RESUMEN

Introduction: The lack of proofreading activity of the viral polymerase and the segmented nature of the influenza A virus (IAV) genome are responsible for the genetic diversity of IAVs and for their ability to adapt to a new host. We tried to adapt avian IAV (avIAV) to the pig by serial passages in vivo and assessed the occurrence of point mutations and their influence on viral fitness in the pig's body. Material and Methods: A total of 25 in vivo avIAV passages of the A/duck/Bavaria/77 strain were performed by inoculation of 50 piglets, and after predetermined numbers of passages 20 uninoculated piglets were exposed to the virus through contact with inoculated animals. Clinical signs of swine influenza were assessed daily. Nasal swabs and lung tissue were used to detect IAV RNA by real-time RT-PCR and isolates from selected passages were sequenced. Results: Apart from a rise in rectal temperature and a sporadic cough, no typical clinical signs were observed in infected pigs. The original strain required 20 passages to improve its replication ability noticeably. A total of 29 amino-acid substitutions were identified. Eighteen of them were detected in the first sequenced isolate, of which 16 were also in all other analysed strains. Additional mutations were detected with more passages. One substitution, threonine (T) 135 to serine (S) in neuraminidase (NA), was only detected in an IAV isolate from a contact-exposed piglet. Conclusion: Passaging 25 times allowed us to obtain a partially swine-adapted IAV. The improvement in isolate replication ability was most likely related to S654 to glycine (G) substitution in the basic protein (PB) 1 as well as to aspartic acid (D) 701 to asparagine (N) and arginine (R) 477 to G in PB2, glutamic acid (E) 204 to D and G239E in haemagglutinin and T135S in NA.

RESUMEN

INTRODUCTION: The study evaluated the patterns of local innate immune response in bronchoalveolar lavage fluid (BALF) cells of pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV) alone or co-infected with swine influenza virus (SIV). MATERIAL AND METHODS: The study was performed on 26 seven-week-old pigs in three groups: PRRSV-infected (n = 11), PRRSV and SIV-infected (n = 11), and control (n = 4). BALF was collected post euthanasia at 2 and 4 dpi (three piglets per inoculated group) and at 21 dpi (all remaining pigs). Expression of IFN-α, IFN-γ, IL-1ß, IL-6, IL-8, and IL-10 mRNA was quantified in BALF cells. PRRSV RNA was quantified in BALF samples using a commercial real-time RT-PCR kit. RESULTS: The three cytokines IFN-α, IFN-γ, and IL-1ß presented significant expression changes in all experimental pigs. In PRRSV-infected animals IL-8 also did, but in co-infected subjects IL-6 and IL-10 were the additional upregulated cytokines. The highest number of differentially expressed genes was observed at 4 dpi, and significant differences in cytokine gene expression did not occur between the experimental groups at any other time point. The mean PRRSV load in the BALF of PRRSV-infected pigs was higher than that of co-infected pigs at each time point, having statistical significance only at 4 dpi. CONCLUSION: The results of the study indicate that infection with PRRSV alone as well as with SIV interferes with innate and adaptive immune response in the infected host. They also showed that co-infection demonstrates additive effects on IL-6 and IL-10 mRNA expression levels.

RESUMEN

The effect of a standard, single dose therapy with tulathromycin was investigated on the postvaccinal humoral and cellular immune response in pigs vaccinated against swine influenza. Forty-five pigs, divided into 3 groups, were used (control not vaccinated (C, n = 15), control vaccinated (CV, n = 15), and experimentally received tulathromycin (TUL, n = 15)). For vaccination of pigs, an inactivated, commercial vaccine was used. Pigs from TUL group received single dose of tulathromycin intramuscularly, at the recommended dose (2.5 mg/kg body weight). Pigs from TUL and CV groups were vaccinated at 8 and 10 weeks of age. The specific humoral and cellular immune response against swine influenza virus (SIV) was evaluated. The results of present study showed that humoral postvaccinal response after vaccination against SIV can be modulated by treatment with tulathromycin. In pigs from TUL group, the significantly higher titers of anti-SIV-specific antibodies were observed 4 and 6 weeks after booster dose of vaccine. Simultaneously, T-cell-mediated immune response against SIV was not affected by tulathromycin. Our recent study confirmed the importance of defining the modulatory activity of tulathromycin because of its influence on the immune response to vaccines. Since the antibodies against hemagglutinin are crucial for the protection against SIV, the present observations should prompt further studies on the practical significance of recent results in terms of clinical implications (postvaccinal protection) in the field conditions.

Asunto(s)

Antibacterianos/farmacología , Disacáridos/farmacología , Compuestos Heterocíclicos/farmacología , Inmunidad Celular/efectos de los fármacos , Inmunidad Humoral/efectos de los fármacos , Vacunas contra la Influenza/inmunología , Animales , Femenino , Vacunas contra la Influenza/uso terapéutico , Masculino , Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/veterinaria , Porcinos/inmunología , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/prevención & control , Enfermedades de los Porcinos/virología

RESUMEN

INTRODUCTION: The aim of the study was to determine the effects of supplementation of sows' and growing pigs' diets with three newly developed synbiotic and two extant commercial probiotic products on selected immune parameters under field conditions. MATERIAL AND METHODS: The study was performed on 30 sows and 48 piglets of the Danbred breed. Immune parameters such as concentration and proportion of white blood cells and their subpopulations, immunoglobulins amount in serum, and serum concentration of cytokines and acute phase proteins were recorded with the use of a haematology analyser and ELISA kits. RESULTS: No significant differences between treatment groups and controls were found with regard to the immune parameters evaluated except for serum immunoglobulin concentration, which was significantly increased by synbiotic products B and C and probiotic product D. CONCLUSION: The results of the study indicate that the synbiotic products B and C and probiotic product D are worthy of further investigation as promising candidates to improve the immune status of healthy sows and their offspring.

RESUMEN

Lactation impairment in sows is a frequent and significant clinical problem. Due to a complex aetiopathogenesis, early diagnosis of postpartum dysgalactia syndrome (PDS) is difficult and so far has usually been based on physical examination performed in the first days after farrowing. To date no data have been provided on the diagnostic usefulness of acute phase proteins (APP) in early diagnosis of peripartum disorders, including lactation disorders in sows. This study aimed at measuring the serum concentration of selected APP (C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA) and pig major acute phase protein (Pig-MAP)) in sows with physiological and pathological course of the peripartum period and at evaluating the possibility of utilising the studied markers in the early diagnosis of lactation disorders. Also, the correlation between the studied APP serum concentration and production parameters was assessed. To the best of the authors' knowledge, the present study is the first such performed on sows. The experiment was conducted on 139 sows divided into three experimental groups based on the course of peripartum period: HEALTHY (n = 58) - clinically healthy sows, PDS (n = 45) - sows with milk production disorders, and OTHERS (n = 36) - sows which had experienced difficult parturitions, inflammations not connected with mammary glands (abscesses, hooves infections), or lameness. Thirteen serum samples from each sow were analysed, samples being taken on days -28 (-30 to -25), -14 (-16 to -11), -7 (-8 to -6), -5, -3, -1, 0 (parturition day), +1, +3, +5, +7, +14 and +28 (prior to or post farrowing). In order to measure the level of serum APP, commercial, quantitative ELISA tests were used. The results of the study indicate that the diagnosis made on the basis of the assessment of SAA levels on day 7 before the farrowing was not statistically different from the diagnosis made on the basis of the physical examination in the first days after the farrowing, that is the so-called "gold standard". The achieved results indicate that SAA may be a useful early marker of lactation impairments in sows, which allows detection of which sows are susceptible to lactation disorders with high probability even as early as one week before parturition.

Asunto(s)

Proteínas de Fase Aguda/metabolismo , Biomarcadores/sangre , Trastornos de la Lactancia/veterinaria , Periodo Periparto/sangre , Enfermedades de los Porcinos/diagnóstico , Animales , Femenino , Haptoglobinas/análisis , Trastornos de la Lactancia/sangre , Trastornos de la Lactancia/diagnóstico , Embarazo , Albúmina Sérica/análisis , Proteína Amiloide A Sérica/análisis , Porcinos , Enfermedades de los Porcinos/sangre

RESUMEN

BACKGROUND: Respiratory co-infections are important factor affecting the profitability of pigs production. Swine influenza virus (SIV) may predispose to secondary infection. Haemophilus parasuis (Hps) can be a primary pathogen or be associated with other pathogens such as SIV. To date, little is known about the effect of coinfection with SIV and Hps on the disease severity and inflammatory response and the role of Hps in the induction of pneumonia in the absence of other respiratory pathogens. In the study we investigated the influence of SIV and Hps coinfection on clinical course, inflammatory response, pathogens shedding and load at various time points following intranasal inoculation. The correlation between local concentration of cytokines and severity of disease as well as serum acute phase proteins (APP) concentration has been also studied. RESULTS: All co-infected pigs had fever, while in single inoculated pigs fever was observed only in part of animals. Necropsy revealed lesions in the lungs all SIV-inoculated and co-inoculated pigs, while in Hps-single inoculated animals only 1 out of 11 pigs revealed gross lung lesions. The SIV shedding was the highest in co-inoculated pigs. There were no differences between Hps-single inoculated and co-inoculated groups with regard to Hps shedding. The significant increase in Hps titre in the lung has been found only in co-inoculated group. All APP increased after co-infection. In single-inoculated animals various kinetics of APP response has been observed. The lung concentrations of cytokines were induced mostly in SIV + Hps pigs in the apical and middle lobe. These results correlated well with localization of gross lung lesions. CONCLUSIONS: The results revealed that SIV increased the severity of lung lesions and facilitated Hps (PIWetHps192/2015) replication in the porcine lung. Furthermore, Hps influenced the SIV nasal shedding. Enhanced Hps and SIV replication, together with stronger systemic and local inflammatory response contributed to a more severe clinical signs and stronger, earlier immune response in co-inoculated animals. We confirmed the previous evidence that single-Hps infection does not produce significant pneumonic lesions but it should be in mind that other strains of Hps may produce lesions different from that reported in the present study.

Asunto(s)

Coinfección/veterinaria , Infecciones por Haemophilus/veterinaria , Haemophilus parasuis , Subtipo H1N1 del Virus de la Influenza A , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/virología , Animales , Coinfección/microbiología , Coinfección/virología , Femenino , Infecciones por Haemophilus/complicaciones , Inflamación/microbiología , Inflamación/veterinaria , Inflamación/virología , Masculino , Infecciones por Orthomyxoviridae/complicaciones , Porcinos , Enfermedades de los Porcinos/microbiología

RESUMEN

BACKGROUND: The influenza A virus is highly variable, which, to some degree, is caused by the reassortment of viral genetic material. This process plays a major role in the generation of novel influenza virus strains that can emerge in a new host population. Due to the susceptibility of pigs to infections with avian, swine and human influenza viruses, they are considered intermediate hosts for the adaptation of the avian influenza virus to humans. In order to test the reassortment process in pigs, they were co-infected with H3N2 A/swine/Gent/172/2008 (Gent/08) and H1N1 A/duck/Italy/1447/2005 (Italy/05) and co-housed with a group of naïve piglets. RESULTS: The Gent/08 strains dominated over Italy/05, but reassortment occurred. The reassortant strains of the H1N1 subtype (12.5%) with one gene (NP or M) of swine-origin were identified in the nasal discharge of the contact-exposed piglets. CONCLUSIONS: These results demonstrate that despite their low efficiency, genotypically and phenotypically different influenza A viruses can undergo genetic exchange during co-infection of pigs.

Asunto(s)

Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/genética , Infecciones por Orthomyxoviridae/veterinaria , Virus Reordenados/genética , Enfermedades de los Porcinos/virología , Animales , Coinfección/veterinaria , Coinfección/virología , Genes Virales , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Infecciones por Orthomyxoviridae/transmisión , Infecciones por Orthomyxoviridae/virología , Virus Reordenados/aislamiento & purificación , Porcinos , Enfermedades de los Porcinos/transmisión

RESUMEN

Porcine respiratory disease complex (PRDC) is a common problem in modern pork production worldwide. Pathogens that are amongst other pathogens frequently involved in PRDC etiology are swine influenza virus (SIV) and A. pleuropneumoniae. The effect of dual infection with mentioned pathogens has not been investigated to date. The aim of the present study was to evaluate the kinetics of single and dual infection of pigs with SIV and A. pleuropneumoniae with regard to clinical course, pathogens shedding, lung lesions and early immune response. The most severe symptoms were observed in co-inoculated piglets. The AUC value for SIV shedding was lower in pigs single inoculated with SIV as compared to co-inoculated animals. In contrast, no significant differences were found between A. pleuropneumoniae shedding in single or dual inoculated pigs. Three out of 5 co-inoculated piglets euthanized at 10 dpi were positive against serotype 2 A. pleuropneumonie. All piglets inoculated with SIV developed specific HI antibodies at 10 dpi. In pigs dual inoculated the specific humoral response against SIV was observed earlier, at 7 dpi. The SIV-like lung lesions were more severe in co-inoculated pigs. In the groups inoculated with A. pleuropneumoniae (single or dual) the acute phase protein response was generally stronger than in SIV-single infected group. Co-infection with SIV and A. pleuropneumoniae potentiated the severity of lung lesions caused by SIV and enhanced virus replication in the lung and nasal SIV shedding. Enhanced SIV replication contributed to a more severe clinical course of the disease as well as earlier and higher magnitude immune response (acute phase proteins, HI antibodies) compared to single inoculated pigs.

Asunto(s)

Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/inmunología , Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/microbiología , Infecciones por Actinobacillus/microbiología , Animales , Coinfección/veterinaria , Inmunidad Humoral , Cinética , Pulmón/microbiología , Pulmón/patología , Pulmón/virología , Infecciones por Orthomyxoviridae/virología , Porcinos , Enfermedades de los Porcinos/virología , Esparcimiento de Virus

RESUMEN

The effect of enrofloxacin on cytokine secretion by porcine peripheral blood mononuclear cells (PBMCs) was studied. Twenty 8-20-week-old pigs were randomly divided into two groups: control (C, n = 10) and experimental (E, n = 10) were used. Pigs from group E received enrofloxacin at therapeutic dose for 5 consecutive days. Blood samples were collected at 0 (before antibiotic administration), 2, 4 (during antibiotic therapy) 6, 9, 14 21, 35, 49, and 63 d of study (after treatment). PBMCs of pigs from both groups were incubated with or without lipopolysaccharide (LPS). Ex vivo production on interleukin (IL)-4, IL-6, IL-10, INF-γ, and TNF-α were analyzed using ELISA assay. Intramuscular administration of enrofloxacin to healthy pigs for 5 consecutive days induced a transitory reduction of the ex vivo response of PBMCs to LPS in terms of IL-6 and TNF-α secretion. The level of IL-6 returned to day 0 level shortly after end of treatment, while the TNF-α production remained reduced 10 d after the end of treatment. Our results indicate that enrofloxacin given in vivo in therapeutic doses has an immunomodulatory effect through its capacity to inhibit ex vivo secretion of IL-6 and TNF-α by porcine PBMC after LPS stimulation.

Asunto(s)

Antiinfecciosos/farmacología , Citocinas/metabolismo , Fluoroquinolonas/farmacología , Inmunomodulación/efectos de los fármacos , Leucocitos Mononucleares/efectos de los fármacos , Lipopolisacáridos/inmunología , Animales , Relación Dosis-Respuesta a Droga , Enrofloxacina , Femenino , Leucocitos Mononucleares/inmunología , Masculino , Porcinos

RESUMEN

INTRODUCTION: The aim of this study was to assess the seroprevalence of swine influenza A virus (SIV) in Polish farrow-to-finish pig herds. MATERIAL AND METHODS: Serum samples collected from 5,952 pigs, from 145 farrow-to-finish herds were tested for the presence of antibodies against H1N1, H1N1pdm09, H1N2, and H3N2 SIV subtypes using haemagglutination inhibition (HI) test. Samples with HI titres equal or higher than 20 were considered positive. RESULTS: HI antibodies to at least one of the analysed SIV subtypes were detected in 129 (89%) herds and in 2,263 (38%) serum samples. Antibodies to multiple SIV subtypes were detected in 104 (71.7%) herds and in 996 (16.7%) serum samples. Concerning the seroprevalence rate, according to age category, the highest prevalence of the antibodies was detected in weaners, with regard to the H1N1, H1N2, and H3N2, and in sows, with regard to the H1N1pdm09. The lowest seroprevalence for all evaluated SIV subtypes was detected in finishers. CONCLUSION: The study indicates that antibodies against single and multiple SIV subtypes are circulating in Polish farrow-to-finish herds and highlights the importance of conducting a molecular surveillance programme in future studies.

RESUMEN

INTRODUCTION: The aim of this study was to evaluate and compare the local innate immune response to the swine influenza virus (SIV) and Actinobacillus pleuropneumoniae (App) infection in pigs. MATERIAL AND METHODS: The study was performed on 37 seven-week-old pigs, divided into four groups: App-infected (n=11), App+SIV-infected (n=11), SIV-infected (n=11), and control (n=4). Lung samples were collected, following euthanasia, on the 2nd and 4th dpi (three piglets per inoculated group) and on the 10th dpi (remaining inoculated and control pigs). Lung concentrations of IL-1ß, IL-6, IL-8, TNF-α, IL-10, IFN-α, and IFN-γ were analysed with the use of commercial porcine cytokine ELISA kits. RESULTS: Lung concentrations of IL-1ß, IL-6, IL-8, TNF-α, IFN-α, and IFN-γ were induced in SIV-infected and App+SIV-infected pigs. In the lung tissue of App-infected pigs, only concentrations of IL-1ß, IL-6, IL-8, and IFN-γ were elevated. Additionally, in App+SIV-infected pigs, significantly greater concentrations of IL-1ß, IL-8, and IFN-α were found when compared with pigs infected with either SIV or App alone. In each tested group, the lung concentration of IL-10 remained unchanged during the entire study. CONCLUSION: The results of the study indicate that the experimental infection of pigs with SIV or App alone and co-infection with both pathogens induced a local lung inflammatory response. However, the local cytokine response was considerably higher in co-infected pigs compared to single-infected pigs.

RESUMEN

BACKGROUND: Cephalosporins are a class of antibiotics that are active against many Gram-positive and some Gram-negative bacteria. Beyond their antibacterial activity, they are reported to have various immunomodulatory properties. It has been shown that they reduce the secretion of cytokines as well as influence the humoral and cellular immune response. In the field conditions antibiotics are frequently administered at the same time as vaccines in pigs and, in the view of their potential immunomodulatory properties, it is important to examine their effect on the development and persistence of the post-vaccinal immune response. Ceftiofur is a very popular veterinary medicine third-generation cephalosporin with a broad spectrum of activity. It has been shown that it can inhibit cytokines secretion and in this way can potentially affect host immune response. The influence of ceftiofur on the immune response has not yet been investigated in pigs. In the present study we evaluated the influence of therapeutic doses of ceftiofur hydrochloride on the post-vaccinal immune response after vaccination with two model vaccines (live and inactivated). METHODS: Seventy pigs were divided into five groups: control, unvaccinated (C), control vaccinated against swine influenza (SI-V), control vaccinated against pseudorabies (PR-V), vaccinated against SI during ceftiofur administration (SI-CEF) and vaccinated against PR during ceftiofur administration (PR-CEF). Pigs from SICEF and PR-CEF groups received therapeutic dose of ceftiofur for five days. Pigs from SI-CEF, PR-CEF, SIV and PR-V groups were vaccinated against SI and PR. Antibodies to PRV were determined with the use of blocking ELISA tests (IDEXX Laboratories, USA). Humoral responses to SIV were assessed based on haemagglutination inhibition assay. T-cell response was analyzed with the use of proliferation test. The concentrations of IFN- γ and IL-4 in culture supernatant were determined with the use of ELISA kits Invitrogen Corporation, USA). RESULTS: The significant delay in the development of humoral response against pseudorabies virus (PRV) as well as a significant suppression of production of antibodies against swine influenza virus (SIV) was found in pigs receiving ceftiofur hydrochloride at the time of vaccination. The cellular immune response against PRV was also significantly affected by ceftiofur. In contrast, there were no significant differences between vaccinated groups with regard to the T-cell response against SIV. From day 28 of study to day 70, the concentration of INF-γ in culture supernatants were significantly lower in group treated with ceftiofur after restimulation with PRV. While, no significant differences were observed after restimulation of PBMC with H3N2 SIV. CONCLUSIONS: The effect of an antibiotic therapy with ceftiofur hydrochloride on the humoral and cellular post-vaccinal immune responses in pigs was investigated. Ceftiofur hydrochloride was given in therapeutic doses. The results of the present study indicate that both, humoral and cell-mediated post-vaccinal immune responses can be modulated by treatment with ceftiofur hydrochloride. The results of our study point out that caution should be taken when administered this antibiotic during vaccination of pigs.

Asunto(s)

Cefalosporinas/farmacología , Inmunidad Celular/efectos de los fármacos , Inmunidad Humoral/efectos de los fármacos , Infecciones por Orthomyxoviridae/veterinaria , Seudorrabia/prevención & control , Enfermedades de los Porcinos/virología , Animales , Antibacterianos/farmacología , Citocinas/genética , Citocinas/metabolismo , Regulación de la Expresión Génica/inmunología , Herpesvirus Suido 1/inmunología , Inmunomodulación/efectos de los fármacos , Subtipo H3N2 del Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/virología , Seudorrabia/virología , Porcinos , Enfermedades de los Porcinos/prevención & control , Factores de Tiempo , Vacunas de Productos Inactivados , Vacunas Virales/inmunología

RESUMEN

CONTEXT: Acute phase proteins (APPs) are proposed as potential markers of the health status in pigs. OBJECTIVE: Circulating APPs in pigs co-infected with swine influenza virus and Pasteurella multocida. METHODS: Serum APPs were measured in co-infected and control pigs with the use of commercial ELISA tests. RESULTS: All investigated APPs revealed significant changes in co-infected pigs during the study period. The concentration of C-reactive protein, haptoglobin and serum amyloid A (SAA) increased significantly at 2 dpi, before respiratory signs and fever were observed. Concentration of Pig-MAP increased significantly at 3 dpi. C-reactive protein and SAA reaction were rapid but short-lived. The concentration of Hp and Pig-MAP in serum also increased at very early stage of co-infection but remained elevated for a longer period of time. CONCLUSIONS: Maximal concentration of serum amyloid A correlated with the disease severity in pigs.

Asunto(s)

Pulmón/metabolismo , Infecciones por Orthomyxoviridae/diagnóstico , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Pasteurella/diagnóstico , Enfermedades de los Porcinos/diagnóstico , Proteínas de Fase Aguda/metabolismo , Animales , Biomarcadores/sangre , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Coinfección , Ensayo de Inmunoadsorción Enzimática , Haptoglobinas/metabolismo , Subtipo H3N2 del Virus de la Influenza A/patogenicidad , Subtipo H3N2 del Virus de la Influenza A/fisiología , Pulmón/microbiología , Pulmón/patología , Pulmón/virología , Infecciones por Orthomyxoviridae/sangre , Infecciones por Orthomyxoviridae/virología , Infecciones por Pasteurella/sangre , Infecciones por Pasteurella/microbiología , Infecciones por Pasteurella/patología , Pasteurella multocida/patogenicidad , Pasteurella multocida/fisiología , Proteína Amiloide A Sérica/metabolismo , Índice de Severidad de la Enfermedad , Porcinos , Enfermedades de los Porcinos/sangre , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/virología

RESUMEN

The present study was planned to study the effect of various subtypes of swine influenza virus (SIV) circulating among pigs (H1N2, H3N2 and emerging pandemic strain of H1N1 influenza A virus (H1N1pdm09) on the course of pregnancy in naïve gilts experimentally infected during the last month of pregnancy. In addition, the clinical course of infection, distribution of viruses in various tissues (blood, placenta, fetal lung), and selected immunological, reproductive and productive parameters were also investigated. All SIV-inoculated gilts became infected. No abortions, stillbirths, intrauterine deaths or mummified fetuses were observed. No clinical signs of influenza virus infection or other disorders were observed in piglets born from infected and control gilts. There was a significant decrease in the number and frequency of lymphocytes in gilts inoculated with all influenza viruses. In general, the concentrations of IL-6, IL-10 and TNF-α were significantly higher in SIV-inoculated gilts as than in control animals, while IL-4 and IFN-γ were not detected in plasma at any time post-inoculation in SIV- or mock-inoculated gilts. No evidence for transplacental transmission of SIV was found. Viremia was also not observed in any of the infected females. On the basis of recent results, we hypothesize that pregnancy failure observed during SIV infection under field conditions is probably related to high fever and pro-inflammatory cytokines rather than a direct effect of the virus on the placenta, embryo or fetus.

Asunto(s)

Transmisión Vertical de Enfermedad Infecciosa/veterinaria , Subtipo H1N1 del Virus de la Influenza A/fisiología , Subtipo H1N2 del Virus de la Influenza A/fisiología , Subtipo H3N2 del Virus de la Influenza A/fisiología , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/virología , Animales , Femenino , Edad Gestacional , Humanos , Interleucina-4/inmunología , Interleucina-6/inmunología , Masculino , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/transmisión , Infecciones por Orthomyxoviridae/virología , Embarazo , Resultado del Embarazo , Porcinos , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/transmisión

RESUMEN

The effect of treatment with enrofloxacin was studied on the postvaccinal immune response in pigs. Forty pigs were used (control not vaccinated (C), control vaccinated (CV), vaccinated, received enrofloxacin (ENRO)). From day -1 to day 3 pigs from ENRO group received enrofloxacin at the recommended dose. Pigs from ENRO and CV groups were vaccinated twice against Aujeszky's disease virus (ADV). There was a significant delay in the production of humoral response of enrofloxacin dosed pigs when compared with CV group. Moreover, in ENRO group the significant decrease in IFN-γ production and significantly lower values of stimulation index after ADV restimulation was noted, as compared with CV group. The secretion of IL-6, IL-10 and TNF-α by PBMC after recall stimulation was also affected in ENRO group. The results indicate that enrofloxacin, in addition to its antimicrobial properties, possess significant immunomodulatory effects and may alter the immune response to vaccines.

Asunto(s)

Antibacterianos/farmacología , Fluoroquinolonas/farmacología , Herpesvirus Suido 1/inmunología , Inmunomodulación/efectos de los fármacos , Seudorrabia/inmunología , Enfermedades de los Porcinos/inmunología , Vacunas Virales/inmunología , Animales , Enrofloxacina , Inmunidad Celular/efectos de los fármacos , Inmunidad Humoral/efectos de los fármacos , Seudorrabia/terapia , Seudorrabia/virología , Porcinos , Enfermedades de los Porcinos/terapia , Enfermedades de los Porcinos/virología

RESUMEN

BACKGROUND: The course of swine influenza in pigs is reported to be similar to human influenza. Occasionally abortions and other reproduction disorders have been associated with influenza A virus (IAV) infection in pigs. Abortions may be a consequence of high fever, pro-inflammatory cytokines or transplacental transmission of the virus.The role of IAV in the complications observed during pregnancy has been scanty and the true importance of this agent as a cause of reproductive problems in swine is not known. The aim was to determine the possible involvement of swine H1N2 IAV strain on reproductive disorders in pregnant gilts under experimental conditions. RESULTS: The gestation length was from 113 to 116 days, no abortion or any other reproduction disorders were noted. A PCR assay confirms the presence of IAV in the nasal swabs taken from inoculated gilts between 1 and 5 dpi. In the nasal swabs from control gilts and newborn piglets, no IAV genetic material was found. No viral RNA was detected in samples of blood taken from gilts and piglets, placentas, lungs and tracheas taken from piglets euthanized after delivery. The significant decrease in the number and percentage of lymphocytes without leukopenia was observed at 4 dpi in inoculated gilts. The percentage of granulocytes increased significantly at 4 dpi in inoculated pigs. The concentration of IL-6, IL-10 and TNF-α were higher in inoculated gilts, while IL-4 and IFN-γ were not detected in the serum of any of animals. The serum concentrations of C-reactive protein remained stable during study, while haptoglobin concentrations increased significantly after inoculation. CONCLUSIONS: The results of the study indicate that infection of pregnant gilts with swine H1N2 IAV in the second month of pregnancy does not cause abortion and other reproduction disorders. No evidence for transplacental transmission of swine H1N2 IAV was found. However, due to subclinical course of influenza in the present experiment caution should be taken in extrapolating these results to the cases of acute influenza. The other limitation is IAV diversity. It cannot be excluded that other subtypes of IAV could be associated to reproduction failure in pigs.

Asunto(s)

Subtipo H1N2 del Virus de la Influenza A , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/virología , Proteínas de Fase Aguda , Animales , Citocinas/genética , Citocinas/metabolismo , Femenino , Regulación de la Expresión Génica , Infecciones por Orthomyxoviridae/metabolismo , Infecciones por Orthomyxoviridae/virología , Embarazo , Porcinos , Enfermedades de los Porcinos/metabolismo

RESUMEN

Swine influenza (SI) is an acute respiratory disease of pigs, caused by swine influenza virus (SIV). Little is known about the inflammatory response in the lung during acute SI and its correlation with clinical signs or lung pathology. Moreover, until now there has been a limited amount of data available on the relationship between the concentrations of pro- and anti-inflammatory cytokines in the lungs and the serum concentration of acute-phase proteins (APPs) in SIV-infected pigs. In the present study, the porcine inflammatory and immune responses during acute influenza caused by H1N1 SIV (SwH1N1) were studied. Nine pigs were infected intratracheally, and five served as controls. Antibodies against SIV were measured by haemagglutination inhibition assay, and the influenza-virus-specific T-cell response was measured using a proliferation assay. C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA), and pig major acute-phase protein (Pig-MAP) the concentrations in serum and concentration of IL-1ß, IL-6, IL-8, IL-10, TNF-α and IFN-γ in lung tissues were measured using commercial ELISAs.

Asunto(s)

Subtipo H1N1 del Virus de la Influenza A/inmunología , Pulmón/inmunología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/patología , Enfermedades de los Porcinos/inmunología , Proteínas de Fase Aguda/inmunología , Animales , Anticuerpos Antivirales/sangre , Proteína C-Reactiva/metabolismo , Proliferación Celular , Citocinas/metabolismo , Haptoglobinas/metabolismo , Inflamación/inmunología , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Pulmón/patología , Pulmón/virología , Proteína Amiloide A Sérica/análisis , Porcinos , Enfermedades de los Porcinos/virología , Linfocitos T/inmunología

RESUMEN

BACKGROUND: Swine influenza (SI) is a contagious, important respiratory disease. Diagnosis of SI is based on the clinical signs, confirmed by the detection of viral RNA or specific antibodies. However, the infection is much more frequent than the disease. OBJECTIVES: The aim of study was to investigate the kinetics of acute-phase protein (APP) response during subclinical and clinical influenza in pigs. The utility of APP measurements in identification of infected animals was also evaluated. METHODS: Twenty-eight piglets were used. C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA) and pig major acute-phase protein (Pig-MAP) concentrations in serum were measured using commercial ELISAs. RESULTS AND CONCLUSIONS: No relevant clinical signs were observed in intranasally infected pigs. In contrast, coughing, nasal discharge, and fever were observed in pigs infected intratracheally. All infected pigs exhibited specific antibodies in the serum at 10 dpi, and viral shedding was confirmed. The concentrations of CRP, Hp and SAA were significantly increased after infection. The level of Pig-MAP remained constant during subclinical and clinical infection. The concentrations of CRP, Hp and SAA were higher in pigs with clinical disease. Although not specific, strategic APP measurements may reveal ongoing clinical and subclinical infection. A close relationship between the magnitude of serum APP response with the severity of disease, providing an objective tool for validation the severity of infection. The maximum concentration of SAA in serum was closely correlated with lung score and makes this APP potential indicator for disease progress or estimation of treatment strategy.

Asunto(s)

Proteínas de Fase Aguda/análisis , Subtipo H3N2 del Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/virología , Animales , Anticuerpos Antivirales/sangre , Infecciones Asintomáticas , Ensayo de Inmunoadsorción Enzimática , Femenino , Masculino , Infecciones por Orthomyxoviridae/patología , Suero/química , Porcinos , Enfermedades de los Porcinos/patología , Factores de Tiempo , Esparcimiento de Virus

RESUMEN

The effect of a seven-day antibiotic therapy with doxycycline was investigated on the postvaccinal humoral and cellular immune response in pigs. The selected parameters of non-specific immunity were also studied. Fifty pigs were used (control not vaccinated (C, n=10), control vaccinated (CV, n=20), and experimental - received doxycycline (DOXY, n=20)). For vaccination live-attenuated vaccine against pseudorabies (PR) was used. From day -1 to day 5 pigs from DOXY group received doxycycline orally with drinking water, at the recommended dose. Pigs from DOXY and CV groups were vaccinated at 8 and 10 weeks of age. The results of the present study showed that cell-mediated postvaccinal immune response can be modulated by oral treatment with doxycycline. Significantly lower values of stimulation index were observed after PRV restimulation in doxycycline-treated pigs. Moreover, in the DOXY group a significant decrease in IFN-γ production after PRV restimulation was noted. The significantly lower number of CD4+CD8+ cells was also observed in doxy-treated, vaccinated pigs, 2 weeks after final vaccination. Simultaneously, specific humoral response was not disturbed. This study demonstrated the importance of defining the immune modulatory activity of doxycycline because it may alter the immune responses to vaccines. The exact mechanism of T-cell response suppression by doxycycline remains to be elucidated, however the influence of doxycycline on the secretion of various cytokines, including IFN-γ, may be considered as a possible cause. The present observations should prompt further studies on the practical significance of such phenomena in terms of clinical implications.

Asunto(s)

Antibacterianos/farmacología , Doxiciclina/farmacología , Inmunidad Celular/efectos de los fármacos , Inmunidad Humoral/efectos de los fármacos , Vacunas contra la Seudorrabia/inmunología , Proteínas de Fase Aguda/metabolismo , Animales , Antibacterianos/administración & dosificación , Anticuerpos Antivirales/sangre , Recuento de Linfocito CD4 , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/virología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Doxiciclina/administración & dosificación , Esquema de Medicación , Interacciones Farmacológicas , Femenino , Interferón gamma/metabolismo , Interleucina-4/metabolismo , Activación de Linfocitos/efectos de los fármacos , Masculino , Modelos Animales , Vacunas contra la Seudorrabia/administración & dosificación , Sus scrofa , Células TH1/efectos de los fármacos , Células TH1/inmunología , Células TH1/virología , Células Th2/efectos de los fármacos , Células Th2/inmunología , Células Th2/virología , Factores de Tiempo , Vacunación , Vacunas Atenuadas/inmunología

RESUMEN

Pigs serve as a valuable animal experimental model for several respiratory pathogens, including Swine Influenza Virus (SIV) and Bordetella bronchiseptica (Bbr). To investigate the effect of SIV and Bbr coinfection on cytokine and viral RNA expression, we performed a study in which pigs were inoculated with SIV, Bbr or both pathogens (SIV/Bbr). Our results indicate that Bbr infection alters SIV clearance. Pulmonary lesions in the SIV/Bbr group were more severe when compared to SIV or Bbr groups and Bbr did not cause significant lesions. Broncho-alveolar lavage fluid (BALF) was examined for inflammatory mediators by qPCR. Interferon (IFN)-α, interleukin IL-8, IL-1 peaked in BALF at 2 DPI, while the virus titres and severity of clinical signs were maximal at the same time. Despite its increased expression in co-infected pigs, interferon-α did not enhance SIV clearance, since the viral replication was detected at the same day as the highest IFN levels. The mRNA levels for IFN-α, IL-1ß and IL-8 were significantly higher in BALF of co-infected pigs and correlated with enhanced viral RNA titers in lungs, trachea and nasal swabs. Transcription of mRNA for IL-1ß was stable in SIV and SIV/Bbr groups throughout all the study. In Bbr group, the levels of mRNAs for IL-1ß were significantly higher at 2, 4 and 9 DPI. The mean levels of mRNAs for TNF-α were lower than the levels of other chemokines and cytokines in all infected groups. Transcript levels of IL-10 and IL-4 did not increase at each time points. Overall, SIV replication was increased by Bbr presence and the enhanced production of pro-inflammatory mediators could contribute to the exacerbated pulmonary lesions.

Asunto(s)

Infecciones por Bordetella/veterinaria , Líquido del Lavado Bronquioalveolar/citología , Citocinas/genética , Regulación de la Expresión Génica/inmunología , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/inmunología , Animales , Infecciones por Bordetella/complicaciones , Infecciones por Bordetella/patología , Bordetella bronchiseptica/inmunología , Líquido del Lavado Bronquioalveolar/inmunología , Coinfección/inmunología , Perfilación de la Expresión Génica , Subtipo H1N1 del Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/patología , ARN Mensajero/genética , ARN Viral/metabolismo , Distribución Aleatoria , Porcinos , Enfermedades de los Porcinos/patología , Carga Viral