Comparative study of the transmission of porcine epidemic dirrhea virus and of the immunity induced during the infection

La diarrhée épidémique porcine (DEP) est apparue en Europe à la fin des années 1970 et est causée par un alpha-coronavirus appelé virus de la diarrhée épidémique porcine (PEDV). Des épizooties sévères ont été rapportées en Asie à partir de 2010 et en Amérique à partir de 2013. Deux génotypes de souches de PEDV, se différenciant par des insertions/délétions dans le gène S, ont été isolés et circulent toujours actuellement dans ces régions. Ils regroupent d’une part les souches « S-InDel » présentes sur tous les continents, notamment en Europe y compris la France, et d’autre part les souches « S-non-InDel » hautement virulentes qui circulent en Asie et sur le continent américain uniquement. Les porcs infectés par le PEDV sont sujets à d’importantes diarrhées aqueuses ainsi qu’à des vomissements parfois accompagnés de signes de déshydratation. Les conséquences de la maladie sont d’autant plus importantes en cas d’infection par une souche « S-non-InDel » avec une mortalité pouvant atteindrLa pathogénicité comparée de deux souches de PEDV a été étudiée dans le cadre de cette thèse : une souche « S-non-InDel » isolée aux Etats-Unis en 2014 et une souche « S-InDel » isolée en France la même année. L’étude de la pathogénicité comparée a consisté à étudier les caractéristiques de transmission horizontale et les conséquences cliniques de l’infection en conditions expérimentales. En outre, l’excrétion dans la semence de ces deux souches a également été explorée. La dernière partie du projet de thèse était consacrée à l’étude des interactions du virus avec l’intestin ainsi que l’immuPorcine epidemic diarrhea (PED) appeared in Europe at the end of 1970s and is caused by an alpha-coronavirus named porcine epidemic diarrhea virus (PEDV). Severe PED epizootic cases have been reported in Asia from 2010 and in America from 2013. Two genotypes of PEDV strains, differing by insertions/deletions in the S gene, have been described and circulating to date. The first genotype is represented by « S-InDel » strains group present on all continents among which Europe, including France. The second one is represented by the so-called highly virulent « S-non-InDel » strains which circulate in Asia and America only. The pigs infected by PEDV are affected by important aqueous diarrheas and sometimes vomiting accompanied by signs of dehydration. The consequences of the disease are more important in case of infection by an « S-non-InDel » strain with a mortality rate that could reach 100 % in suckling piglets.Uncertainties remained on pathogenicity differences according to the strains of PEDV and on impacts of a potential introduction of « S-non-InDel » PEDV strain in France. This thesis aimed at studying and comparing the pathogenicity of two strains of PEDV, an « S-non-InDel » PEDV strain isolated in the United-States in 2014 and an « S-InDel » PEDV strain isolated in France the same year. To compare pathogenicity between strains, the horizontal transmission and the clinical consequences of the infection in experimental conditions have been studied. Moreover the virus shedding in semen was also explored for the two strains. The last part of the project of the thesis wa

Etude comparative de la transmission de virus de la diarrhée épidémique porcine et de l'immunité induite lors de l'infection

Porcine epidemic diarrhea (PED) appeared in Europe at the end of 1970s and is caused by an alpha-coronavirus named porcine epidemic diarrhea virus (PEDV). Severe PED epizootic cases have been reported in Asia from 2010 and in America from 2013. Two genotypes of PEDV strains, differing by insertions/deletions in the S gene, have been described and circulating to date. The first genotype is represented by « S-InDel » strains group present on all continents among which Europe, including France. The second one is represented by the so-called highly virulent « S-non-InDel » strains which circulate in Asia and America only. The pigs infected by PEDV are affected by important aqueous diarrheas and sometimes vomiting accompanied by signs of dehydration. The consequences of the disease are more important in case of infection by an « S-non-InDel » strain with a mortality rate that could reach 100 % in suckling piglets.Uncertainties remained on pathogenicity differences according to the strains of PEDV and on impacts of a potential introduction of « S-non-InDel » PEDV strain in France. This thesis aimed at studying and comparing the pathogenicity of two strains of PEDV, an « S-non-InDel » PEDV strain isolated in the United-States in 2014 and an « S-InDel » PEDV strain isolated in France the same year. To compare pathogenicity between strains, the horizontal transmission and the clinical consequences of the infection in experimental conditions have been studied. Moreover the virus shedding in semen was also explored for the two strains. The last part of the project of the thesis wasLa diarrhée épidémique porcine (DEP) est apparue en Europe à la fin des années 1970 et est causée par un alpha-coronavirus appelé virus de la diarrhée épidémique porcine (PEDV). Des épizooties sévères ont été rapportées en Asie à partir de 2010 et en Amérique à partir de 2013. Deux génotypes de souches de PEDV, se différenciant par des insertions/délétions dans le gène S, ont été isolés et circulent toujours actuellement dans ces régions. Ils regroupent d’une part les souches « S-InDel » présentes sur tous les continents, notamment en Europe y compris la France, et d’autre part les souches « S-non-InDel » hautement virulentes qui circulent en Asie et sur le continent américain uniquement. Les porcs infectés par le PEDV sont sujets à d’importantes diarrhées aqueuses ainsi qu’à des vomissements parfois accompagnés de signes de déshydratation. Les conséquences de la maladie sont d’autant plus importantes en cas d’infection par une souche « S-non-InDel » avec une mortalité pouvant atteindrLa pathogénicité comparée de deux souches de PEDV a été étudiée dans le cadre de cette thèse : une souche « S-non-InDel » isolée aux Etats-Unis en 2014 et une souche « S-InDel » isolée en France la même année. L’étude de la pathogénicité comparée a consisté à étudier les caractéristiques de transmission horizontale et les conséquences cliniques de l’infection en conditions expérimentales. En outre, l’excrétion dans la semence de ces deux souches a également été explorée. La dernière partie du projet de thèse était consacrée à l’étude des interactions du virus avec l’intestin ainsi que l’imm

Tobacco Policies at Colleges and Universities Housing PreK – 12 Laboratory Schools: An Exploratory Study

Objective. This study examined the current status of tobacco-/smoke-free campus policies at PreK - 12 laboratory schools and their affiliated colleges/universities. Perceived barriers to passage of tobacco-/smoke-free policies and aspects of the school environment perceived to aid in passage of such polices were also examined. Methods. Data were collected through electronic surveys to administrators of 61 U.S. International Association of Laboratory School members and their affiliated colleges/universities. Information on state tobacco policies was obtained from the National Association of State Board of Education’s State School Healthy Policy Database on tobacco use. Results. Inconsistencies between college/university tobacco-/smoke-free policies and state board of education guidelines existed. Faculty/staff issues, social issues, and internal policy implementation challenges emerged as the top categories of barriers. Laws and policies, support from key stakeholders, and communication strategies were the strongest aids. Conclusions. There is not a consistent standard of protection offered for PreK - 12 students across the country. Colleges/universities housing laboratory schools may be placing their PreK - 12 students at greater risk of exposure to pro-tobacco influences and secondhand smoke if they are not governed by comprehensive tobacco policies

Porcine epidemic diarrhea: the return of an old disease

In 2013, 40 years after the first case of porcine epidemic diarrhea (PED) in Europe, PED has emerged in USA that was free of that disease before. The coronavirus, etiological agent of the disease and called PEDV, spread quickly within all the country and in America leading to a significant impact on the pig production. Two types of viral strains have been identified: highly virulent "non-InDel" strains and "InDel" strains because of insertion/deletion in the S gene and associated with less severe clinical cases. PEDV infection causes watery diarrhea and a mortality of up to 100 % in piglets. This review sums up the current knowledge on the virus, its transmission and its worldwide molecular epidemiology, on the physiopathology of the disease and the control measures.En 2013, 40 ans après le premier cas de diarrhée épidémique porcine (DEP) en Europe, la DEP est apparue aux États-Unis jusqu’alors indemne de cette maladie. Le coronavirus responsable de la maladie, le virus de la DEP (PEDV) s’est rapidement propagé dans tout le pays et dans plusieurs pays d’Amérique entraînant un impact significatif sur la production de porcs (perte de 10 % de la production totale aux États-Unis). Deux types de souches ont été identifiés : des souches hautement virulentes dites « non-InDel », et des souches dites « InDel » de part des insertions/délétions dans le gène S et associées à des cas cliniques moins sévères. L’infection par le PEDV provoque l’apparition de diarrhées aqueuses et peut entraîner 100 % de mortalité chez les porcelets nouveau-nés. Cette revue fait le bilan des connaissances actuelles sur le virus, sa transmission et l’épidémiologie moléculaire mondiale, sur la physiopathologie de la maladie et les moyens de contrôle

Compressed Brown Algae as a Potential Environmental Enrichment Material in Growing Pigs

In barren housing conditions, enrichment materials are given to pigs to improve their welfare. Here, we assessed the suitability of an algae-based cylinder as an enrichment material on the behavioral, physiological, health and productivity welfare indicators of pigs. Algae was compared with metal chains and wood logs. The study involved 444 pigs from two successive batches on one single farm. During the suckling period, half of the pigs received algae and the control pigs received no material. After weaning and until the end of fattening, algae, wood or chains were equally distributed among the pigs. Consumption of algae cylinders was different between pens and between batches. After weaning and during the fattening period, although the results differed between batches, no significant difference was observed in the object manipulations. Salivary cortisol, used as biomarker to measure the stress levels after pig transfers, were similar between the treatments. Enrichment material made from algae had no negative effect on pig health and no effect on performance and body condition. Regarding their characteristics and according to Commission Recommendation (EU) 2016/336 classification, algae cylinders can be categorized as suboptimal enrichment materials, although the present results suggest that it does not significantly improve pig welfare compared to a metal chain, which is categorized as a material of marginal interest

Assessment of within and between-pen transmission of porcine epidemic diarrhea virus InDel strain

International audienc

Body size and life history shape the historical biogeography of tetrapods

Dispersal across biogeographic barriers is a key process determining global patterns of biodiversity as it allows lineages to colonize and diversify in new realms. Here we demonstrate that past biogeographic dispersal events often depended on species' traits, by analysing 7,009 tetrapod species in 56 clades. Biogeographic models incorporating body size or life history accrued more statistical support than trait-independent models in 91% of clades. In these clades, dispersal rates increased by 28-32% for lineages with traits favouring successful biogeographic dispersal. Differences between clades in the effect magnitude of life history on dispersal rates are linked to the strength and type of biogeographic barriers and intra-clade trait variability. In many cases, large body sizes and fast life histories facilitate dispersal success. However, species with small bodies and/or slow life histories, or those with average traits, have an advantage in a minority of clades. Body size-dispersal relationships were related to a clade's average body size and life history strategy. These results provide important new insight into how traits have shaped the historical biogeography of tetrapod lineages and may impact present-day and future biogeographic dispersal