included as a routine post-hoc quality check prior to any data analysis and prior to data submission to public repositories.
{"title":"Efficient k-mer based curation of raw sequence data: application in Drosophila suzukii","authors":"Mathieu Gautier","doi":"10.24072/pcjournal.309","DOIUrl":"https://doi.org/10.24072/pcjournal.309","url":null,"abstract":"Several studies have highlighted the presence of contaminated entries in public sequence repositories, calling for special attention to the associated metadata. Here, we propose and evaluate a fast and efficient k–mer-based approach to assess the degree of mislabeling or contamination. We applied it to high-throughput whole-genome raw sequence data for 236 Ind-Seq and 22 Pool-Seq samples of the invasive species Drosophila suzukii. We first used Clark software to build a dictionary of species-discriminating k–mers from the curated assemblies of 29 target drosophilid species (including D. melanogaster, D. simulans, D. subpulchrella, or D. biarmipes) and 12 common drosophila pathogens and commensals (including Wolbachia). Counting the number of k–mers composing each query sample sequence that matched a discriminating k–mer from the dictionary provided a simple criterion for assignment to target species and evaluation of the entire sample. Analyses of a wide range of samples, representative of both target and other drosophilid species, demonstrated very good performance of the proposed approach, both in terms of run time and accuracy of sequence assignment. Of the 236 D. suzukii individuals, five were reassigned to D. simulans and eleven to D. subpulchrella. Another four showed moderate to substantial microbial contamination. Similarly, among the 22 Pool-Seq samples analyzed, two from the native range were found to be contaminated with 1 and 7 D. subpulchrella individuals, respectively (out of 50), and one from Europe was found to be contaminated with 5 to 6 D. immigrans individuals (out of 100). Overall, the present analysis allowed the definition of a large curated dataset consisting of > 60 population samples representative of the worldwide genetic diversity, which may be valuable for further population genetics studies on D. suzukii. More generally, while we advocate careful sample identification and verification prior to sequencing, the proposed framework is simple and computationally efficient enough to be included as a routine post-hoc quality check prior to any data analysis and prior to data submission to public repositories.","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136355055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arnoul Van Rooij, É. Badel, J. Barczi, Y. Caraglio, T. Alméras, J. Gril
9 This work aims to model the mechanical processes used by tree branches to control their posture despite 10 their increasing weight loading. The two known options for a branch to maintain its orientation are the 11 asymmetry of maturation stress, including reaction wood formation, and eccentric radial growth. Both 12 options can be observed in nature and influence the stress distribution developed in the branch each 13 year. This so-called "growth stress" reflects the mechanical state of the branch. In this work, a growth 14 stress model was developed at the cross-section level in order to quantify and study the bio-mechanical 15 impact of each process. For illustration, this model was applied to branches of two 50-year-old trees, 16 one softwood Pinus pinaster and one hardwood Prunus avium (wild cherry tree), both simulated with 17 the AmapSim discrete element software. For the wild cherry tree, the computed ouputs enlightened that 18 the eccentricity of radial growth seems to be as efficient as the formation of reaction wood to maintain 19 the postural control despite the increasing gravity. err The computed outputs enlightened that, for both 20 Prunus avium and Pinus pinaster , eccentric radial growth appears less efficient than the formation of 21 reaction wood to counter the increasing gravity stress applied to the branch. err For the pine tree, eccentric 22 radial growth appears to be less efficient than the formation of reaction wood err . But although eccentric 23 growth err it err does not necessarily act as a relevant lever for postural control, it greatly modifies the
{"title":"Modelling the growth stress in tree branches: eccentric growth vs. reaction wood","authors":"Arnoul Van Rooij, É. Badel, J. Barczi, Y. Caraglio, T. Alméras, J. Gril","doi":"10.24072/pcjournal.308","DOIUrl":"https://doi.org/10.24072/pcjournal.308","url":null,"abstract":"9 This work aims to model the mechanical processes used by tree branches to control their posture despite 10 their increasing weight loading. The two known options for a branch to maintain its orientation are the 11 asymmetry of maturation stress, including reaction wood formation, and eccentric radial growth. Both 12 options can be observed in nature and influence the stress distribution developed in the branch each 13 year. This so-called \"growth stress\" reflects the mechanical state of the branch. In this work, a growth 14 stress model was developed at the cross-section level in order to quantify and study the bio-mechanical 15 impact of each process. For illustration, this model was applied to branches of two 50-year-old trees, 16 one softwood Pinus pinaster and one hardwood Prunus avium (wild cherry tree), both simulated with 17 the AmapSim discrete element software. For the wild cherry tree, the computed ouputs enlightened that 18 the eccentricity of radial growth seems to be as efficient as the formation of reaction wood to maintain 19 the postural control despite the increasing gravity. err The computed outputs enlightened that, for both 20 Prunus avium and Pinus pinaster , eccentric radial growth appears less efficient than the formation of 21 reaction wood to counter the increasing gravity stress applied to the branch. err For the pine tree, eccentric 22 radial growth appears to be less efficient than the formation of reaction wood err . But although eccentric 23 growth err it err does not necessarily act as a relevant lever for postural control, it greatly modifies the","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44762174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katerina Newman, Cyril Forestier, Boris Cheval, Zachary Zenko, Margaux de Chanaleilles, Benjamin Gardner, Amanda L Rebar
Evidence shows that people with strong physical activity habits tend to engage in more physical activity than those with weaker habits, but little is known about how habit influences specific types of physical activity. This study aimed to test whether mean level of habit strength and magnitude of the habit strength - behaviour association differed as a function of physical activity modality. Participants (N = 120; M age = 25 years, 75% female) who reported engaging in organised sport separately reported their habit strength for organised sport and leisure time physical activity as well as the time they spent engaging in these physical activity behaviours. Means comparisons and multilevel modelling revealed that people had significantly stronger habit for organised sport than for leisure time physical activity. Crucially, no significant difference was found in the magnitude of the sport-habit and leisure-habit link. Post-hoc analyses revealed that habit was stronger for team sport compared to individual sport, but that there was no significant difference in sport-habit association between team and individual sports. Research should therefore focus on identifying the characteristics of team sports-based activity that are particularly conducive to habit formation as a precursor to developing interventions to promote performance of leisure time activity in a way that would attain such characteristics.
{"title":"Comparing habit-behaviour relationships for organised versus leisure time physical activity.","authors":"Katerina Newman, Cyril Forestier, Boris Cheval, Zachary Zenko, Margaux de Chanaleilles, Benjamin Gardner, Amanda L Rebar","doi":"10.24072/pcjournal.311","DOIUrl":"10.24072/pcjournal.311","url":null,"abstract":"<p><p>Evidence shows that people with strong physical activity habits tend to engage in more physical activity than those with weaker habits, but little is known about how habit influences specific types of physical activity. This study aimed to test whether mean level of habit strength and magnitude of the habit strength - behaviour association differed as a function of physical activity modality. Participants (N = 120; M age = 25 years, 75% female) who reported engaging in organised sport separately reported their habit strength for organised sport and leisure time physical activity as well as the time they spent engaging in these physical activity behaviours. Means comparisons and multilevel modelling revealed that people had significantly stronger habit for organised sport than for leisure time physical activity. Crucially, no significant difference was found in the magnitude of the sport-habit and leisure-habit link. Post-hoc analyses revealed that habit was stronger for team sport compared to individual sport, but that there was no significant difference in sport-habit association between team and individual sports. Research should therefore focus on identifying the characteristics of team sports-based activity that are particularly conducive to habit formation as a precursor to developing interventions to promote performance of leisure time activity in a way that would attain such characteristics.</p>","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7617183/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45648624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Diphtheria, caused by Corynebacterium diphtheriae, reemerges in Europe since 2022. Genomic sequencing can inform on transmission routes and genotypes of concern, but currently, no standard approach exists to detect clinically important genomic features and to interpret emergence in the global C. diphtheriae population framework. Methods: We developed the bioinformatics pipeline diphtOscan (available at https://gitlab.pasteur.fr/BEBP/diphtoscan) to extract from genomes of Corynebacteria of the diphtheriae species complex, medically relevant features including tox gene presence and disruption. We analyzed 101 human C. diphtheriae isolates collected in 2022 in metropolitan and overseas France (France-2022). To define the population background of this emergence, we sequenced 379 additional isolates (mainly from France, 2018-2021) and collated 870 publicly-available genomes. Results: The France-2022 isolates comprised 45 tox-positive (44 toxigenic) isolates, mostly imported, belonging to 10 sublineages (<500 distinct core genes). The global dataset comprised 245 sublineages and 33.9% tox-positive genomes, with diphtOscan predicting non-toxigenicity in 16.0% of these. 12% of the global isolates, and 43.6% of France-2022 ones, were multidrug resistant. Convergence of toxigenicity with penicillin and erythromycin resistance was observed in 2 isolates from France-2022. Phylogenetic lineages Gravis and Mitis contrasted strikingly in their pathogenicity-associated genes. Conclusions: This work provides a bioinformatics tool and global population framework to analyze C. diphtheriae genomes, revealing important heterogeneities in virulence and resistance features. Emerging genotypes combining toxigenicity and first-line antimicrobial resistance represent novel threats. Genomic epidemiology studies of C. diphtheriae should be intensified globally to improve understanding of reemergence and spatial spread.
{"title":"A global Corynebacterium diphtheriae genomic framework sheds light on current diphtheria reemergence","authors":"Mélanie Hennart, Chiara Crestani, Sébastien Bridel, Nathalie Armatys, Sylvie Brémont, Annick Carmi-Leroy, Annie Landier, Virginie Passet, Laure Fonteneau, Sophie Vaux, Julie Toubiana, Edgar Badell, Sylvain Brisse","doi":"10.24072/pcjournal.307","DOIUrl":"https://doi.org/10.24072/pcjournal.307","url":null,"abstract":"Background: Diphtheria, caused by Corynebacterium diphtheriae, reemerges in Europe since 2022. Genomic sequencing can inform on transmission routes and genotypes of concern, but currently, no standard approach exists to detect clinically important genomic features and to interpret emergence in the global C. diphtheriae population framework. Methods: We developed the bioinformatics pipeline diphtOscan (available at https://gitlab.pasteur.fr/BEBP/diphtoscan) to extract from genomes of Corynebacteria of the diphtheriae species complex, medically relevant features including tox gene presence and disruption. We analyzed 101 human C. diphtheriae isolates collected in 2022 in metropolitan and overseas France (France-2022). To define the population background of this emergence, we sequenced 379 additional isolates (mainly from France, 2018-2021) and collated 870 publicly-available genomes. Results: The France-2022 isolates comprised 45 tox-positive (44 toxigenic) isolates, mostly imported, belonging to 10 sublineages (<500 distinct core genes). The global dataset comprised 245 sublineages and 33.9% tox-positive genomes, with diphtOscan predicting non-toxigenicity in 16.0% of these. 12% of the global isolates, and 43.6% of France-2022 ones, were multidrug resistant. Convergence of toxigenicity with penicillin and erythromycin resistance was observed in 2 isolates from France-2022. Phylogenetic lineages Gravis and Mitis contrasted strikingly in their pathogenicity-associated genes. Conclusions: This work provides a bioinformatics tool and global population framework to analyze C. diphtheriae genomes, revealing important heterogeneities in virulence and resistance features. Emerging genotypes combining toxigenicity and first-line antimicrobial resistance represent novel threats. Genomic epidemiology studies of C. diphtheriae should be intensified globally to improve understanding of reemergence and spatial spread.","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135890669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Loïs Rancilhac, Aurélien Miralles, Philippe Geniez, Daniel Mendez-Aranda, Menad Beddek, José Carlos Brito, Raphaël Leblois, Pierre-André Crochet
Aim: Discontinuity in the distribution of genetic diversity (often based on mtDNA) is usually interpreted as evidence for phylogeographic breaks, underlying vicariant units. However, a misleading signal of phylogeographic break can arise in the absence of barrier to gene flow, under mechanisms of isolation by distance (IBD). How and under which conditions phylogeographic breaks can be reliably differentiated from populations evolving under IBD remain unclear. Here, we use multi-locus sequence data from a widely distributed lizard species to address these questions in an empirical setting. Location: Morocco. Taxon: Spiny-footed lizard (Acanthodactylus erythrurus), Squamata: Lacertidae. Methods: Using 325 samples from 40 localities, we identified genetic discontinuities within A. erythrurus based on a mitochondrial fragment and nine nuclear markers independently. Using the nuclear markers, we then applied linear regression models to investigate whether genetic divergence could be explained by geographical distances alone, or barriers to gene flow (real phylogeographic breaks). Results: A. erythrurus is characterized by an important mitochondrial diversity, with 11 strongly supported phylogeographic lineages with a crown age of 6 Mya. Nuclear markers, however, yielded weak phylogenetic support for these lineages. Using clustering methods based on genotypes at nine nuclear loci, we identified phylogeographic clusters that were partly discordant with the mtDNA lineages. Tests of IBD delimited at least four groups of populations separated by barriers to gene flow, but unambiguous separation of vicariance from IBD remained challenging in several cases. Main conclusions: The genetic diversity of A. erythrurus originates from a mix of IBD and vicariance, which were difficult to distinguish, and resulted in similar levels of mitochondrial differentiation. These results highlight that phylogeographic breaks inferred from mitochondrial data should be further investigated using multi-locus data and explicit testing to rule out alternative processes generating discontinuities in mitochondrial diversity, including IBD. We identified four groups of populations within A. erythrurus, separated by barriers to gene flow, but even using nine independent nuclear makers the power of our approach was limited, and further investigation using genome-wide data will be required to resolve the phylogeographic history of this species.
{"title":"Phylogeographic breaks and how to find them: An empirical attempt at separating vicariance from isolation by distance in a lizard with restricted dispersal","authors":"Loïs Rancilhac, Aurélien Miralles, Philippe Geniez, Daniel Mendez-Aranda, Menad Beddek, José Carlos Brito, Raphaël Leblois, Pierre-André Crochet","doi":"10.24072/pcjournal.301","DOIUrl":"https://doi.org/10.24072/pcjournal.301","url":null,"abstract":"Aim: Discontinuity in the distribution of genetic diversity (often based on mtDNA) is usually interpreted as evidence for phylogeographic breaks, underlying vicariant units. However, a misleading signal of phylogeographic break can arise in the absence of barrier to gene flow, under mechanisms of isolation by distance (IBD). How and under which conditions phylogeographic breaks can be reliably differentiated from populations evolving under IBD remain unclear. Here, we use multi-locus sequence data from a widely distributed lizard species to address these questions in an empirical setting. Location: Morocco. Taxon: Spiny-footed lizard (Acanthodactylus erythrurus), Squamata: Lacertidae. Methods: Using 325 samples from 40 localities, we identified genetic discontinuities within A. erythrurus based on a mitochondrial fragment and nine nuclear markers independently. Using the nuclear markers, we then applied linear regression models to investigate whether genetic divergence could be explained by geographical distances alone, or barriers to gene flow (real phylogeographic breaks). Results: A. erythrurus is characterized by an important mitochondrial diversity, with 11 strongly supported phylogeographic lineages with a crown age of 6 Mya. Nuclear markers, however, yielded weak phylogenetic support for these lineages. Using clustering methods based on genotypes at nine nuclear loci, we identified phylogeographic clusters that were partly discordant with the mtDNA lineages. Tests of IBD delimited at least four groups of populations separated by barriers to gene flow, but unambiguous separation of vicariance from IBD remained challenging in several cases. Main conclusions: The genetic diversity of A. erythrurus originates from a mix of IBD and vicariance, which were difficult to distinguish, and resulted in similar levels of mitochondrial differentiation. These results highlight that phylogeographic breaks inferred from mitochondrial data should be further investigated using multi-locus data and explicit testing to rule out alternative processes generating discontinuities in mitochondrial diversity, including IBD. We identified four groups of populations within A. erythrurus, separated by barriers to gene flow, but even using nine independent nuclear makers the power of our approach was limited, and further investigation using genome-wide data will be required to resolve the phylogeographic history of this species.","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":"173 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136242994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christopher A Emerling, Gillian C Gibb, Marie-Ka Tilak, Jonathan J Hughes, Melanie Kuch, Ana T Duggan, Hendrik N Poinar, Michael W Nachman, Frédéric Delsuc
The recent influx of genomic data has provided greater insights into the molecular basis for regressive evolution, or vestigialization, through gene loss and pseudogenization. As such, the analysis of gene degradation patterns has the potential to provide insights into the evolutionary history of regressed anatomical traits. We specifically applied these principles to the xenarthran radiation (anteaters, sloths, armadillos), which is characterized by taxa with a gradation in regressed dental phenotypes. Whether the pattern among extant xenarthrans is due to an ancient and gradual decay of dental morphology or occurred repeatedly in parallel is unknown. We tested these competing hypotheses by examining 11 core dental genes in most living species of Xenarthra, characterizing shared inactivating mutations and patterns of relaxed selection during their radiation. Here we report evidence of independent and distinct events of dental gene loss in the major xenarthran subclades. First, we found strong evidence of complete enamel loss in the common ancestor of sloths and anteaters, suggested by the inactivation of five enamel-associated genes (AMELX, AMTN, MMP20, ENAM, ACP4). Next, whereas dental regression appears to have halted in sloths, presumably a critical event that ultimately permitted adaptation to an herbivorous lifestyle, anteaters continued losing genes on the path towards complete tooth loss. Echoes of this event are recorded in the genomes of all living anteaters, being marked by a 2-bp deletion in a gene critical for dentinogenesis (DSPP) and a putative shared 1-bp insertion in a gene linked to tooth retention (ODAPH). By contrast, in the two major armadillo clades, genes pertaining to the dento-gingival junction and amelogenesis appear to have been independently inactivated prior to losing all or some enamel. These genomic data provide evidence for multiple pathways and rates of anatomical regression, and underscore the utility of using pseudogenes to reconstruct evolutionary history when fossils are sparse.
{"title":"Genomic data suggest parallel dental vestigialization within the xenarthran radiation","authors":"Christopher A Emerling, Gillian C Gibb, Marie-Ka Tilak, Jonathan J Hughes, Melanie Kuch, Ana T Duggan, Hendrik N Poinar, Michael W Nachman, Frédéric Delsuc","doi":"10.24072/pcjournal.303","DOIUrl":"https://doi.org/10.24072/pcjournal.303","url":null,"abstract":"The recent influx of genomic data has provided greater insights into the molecular basis for regressive evolution, or vestigialization, through gene loss and pseudogenization. As such, the analysis of gene degradation patterns has the potential to provide insights into the evolutionary history of regressed anatomical traits. We specifically applied these principles to the xenarthran radiation (anteaters, sloths, armadillos), which is characterized by taxa with a gradation in regressed dental phenotypes. Whether the pattern among extant xenarthrans is due to an ancient and gradual decay of dental morphology or occurred repeatedly in parallel is unknown. We tested these competing hypotheses by examining 11 core dental genes in most living species of Xenarthra, characterizing shared inactivating mutations and patterns of relaxed selection during their radiation. Here we report evidence of independent and distinct events of dental gene loss in the major xenarthran subclades. First, we found strong evidence of complete enamel loss in the common ancestor of sloths and anteaters, suggested by the inactivation of five enamel-associated genes (AMELX, AMTN, MMP20, ENAM, ACP4). Next, whereas dental regression appears to have halted in sloths, presumably a critical event that ultimately permitted adaptation to an herbivorous lifestyle, anteaters continued losing genes on the path towards complete tooth loss. Echoes of this event are recorded in the genomes of all living anteaters, being marked by a 2-bp deletion in a gene critical for dentinogenesis (DSPP) and a putative shared 1-bp insertion in a gene linked to tooth retention (ODAPH). By contrast, in the two major armadillo clades, genes pertaining to the dento-gingival junction and amelogenesis appear to have been independently inactivated prior to losing all or some enamel. These genomic data provide evidence for multiple pathways and rates of anatomical regression, and underscore the utility of using pseudogenes to reconstruct evolutionary history when fossils are sparse.","PeriodicalId":74413,"journal":{"name":"Peer community journal","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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