The aim of the study was to estimate the current epidemiological situation concerning swine influenza (SI) in Poland. The study was based on an annual passive survey of 11,770 fatteners’ sera from 584 herds, taken at slaughterhouses within the last 30 months (from January 2010 till June 2012), as well as, an active monitoring conducted in 2011 and 2012, in 25 farms, using 388 sera taken from life pigs of different age/technological groups. The analysis of simultaneous circulation of different swine influenza virus (SIV) subtypes was taken into a deep consideration. The wide spread of SIV in Poland, including the occurrence of multiple SIV infections was demonstrated. In 2010 and 2011, the domination of H1N1 subtype and the most frequently co-circulation of H1N1 and H1N2 viruses was evidenced, while in the first 6 months of 2012, the co-circulation of H1N1 and H3N2 viruses was detected more often. Based on the obtained results, it can be stated that the epidemiological situation concerning SI in Poland is dynamic and similar to that observed in other European regions with high pigs’ density; however, the prevalence of antibodies and the occurrence of mixed SIV infections is lower than in Western Europe.
Age-related changes in serum concentrations of C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA), and pig major acute phase protein (pig-MAP) were investigated in healthy pigs from birth to slaughter under field conditions. Repeated blood samples were obtained from 60 pigs at ages of 1-19 weeks. Concentrations of acute phase proteins (APP) were measured with the use of commercial ELISA kits. Concentrations of all APP increased with age (P<0.05) and positive correlations were evidenced between their concentrations and the age of pigs. Great variations in CRP, Hp, and SAA concentrations were found, as can been seen from standard deviation values. The minimal individual variability was found in regard to pig-MAP. A significant increase in all APP was observed in pigs’ serum after weaning, constituting an important characteristic of this period. The elevation of APP after weaning may be associated with stress induced by mixing animals after weaning or changes in the pattern of feed administration. The peak in APP may be also caused by the initiation of synthesis of these proteins by piglets. Because a significant association between age and APP concentrations exists, further studies are needed to decide whether the age may influence the diagnostic value of APP as a marker of infection. Additionally, studies are needed to estimate whether the APP response in infection is age-dependent to any clinical importance degree.
The kinetics of C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA), and pig major acute protein (Pig-MAP) response in pigs co-infected with H3N2 swine influenza virus (SwH3N2) and Bordetella bronchiseptica (Bbr) was studied, with assessment of potential correlations between the concentration of acute phase proteins (APPs) in serum samples, lung lesions, and the clinical course of the disease in co-infected pigs. The standard bacteriological methods for detection of Bbr and PCR technique for identification of Bbr and SwH3N2 were used. The serum concentrations of APPs were measured using ELISA. The concentration of CRP, SAA, and Pig-MAP was significantly higher from 2 to 4 or 5 dpi. The concentration of Hp was elevated until the end of the study. Significant correlations were found between the serum concentration of SAA and Pig-MAP and clinical score, and between the concentration of SAA and lung score. Apart from their potential as biological markers for co-infections, SAA and Pig-MAP levels have additive value since they are related to the severity of infection. The results indicate that measurement of APP (i.e SAA) may prove valuable in assessing the severity of respiratory infection in pigs, and may be of supportive value in the clinical evaluation of animals and in the selection of more appropriate treatment.
The aim of the study was to determine the effects of supplementation of sows’ and weaners’ diet with Stresomix, preparation containing extracts from Magnifera indica, Withania somnifera, Phyllanthus emblica, and Ocimum sanctum, on pig performance and immunity under field condition. The hypothesis was that anti-inflammatory, antistress, and immunomodulatory properties of the herbs would enhance production parameters and immune response, according to the manufacturer's claim. The study was performed on 16 sows and 160 piglets. The following parameters were recorded: concentration and proportion of white blood cells and their populations, concentration of serum immunoglobulins, specific humoral postvaccinal response after vaccination against swine influenza and swine erysipelas, and main production parameters. No significant differences among treatment groups were found with regard to concentrations of leukocyte subpopulations and immunoglobulins, as well as all investigated production parameters (P>0.05). In conclusion, the results of the study did not confirm that the investigated polyherbal product, administered at dose recommended by manufacturer, is able to significantly improve the performance and postvaccinal humoral response in clinically healthy pigs under field condition.
Introduction: The aim of the study was to evaluate the effect of administration of therapeutic doses of ceftiofur and tulathromycin on the circulating lymphocyte subpopulations in healthy pigs. Material and Methods: The study was conducted on thirty healthy 7- to 10-week-old pigs, assigned to three groups: the TUL group, injected with tulathromycin (n = 10); the CEF group, injected with ceftiofur (n = 10); and the C group, the control with no antibiotic administration (n = 10). Blood samples were collected before, during, and after treatment with antimicrobials. Lymphocyte subpopulations circulating in the blood were determined by immunostaining and flow cytometry analyses. Results: Following administration of a therapeutic dose of tulathromycin, there were no changes in the lymphocyte subpopulations circulating in blood. In contrast, administration of ceftiofur at the recommended dose decreased the absolute number of CD3+, CD21+, CD4+CD8-, CD4-CD8+, and double positive CD4CD8 cells. Conclusion: Results from the study indicate that ceftiofur possesses the ability to modulate the immune system in healthy pigs by decreasing lymphocyte subpopulations circulating in blood.
Introduction: The aim of the study was to explore the effect of enrofloxacin on production of selected cytokines by porcine peripheral blood mononuclear cells (PBMCs).
Material and Methods: Twenty pigs (10 control and 10 experimental) were used in this research. Pigs from experimental group received enrofloxacin at therapeutic doses. Blood samples were collected before, during, and after treatment with enrofloxacin. PBMCs were incubated with or without lipopolysaccharide (LPS). Production of IL-6, IL-10, INF-γ, and TNF-α were determined by ELISA.
Results: Administration of enrofloxacin to healthy pigs for 5 d induced a transient reduction of the PBMCs response to LPS in terms of IL-6 and TNF-α secretion. The concentration of IL-6 returned to the day 0 level shortly after treatment, while TNF-α production remained reduced for 10 d after the treatment. The production of IL-10 was not affected by enrofloxacin. The level of IFN-γ was below the detection limit of the tests.
Conclusion: The results indicate that enrofloxacin administered in vivo in therapeutic doses has an immunomodulatory effect through its capacity to inhibit secretion of IL-6 and TNF-α by porcine PBMC stimulated by LPS.
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-1β, 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-1β, 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-1β, IL-6, IL-8, and IFN-γ were elevated. Additionally, in App+SIV-infected pigs, significantly greater concentrations of IL-1β, 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 singleinfected pigs
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.
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.
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.
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.
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-1β, 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.
The three cytokines IFN-α, IFN-γ, and IL-1β 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.
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.