First molecular detection of Brachyspira hampsonii on pig farms in Poland.

Nowadays, the three strongly beta-haemolytic spirochaetes, Brachyspira hyodysenteriae, Brachyspira suanatina and Brachyspira hampsonii are thought to be causative agents of swine dysentery, an economically devastating disease of grow-finish pigs characterised by severe mucohaemorrhagic diarrhoea. B. hyodysenteriae has been reported in most leading swine-producing regions. B. suanatina and B. hampsonii have been successfully recovered from faecal samples collected in a few countries only. The present study was performed in March 2023 on faecal samples originating from nine Polish finisher farms with 6,000 to 18,000 animals in a location. Samples were obtained from 40 diarrhoeic finishers. Nucleic acid extracted from the samples was analysed using multiplex PCR for Brachyspira spp. From a total of nine sample populations examined in our study, the genetic material of B. hampsonii was identified in two. To the best of our knowledge, this is the first report on molecular detection of B. hampsonii on pig farms outside North America, Belgium and Germany. Our research highlights the need for increased focus directed on laboratory testing strategies, the lack of which may perplex swine practitioners and severely hinder a definite diagnosis.

Determination of Tiamulin Concentration in Sow Milk and in Sera of Suckling Piglets.

Although modern analytical methods developed for monitoring antibiotics in several biological matrices are easily available, none of them have been applied to evaluate the transfer of tiamulin into sow milk. Therefore, this work was intended to analyse the concentrations of tiamulin in milk samples collected from lactating sows during and after a treatment consisting of three consecutive intramuscular applications of the antibiotic. The second aim of this investigation was to determine tiamulin concentrations in serum samples obtained from suckling piglets ingesting milk contaminated with the compound. Ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) was used to quantify the analyte in both matrices. Our investigation proved tiamulin was transmitted into the milk of lactating sows. The mean concentration of the antibiotic among samples collected 3 h after administration was 1043 µg/L. The mean level of tiamulin on days 1 and 2 was 876 µg/L and 902 µg/L, respectively. The highest mean concentration of the antibiotic (1061 µg/L) was observed in samples collected on day 3. The mean concentration of the antibiotic in serum samples collected from 3-day-old piglets was 22.2 µg/L. The association between their body weight and serum tiamulin concentration was not statistically significant (p = 0.456).

A Preliminary Study on the Concentration of Oxytetracycline and 4-Epi-Oxytetracycline in Sow Milk.

Even though modern analytical chemistry has developed a methodology enabling evaluation of the presence of OTC in milk, data regarding its concentration in the material collected from lactating sows are missing. Therefore, this paper was intended to provide new data on the transmission of OTC and its epimer, 4-epi-oxytetracycline (4-epi-OTC), in the milk of lactating sows after a singular intramuscular administration of a long-acting form of the antibiotic. The determination of OTC and 4-epi-OTC was carried out using ultrahigh-performance liquid chromatography with mass spectrometry (UHPLC-MS/MS). The highest average concentration of antibiotic (1132.2 µgL-1) was observed in samples collected 1 day after the administration of the drug. The average OTC level at day 3 was 358 µgL-1. The average concentration of the antibiotic found on the 21st day was 12.3 µgL-1. The highest average concentration of 4-epi-OTC-i.e., 54 µgL-1-was noted 1 day after the administration. Amongst samples collected at day 3, the average level of the substance in question was 26.4 µgL-1. The average value observed at day 21 was 1.5 µgL-1. Our results indicated considerable OTC and 4-epi-OTC transmission into the milk of lactating sows.

Cymantrenyl-Nucleobases: Synthesis, Anticancer, Antitrypanosomal and Antimicrobial Activity Studies.

The synthesis of four cymantrene-5-fluorouracil derivatives (1-4) and two cymantrene-adenine derivatives (5 and 6) is reported. All of the compounds were characterized by spectroscopic methods and the crystal structure of two derivatives (1 and 6), together with the previously described cymantrene-adenine compound C was determined by X-ray crystallography. While the compounds 1 and 6 crystallized in the triclinic P-1 space group, compound C crystallized in the monoclinic P21/m space group. The newly synthesized compounds 1-6 were tested together with the two previously described cymantrene derivatives B and C for their in vitro antiproliferative activity against seven cancer cell lines (MCF-7, MCF-7/DX, MDA-MB-231, SKOV-3, A549, HepG2m and U-87-MG), five bacterial strains Staphylococcus aureus (methicillin-sensitive, methicillin-resistant and vancomycin-intermediate strains), Staphylococcus epidermidis, and Escherichia coli, including clinical isolates of S. aureus and S. epidermidis, as well as against the protozoan parasite Trypanosoma brucei. The most cytotoxic compounds were derivatives 2 and C for A549 and SKOV-3 cancer cell lines, respectively, with 50% growth inhibition (IC50) values of about 7 µM. The anticancer activity of the cymantrene compounds was determined to be due to their ability to induce oxidative stress and to trigger apoptosis and autophagy in cancer cells. Three derivatives (1, 4 and 5) displayed promising antitrypanosomal activity, with GI50 values in the low micromolar range (3-4 µM). The introduction of the 5-fluorouracil moiety in 1 enhanced the trypanocidal activity when compared to the activity previously reported for the corresponding uracil derivative. The antibacterial activity of cymantrene compounds 1 and C was within the range of 8-64 µg/mL and seemed to be the result of induced cell shrinking.

Pyrene-nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies.

Fluorescent pyrene-linker-nucleobase (nucleobase = thymine, adenine) conjugates with carbonyl and hydroxy functionalities in the linker were synthesized and characterized. X-ray single-crystal structure analysis performed for the pyrene-C(O)CH2CH2-thymine (2) conjugate reveals dimers of molecules 2 stabilized by hydrogen bonds between the thymine moieties. The photochemical characterization showed structure-dependent fluorescence properties of the investigated compounds. The conjugates bearing a carbonyl function represent weak emitters as compared to compounds with a hydroxy function in the linker. The self-assembly properties of pyrene nucleobases were investigated in respect to their binding to single and double strand oligonucleotides in water and in buffer solution. In respect to the complementary oligothymidine T10 template in water, compounds 3 and 5 both show a self-assembling behavior according to canonical base-base pairing. However, in buffer solution, derivative 5 was much more effective than 3 in binding to the T10 template. Furthermore the adenine derivative 5 binds to the double-stranded (dA)10-T10 template with a self-assembly ratio of 112%. Such a high value of a self-assembly ratio can be rationalized by a triple-helix-like binding, intercalation, or a mixture of both. Remarkably, compound 5 also shows dual staining pattern in living HeLa cells. Confocal microscopy confirmed that 5 predominantly stains mitochondria but it also accumulates in the nucleoli of the cells.

Gastric ulcers in finishing pigs: the evaluation of selected non-dietary risk factors and impact on production performance.

BACKGROUND: The complex aetiology of gastric lesions in pigs remains largely unknown and effective preventive measures and pharmaceutical treatment of the disease have not been developed yet. Regardless of the fact that the overwhelming majority of previous research works dealing with gastric ulceration in pigs focused on the role of the nutritional determinants, including chemical composition of feeds, cereal type, finely ground pelleted diets, and feed additives, conclusions presented therein remain highly ambiguous. Thus, the purpose of this study was to evaluate the impact of the disease on production performance, and investigate the influence of selected non-dietary risk factors on the prevalence of gastric alterations in finishing pigs reared under conditions of 11 modern farms located in Poland. RESULTS: A total number of 26,043 finishing pigs was examined. 15,228 (58.47%) had gastric ulcers. Intact stomachs were detected in 6176 animals (23.71%). Parakeratosis and erosion were observed in 2551 (9.80%) and 2088 (8.02%), respectively. Among eight continuous variables two were found to be significantly associated with prevalence of the gastric ulcer: the growing number of animals in the herd, which was negatively correlated (P = 0.002; ρ = -0.37), and the growing average entry weight of animals transported to the finisher farm (P = 0.047; ρ = 0.24), which increased the risk of gastric ulcers prevalence. Among 12 nominal variables, problems with the quality of farm management (P = 0.041), and usage of straw as a bedding material (P = 0.002) were identified as determinants significantly associated with occurrence of the analysed health problem. CONCLUSIONS: Among 20 non-nutritional variables analysed in our study only few factors were found to be associated with the prevalence of the disease. The impact of broadly understood management issues on gastric health in finishing pigs deserves further research.

First molecular detection of Brachyspira suanatina on pig farms in Poland.

Introduction: Prior to the 2000s, swine dysentery was considered to be caused only by Brachyspira hyodysenteriae with contributing commensal intestinal anaerobes. Nowadays, it is known that the disease is caused by three strongly beta-haemolytic species of the anaerobic spirochaetal genus Brachyspira, i.e. B. hyodysenteriae and newly emerged B. hampsonii and B. suanatina. Material and Methods: The present investigation was carried out in November 2022 on nine Polish high-performing finisher pig farms. At every location one fresh pooled faecal sample was collected from 40 randomly selected pigs of between 60 and 110 kg live weight. Nucleic acid extracted from each pooled faecal sample was analysed by an in-house multiplex PCR for Brachyspira spp., which is capable of confirming the Brachyspira genus and detecting and differentiating Brachyspira species. Results: From a total of nine samples examined, the genetic material of B. suanatina was detected in seven. Non-pathogenic/questionably pathogenic Brachyspira spp. were found in six samples. Conclusion: To the best of our knowledge, this is the first report on the identification of B. suanatina in pigs outside Scandinavia, Germany and the United Kingdom. Our research not only provides valuable epidemiological data on B. suanatina infection in Europe but also highlights both the importance of modern laboratory diagnostics and the need for thorough investigation across regions, including retrospective studies.

Automatic air volume control system for ventilation of two patients using a single ventilator: a large animal model study.

The COVID-19 pandemic outbreak led to a global ventilator shortage. Hence, various strategies for using a single ventilator to support multiple patients have been considered. A device called Ventil previously validated for independent lung ventilation was used in this study to evaluate its usability for shared ventilation. We performed experiments with a total number of 16 animals. Eight pairs of pigs were ventilated by a ventilator or anesthetic machine and by Ventil for up to 27 h. In one experiment, 200 ml of saline was introduced to one subject's lungs to reduce their compliance. The experiments were analyzed in terms of arterial blood gases and respiratory parameters. In addition to the animal study, we performed a series of laboratory experiments with artificial lungs (ALs). The resistance and compliance of one AL (affected) were altered, while the tidal volume (TV) and peak pressure (Ppeak) in the second (unaffected) AL were analyzed. In addition, to assess the risk of transmission of pathogens between AL respiratory tracts, laboratory tests were performed using phantoms of virus particles. The physiological level of analyzed parameters in ventilated animals was maintained, except for CO2 tension, for which a permissive hypercapnia was indicated. Experiments did not lead to injuries in the animal's lungs except for one subject, as indicated by CT scan analysis. In laboratory experiments, changes in TV and Ppeak in the unaffected AL were less than 11%, except for 2 cases where the TV change was 20%. No cross-contamination was found in simulations of pathogen transmission. We conclude that ventilation using Ventil can be considered safe in patients undergoing deep sedation without spontaneous breathing efforts.

Serologic Survey for West Nile Virus in Wild Boars (Sus scrofa) in Poland.

Serum samples obtained from 474 wild boars (Sus scrofa) were collected from June 2017 to September 2018 from various areas of northern and southern Poland. Serum samples were examined by enzyme-linked immunosorbent assay. However, West Nile virus (WNV) antibodies were not detected. Previous studies on WNV in Poland have focused on experimental evidence and the presence of WNV antibodies in wild birds, horses, and humans, indicating a need for more surveys of domestic and wild mammals in Poland.

The Markers of Stress in Swine Oral Fluid.

INTRODUCTION: The study measured the hormonal and protein markers of acute stress, those of oxidative stress and total antioxidant capacity (TAC) in swine oral fluid, determined which of these parameters would be the most appropriate for future livestock welfare assessment and established the time when the samples should be taken. MATERIAL AND METHODS: Stress was induced in 7 out of 14 castrated six-week-old Danbred×Duroc pigs by immobilisation on a nasal snare at 8 a.m., 1 p.m., and 6 p.m. and samples were taken both directly after the stressor was applied and 30 min later. The remaining pigs were the control group, which were not immobilised; their samples were taken at the same times. The concentrations of hormones and malondialdehyde (MDA) were measured using liquid chromatography with tandem mass spectrometry, while those of alpha-amylase and TAC were measured using spectrophotometry. RESULTS: The levels of cortisol and cortisone increased with statistical significance immediately after the acute stress response and 30 min later. A cut-off value set at 0.25 ng/mL cortisol concentration was capable of distinguishing between the stressed and control groups with 100% accuracy in evening samples and 95% accuracy overall. Prednisolone was not present, and the levels of testosterone and corticosterone were low and not distinctive. Alpha-amylase became significantly more concentrated during stress induction and 30 min later. The TAC and MDA levels rose after the stress but without statistical significance. CONCLUSION: The most suitable markers of acute stress were cortisol, cortisone and alpha-amylase. Oral fluid is a reliable material for monitoring the level of pigs' stress and should be collected in the evening.

Genetic Diversity and Epidemiological Significance of Wild Boar HEV-3 Strains Circulating in Poland.

The wild boar is the most important reservoir of zoonotic HEV-3 strains among different wildlife species. The aim of the study was subtype identification of wild boar HEV-3 strains circulating in Poland. Wild boar liver was used in the study in the form of homogenates prepared from 57 samples positive for HEV in a real-time RT-PCR. These samples were collected from juvenile and adult wild boars hunted in the jurisdictions of different Regional Directorates of State Forests (RDSF) across Poland. Subtype identification of detected HEV strains was based on a phylogenetic analysis of the most conserved HEV ORF2 genome fragment. Out of 57 tested samples, consensus HEV ORF2 sequences of 348 bp were obtained for 45 strains. Nineteen strains were identified and belonged to the HEV gt 3a and 3i subtypes, whereas 26 were not assigned to any virus subtype. HEV gt 3i strains prevailed in the Polish wild boar population, 16 of such were identified, and they were significantly more often observed in the RDSF Katowice area (χ2 = 28.6, p = 0.027 (<0.05)) compared to other regions of the country. Circulation of 3a strains was limited only to the RDSF Gdansk territory (χ2 = 48, p = 0.000 (<0.05)). The virus strains detected in the Polish population of wild boars representing previously identified HEV subtypes in wild boars, pigs, or humans in Europe are of epidemiological importance for public health.

Wild Boar as a Sylvatic Reservoir of Hepatitis E Virus in Poland: A Cross-Sectional Population Study.

The most important wildlife species in the epidemiology of hepatitis E virus (HEV) infections are wild boars, which are also the main reservoir of the virus in a sylvatic environment. The aim of the study was a serological and molecular assessment of the prevalence of HEV infections in wild boars in Poland. In total, 470 pairs of samples (wild boar blood and livers) and 433 samples of faeces were tested. An ELISA (ID.vet, France) was used for serological analysis. For the detection of HEV RNA, real-time (RT)-qPCR was employed. The presence of specific anti-HEV IgG antibodies was found in 232 (49.4%; 95%CI: 44.7-54%) sera, with regional differences observed in the seroprevalence of infections. HEV RNA was detected in 57 (12.1%, 95%CI: 9.3-15.4%) livers and in 27 (6.2%, 95%CI: 4.1-8.9%) faecal samples, with the viral load ranging from 1.4 to 1.7 × 1011 G.C./g and 38 to 9.3 × 107 G.C./mL, respectively. A correlation between serological and molecular results of testing of wild boars infected with HEV was shown. HEV infections in wild boars appeared to be common in Poland.

Salmonella and Antimicrobial Resistance in Wild Rodents-True or False Threat?

Transmission of pathogenic and resistant bacteria from wildlife to the bacterial gene pool in nature affects the ecosystem. Hence, we studied intestine content of five wild rodent species: the yellow-necked wood mouse (Apodemus flavicollis, n = 121), striped field mouse (Apodemus agrarius, n = 75), common vole (Microtus arvalis, n = 37), bank vole (Myodes glareolus, n = 3), and house mouse (Mus musculus, n = 1) to assess their potential role as an antimicrobial resistance (AMR) and Salmonella vector. The methods adopted from official AMR monitoring of slaughtered animals were applied and supplemented with colistin resistance screening. Whole-genome sequencing of obtained bacteria elucidated their epidemiological relationships and zoonotic potential. The study revealed no indications of public health relevance of wild rodents from the sampled area in Salmonella spread and their limited role in AMR dissemination. Of 263 recovered E. coli, the vast majority was pan-susceptible, and as few as 5 E. coli showed any resistance. In four colistin-resistant strains neither the known mcr genes nor known mutations in pmr genes were found. One of these strains was tetracycline-resistant due to tet(B). High diversity of virulence factors (n = 43) noted in tested strains including ibeA, cdtB, air, eilA, astA, vat, pic reported in clinically relevant types of enteric E. coli indicate that rodents may be involved in the ecological cycle of these bacteria. Most of the strains represented unique sequence types and ST10805, ST10806, ST10810, ST10824 were revealed for the first time, showing genomic heterogeneity of the strains. The study broadened the knowledge on phylogenetic diversity and structure of the E. coli population in wild rodents.

Evaluation of the Effect of Surgical and Immunological Castration of Male Pigs on Boar Taint Compounds in Oral Fluid and Fat Tissue by LC-MS/MS Method.

INTRODUCTION: An effective way of preventing undesirable boar taint in pork meat caused by the presence of androstenone, skatole and indole is surgical castration of piglets. This, however, arouses growing social opposition. An alternative method of inhibiting the development of unpleasant odour is immune castration. The aim of the study was to compare the effectiveness of both methods of castration for the elimination of the compounds responsible and to assess the suitability of oral fluid for pre-slaughter predictive testing for boar taint. MATERIAL AND METHODS: The research material was pooled oral fluid and fat samples taken from gilts and surgically and immunologically castrated piglets. The samples were tested with a liquid chromatography- tandem mass spectrometry method developed in this research. RESULTS: The compounds giving rise to boar taint were found only sporadically above the accepted limits; only one sample of oral fluid contained skatole at a concentration above 200 µg L-1 and one contained indole more concentrated than 100 µg L-1. Indole above the limit value was also detected in one fat sample. In none of the tested samples was androstenone found. CONCLUSION: The results indicate the similar effectiveness of both methods of piglet castration on the reduction of compounds generating boar taint. The usefulness of testing oral fluid for the ante-mortem prediction of boar taint has not been fully confirmed and further investigation is needed.

Tritrichomonas Foetus: A Study of Prevalence in Animal Hosts in Poland.

Tritrichomonas foetus is described as a pathogen of cattle and cats and also exhibits commensalism with pigs. In order to estimate the prevalence and determine the risk factors for parasite infection, specimens from animal hosts (cat, pigs, and cattle) from Poland were investigated. To our best knowledge, this is the first such study to examine samples from wild boars (Sus scrofa) for the presence of T. foetus. Data were collected from 117 cats, 172 pigs, 236 wild boars, and 180 cattle. The sensitivity of T. foetus identification was increased by using two molecular assays: PCR and loop-mediated isothermal amplification (LAMP). The prevalence of feline tritrichomonosis was 20.51%, and statistically significant differences were obtained between groups of animals regarding age, breed, number of cats, diarrhea, and place of living. Positive PCR and LAMP results for T. foetus were estimated for 16.28% of pigs, and the obtained data were significantly correlated with age. Conversely, no significant differences were observed concerning the farm size factor. In our survey, no cases of bovine tritrichomonosis were found, which is consistent with the data from the other countries of the European Union. Similarly, all wild boar samples were also T. foetus-negative according to LAMP and PCR.

Seroprevalence and risk factors for selected respiratory and reproductive tract pathogen exposure in European bison (Bison bonasus) in Poland.

After the complete extinction from the wild of European bison (Bison bonasus) at the beginning of the twentieth century, the worldwide species population was restored to approximately 5500 individuals, with the species however remaining endangered. Despite numerous studies on the ecology and genetics of European bison, the threats of infectious diseases have been largely unexamined. The aim of this study was to screen the exposure of the world's largest population of European bison to the pathogens, which may influence the condition and development of the endangered species. A total of 240 free-ranging and captive European bison from eight main Polish populations sampled were tested for the presence of specific antibodies against ten different viruses, bacteria or protozoan. The samples were collected from chemically immobilized, selectively culled or found dead animals. Based on serology, the exposure to bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BoHV-1), Mycoplasma and Brucella spp. was determined as rather accidental. Using gamma-interferon assay followed by Mycobacterium tuberculosis subs. caprae detection in tissues, diagnosis of bovine tuberculosis was made for 6 out of 78 (7.7%) bison from one captive herd. The highest seroprevalence was found for bovine adenovirus type 3 (BAdV-3) -60.2% and bovine parainfluenza type 3 (PIV-3) -34.0%, while the antibodies against bovine respiratory syncytial virus (BRSV), Toxoplasma gondii and Leptospira spp. were found in 10.4%, 10.4% and 8.7% of samples, respectively. In the multivariable statistical analysis using generalized linear mixed models (GLMMS), the risk factors for PIV-3 seropositivity included population type (free-living/captive), age and health status (apparently healthy/eliminated due to the poor condition). Higher risk of BAdV-3 seropositive result was observed in free-living female European bison. The high BAdV-3 and PIV-3 seroprevalences may suggest involvement of these pathogens in the most frequently observed respiratory disorders in European bison. Moreover, this is the first study demonstrating BAdV-3 exposure in the species.

Seroprevalence of 12 serovars of pathogenic Leptospira in red foxes (Vulpes vulpes) in Poland.

BACKGROUND: Leptospira spp. infect humans and a wide range of domestic and wild animals, but certain species such as small rodents and red foxes (Vulpes vulpes) play a particular role as reservoirs and transmission of leptospirosis as they easily adapt to many habitats including human environments. To investigate the significance of red foxes in the epidemiology of leptospirosis in Poland, a seroprevalence survey was conducted. During the 2014-2015 hunting season, blood samples of 2134 red foxes originating from the central-eastern part of Poland were collected. Serum samples were tested by a microscopic agglutination test for the presence of specific antibodies to Leptospira serovars Icterohaemorrhagiae, Grippotyphosa, Sejroe, Tarassovi, Pomona, Canicola, Hardjo, Ballum, Australis, Bataviae, Saxkoebing and Poi. RESULTS: Antibodies to at least one serovar were detected in 561 sera (26.3%). The highest seroprevalence was found in the Subcarpathia (41.6%) and Warmia-Masuria (40.3%) provinces. Antibodies were mainly directed against serovars Poi (12.4%), Saxkoebing (11.3%), and Sejroe (6.0%). CONCLUSIONS: Exposure of red foxes to certain Leptospira serovars seems to be common in central and eastern Poland. In addition, the high prevalence of antibodies against Leptospira spp. in foxes may indicate a potential risk of infection for humans and other species coming into contact with these animals.

Antimicrobial Resistance in Escherichia coli Isolated from Wild Animals in Poland.

Antimicrobial resistance was tested in Escherichia coli isolated from feces (n = 660) of red deer, roe deer, fallow deer, European bison, and wild boar shot in regional forests in Poland during two winter hunting seasons. Indicator E. coli (n = 542) was resistant against 11 of 14 tested compounds, mostly sulfamethoxazole, streptomycin, ampicillin, trimethoprim, and tetracycline (1.3-6.6% range). No significant differences were observed between boar and ruminant isolates. Most of deer and bison isolates showed no resistance. Selective screening of wildlife samples revealed 1.7% prevalence of cephalosporin-resistant E. coli found mostly in wild boars. They produced extended-spectrum beta-lactamases (blaCTX-M-1, blaCTX-M-15) and plasmid-mediated AmpC-type cephalosporinase (blaCMY-2). The majority of the isolates originated from boars shot in a narrow time frame and space; therefore, common antimicrobial selection pressure in the environment was assumed. Three E. coli isolates carried plasmid-mediated quinolone resistance genes (qnrS1/S3). No transferable colistin resistance mechanisms were found in two resistant E. coli. Transferability of resistance was proved in a single pAmpC-positive isolate carrying IncI1-alpha 95 kb plasmid. No cephalosporin-resistant E. coli harbored pathogenicity markers; therefore, they might be considered a vector of resistance determinants, but not a pathogen themselves.

Were Polish Wild Boars Exposed to Schmallenberg Virus?

INTRODUCTION: A novel to Europe Schmallenberg virus (SBV) causes clinical disease manifested by reproduction disorders in farm ruminants. In free-living ruminants, SBV antibodies as well as the virus were detected. Recent studies also revealed SBV antibodies in wild boars. The study investigates SBV antibodies occurring in wild boars in Poland at the peak of recent virus epidemics in the country. MATERIAL AND METHODS: Samples collected from 203 wild boars culled during the 2012/2013 and 2013/2014 hunting season were serologically tested using multi-species cELISA. Attempted neutralisation tests failed due to poor serum quality. RT-PCR was implemented in seropositive and doubtful animals. RESULTS: Two samples collected from wild boar in the winter of 2013 gave a positive result in ELISA, while another two from the 2012/2013 hunting season were doubtful. No SBV RNA was detected in spleen and liver tissues. CONCLUSION: Low SBV seroprevalence in wild boars, despite high incidence of SBV infections occurring simultaneously in wild ruminants, suggests that boars are unlikely to be a significant reservoir of the virus in the sylvatic environment in Poland.

Oral Fluid as a Biological Material for Antemortem Detection of Oxytetracycline in Pigs by Liquid Chromatography-Tandem Mass Spectrometry.

The presence of antibiotic residues in pig tissues requires a search for new methods for their antemortem detection. To find an alternative for postmortem pig carcass analysis, an oral fluid was tested. To prove the suitability of oral fluid for the detection of antibiotics administered by injection, oxytetracycline was chosen. Research was conducted on two groups of animals: group 1, 100% treated; and group 2, 50% treated and 50% untreated. Oxytetracycline was assayed by a high-performance liquid chromatography-tandem mass spectrometry method. The antibiotic was detectable 2 h post administration in group 1 and group 2 at the concentrations of 10653 ± 1421 µg/kg and 7457 ± 1145 µg/kg, respectively. At withdrawal period (21st day), oxytetracycline concentrations in oral fluid (30.8 ± 9.4 µg/kg in group 1 and 11.6 ± 5.6 µg/kg in group 2) were similar to those determined in muscle (34.5 ± 8.2 µg/kg). The concentrations of oxytetracycline in liver and kidney were 76.8 ± 22 µg/kg and 204 ± 49 µg/kg, respectively. The results of this study indicate that oral fluid analysis can be used for antemortem oxytetracycline detection in pigs, even if the half of animals in one pen are treated.