Introduction: The transition period is the most challenging time for dairy cattle, which is characterised not only by negative energy balance but also by fatty tissue mobilisation.

Introduction: The transition period is the most challenging time for dairy cattle, which is characterised not only by negative energy balance but also by fatty tissue mobilisation.Material and Methods: The efficiency of energy pathways, β-oxidation in WBC and glycolysis in RBC (based on deoxyglucose transmembrane transport) were estimated. Insulin in blood plasma was determined using ELISA.Results: After calving and up to one month after delivery, a significant drop in blood plasma level was noticed, simultaneously with a rise in β-oxidation from 18.93 ±3.64 to 30.32 ±5.28 pmol/min/mg protein in WBC. A strong negative correlation between these two indices (r = −0.68) was found. During the period of transition to lactation an increase in glucose cross-membrane transportation from 41.44 ±4.92 to 50.49 ±6.41 μmol/h/g Hb was observed. A strong positive correlation between glucose transportation in RBC and β-oxidation in WBC (r = 0.71) was noticed. These data are in agreement with results of studies on dairy cows using liver slices from dairy cows in late pregnancy and different stages of lactation, in which changes in gene expression were analysed.Conclusion: It seems that measuring fatty acids oxidation and glycolysis using isolated blood cells may be an adequate and relatively simple method for energy state analysis to estimate the state of dairy cow metabolism and animal health.

Introduction: Data collection on the Salmonella occurrence is crucial in effective implementation of different actions or control programmes aiming to protect consumers’ health and to reduce the level of Salmonella prevalence in farm animals. The goal was to describe Salmonella serovar distribution along the food chain in Poland during 2010–2015 and to identify their epidemiological importance.

Introduction: Data collection on the Salmonella occurrence is crucial in effective implementation of different actions or control programmes aiming to protect consumers’ health and to reduce the level of Salmonella prevalence in farm animals. The goal was to describe Salmonella serovar distribution along the food chain in Poland during 2010–2015 and to identify their epidemiological importance.Material and Methods: Slide agglutination according to White-Kauffmann-Le Minor scheme was used to identify Salmonella serovars of 6,928 isolates originating from animals, food, feeds, and fertilisers.Results: In total, 160 Salmonella serovars were identified. Differences in serovar distribution were observed depending on animal species. Among isolates from hens, S. Enteritidis and S. Infantis were the most prevalent. Serovar pattern in turkeys differed from those in hens, with S. Kentucky, S. Newport, S. Saintpaul being the most prevalent. Monophasic S. Typhimurium was predominant in pigs. Serovars found in food reflected those observed among livestock animals. Nine out of the ten most prevalent serovars in animals and humans were also found in organic fertilisers.Conclusion: Serotyping of large number of isolates from different sources is essential for insight on emerging serovars and trends of Salmonella occurrence. This may increase the value of epidemiological data and result in updating of Salmonella control programmes to target further epidemiologically important serovars in animals and better protection of consumers’ health.

Introduction: Ornamental fish can suffer from different bacterial diseases. Among them the most prevalent are infections caused by Aeromonas, Shewanella, Citrobacter, Plesiomonas, Edwardsiella, and Pseudomonas. But there is a broad spectrum of rarely identified bacteria which may be causative agents of diseases. The aim of the study was to determine the species of bacteria pathogenic for fish which are prevalent in aquariums.

Introduction: Ornamental fish can suffer from different bacterial diseases. Among them the most prevalent are infections caused by Aeromonas, Shewanella, Citrobacter, Plesiomonas, Edwardsiella, and Pseudomonas. But there is a broad spectrum of rarely identified bacteria which may be causative agents of diseases. The aim of the study was to determine the species of bacteria pathogenic for fish which are prevalent in aquariums. Material and Methods: Bacteria were isolated from infected ornamental fish from pet shops and private aquariums in the Lublin region in 2015 and classified to species using MALDI-TOF MS. Results: A total of 182 isolates from ornamental fish were identified. The most frequent bacteria found in diseased fish were Aeromonas veronii (30.8% of total number of strains), A. hydrophila (18.7%), Shewanella putrefaciens (7.1%), Citrobacter freundii (7.1%), Pseudomonas spp. (7.1%), Shewanella baltica (4.9%), and Plesiomonas shigelloides (3.3%). Conclusion: Isolated bacterial species are facultative pathogens for fish and humans and may be isolated from fish without apparent symptoms of the disease.

Introduction: Infectious bursal disease virus (IBDV) is a causative agent of immunosuppressive disorder resulting in significant losses to the world poultry industry. This study describes the molecular characterisation of an atypical IBDV from a field outbreak that occurred in vaccinated chicken flocks in Latvia in 2011.

Introduction: Infectious bursal disease virus (IBDV) is a causative agent of immunosuppressive disorder resulting in significant losses to the world poultry industry. This study describes the molecular characterisation of an atypical IBDV from a field outbreak that occurred in vaccinated chicken flocks in Latvia in 2011.Material and Methods: Ten bursae of Fabricius from each flock were collected for laboratory examination. Virus isolation was performed in embryonated eggs and CEF culture. The RT-PCR aimed at hypervariable domain of VP2 gene combined with sequencing was performed for detection and identification of IBDV.Results: The molecular examinations confirmed the IBDV infection. The analysis of the amino acid sequence revealed that the strain possessed four amino acids at VP2 protein (222A, 256I, 294I, and 299S), indicating a genetic relatedness to a very virulent IBDV. However, some unique or rare amino acid substitutions (219L, 220F, 254D, 279N, and 280T) were also detected.Conclusion: The obtained results demonstrate the occurrence of IBDV with a high mutation rate within the hypervariable domain of VP2 peptide, and highlight the necessity of implementation of IBDV surveillance in Eastern European poultry industry to determine whether this strain is an exception or a new wave of IBDV with new genetic features emerged in the field.

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a highly resistant and difficult to cure zoonotic microorganism, which makes up a large part of food toxic infections and has shown high prevalence among pig population all over the world. The aim of the study was to establish the occurrence of MRSA in slaughterhouses, evaluate its antimicrobial resistance, and verify whether there are any differences or similarities with reference to other European countries. Material and Methods: A total of 100 pigs, 105 carcasses, 19 workers, and 24 samples from the environment of several slaughterhouses were examined by conventional microbial and molecular methods. Results: In total, 78 MRSA isolates were found. MRSA prevalence in slaughtered pigs varied from 8.0% to 88.6% depending on the slaughterhouse, reaching higher prevalence in slaughterhouses with higher slaughter capacity. In total, 21.1% of all workers were carriers of MRSA and 6.7% of carcasses were contaminated with MRSA. The 98.2% of MRSA isolates were resistant to penicillin, 89.1% to tetracycline, 60.1% to erythromycin, 65.5% to gentamycin, and 15 different spa types were found, among which spa type t01333 was most widespread. Conclusion: The study indicated that MRSA prevalence and spa types differed according to slaughterhouse slaughter capacity and good hygiene practices. Quite high MRSA occurrence among slaughterhouse workers is one of the main factors which increase pork contamination risk.

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a highly resistant and difficult to cure zoonotic microorganism, which makes up a large part of food toxic infections and has shown high prevalence among pig population all over the world. The aim of the study was to establish the occurrence of MRSA in slaughterhouses, evaluate its antimicrobial resistance, and verify whether there are any differences or similarities with reference to other European countries. Material and Methods: A total of 100 pigs, 105 carcasses, 19 workers, and 24 samples from the environment of several slaughterhouses were examined by conventional microbial and molecular methods. Results: In total, 78 MRSA isolates were found. MRSA prevalence in slaughtered pigs varied from 8.0% to 88.6% depending on the slaughterhouse, reaching higher prevalence in slaughterhouses with higher slaughter capacity. In total, 21.1% of all workers were carriers of MRSA and 6.7% of carcasses were contaminated with MRSA. The 98.2% of MRSA isolates were resistant to penicillin, 89.1% to tetracycline, 60.1% to erythromycin, 65.5% to gentamycin, and 15 different spa types were found, among which spa type t01333 was most widespread. Conclusion: The study indicated that MRSA prevalence and spa types differed according to slaughterhouse slaughter capacity and good hygiene practices. Quite high MRSA occurrence among slaughterhouse workers is one of the main factors which increase pork contamination risk.

Introduction: In 2014–2015, the epidemic of classical swine fever (CSF) occurred in many large-scale pig farms in different provinces of China, and a subgenotype 2.1d of CSF virus (CSFV) was newly identified.

Introduction: In 2014–2015, the epidemic of classical swine fever (CSF) occurred in many large-scale pig farms in different provinces of China, and a subgenotype 2.1d of CSF virus (CSFV) was newly identified. Material and Methods: The phylogenetic relationship, genetic diversity, and epidemic status of the 2014–2015 CSFV isolates, 18 new CSFV isolates collected in 2015, and 43 other strains isolated in 2014–2015 were fully analysed, together with 163 CSFV reference isolates. Results: Fifty-two 2014–2015 isolates belonged to subgenotype 2.1d and nine other isolates belonged to subgenotype 2.1b. The two subgenotype isolates showed unique molecular characteristics. Furthermore, the 2.1d isolates were found to possibly diverge from 2.1b isolates. Conclusion: This study suggests that the Chinese CSFVs will remain pandemic.

Introduction: The purpose of this study was to determine the occurrence of avian reovirus (ARV) infections in wild birds in Poland and attempt to propagate the selected ARV strains in chicken embryo kidney (CEK) cells or chicken SPF embryos. Material and Methods: The study included 192 wild birds representing 32 species, collected between 2014 and 2016. A part of the S4 segment encoding the σNS protein of avian reoviruses (ARVs) isolated from different species of wild birds from that period was amplified. Results: The presence of ARV was demonstrated in 58 (30.2%) wild birds belonging to nine orders. The isolated strains were propagated in chicken embryos by yolk sac inoculation, and CPE was induced in the infected CEK monolayer. Agar gel precipitation showed that two ARV isolates from rock pigeon and mute swan shared a common groupspecific antigen with chicken reovirus S1133. Specific products of predicted size were found in two ARV isolates from the chicken embryo passage and 13 ARVs isolated from CEK cells. Conclusion: The study indicates the high prevalence of ARV among wild birds in Poland and its possible transmission to farmed birds.

Introduction: The purpose of this study was to determine the occurrence of avian reovirus (ARV) infections in wild birds in Poland and attempt to propagate the selected ARV strains in chicken embryo kidney (CEK) cells or chicken SPF embryos. Material and Methods: The study included 192 wild birds representing 32 species, collected between 2014 and 2016. A part of the S4 segment encoding the σNS protein of avian reoviruses (ARVs) isolated from different species of wild birds from that period was amplified. Results: The presence of ARV was demonstrated in 58 (30.2%) wild birds belonging to nine orders. The isolated strains were propagated in chicken embryos by yolk sac inoculation, and CPE was induced in the infected CEK monolayer. Agar gel precipitation showed that two ARV isolates from rock pigeon and mute swan shared a common groupspecific antigen with chicken reovirus S1133. Specific products of predicted size were found in two ARV isolates from the chicken embryo passage and 13 ARVs isolated from CEK cells. Conclusion: The study indicates the high prevalence of ARV among wild birds in Poland and its possible transmission to farmed birds.