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1.
Psychol Addict Behav ; 38(2): 211-221, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37602996

RESUMO

OBJECTIVE: This study examined how social associations from a person's social network may be associated with their own alcohol consumption. METHOD: Alcohol consumption behavior was examined among the social networks of 784 survey respondents (54% female, Mage = 35.3 years), using egocentric social network analysis. Participants (egos) were recruited via a panel aggregator and completed an online survey about the frequency of their alcohol consumption and that of the 20 most influential people in their lives (alters). The survey also explored who these alters were (family, friends, work colleagues) and the interrelationships among these alters. RESULTS: Egos who consumed alcohol, or consumed alcohol more frequently, were surrounded by more alters who also drank alcohol and felt closer (had stronger ties) to these alters. These relationships remained statistically significant when controlling for demographic and other variables. The social networks of those who consumed alcohol more frequently were more densely intertwined. CONCLUSIONS: Alcohol may serve to initiate social connections and be a "social glue" that reinforces relationships. These strong social associations present a potential barrier to individuals who wish to reduce their alcohol consumption because they have few close social connections who do not drink alcohol (or who do so infrequently), and their highly interconnected social networks make it difficult to socialize only with those who do not drink frequently. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Assuntos
Comportamento Social , Análise de Rede Social , Humanos , Feminino , Adulto , Masculino , Austrália/epidemiologia , Amigos , Consumo de Bebidas Alcoólicas/epidemiologia , Etanol
2.
Vaccine X ; 14: 100352, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37519775

RESUMO

Background: Vaccination for COVID-19 has become a cornerstone management plan for many countries. Australian state governments made vaccinations mandatory for all healthcare workers. Despite evidence on the important role vaccines hold in preventing or decreasing serious disease, there have been many nurses and midwives who have demonstrated vaccine hesitancy. This hesitancy has also been present in undergraduate nursing and midwifery students. The aim of this study was to explore factors influencing Australian nursing and midwifery students' intentions towards receiving the COVID-19 vaccine; identify the barriers and facilitators to obtaining the COVID-19 vaccine; and understand students' perceptions of mandating the COVID-19 vaccine and identify any impact on their studies.. Methods: Cross-sectional mixed method study utilising an online survey platform. Data were analysed using binomial and multinomial logistic regression through Statistical Package for the Social Sciences. A content analysis was completed for the qualitative data. Results: There were 715 participants and 556 who completed the survey in full. Nurses made up the majority of participants (n = 409), 133 participants were midwives and 30 were in dual nursing/midwifery programs. Education and communication were identified as two major factors that facilitate vaccine acceptance. Conclusions: Vaccines are integral in the prevention of contracting COVID-19 or reducing the severity of the symptoms. However, many nursing and midwifery students have shown reluctance towards getting vaccinated. The mandate to be vaccinated to attend clinical placement has led to the inability of some students to complete their course. The findings from this study are valuable in informing the future COVID-19 vaccination strategies and improving vaccine acceptance. COVID-19 remains a global health risk and therefore further research is needed of vaccine acceptance amongst the future health workforces. It is crucial knowledge for policy makers and healthcare services as they plan for any future pandemics and implement Australia's national vaccine strategy.

3.
Vet Microbiol ; 230: 273-277, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30827400

RESUMO

Mycoplasma hyorhinis (Mhr) is a pathogen of pigs causing polyserositis and polyarthritis. The most susceptible population are nursery pigs of approximately 7 weeks of age, although we have shown that clinical signs can persist into finishing aged animals after a late-nursery infection. We have previously demonstrated the efficacy of a novel inactivated Mhr vaccine for the reduction of lameness and polyserositis in caesarian-derived colostrum-deprived (CDCD) pigs vaccinated at 3 weeks and challenged with Mhr at 6 weeks of age. Here we evaluated the duration of immunity (DOI) of the same vaccine. Vaccine or placebo was administered to CDCD pigs at 3 weeks of age. Pigs were challenged with Mhr at either 10 weeks of age (=7 week DOI) or 13 weeks of age (=10 week DOI). In the 7 week DOI, vaccination provided significant reductions in lameness (p = 0.0018), arthritis (p = 0.0002), and pericarditis (p = 0.0312) versus the placebo control. In the 10 week DOI, a significant reduction in arthritis (p = 0.0320) was observed in the vaccine group as compared to the placebo group. Both vaccine groups showed a significant increase (p < 0.0001) in the post-challenge average daily gain (ADG), gaining 0.2 kg/day more than their respective placebo groups.


Assuntos
Artrite/veterinária , Vacinas Bacterianas/imunologia , Infecções por Mycoplasma/veterinária , Mycoplasma hyorhinis/imunologia , Pericardite/veterinária , Doenças dos Suínos/prevenção & controle , Animais , Artrite/prevenção & controle , Vacinas Bacterianas/administração & dosagem , Feminino , Pulmão/imunologia , Pulmão/microbiologia , Masculino , Infecções por Mycoplasma/imunologia , Infecções por Mycoplasma/prevenção & controle , Pericardite/prevenção & controle , Suínos/imunologia , Suínos/microbiologia , Doenças dos Suínos/imunologia , Vacinação , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia
4.
Porcine Health Manag ; 4: 23, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30151235

RESUMO

BACKGROUND: Porcine reproductive and respiratory syndrome (PRRS) causes respiratory distress in pigs, reproductive failure in breeding-age gilts and sows, and can have devastating economic consequences in domestic herds. Several PRRS vaccines are available commercially. This study compared the effectiveness of single-vaccination and revaccination schedules using the PRRS 94881 Type I modified live virus (MLV) vaccine ReproCyc® PRRS EU with no vaccination (challenge control) in protecting against a PRRS virus (PRRSV) challenge in non-pregnant gilts. RESULTS: Data were available from 48 gilts across three groups: a challenge control group (n = 16), which received no vaccination; a revaccination group (n = 16), which received ReproCyc® PRRS EU on Days 0 and 56; and a single vaccination group (n = 16), which received ReproCyc® PRRS EU on Day 56. All gilts were PRRSV RNA-negative (based on reverse transcription and quantitative polymerase chain reaction [RT-qPCR]) and PRRSV seronegative (based on enzyme-linked immunosorbent assay [ELISA]) at Day 0. All gilts were challenged with PRRSV strain 190136 on Day 91.Viral RNA loads in both vaccination groups were significantly reduced compared with the challenge control group on Days 98 (P < 0.0001) and 101 (P < 0.0001), indicating that vaccinated gilts were better able to respond to challenge than unvaccinated gilts. At all timepoints following challenge, mean viral RNA load and the percentage of PRRSV RNA-positive gilts were numerically higher in the single-vaccination group than in the revaccination group; these differences were statistically significant on Day 101 (P = 0.0434). Furthermore, viremia levels after challenge were significantly lower in the revaccination group than in the single-vaccination group based on median area under the curve (AUC) values for viral RNA load from Day 91 to Day 112, suggesting that revaccinated gilts had better protection from viral infection than gilts who received a single vaccination. Protection from viremia did not correlate with the proportion of seropositive gilts on Day 91. In the single-vaccination group, 94% of pigs were seropositive on Day 91 compared with 56% in the revaccination group. Vaccination was well tolerated and no safety concerns were identified. CONCLUSIONS: Both single-vaccination and revaccination with ReproCyc® PRRS EU were effective in reducing PRRSV viremia post-challenge. These findings have important implications for herd management as both the single-vaccination and revaccination schedules protect against PRRSV challenge, with revaccination appearing to provide better protection from viremia than single vaccination.

5.
Porcine Health Manag ; 4: 11, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29785280

RESUMO

BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) is widespread in commercial pig farms worldwide, and has a significant cost to the swine industry. Herd owners need a vaccine that will confer long-lasting immunity to prevent PRRSV infection and transmission. The studies described here evaluated duration of immunity conferred by a European-derived PRRS (isolate 94,881) modified live virus (MLV) vaccine, Ingelvac PRRSFLEX® EU, at 20, 24, and 26 weeks post-vaccination. Primary endpoints were the assessment of gross and histological lung lesions and viral RNA load in lung tissue 10 days following heterologous PRRSV challenge. Secondary endpoints included clinical observations, average daily weight gain (ADWG) and viral RNA load in serum 10 days post-challenge. Three blinded, vaccination-challenge efficacy studies were performed using separate cohorts of pigs (n = 56 per study). Pigs received either Ingelvac PRRSFLEX® EU (Group 1) or placebo (Groups 2 and 3). Groups 1 and 2 were subsequently challenged with heterologous European PRRSV isolate 205,817 at 20, 24 or 26 weeks post-vaccination. RESULTS: Mean gross lung lesion scores were significantly lower in Group 1 than in Group 2 at 24 and 26 weeks (p <  0.0001), but not at 20 weeks (p = 0.299). Significantly lower mean histological lung lesion scores were observed in Group 1 versus Group 2 at 20 (p = 0.0065), 24 (p <  0.0001) and 26 weeks (p <  0.0001). Mean viral RNA load in lung tissue was significantly lower in Group 1 than in Group 2 (p <  0.0001) at 20 (p <  0.0001), 24 (p <  0.0001) and 26 weeks (p <  0.0001). Cumulative viral RNA loads in serum during days 1-10 post-challenge were significantly lower in Group 1 than in Group 2 (p <  0.0001) in all studies. A significant increase in ADWG was observed in Group 1 compared with Group 2 at 20 weeks (p = 0.0027) and 24 weeks (p = 0.0004), but not at 26 weeks (p = 0.1041). There were no significant differences in clinical signs post-challenge in any study. CONCLUSION: These results suggest that Ingelvac PRRSFLEX® EU confers long-term immunity to European heterologous PRRSV, which is maintained up to 26 weeks after vaccination, corresponding to the expected lifespan of commercial pigs.

6.
Vaccine ; 36(3): 408-412, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29221894

RESUMO

Lameness and polyserositis in pigs caused by Mycoplasma hyorhinis are generally treated with antibiotics and may require multiple doses. The costs of these antibiotics combined with economic losses from culling and reduced feed conversion due to lameness are hardships to the swine producer. In this study we have demonstrated efficacy of an inactivated M. hyorhinis vaccine administered to three-week old caesarian-derived colostrum-deprived piglets. Three doses of vaccine (high, medium, and low) were evaluated and compared to a placebo control. Mycoplasma hyorhinis challenge occurred three weeks after vaccination. Pigs were observed for lameness and respiratory distress for three weeks following challenge. Pigs were then euthanized and a gross pathological evaluation for polyserositis and arthritis was performed. A minimum immunizing dose of vaccine was defined as containing at least 7.41 × 107 CCU of M. hyorhinis per 2.0 mL dose as represented by the medium dose vaccine. This vaccine provided significant reductions in lameness and pericarditis with preventive fractions of 0.76 (95% CI [0.26, 0.92]) and 0.58 (95% CI [0.31, 0.74]), respectively, compared to the placebo control group. A significant increase in post-challenge weight gain (P < .0001) was also achieved with this vaccine, with an average daily gain (ADG) of 0.92 lbs/day compared to 0.57 lbs/day in the placebo group.


Assuntos
Vacinas Bacterianas/imunologia , Coxeadura Animal/prevenção & controle , Infecções por Mycoplasma/veterinária , Mycoplasma hyorhinis/imunologia , Serosite/veterinária , Doenças dos Suínos/prevenção & controle , Animais , Vacinas Bacterianas/administração & dosagem , Peso Corporal , Infecções por Mycoplasma/prevenção & controle , Placebos/administração & dosagem , Serosite/prevenção & controle , Suínos , Doenças dos Suínos/microbiologia , Resultado do Tratamento , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia
7.
Vet Microbiol ; 210: 147-152, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29103684

RESUMO

Mycoplasma hyorhinis (MHR) is a major cause of lameness, arthritis, and polyserositis among growing pigs. Reduced performance and culling due to MHR infection result in economic losses in swine production. We have previously developed an MHR challenge model in seven week-old CDCD pigs using cell-associated challenge material which results in both severe pericarditis and lameness. In this study we sequentially challenged CDCD pigs at seven, ten, thirteen, and sixteen weeks of age. Lameness was observed in >60% of the animals in the first three age groups but only 33% in the oldest age group. The number of animals with arthritis declined from 100% at seven weeks, to 56% at ten weeks and approximately 25% at both thirteen and sixteen weeks of age. Pericarditis was observed in 87% of the seven week challenge group, 28% in the ten week challenge group, 8% in the thirteen week challenge group and 4% in the sixteen week challenge group. All challenged groups showed a reduced average daily gain (ADG) compared to their age-matched non-challenged control groups. The largest disparity in ADG (1.2 lbs/day difference) was noted at thirteen weeks of age. Results of this study demonstrate that these animals were susceptible to MHR-associated lameness through sixteen weeks of age while susceptibility to MHR-associated polyserositis appeared to peak at seven weeks of age.


Assuntos
Artrite/veterinária , Coxeadura Animal/microbiologia , Infecções por Mycoplasma/veterinária , Mycoplasma hyorhinis/fisiologia , Pericardite/veterinária , Doenças dos Suínos/microbiologia , Fatores Etários , Animais , Artrite/microbiologia , Colostro/imunologia , Modelos Animais de Doenças , Suscetibilidade a Doenças/microbiologia , Suscetibilidade a Doenças/veterinária , Feminino , Masculino , Infecções por Mycoplasma/microbiologia , Pericardite/microbiologia , Gravidez , Suínos
8.
Can J Vet Res ; 80(4): 269-280, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27733781

RESUMO

Porcine reproductive and respiratory syndrome virus (PRRSV) can be devastating to commercial breeding operations. The objective of this study was to evaluate a novel European PRRSV vaccinal strain for safety and efficacy in bred gilts. In 2 experiments, 110 gilts were vaccinated intramuscularly and the vaccine was evaluated for safety and efficacy. Gilts in Experiment 1 were evaluated for local and systemic reactions and gilts in both experiments were observed for clinical signs of disease through farrow. In both experiments, piglet clinical observations, piglet average daily weight gain (ADWG), gilt serology [determined by enzyme-linked immunosorbent assay (ELISA)], gilt and piglet viremia [determined by quantitative real-time polymerase chain reaction (qPCR)], as well as piglet lung lesion scores and PRRS virus in lung tissue (qPCR) were determined. The vaccine was shown to be safe as there were no significant differences among groups in either experiment. Efficacy was established in Experiment 2 as both vaccinated groups were associated with desirable significant differences in percentage of gilts with abnormal clinical findings; gilt viral load post-challenge [day 125, day of farrowing (DOF), and DOF + 13]; percentages of alive, healthy live, weak live, and mummified piglets per litter at farrowing and weaning; percentage of piglets per gilt that were positive for viremia; percentage of piglets per gilt with clinical disease; and piglet viral load on DOF. It was concluded that a vaccine formulated from the PRRSV modified live virus (MLV) strain 94881 is a safe and effective method of protection against the detrimental effects of virulent PRRSV infection in breeding female pigs.


Le virus du syndrome reproducteur et respiratoire porcin (VSRRP) peut être dévastateur pour les opérations de reproduction commerciales. L'objectif de la présente étude était d'évaluer l'innocuité et l'efficacité d'une nouvelle souche vaccinale européenne du VSRRP chez des cochettes saillies. Lors de deux expériences, 110 cochettes ont été vaccinées par voie intramusculaire afin d'évaluer l'innocuité et l'efficacité du vaccin. Les cochettes de l'Expérience 1 ont été évaluées pour la présence de réactions locales et systémiques et les cochettes dans les deux expériences ont été observées pour vérifier la présence de signes cliniques de maladie jusqu'au moment de la mise-bas. Lors des deux expériences on nota les observations cliniques des porcelets, le gain de poids quotidien moyen des porcelets (GMQ), les titres sérologiques des truies [déterminés par épreuve immuno-enzymatique (ELISA)], la virémie chez les cochettes et les porcelets [déterminées par réaction d'amplification en chaine par la polymérase quantitative (qACP)], ainsi que par les pointages de lésions pulmonaires des porcelets et la quantité de virus SRRP dans le tissu pulmonaire (qACP). Le vaccin s'est avéré sécuritaire et il n'y avait pas de différence significative entre les groupes dans les deux expériences. L'efficacité a été établie lors de l'Expérience 2 alors que les deux groupes vaccinés ont été associés à des différences significatives souhaitées dans le pourcentage de cochettes avec des trouvailles cliniques anormales; dans la charge virale post-challenge par cochette [jour 125, jour de la mise-bas (JMB), et JMB + 13]; pourcentages de porcelets vivants, vivants en santé, vivants faibles, et momifiés par portée au moment de la mise-bas et au sevrage; pourcentages de porcelets par truie qui étaient positifs pour une virémie; pourcentage de porcelets par cochette avec une maladie clinique; et charge virale des porcelets au JMB. Il a été conclu qu'un vaccin formulé à partir de la souche 94881 du VSRRP vivant modifié est une méthode sécuritaire et efficace de protection contre les effets néfastes d'une infection par le VSRRP chez des porcs femelles de reproduction.(Traduit par Docteur Serge Messier).


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Temperatura Corporal , Europa (Continente) , Feminino , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Complicações Infecciosas na Gravidez/veterinária , Complicações Infecciosas na Gravidez/virologia , Suínos , Fatores de Tempo , Carga Viral , Vacinas Virais/efeitos adversos , Viremia/veterinária , Aumento de Peso
9.
Can J Vet Res ; 80(2): 124-33, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27127339

RESUMO

Porcine reproductive and respiratory syndrome virus (PRRSV) can be difficult to manage in commercial settings. A novel type I PRRSV vaccinal strain (94881) was evaluated for safety and efficacy/onset of immunity (OOI) in piglets. In 2 experiments, groups of piglets were vaccinated intramuscularly (IM) at approximately 14 d of age with a maximum-range commercial dose, an overdose, or a placebo in experiment 1 and either a minimum-range commercial dose or a placebo in experiment 2. The piglets in experiment 1 were evaluated for local and systemic reactions from days -2 through 14 after vaccination. The piglets in experiment 2 were challenged with a virulent heterologous type I PRRSV isolate 14 d after vaccination and observed once daily for general health from days -1 through 12 after vaccination and once daily for clinical signs associated with challenge from days 13 through 24 after vaccination. The average daily weight gain (ADWG) and the results of serologic and viremia testing were evaluated in experiments 1 and 2. Lung lesion scores and results of testing for PRRSV in lung tissue were evaluated in experiment 2. In experiment 1 the vaccine was shown to be safe, as there were no relevant differences between the vaccinated piglets and the piglets given a placebo. In experiment 2 the vaccine's efficacy, with an OOI of 14 d after vaccination, was established, as the vaccinated and challenged piglets exhibited significantly lower lung lesion scores, viremia, viral load in lung tissue, and total clinical sign scores, along with a significantly greater ADWG, compared with the placebo-vaccinated and challenged piglets.


La gestion du virus du syndrome reproducteur et respiratoire porcin (VSRRP) peut être difficile dans un environnement de production commerciale. Une nouvelle souche vaccinale du VSRRP de type 1 (94881) a été évaluée d'un point de vue sécurité et efficacité/début de l'immunité (DDI) chez des porcelets. Dans deux expériences, des groupes de porcelets ont été vaccinés par voie intramusculaire (IM) à l'âge d'environ 14 j avec une dose commerciale maximale, une surdose, ou un placebo dans l'expérience 1 et une dose commerciale minimale ou un placebo dans l'expérience 2. Les porcelets dans l'expérience 1 furent évalués pour des réactions locale et systémique à compter du jour −2 jusqu'au jour 14 post-vaccination. Les porcelets dans l'expérience 2 furent soumis à une infection défi avec un isolat virulent hétérologue de VSRRP de type 1 14 j après la vaccination et observés une fois par jour pour leur état de santé général du jour −1 jusqu'au jour 12 après la vaccination et une fois par jour pour des signes cliniques associés avec l'infection du jour 13 au jour 24 après l'infection. Le gain moyen quotidien (GMQ) et les résultats des analyses sérologiques et de virémie ont été évalués dans les expériences 1 et 2. Les pointages de lésions pulmonaires et les résultats de détection du VSRRP dans le tissu pulmonaire ont été évalués dans l'expérience 2. Dans l'expérience 1, le vaccin s'est montré sécuritaire étant donné qu'il n'y avait aucune différence significative entre les porcelets vaccinés et les porcelets ayant reçu un placebo. Dans l'expérience 2, l'efficacité du vaccin, avec un DDI de 14 j après la vaccination, a été établie, étant donné que les porcelets vaccinés, et soumis à une infection défi avaient des valeurs significativement moins élevées de pointage de lésions pulmonaires, de virémie, de charge virale dans le tissu pulmonaire, et des pointages de signes cliniques totaux, avec un GMQ significativement plus élevé, comparativement au porcs vaccinés avec un placebo et soumis à une infection défi.(Traduit par Docteur Serge Messier).


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Vacinas Virais/imunologia , Animais , Europa (Continente)/epidemiologia , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Suínos , Vacinas Virais/efeitos adversos
10.
Porcine Health Manag ; 2: 22, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28405448

RESUMO

BACKGROUND: PRRS is a viral disease of pigs and sows that is one of the most costly to the pig industry worldwide. The disease can be controlled by focusing on different aspects. One of them is the vaccination of piglets, which is more controversial and difficult to manage than the vaccination of sows. However, pig producers could consider a piglet vaccination strategy if it reduces the negative clinical disease and improves zootechnical performance, decreases the probability to be infected and/or reduces the spread of the virus once the vaccinated piglet is infected. The efficacy of a novel PRRS modified live vaccine (Ingelvac PRRSFLEX® EU) was studied in a blinded, side-by-side placebo controlled field study of piglet vaccination including piglets weaned for three consecutive weeks (week groups 1, 2 and 3). RESULTS: This study established that PRRS piglet vaccination resulted in significantly better weight gain, seen as early as 4 weeks after vaccination, in naturally challenged pigs. Vaccine efficacy was supported by statistically significant increases in Average Daily Weight Gain (ADWG) among week group 3 vaccinated pigs from vaccination to the end of the study and statistically significant increases in bodyweight and ADWG from inclusion to 10 weeks of age in week group 2 vaccinated piglets. However, no differences were noted in week group 1 presumably because more than 30 % of the vaccinated pigs were viremic at the time of vaccination. Furthermore, the proportion of pigs showing any abnormal clinical sign at least once at any of the examination time points was lower in vaccinated pigs than in control pigs. Based on the viremia results (qPCR), early onset of PRRS was detected in this herd. Viremia occurred at the time of vaccination in week group 1 and shortly after vaccination in week groups 2 and 3. Peak wild type PRRSV infection was assumed at 4 weeks post vaccination in all groups based on the number of PRRS positive pigs in the control groups. CONCLUSION: This study establishes that vaccination of piglets with Ingelvac PRRSFLEX® EU at 4 weeks of age improves weight gain and reduces the appearance of clinical sings during the growing period, even when the piglets are infected shortly after vaccination.

11.
J Vet Diagn Invest ; 23(5): 885-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21908342

RESUMO

In the current study, the development and validation of a real-time polymerase chain reaction (PCR) assay using a TaqMan-labeled probe for the detection of Actinobacillus suis from porcine lung samples is described. This real-time PCR amplified a 110-bp region of the 23S ribosomal RNA gene from A. suis but not from other bacteria. First, the assay was validated with 183 bacterial strains representing different species of bacteria. Subsequently, 85 porcine lung specimens that were declared A. suis-positive and -negative by bacterial culture and identification were tested to assess whether it can be performed directly on tissue specimens. The bacterial culture results and real-time PCR results agreed across all the samples tested assigning 100% positive and negative predictive values to the PCR. Further, the detection limit of the assay was 380 colony-forming units (CFU) per ml or approximately 1 CFU per reaction. In conclusion, the TaqMan real-time PCR assay described herein is a highly specific, sensitive, and reproducible test, which can be used to detect A. suis DNA in porcine lung specimens, thus providing a timely diagnosis.


Assuntos
Infecções por Actinobacillus/veterinária , Actinobacillus suis/isolamento & purificação , Pneumopatias/veterinária , Pulmão/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Doenças dos Suínos/microbiologia , Infecções por Actinobacillus/diagnóstico , Infecções por Actinobacillus/microbiologia , Animais , Pneumopatias/diagnóstico , Pneumopatias/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/diagnóstico
12.
Anim Health Res Rev ; 6(2): 173-97, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16583781

RESUMO

Proliferative enteropathy (PE; ileitis) is a common intestinal disease affecting susceptible pigs raised under various management systems around the world. Major developments in the understanding of PE and its causative agent, Lawsonia intracellularis, have occurred that have led to advances in the detection of this disease and methods to control and prevent it. Diagnostic tools that have improved overall detection and early onset of PE in pigs include various serological and molecular-based assays. Histological tests such as immunohistochemistry continue to be the gold standard in confirming Lawsonia-specific lesions in pigs post mortem. Despite extreme difficulties in isolating L. intracellularis, innovations in the cultivation and the development of pure culture challenge models, have opened doors to better characterization of the pathogenesis of PE through in vivo and in vitro L. intracellularis-host interactions. Advancements in molecular research such as the genetic sequencing of the entire Lawsonia genome have provided ways to identify various immunogens, metabolic pathways and methods for understanding the epidemiology of this organism. The determinations of immunological responsiveness in pigs to virulent and attenuated isolates of L. intracellularis and identification of various immunogens have led to progress in vaccine development.


Assuntos
Vacinas Bacterianas/imunologia , Infecções por Desulfovibrionaceae/veterinária , Enterite/veterinária , Lawsonia (Bactéria) , Doenças dos Suínos/patologia , Animais , Infecções por Desulfovibrionaceae/epidemiologia , Infecções por Desulfovibrionaceae/patologia , Infecções por Desulfovibrionaceae/prevenção & controle , Enterite/epidemiologia , Enterite/patologia , Enterite/prevenção & controle , Imuno-Histoquímica/veterinária , Lawsonia (Bactéria)/genética , Lawsonia (Bactéria)/isolamento & purificação , Lawsonia (Bactéria)/patogenicidade , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/prevenção & controle , Virulência/genética
13.
Am J Vet Res ; 65(5): 559-65, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15141873

RESUMO

OBJECTIVE: To evaluate the efficacy of an orally administered avirulent live vaccine to protect pigs against challenge exposure with virulent Lawsonia intracellularis. ANIMALS: 108 weaned 3-week-old pigs (35 in experiment 1 and 73 in experiment 2). PROCEDURE: 2 experiments were conducted. On day 0, vaccinates were orally administered vaccine via drench or in drinking water, whereas challenge-control pigs were administered cultured medium. On day 21, pigs were challenge exposed with a virulent heterologous isolate of L. intracellularis. Clinical observations, weights, seroconversion, and fecal excretion of L. intracellularis were measured until day 42. At study termination, pigs were euthanatized and examined for L. intracellularis-specific lesion development of the ileum and colon. RESULTS: Pigs receiving a single dose of vaccine were protected when challenge exposed with virulent L. intracellularis (at least 10(77) TCID50/dose). In experiment 1, vaccinates had significantly less fecal excretion (47% and 40% for days 35 and 42, respectively), compared with challenge-control pigs. In experiment 2, vaccinates had significantly less fecal excretion (50% and 58% for days 35 and 42, respectively), compared with challenge-control pigs. Significant reductions in lesion development were evident in the ileum of vaccinated pigs (70% and 56% at day 42 for experiments 1 and 2, respectively), compared with challenge-control pigs. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration by drench or via drinking water of an avirulent live vaccine against L. intracellularis resulted in substantial protection against proliferative enteropathy among vaccinates and offers a better way to reduce stress of pigs during vaccine administration.


Assuntos
Vacinas Bacterianas/imunologia , Infecções por Desulfovibrionaceae/veterinária , Enteropatias/veterinária , Lawsonia (Bactéria)/imunologia , Doenças dos Suínos/imunologia , Administração Oral , Análise de Variância , Animais , Vacinas Bacterianas/administração & dosagem , Colo/patologia , Infecções por Desulfovibrionaceae/imunologia , Determinação de Ponto Final , Fezes/microbiologia , Imunofluorescência , Íleo/patologia , Imuno-Histoquímica , Enteropatias/imunologia , Enteropatias/patologia , Sus scrofa , Doenças dos Suínos/microbiologia
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