Concentrations of selected immunological parameters in the serum and processing fluid of suckling piglets and the serum and colostrum of their mothers.

BACKGROUND: Blood sampling from neonatal piglets is related to multiple disadvantages. Therefore, a new, alternative matrix is required to assess piglets' early immune status efficiently. The present study aimed to assess the usefulness of processing fluid for determining selected piglets' immune parameters. 264 pigs - 31 sows, 146 male piglets, and 87 female piglets from commercial indoor farrow-to-finish pig herd were included in this study. 264 serum, 31 colostrum, and 146 processing fluid samples were collected. Serum was collected from all animals, colostrum was collected from sows, and processing fluid was collected from male piglets only. Using commercial ELISA tests, the concentration of various immunoglobulins, cytokines, and acute phase proteins was assessed in each matrix. Statistical analyses were employed to determine differences in the concentration of measured indices between piglets' serum and processing fluid and correlations in the concentration of tested indices between particular sets of matrices. RESULTS: Statistical analyses did not reveal significant differences in the IgG, IgA, IL-1ß, IL-4, IL-6, and IFN-γ concentration between piglets' serum and processing fluid (p > 0.05). A positive correlation (p < 0.05) regarding the concentration of some indices between processing fluid and samples collected from sows was also observed. CONCLUSIONS: Processing fluid can be considered a promising alternative to blood for assessing some immunological indices in piglets, such as IgG, IgA, IL-1ß, IL-4, IL-6, and IFN-γ, and, possibly, in the indirect assessment of some indices in lactating sows, including IgA, IL-1ß, IL-4, IL-6, IL-8, IFN-γ, or Pig-MAP.

Serum Concentrations of Immunoglobulins and Cortisol Around Parturition in Clinically Healthy Sows and Sows with Postpartum Dysgalactia Syndrome (PDS).

Introduction: This study aimed to determine the profile of immunoglobulins and cortisol concentrations in serum around the periparturient period in sows suffering from postpartum dysgalactia syndrome (PDS) and in healthy sows. Material and Methods: A total of 45 sows with lactation impairment (Group PDS) and 58 clinically healthy sows with a physiological peripartum period (Group H) were subjected to a serological test (ELISA) for measurement of serum immunoglobulins (IgG, IgM, and IgA) and cortisol concentration. Results: The serum contents of IgG, IgM and IgA had highly similar profiles in PDS-affected sows and healthy ones. A significantly higher concentration of IgG at 28 and 14 days ante partum compared to days 3 and 7 post partum was only observed in Group H. The mean cortisol content remained at a highly similar level throughout the entire experiment in both groups. Conclusion: The results of the study indicate that lactation impairment such as PDS did not influence the immunoglobulin or cortisol concentration in sow serum.

Respiratory viral infections drive different lung cytokine profiles in pigs.

BACKGROUND: Swine influenza A virus (IAV) and porcine reproductive and respiratory syndrome virus (PRRSV) are considered key viral pathogens involved in the porcine respiratory disease complex. Concerning the effect of one virus on another with respect to local immune response is still very limited. Determination of presence and quantity of cytokines in the lung tissue and its relation to the lung pathology can lead to a better understanding of the host inflammatory response and its influence on the lung pathology during single or multi-virus infection. The aim of the present study was to explore and compare the patterns of lung cytokine protein response in pigs after single or dual infection with swine IAV and/or PRRSV. RESULTS: Inoculation with IAV alone causes an increase in lung concentration of IFN-α, IFN-É£, TNF-α, IL-6, IL-8 and IL-10, especially at 2 and 4 DPI. In PRRSV group, beyond early IFN-α, IFN-É£, IL-6, IL-8 and IL-10 induction, elevated levels of cytokines at 10 and 21 DPI have been found. In IAV+PRRSV inoculated pigs the lung concentrations of all cytokines were higher than in control pigs. CONCLUSIONS: Current results indicate that experimental infection of pigs with IAV or PRRSV alone and co-infection with both pathogens induce different kinetics of local cytokine response. Due to strong positive correlation between local TNF-α and IL-10 concentration and lung pathology, we hypothesize that these cytokines are involved in the induction of lung lesions during investigates infection. Nevertheless, no apparent increase in lung cytokine response was seen in pigs co-inoculated simultaneously with both pathogens compared to single inoculated groups. It may also explain no significant effect of co-infection on the lung pathology and pathogen load, compared to single infections. Strong correlation between local concentration of TNF-α, IFN-É£, IL-8 and SwH1N1 load in the lung, as well as TNF-α, IL-8 and PRRSV lung titres suggested that local replication of both viruses also influenced the local cytokine response during infection.

Kinetics of single and dual simultaneous infection of pigs with swine influenza A virus and porcine reproductive and respiratory syndrome virus.

BACKGROUND: Simultaneous viral infections exhibit the phenomenon of viral interference, but understanding of the effect of one virus on another is limited. OBJECTIVE: Evaluate and compare clinical characteristics, immune and acute phase response, viral shedding and viral load in pigs singly and doubly inoculated with swine influenza A virus (swIAV) and porcine reproductive and respiratory syndrome virus (PRRSV). ANIMALS: Fifty-four 7-week-old piglets. METHODS: Clinical status and gross lung lesions were scored. Titration of swIAV was carried out in Madin-Darby canine kidney cells. The PRRSV RNA was quantified using a commercial qPCR kit. Antibodies were detected by hemagglutination inhibition assay and commercial ELISA. A lymphocyte proliferation assay was used to measure antigen-specific T-cell responses. Acute phase proteins were determined using ELISA. RESULTS: No differences were found between mean clinical scores, swIAV and PRRSV shedding, and magnitude of the humoral and T-cell response between single-inoculated and dual-inoculated groups. Concentrations of C-reactive protein and haptoglobin increased in PRRSV-inoculated and coinoculated groups, whereas serum amyloid A concentration was increased in groups inoculated or coinoculated with swIAV. Mean swIAV TCID50 titers in the lungs did not differ significantly between coinoculated and swIAV single-inoculated pigs. A significantly higher mean copy number of PRRSV was found in the lungs of PRRSV only-inoculated pigs at 2 day postinoculation (DPI). From 4 DPI, no significant differences in PRRSV load were identified. CONCLUSIONS AND CLINICAL IMPORTANCE: Coinfection of pigs with swIAV and PRRSV did not potentiate clinical signs, lung lesions, immune response, and replication of the viruses in the respiratory tract.

Detection of Porcine Circovirus 3 in Wildlife Species in Spain.

Porcine circovirus 3 (PCV-3) is the third member of the family Circoviridae, genus Circovirus, able to infect swine. A high prevalence of viral DNA has been recorded in wild boars. Recently, PCV-3 DNA was identified in Italian wild ruminants. Based on these previous results, this study assessed the frequency of PCV-3 DNA detection in free-ranging ruminants and Lagomorpha species in Spain. In addition, the genetic characterization of the PCV-3 PCR-positive samples was performed. A total of 801 serum samples, including red deer (Cervus elaphus, [CE]; n = 108), roe deer (Capreolus capreolus, [CC]; n = 87), Pyrenean chamois (Rupicapra pyrenaica, [RP]; n = 133), Iberian ibex (Capra pyrenaica, [CP]; n = 92), mouflon (Ovis aries, [OA]; n = 91), fallow deer (Dama dama, [DD]; n = 104), European rabbit (Oryctolagus cuniculus, [OC]; n = 101), and European hare (Lepus europaeus, [LE]; n = 85) from Catalonia (northeast Spain) were tested by conventional polymerase chain reaction (PCR) and, when positive, sequenced. Overall, PCV-3 DNA was found in three out of 801 analyzed sera (0.37%) corresponding to one red deer (1/108, 0.9%), one mouflon (1/91, 1.1%), and one fallow deer (1/104, 0.96%). None of the samples collected from Lagomorpha species resulted PCR positive. The partial genome sequences detected in positive samples displayed high identity with some PCV-3 sequences detected in wild boars and domestic pigs (99.7% and 100%, respectively). In conclusion, the present study indicated that free-ranging ruminant and Lagomorpha species are not relevant in the epidemiology of PCV-3 in Spain.

A survey on the occurrence of Brachyspira pilosicoli and Brachyspira hyodysenteriae in growing-finishing pigs.

Background: The major pathogenic intestinal spirochetes affecting pigs during the growing- finishing stage of production include Brachyspira hyodysenteriae and Brachyspira pilosicoli. The aim of this study was to assess the current occurrence of B. hyodysenteriae and B. pilosicoli in Polish pig herds. Moreover, associations between the presence of diarrhea or other intestinal pathogens and occurrence of B. hyodysenteriae and B. pilosicoli in pigs were investigated. Methods: Between January 2017 and August 2019, a total of 401 samples of pig feces from 95 different herds were submitted to the National Veterinary Research Institute of Poland. These samples were obtained from pigs older than 7 weeks. All the received fecal samples were examined for the presence of B. hyodysenteriae, B. pilosicoli and Lawsonia intracellularis by real-time PCR. Results: B. pilosicoli was detected in 4.5% (95% CI, 2.5-7.0%) (18/401) of pig fecal samples. At the herd level 13.7% (95% CI, 7.5-22.3%) (13/95) of herds were positive for B. pilosicoli. B. hyodysenteriae was detected in 7.0% (95% CI, 4.7-9.9%) (28/401) of pig fecal samples and 18.9% (95% CI, 11.6-28.3%) (18/95) of pig herds were positive. Out of 18 B. pilosicoli positive samples, this pathogen was detected alone in 5 samples; simultaneously with L. intracellularis in 9 samples; simultaneously with B. hyodysenteriae in 1 sample and in 3 samples was detected simultaneously with both of these bacteria. The presence of B. hyodysenteriae in fecal samples was associated with the presence of diarrhea in pigs. Conclusions: This study confirmed that B. pilosicoli infections occur in Polish pig herds, but the prevalence is at a low level and the presence of B. pilosicoli is not associated with the development of diarrhea in pigs. B. hyodysenteriae is still a common cause of diarrhea among pigs from Polish herds.

Proinflammatory Cytokine Changes in Bronchoalveolar Lavage Fluid Cells Isolated from Pigs Infected Solely with Porcine Reproductive and Respiratory Syndrome Virus or Co-infected with Swine Influenza Virus.

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.

Tulathromycin enhances humoral but not cellular immune response in pigs vaccinated against swine influenza.

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.

Effects of Newly Developed Synbiotic and Commercial Probiotic Products on The Haematological Indices, Serum Cytokines, Acute Phase Proteins Concentration, and Serum Immunoglobulins Amount in Sows and Growing Pigs - A Pilot Study.

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.

Efficacy of the Porcine circovirus 2 (PCV2) vaccination under field conditions.

The objective of this study was to determine the effect of the porcine circovirus type 2 (PCV2) vaccination on the levels of viremia, the number of viremic-positive pigs, and production performance [i.e. nursery mortality, post-weaning mortality, and average daily weight gain (ADWG)] under field conditions. There were 140 farrow-to-finish pig herds involved in this study. The vaccination of piglets was implemented in 82 of the 140 herds. In each herd blood samples were collected from sows and pigs in different age category. In addition, a questionnaire regarding the production performance was provided for each herd. Results demonstrate that the vaccination of piglets prevented the development of viremia in 23.2% of herds. Significant decreases in the levels of PCV2 DNA in serum and in the number of viremic pigs were also noted. These results indicate that the vaccination of piglets against PCV2 is a useful tool in controlling the PCV2 infection in herds with a high risk of a wide range of viral and bacterial agents, poor management strategies, and a low level of biosecurity practices.

Coinfection modulates inflammatory responses, clinical outcome and pathogen load of H1N1 swine influenza virus and Haemophilus parasuis infections in pigs.

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.

Livestock-associated Staphylococcus aureus on Polish pig farms.

BACKGROUND: Livestock-associated Staphylococcus aureus (LA-SA) draws increasing attention due to its particular ability to colonize farm animals and be transmitted to people, which in turn leads to its spread in the environment. The aim of the study was to determine the dissemination of LA-SA on pig farms selected throughout Poland, characterize the population structure of identified S. aureus, and assess the prevalence of LA-SA carriage amongst farmers and veterinarians being in contact with pigs. METHODS AND FINDINGS: The study was conducted on 123 pig farms (89 farrow-to-finish and 34 nucleus herds), located in 15 out of 16 provinces of Poland. Human and pig nasal swabs, as well as dust samples were analyzed. S. aureus was detected on 79 (64.2%) farms from 14 provinces. Amongst these farms LA-SA-positive farms dominated (71/79, 89.9%, 95% CI [81.0%, 95.5%]). The prevalence of LA-MRSA-positive farms was lower than LA-MSSA-positive (36.6% of LA-SA-positive farms, 95% CI [25.5%, 48.9%] vs. 74.6%, 95% CI [62.9%, 84.2%]). In total, 190 S. aureus isolates were identified: 72 (38%) MRSA and 118 (62%) methicillin-susceptible S. aureus (MSSA), of which 174 (92%) isolates were classified to three livestock-associated lineages: CC398 (73%), CC9 (13%), and CC30/ST433 (6%). All CC398 isolates belonged to the animal clade. Four LA-MRSA clones were detected: ST433-IVa(2B) clone (n = 8, 11%), described to the best of our knowledge for the first time, and three ST398 clones (n = 64, 89%) with the most prevalent being ST398-V(5C2&5)c, followed by ST398-V(5C2), and ST398-IVa(2B). Nasal carriage of LA-SA by pig farmers was estimated at 13.2% (38/283), CC398 carriage at 12.7% (36/283) and ST398-MRSA carriage at 3.2% (9/283), whereas by veterinarians at 21.1% (8/38), 18.4% (7/38) and 10.5% (4/38), respectively. CONCLUSIONS: The prevalence of LA-MRSA-positive pig farms in Poland has increased considerably since 2008, when the first MRSA EU baseline survey was conducted in Europe. On Polish pig farms CC398 of the animal clade predominates, this being also reflected in the prevalence of CC398 nasal carriage in farmers and veterinarians. However, finding a new ST433-IVa(2B) clone provides evidence for the continuing evolution of LA-MRSA and argues for further monitoring of S. aureus in farm animals.

Enrofloxacin in therapeutic doses alters cytokine production by porcine PBMCs induced by lipopolysaccharide.

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.

Serological Survey of the Influenza a Virus in Polish Farrow-to-finish Pig Herds in 2011-2015.

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.

Pig Lung Immune Cytokine Response to the Swine Influenza Virus and the Actinobacillus Pleuropneumoniae Infection.

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.

Occurrence of Intestinal Parasites in Pigs in Poland - the Influence of Factors Related to the Production System.

INTRODUCTION: The aim of study was to estimate the prevalence and intensity of intestinal parasite infections in pigs in Poland and evaluate the influence of factors related to the production system on the infection intensity. MATERIAL AND METHODS: A total of 70 pig farms of all Polish provinces, differing in the herd size and production system, were selected for the study. Fresh faecal samples were collected from all age groups: suckling piglets, weaners, fatteners, and lactating sows. Moreover, data were obtained regarding the size of the herd, the use of paddock and all-in/all-out system, the presence of diarrhoea, and the type of flooring. RESULTS: Parasite eggs or oocysts were detected in 57 of the 70 examined pig farms. Oesphagostomum spp. eggs were found in the largest number of farms (68.6%). Moreover, coccidia (42.9%), Ascaris suum(28.6%), Trichuris suis (21.4%), and Strongyloides spp. (11.4%) were detected. The highest prevalence of coccidia and Strongyloides spp. was found in suckling piglets, A. suum and T. suis in fatteners, and Oesphagostomum spp. in sows. Higher prevalence of parasites was detected in small farms than in medium and large farms, except the prevalence of coccidia, which was the highest in medium farms. Simultaneous infection with several parasites was more often detected than with one parasite. Odds ratio of parasites occurrence was higher in farms with paddock and litter floor and in farms which do not use all-in/all-out system. CONCLUSION: Relatively high prevalence of intestinal parasites was found in pigs in Poland. Moreover, specific distribution of parasites in different age groups and farms of different size was observed. Influence of breeding factors on parasite prevalence was identified.

Ceftiofur hydrochloride affects the humoral and cellular immune response in pigs after vaccination against swine influenza and pseudorabies.

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.

Immune response in pigs treated with therapeutic doses of enrofloxacin at the time of vaccination against Aujeszky's disease.

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.