Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Transbound Emerg Dis ; 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31821736

RESUMO

In Europe, African swine fever virus (ASFV) is one of the most threatening infectious transboundary diseases of domestic pigs and wild boar. In September 2018, ASF was detected in wild boar in the South of Belgium. France, as a bordering country, is extremely concerned about the ASF situation in Belgium, and an active preparedness is ongoing in the country. One of the questions raised by this situation relates to disturbing activities that may affect wild boar movements and their possible impact on the spread of ASFV. Despite evidence of disturbance related to hunting practices, there is a paucity of information on the impact of forestry and human leisure activities. To assess this impact on wild boar movements, a systematic review was first conducted but very few useful data were obtained. For this reason, an expert elicitation was carried out by the French Agency for Food, Environmental and Occupational Health & Safety in order to deal with this knowledge gap. A total of 30 experts originating from France and adjacent neighbouring countries (Spain, Belgium and Switzerland) were elicited about the relative importance of six factors of spatial disturbance of wild boar (noise, smell, invasion of space, modification of the environment, duration and frequency of the activity). Then, for each factor of disturbance, they were asked about the impact of 16 different commercial forestry and human leisure activities. A global weighted score was estimated in order to capture the variability of a wide range of territorial conditions and the uncertainty of expert elicitation. This estimate permitted ranking all 16 activities and aggregating them in three groups according to their potential for disturbance of wild boar, using a regression tree analysis. The results of this expert elicitation provide a methodological approach that may be useful for French and other European decision makers and stakeholders involved in the crisis management of ASF.

2.
Vet Microbiol ; 230: 249-259, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30827397

RESUMO

The porcine reproductive and respiratory syndrome virus (PRRSV) is plaguing porcine production. Previously piglets were immunized with a PRRSV-1 commercial modified live virus vaccine (MLV1), a PRRSV-2 MLV (MLV2) or a Western European strain (Finistere: Fini) to assess and compare the protection brought by these strains upon challenge with virulent Lena strain. Lena viremia was reduced in all the immunized groups with a slightly higher level of protection following immunization with Fini. Using lung samples collected from the same experiment, tissue response to Lena challenge was assessed at the acute and chronic stages of infection. A pre-immunization with any one of the three PRRSV strains globally exacerbated microscopic lung lesions. Ten days post-challenge (DPC), MLV1 group score was higher than unimmunized group score and 42 DPC, MLV2 group score was higher than in unimmunized group. Lowest lung Lena viral loads were measured in Fini group. Using principal component analysis, we showed 10 DPC that the lesion score was positively correlated with chemokine receptors and negatively correlated with viral load. Forty-two DPC, variables for lesion score, IL6, IL8, and CCL20 transcripts were positively correlated together and negatively correlated with CCL28, CXCL6, and CXCR4 transcripts suggesting a role for the latter ones in the tissue recovery process. In conclusions, our study shows a significant impact of the three immunizations on pulmonary tissue with the best protection against Lena challenge conferred by Fini strain. Furthermore, it gives insight into the interactions between vaccine and Fini strains and the lung upon Lena challenge.


Assuntos
Anticorpos Antivirais/sangue , Pulmão/virologia , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vacinas Virais/imunologia , Animais , Quimiocinas/imunologia , Citocinas/imunologia , Pulmão/imunologia , Pulmão/patologia , Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Análise de Componente Principal , Suínos , Vacinas Atenuadas/imunologia , Carga Viral , Viremia
3.
BMC Syst Biol ; 13(1): 15, 2019 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-30696429

RESUMO

BACKGROUND: Understanding what determines the between-host variability in infection dynamics is a key issue to better control the infection spread. In particular, pathogen clearance is desirable over rebounds for the health of the infected individual and its contact group. In this context, the Porcine Respiratory and Reproductive Syndrome virus (PRRSv) is of particular interest. Numerous studies have shown that pigs similarly infected with this highly ubiquitous virus elicit diverse response profiles. Whilst some manage to clear the virus within a few weeks, others experience prolonged infection with a rebound. Despite much speculation, the underlying mechanisms responsible for this undesirable rebound phenomenon remain unclear. RESULTS: We aimed at identifying immune mechanisms that can reproduce and explain the rebound patterns observed in PRRSv infection using a mathematical modelling approach of the within-host dynamics. As diverse mechanisms were found to influence PRRSv infection, we established a model that details the major mechanisms and their regulations at the between-cell scale. We developed an ABC-like optimisation method to fit our model to an extensive set of experimental data, consisting of non-rebounder and rebounder viremia profiles. We compared, between both profiles, the estimated parameter values, the resulting immune dynamics and the efficacies of the underlying immune mechanisms. Exploring the influence of these mechanisms, we showed that rebound was promoted by high apoptosis, high cell infection and low cytolysis by Cytotoxic T Lymphocytes, while increasing neutralisation was very efficient to prevent rebounds. CONCLUSIONS: Our paper provides an original model of the immune response and an appropriate systematic fitting method, whose interest extends beyond PRRS infection. It gives the first mechanistic explanation for emergence of rebounds during PRRSv infection. Moreover, results suggest that vaccines or genetic selection promoting strong neutralising and cytolytic responses, ideally associated with low apoptotic activity and cell permissiveness, would prevent rebound.


Assuntos
Modelos Imunológicos , Vírus da Síndrome Respiratória e Reprodutiva Suína/fisiologia , Viremia/imunologia , Animais , Apoptose/imunologia , Suínos , Viremia/patologia
4.
Math Med Biol ; 36(2): 179-206, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-29790952

RESUMO

Understanding the impact of pathogen exposure on the within-host dynamics and its outcome in terms of infectiousness is a key issue to better understand and control the infection spread. Most experimental and modelling studies tackling this issue looked at the impact of the exposure dose on the infection probability and pathogen load, very few on the within-host immune response. Our aim was to explore the impact on the within-host response not only of the exposure dose, but also of its duration and peak, for contrasted virulence levels. We used an integrative modelling approach of the within-host dynamics at the between-cell level. We focused on the porcine reproductive and respiratory syndrome virus, a major concern for the swine industry. We quantified the impact of exposure and virulence on the viral dynamics and immune response by global sensitivity analyses and descriptive statistics. We found that the area under the viral curve, an indicator of the infection severity, was fully determined by the exposure intensity. The infection duration increased with the strain virulence and, for a given strain, exhibited a positive linear correlation with the exposure intensity logarithm and the exposure duration. Taking into account the exposure intensity is hence necessary. Besides, representing the exposure due to contacts by a single punctual dose would tend to underestimate the infection duration. As the infection severity and duration both contribute to the pig infectiousness, a prolonged exposure of the adequate intensity would be recommended in an immuno-epidemiological context.

5.
PLoS One ; 13(6): e0197612, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29897988

RESUMO

The effectiveness of infectious disease control depends on the ability of health managers to act in a coordinated way. However, with regards to non-notifiable animal diseases, farmers individually decide whether or not to implement control measures, leading to positive and negative externalities for connected farms and possibly impairing disease control at a regional scale. Our objective was to facilitate the identification of optimal incentive schemes at a collective level, adaptive to the epidemiological situation, and minimizing the economic costs due to a disease and its control. We proposed a modelling framework based on Markov Decision Processes (MDP) to identify effective strategies to control PorcineReproductive andRespiratorySyndrome (PRRS), a worldwide endemicinfectiousdisease thatsignificantly impactspig farmproductivity. Using a stochastic discrete-time compartmental model representing PRRS virus spread and control within a group of pig herds, we defined the associated MDP. Using a decision-tree framework, we translated the optimal policy into a limited number of rules providing actions to be performed per 6-month time-step according to the observed system state. We evaluated the effect of varying costs and transition probabilities on optimal policy and epidemiological results. We finally identifiedan adaptive policy that gave the best net financial benefit. The proposed framework is a tool for decision support as it allows decision-makers to identify the optimal policy and to assess its robustness to variations in the values of parameters representing an impact of incentives on farmers' decisions.


Assuntos
Doenças dos Bovinos/prevenção & controle , Doenças Transmissíveis/epidemiologia , Criação de Animais Domésticos , Animais , Bovinos , Doenças dos Bovinos/economia , Doenças dos Bovinos/epidemiologia , Doenças Transmissíveis/economia , Doenças Transmissíveis/veterinária , Custos e Análise de Custo , Tomada de Decisões , Fazendeiros , Fazendas , Humanos , Cadeias de Markov , Suínos
6.
Vet Rec ; 181(24): 657, 2017 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-29051316

RESUMO

Pig farmers are strongly encouraged to reduce their antimicrobial usage because of the rising threat from antimicrobial resistance. However, such efforts should not compromise the herd health status and performance. This study aimed to describe the profile of so-called 'top-farms' that managed to combine both high technical performance and low antimicrobial usage. A cross-sectional study was conducted among 227 farrow-to-finish farms in Belgium, France, Germany and Sweden. Among them, 44 farms were allocated to the top-farms group and were compared with the 'regular' farms group in terms of farm characteristics, biosecurity and health status. Top-farms had fewer gastrointestinal symptoms in suckling pigs and fewer respiratory symptoms in fatteners, which could partly explain their reduced need for antimicrobials and higher performance. They also had higher biosecurity and were located in sparsely populated pig areas. However, 14 farms of the top-farms group were located in densely populated pig areas, but still managed to have low usage and high technical performance; they had higher internal biosecurity and more extensive vaccination against respiratory pathogens. These results illustrate that it is possible to control infectious diseases using other approaches than high antimicrobial usage, even in farms with challenging environmental and health conditions.


Assuntos
Criação de Animais Domésticos/métodos , Anti-Infecciosos/uso terapêutico , Fazendas/organização & administração , Doenças dos Suínos/prevenção & controle , Animais , Estudos Transversais , Europa (Continente) , Humanos , Suínos , Vacinação/veterinária
7.
PLoS One ; 12(5): e0178487, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28542567

RESUMO

Weaning is a source of social, nutritional and environmental disorders that challenge piglet health. This study assesses the relevance of using plasma indicators of oxidative status as biomarkers of health around weaning in pigs. Blood antioxidant potential (BAP), hydroperoxides (HPO), oxidative stress index (OSI, e.g. HPO/BAP), vitamin A and E concentrations were investigated in two different trials. Trial A was carried out in an experimental unit to investigate the effects of age (from 12 to 147 days of age), weaning (at 21 or 28 days of age) and management at weaning (in optimal (OC) or deteriorated (DC) conditions) on those parameters. Trial B was performed in 16 commercial pig farms to describe the variability of these indicators on field between 26 and 75 days of age. In trial A, between 12 and 147 days of age, HPO globally increased (P < 0.001), vitamin E concentration decreased (P < 0.001) whereas BAP and vitamin A concentration remained relatively stable (P > 0.1). Vitamins E and A concentrations dropped 5 days after weaning independently of weaning age, weaning conditions and expression of diarrhea (P < 0.001). Twelve days after weaning, whatever the weaning age, HPO and OSI increased in DC compared to OC piglets (P = 0.05 and P < 0.01) and in piglets exhibiting diarrhea compared to those without diarrhea (P < 0.01 and P < 0.001). In DC pigs, BAP was also decreased (P < 0.05) 12 days after weaning. On trial B, plasma concentrations of vitamins A and E decreased and HPO increased 5 and 19 days respectively after weaning (P < 0,001). Contrarily to trial A, BAP values did not drop after weaning. Piglets which had the lowest ADG (Average Daily Gain) after weaning had greater HPO and OSI and lower vitamin A and E concentrations after weaning but also lower vitamin E concentration before weaning (P < 0.05). In conclusion, HPO or OSI seem to be good indicators of health disorders around weaning and plasma concentration of vitamin E before weaning is associated to growth after weaning.


Assuntos
Antioxidantes/metabolismo , Sus scrofa/sangue , Desmame , Fatores Etários , Criação de Animais Domésticos , Bem-Estar do Animal , Animais , Biomarcadores/sangue , Feminino , Peróxido de Hidrogênio/sangue , Masculino , Estresse Oxidativo , Vitamina A/sangue , Vitamina E/sangue
8.
Vet Res ; 48(1): 15, 2017 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-28241868

RESUMO

Porcine reproductive and respiratory syndrome virus (PRRSV) replicates primarily in pulmonary alveolar macrophages (PAMs) and the resulting lung damage is influenced by strain virulence. To better understand the pathogenesis of PRRSV infection, we performed a longitudinal study of the PAM population and lung cytokines in specific pathogen-free pigs infected either with the highly pathogenic Lena strain or with the low pathogenic Finistere strain in comparison to uninfected pigs. Bronchoalveolar lavage fluid (BALF) and blood were collected to follow viral, cellular and cytokine changes in lung with respect to clinical signs and systemic events. Compared to Finistere-infected pigs, Lena-infected pigs exhibited more severe clinical signs and 10- to 100-fold higher viral loads in BALF and blood. Similarly, they showed an earlier drop in BALF cell viability and phagocytic activity along with a decrease in the macrophage count. From 8 to 15 days post-infection (dpi), monocytes increased both in BALF and blood from Lena-infected pigs. BALF and blood showed contrasting cytokine patterns, with low increase of IFN-α and TNF-α levels and high increase for IL-1α and IL-8 in BALF after Lena-infection. In contrast, in the blood, the increase was marked for IFN-α and TNF-α but limited for IL-1ß and IL-8. Down-regulation of PAM functions combined with inflammatory cytokine and monocyte recruitment may promote lung pathogenesis and virus replication in PRRSV infections with the highly pathogenic Lena strain. In contrast, the low pathogenic Finistere strain showed prolonged viral replication in lung, possibly related to the weak IFN-γ response.


Assuntos
Citocinas/fisiologia , Macrófagos Alveolares/fisiologia , Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína , Animais , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Citocinas/análise , Citometria de Fluxo/veterinária , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Suínos/imunologia , Suínos/virologia , Carga Viral/veterinária
9.
Int J Food Microbiol ; 229: 33-43, 2016 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-27099983

RESUMO

Salmonella carriage and cutaneous contamination of pigs at slaughter are a major risk for carcass contamination. They depend on Salmonella prevalence at farm, but also on transmission and skin soiling among pigs during their journey from farm to slaughterhouse. To better understand and potentially control what influences Salmonella transmission within a pig batch during this transport and lairage step, we proposed a compartmental, discrete-time and stochastic model. We calibrated the model using pork chain data from Brittany. We carried out a sensitivity analysis to evaluate the impact of the variability in management protocols and of the uncertainty in epidemiological parameters on three model outcomes: prevalence of infection, average cutaneous contamination and number of new infections at slaughter. Each outcome is mainly influenced by a single management factor: prevalence at slaughter mainly depends on the prevalence at farm, cutaneous contamination on the contamination of lairage pens and new infections on the total duration of transport and lairage. However, these results are strongly affected by the uncertainty in epidemiological parameters. Re-excretion of carriers due to stress does not have a major impact on the number of new infections.


Assuntos
Modelos Biológicos , Salmonelose Animal/transmissão , Doenças dos Suínos/transmissão , Matadouros/normas , Criação de Animais Domésticos/normas , Animais , Fazendas/normas , Contaminação de Alimentos/prevenção & controle , Carne/microbiologia , Prevalência , Salmonella , Salmonelose Animal/epidemiologia , Sus scrofa , Suínos , Doenças dos Suínos/epidemiologia
10.
J R Soc Interface ; 13(116)2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26984191

RESUMO

Conventional epidemiological studies of infections spreading through trade networks, e.g., via livestock movements, generally show that central large-size holdings (hubs) should be preferentially surveyed and controlled in order to reduce epidemic spread. However, epidemiological strategies alone may not be economically optimal when costs of control are factored in together with risks of market disruption from targeting core holdings in a supply chain. Using extensive data on animal movements in supply chains for cattle and swine in France, we introduce a method to identify effective strategies for preventing outbreaks with limited budgets while minimizing the risk of market disruptions. Our method involves the categorization of holdings based on position along the supply chain and degree of market share. Our analyses suggest that trade has a higher risk of propagating epidemics through cattle networks, which are dominated by exchanges involving wholesalers, than for swine. We assess the effectiveness of contrasting interventions from the perspectives of regulators and the market, using percolation analysis. We show that preferentially targeting minor, non-central agents can outperform targeting of hubs when the costs to stakeholders and the risks of market disturbance are considered. Our study highlights the importance of assessing joint economic-epidemiological risks in networks underlying pathogen propagation and trade.


Assuntos
Doenças dos Animais/economia , Doenças dos Animais/epidemiologia , Gado , Modelos Biológicos , Modelos Econômicos , Animais , Bovinos
11.
Artigo em Inglês | MEDLINE | ID: mdl-28405435

RESUMO

BACKGROUND: High antimicrobial usage and the threat of antimicrobial resistance highlighted the need for reduced antimicrobial usage in pig production. Prevention of disease however, is necessary to obtain a reduced need for antimicrobial treatment. This study aimed at assessing possible associations between the biosecurity level, antimicrobial usage and farm and production characteristics in order to advice on best practices for a low antimicrobial usage and maximum animal health and production. A cross-sectional study was conducted in 227 farrow-to-finish pig herds in Belgium, France, Germany and Sweden between December 2012 and December 2013. Associations between biosecurity status, antimicrobial usage, and production parameters were evaluated with multivariable general linear models, according to an assumed causal pathway. RESULTS: The results showed that higher antimicrobial usage in sows tended to be associated with higher antimicrobial usage from birth until slaughter (p = 0.06). The antimicrobial usage from birth until slaughter was positively associated with the number of pathogens vaccinated against (p < 0.01). A shorter farrowing rhythm (p < 0.01) and a younger weaning age (p = 0.06) tended to be also associated with a higher antimicrobial usage from birth until slaughter whereas a better external biosecurity (p < 0.01) was related with a lower antimicrobial usage from birth until slaughter. CONCLUSION: Management practices such as weaning age and biosecurity measures may be important factors indirectly impacting on antimicrobial usage. We therefore promote a holistic approach when assessing the potential to reduce the need for antimicrobial treatments.

12.
Prev Vet Med ; 118(4): 457-66, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25650306

RESUMO

Nineteen alternatives to antimicrobial agents were ranked on perceived effectiveness, feasibility and return on investment (ROI) from 0 (not effective, not feasible, no ROI) to 10 (fully effective, completely feasible, maximum ROI) by 111 pig health experts from Belgium, Denmark, France, Germany, Sweden and Switzerland. The top 5 measures in terms of perceived effectiveness were (1) improved internal biosecurity, (2) improved external biosecurity, (3) improved climate/environmental conditions, (4) high health/Specific Pathogen Free/disease eradication and (5) increased vaccination. The top 5 measures in terms of perceived feasibility were (1) increased vaccination, (2) increased use of anti-inflammatory products, (3) improved water quality, (4) feed quality/optimization and (5) use of zinc/metals. The top 5 measures in terms of perceived ROI were (1) improved internal biosecurity, (2) zinc/metals, (3) diagnostics/action plan, (4) feed quality/optimization and (5) climate/environmental improvements. Univariate linear regression showed that veterinary practitioners rank internal biosecurity, vaccination, use of zinc/metals, feed quality optimization and climate/environmental on average highest, while researchers and professors focused more on increased use of diagnostics and action plans. Financial incentives/penalties ranked low in all countries. Belgian respondents ranked feed quality significantly lower compared to the German respondents while reduction of stocking density was ranked higher in Belgium compared to Denmark. Categorical Principal Component Analysis applied to the average ranking supported the finding that veterinary practitioners had a preference for more practical, common and already known alternatives. The results showed that improvements in biosecurity, increased use of vaccination, use of zinc/metals, feed quality improvement and regular diagnostic testing combined with a clear action plan were perceived to be the most promising alternatives to antimicrobials in industrial pig production based on combined effectiveness, feasibility and ROI.


Assuntos
Criação de Animais Domésticos/métodos , Anti-Infecciosos/uso terapêutico , Conhecimentos, Atitudes e Prática em Saúde , Ração Animal , Criação de Animais Domésticos/economia , Animais , Anti-Infecciosos/economia , Análise Custo-Benefício , Europa (Continente) , Estudos de Viabilidade , Humanos , Modelos Lineares , Suínos , Vacinação/veterinária , Zinco/uso terapêutico
13.
Antibiotics (Basel) ; 4(4): 435-54, 2015 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-27025634

RESUMO

Since 2011, French public policy has been encouraging a reduction in the use of antibiotics in animal farming. The aim of this article is to look at how some farms have already managed to lower their consumption of antibiotics, and to highlight the levers of change in farming health practices. Our research uses a qualitative study based on 21 semi-structured interviews with farmers and veterinarians in the French pig-farming sector. We use the notion of "trajectory of change" to examine, over time, the intersection of the technical, economic, social and organisational determinants which affect the reduced use of antibiotics. The "learning process" concept makes it possible to take account of the way in which the actors assimilate, appropriate and implement new health practices. We have identified three interdependent levels of learning: technical learning, cognitive learning and organisational learning.

14.
PLoS One ; 9(9): e107818, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25233096

RESUMO

The immune mechanisms which determine the infection duration induced by pathogens targeting pulmonary macrophages are poorly known. To explore the impact of such pathogens, it is indispensable to integrate the various immune mechanisms and to take into account the variability in pathogen virulence and host susceptibility. In this context, mathematical models complement experimentation and are powerful tools to represent and explore the complex mechanisms involved in the infection and immune dynamics. We developed an original mathematical model in which we detailed the interactions between the macrophages and the pathogen, the orientation of the adaptive response and the cytokine regulations. We applied our model to the Porcine Respiratory and Reproductive Syndrome virus (PRRSv), a major concern for the swine industry. We extracted value ranges for the model parameters from modelling and experimental studies on respiratory pathogens. We identified the most influential parameters through a sensitivity analysis. We defined a parameter set, the reference scenario, resulting in a realistic and representative immune response to PRRSv infection. We then defined scenarios corresponding to graduated levels of strain virulence and host susceptibility around the reference scenario. We observed that high levels of antiviral cytokines and a dominant cellular response were associated with either short, the usual assumption, or long infection durations, depending on the immune mechanisms involved. To identify these mechanisms, we need to combine the levels of antiviral cytokines, including IFNγ, and IL10. The latter is a good indicator of the infected macrophage level, both combined provide the adaptive response orientation. Available PRRSv vaccines lack efficiency. By integrating the main interactions between the complex immune mechanisms, this modelling framework could be used to help designing more efficient vaccination strategies.


Assuntos
Imunidade Celular , Macrófagos Alveolares/imunologia , Modelos Biológicos , Viroses/imunologia , Algoritmos , Animais , Suscetibilidade a Doenças/imunologia , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno , Humanos , Sensibilidade e Especificidade , Vacinação , Virulência , Viroses/prevenção & controle
15.
J Vet Med Educ ; 41(4): 337-43, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25172107

RESUMO

Recent crises concerning poultry production revealed a relative deficit in the availability of veterinary competencies to manage some acute public health and animal welfare concerns. Veterinary education might be critically questioned about this deficit. The authors present the experience of the education program on poultry production medicine at the Veterinary College of Nantes in France over a 10-year period. First, the program consists of integrative teaching focused on a holistic multidisciplinary approach to this professional field on a compulsory basis. Evaluation of the course by the students through a questionnaire (N=1,032) showed a large favorable consensus. Second, the completion of an elective program targeting profession-specific competencies may allow the student to challenge his or her choice of this professional orientation in the undergraduate curriculum. According to the importance they want to give to poultry, and concurrently to other species, students have the possibility of building a curriculum that is either partly or fully devoted to poultry production medicine: a 6-month thesis, 2-10 weeks of professional training, 2 weeks in the field to solve a poultry flock health problem, and 2-4 weeks of specialized courses in poultry production medicine. To round off this curriculum, the national post-graduate program in poultry production medicine is highlighted, as well as its links with the residency program of the European College of Poultry Veterinary Science.


Assuntos
Criação de Animais Domésticos/educação , Currículo , Educação em Veterinária/normas , Competência Profissional , Animais , Educação de Pós-Graduação/normas , França , Aves Domésticas
16.
Vet Res ; 43: 69, 2012 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-23061672

RESUMO

The time-dependent transmission rate of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and the correlation between infectiousness, virological parameters and antibody responses of the infected pigs were studied in experimental conditions. Seven successive transmission trials involving a total of 77 specific pathogen-free piglets were carried out from 7 to 63 days post-inoculation (dpi). A semi-quantitative real time RT-PCR was developed to assess the evolution of the viral genome load in blood and nasal swabs from inoculated and contact pigs, with time. Virus genome in blood was detectable in inoculated pigs from 7 to 77 dpi, whereas viral genome shedding was detectable from nasal swabs from 2 to 48 dpi. The infectiousness of inoculated pigs, assessed from the frequency of occurrence of infected pigs in susceptible groups in each contact trial, increased from 7 to 14 dpi and then decreased slowly until 42 dpi (3, 7, 2, 1 and 0 pigs infected at 7, 14, 21, 28 and 42 dpi, respectively). These data were used to model the time-dependent infectiousness by a lognormal-like function with a latency period of 1 day and led to an estimated basic reproduction ratio, R0 of 2.6 [1.8, 3.3]. The evolution of infectiousness was mainly correlated with the time-course of viral genome load in the blood whereas the decrease of infectiousness was strongly related to the increase in total antibodies.


Assuntos
Anticorpos Antivirais/sangue , Genoma Viral , Síndrome Respiratória e Reprodutiva Suína/transmissão , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Eliminação de Partículas Virais , Animais , Anticorpos Neutralizantes/sangue , Ensaio de Imunoadsorção Enzimática/veterinária , Modelos Biológicos , Nariz/virologia , Reação em Cadeia da Polimerase/veterinária , Síndrome Respiratória e Reprodutiva Suína/virologia , Distribuição Aleatória , Organismos Livres de Patógenos Específicos , Suínos , Fatores de Tempo
17.
Vet Microbiol ; 154(1-2): 171-9, 2011 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-21831540

RESUMO

Campylobacter, a leading cause of food-borne illness worldwide, has a widespread distribution with a broad range of animal hosts and environmental reservoirs. The genetic description of bacterial strains is a powerful tool for epidemiological studies but can be impaired by the high genomic variability of Campylobacter. Our study aimed (i) at investigating the genotypic instability of Campylobacter generated either in vitro by subculturing or after in vivo passage on specific pathogen-free pigs and (ii) at evaluating the suitability of typing methods to detect such variation. Pigs were inoculated per os with three Campylobacter strains (one C. coli originating from pig faeces, one C. jejuni and one C. coli originating from poultry faeces) alone or in mixture and non-inoculated pigs were housed in adjacent pens. Genotypic instability was investigated using both macrorestriction combined with pulsed-field gel electrophoresis analysis (PFGE) and PCR restriction fragment length polymorphism analysis of the flaA gene (flaA PCR-RFLP). No variability in the genetic profile was observed for the three strains maintained through twenty times subculturing events in vitro. Genotypic variability was evidenced in vivo only in pigs inoculated with C. coli of porcine origin, either alone or in a mix, with both genotyping methods. In our study, for one porcine C. coli strain, 13% and 21% of variability were generated in the digestive tract of pigs by PFGE and flaA PCR-RFLP typing methods, respectively. This study is a first approach for a better understanding of the genomic instability of Campylobacter in pig under field conditions.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter coli/genética , Trato Gastrointestinal/microbiologia , Instabilidade Genômica , Doenças dos Suínos/microbiologia , Suínos/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Infecções por Campylobacter/microbiologia , Campylobacter coli/classificação , Campylobacter jejuni/classificação , Campylobacter jejuni/genética , Análise por Conglomerados , Coinfecção/microbiologia , Eletroforese em Gel de Campo Pulsado , Fezes/microbiologia , Flagelina/genética , Genótipo , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , Organismos Livres de Patógenos Específicos
18.
Prev Vet Med ; 102(1): 30-40, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21763020

RESUMO

Movement restrictions are a key measure to control pathogen transmission in the swine industry due when purchasing animals. Here recorded animal movements between herds in France are used to generate a network model. This network consists of different types of herds together with specific links between them, with some herds being suppliers (of reproductive gilts or piglets) for others. The connectivity between herds within this network exhibits a highly variable number of contacts according to the type of animal moved (8 kg piglets, 25 kg piglets or reproductive gilts). A simulation model is used to assess the impact of control measures aimed at reducing Salmonella prevalence at every level of the production network. In particular we consider restricting animal purchases according to the infectious status of herds (level of prevalence) such that animals do not move from higher to lower herd prevalence; this measure can additionally be combined with infection control at the herd-level. When Salmonella initially invades the production structure, the restriction of animal movements alone is sufficient to significantly decrease the number of herds infected. In contrast, once infection is endemic within the production structure, movement restrictions have to be supplemented by within-herd control applied to a large proportion of herds to reduce the pathogen prevalence. These results demonstrate the important distinction between the control of epidemics and endemic infections and highlight the different impacts of control measures at the within- and at the between-herd levels.


Assuntos
Modelos Biológicos , Salmonelose Animal/prevenção & controle , Salmonelose Animal/transmissão , Salmonella , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/transmissão , Criação de Animais Domésticos , Animais , França/epidemiologia , Prevalência , Salmonelose Animal/epidemiologia , Sus scrofa , Suínos , Doenças dos Suínos/epidemiologia
19.
Int J Food Microbiol ; 150(1): 8-13, 2011 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-21788093

RESUMO

A study was conducted in 2009 to identify risk factors of Campylobacter spp. transmission from the digestive tract to the carcasses of standard broilers (slaughter age: 37 day, carcass weight: 1.3 kg on average). Counts of Campylobacter were performed on pools of 10 ceca and 10 neck-skins from 108 Campylobacter ceca-positive batches in three slaughterhouses. Technical and health data also was collected on the broilers: age, size, carcass weight (mean and standard deviation), condemnation rate, mortality rate and nature of treatment during the rearing period. Cecal counts varied from 4.8 to 10.2 log(10) cfu/g. In seventeen batches (15.7%), the skin count was below the detection limit. In the 91 batches with positive neck-skin test results, the counts varied from 2.0 to 5.2 log(10) cfu/g. Standard deviation of carcass weight, condemnation rate, slaughter rate and cecal count were significantly lower and growth rate higher in the 17 batches where neck-skin results were not detected positive. Multivariate analysis showed that batches with higher standard deviation of carcass weight were 5 to 9 fold more at risk of having detectable carcass contamination. Among the 91 positive neck-skin batches, only slaughter rate and cecal counts were found to have a significant but limited effect on the level of neck-skin contamination. As far as body weight homogeneity may be affected by disease, better health control can contribute to a reduction of the contamination of the broiler carcasses in Campylobacter carrier batches.


Assuntos
Matadouros , Campylobacter/crescimento & desenvolvimento , Ceco/microbiologia , Microbiologia de Alimentos , Aves Domésticas/microbiologia , Animais , Campylobacter/isolamento & purificação , Galinhas/microbiologia , Contagem de Colônia Microbiana , Manipulação de Alimentos/métodos , Humanos
20.
BMC Microbiol ; 11: 113, 2011 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-21600037

RESUMO

BACKGROUND: Campylobacter spp., especially Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli), are recognized as the leading human foodborne pathogens in developed countries. Livestock animals carrying Campylobacter pose an important risk for human contamination. Pigs are known to be frequently colonized with Campylobacter, especially C. coli, and to excrete high numbers of this pathogen in their faeces. Molecular tools, notably real-time PCR, provide an effective, rapid, and sensitive alternative to culture-based methods for the detection of C. coli and C. jejuni in various substrates. In order to serve as a diagnostic tool supporting Campylobacter epidemiology, we developed a quantitative real-time PCR method for species-specific detection and quantification of C. coli and C. jejuni directly in faecal, feed, and environmental samples. RESULTS: With a sensitivity of 10 genome copies and a linear range of seven to eight orders of magnitude, the C. coli and C. jejuni real-time PCR assays allowed a precise quantification of purified DNA from C. coli and C. jejuni. The assays were highly specific and showed a 6-log-linear dynamic range of quantification with a quantitative detection limit of approximately 2.5 × 10² CFU/g of faeces, 1.3 × 10² CFU/g of feed, and 1.0 × 10³ CFU/m² for the environmental samples. Compared to the results obtained by culture, both C. coli and C. jejuni real-time PCR assays exhibited a specificity of 96.2% with a kappa of 0.94 and 0.89 respectively. For faecal samples of experimentally infected pigs, the coefficients of correlation between the C. coli or C. jejuni real-time PCR assay and culture enumeration were R² = 0.90 and R² = 0.93 respectively. CONCLUSION: The C. coli and C. jejuni real-time quantitative PCR assays developed in this study provide a method capable of directly detecting and quantifying C. coli and C. jejuni in faeces, feed, and environmental samples. These assays represent a new diagnostic tool for studying the epidemiology of Campylobacter by, for instance, investigating the carriage and excretion of C. coli and C. jejuni by pigs from conventional herds.


Assuntos
Carga Bacteriana/métodos , Campylobacter coli/classificação , Campylobacter coli/isolamento & purificação , Campylobacter jejuni/classificação , Campylobacter jejuni/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Ração Animal/microbiologia , Animais , Campylobacter coli/genética , Campylobacter jejuni/genética , Microbiologia Ambiental , Fezes/microbiologia , Sensibilidade e Especificidade , Suínos/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA