Journal of Veterinary Research最新文献

Introduction: Piglets are vulnerable to stress during weaning because of changes in the feeding environment, nutrients, and other growth-impacting conditions. In this study, stress injury was modelled by continuous intraperitoneal injection of lipopolysaccharide (LPS) and was used to investigate the dynamics of antioxidant indices and immunoinflammatory factors in the piglet thymus.

Material and methods: Forty-eight weaned piglets were divided into an LPS group and a control group. One group was injected with LPS solution (100 μg/kg) and the other with sterile saline daily. The experiment ran over 13 days, and six piglets from each group were euthanised for necropsy on days 1, 5, 9 and 13. Thymic tissues were collected, and the antioxidant indices and mRNA expression levels of related genes were measured by enzyme activity assay and reverse-transcription quantitative PCR.

Results: In the LPS group, catalase activities were significantly increased on days 1 and 5, that of superoxide dismutase was significantly higher on day 9 and glutathione activity was elevated throughout. Messenger RNA (mRNA) expression of the toll-like receptor 4 (TLR4) pathway, interleukin (IL) 6, and IL-2 increased in the thymus on day 1. By day 5, the mRNA expression of the TLR pathway, the janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, the kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, tumour necrosis factor α, IL-10, IL-6 and IL-2 were decreased. On day 13, the mRNA expression levels of the TLR4 and Keap1/Nrf2 pathways, TNF-α, IL-10 and IL-6 increased again.

Conclusion: Continuous LPS induction led to high activation of the thymic immune system in piglets during the prophase. However, this activation was accompanied by atrophy and immunosuppression mid-experiment. Nevertheless, the immune function gradually recovered in the later stages.

Introduction: Dimethyl sulfoxide (DMSO) is an amphipathic solvent for molecules in in vitro tests for detection of anthelmintic resistance of gastrointestinal nematodes (GIN). It has been shown to have a concentration-dependent detrimental effect on Caenorhabditis elegans, a free-living nematode. If GIN are likewise affected, using DMSO in egg-hatch test and larval development test (LDT) may confound their results. Therefore, the DMSO concentration was determined at which it exerted an inhibitory effect on GIN larval development to the third stage.

Material and methods: A standard LDT was performed in 30 replications at DMSO concentrations of 0.0% (control), 0.6%, 1.3%, 2.6%, 5.2%, 10.4%, and 20.8%. The numbers of all developmental stages of Haemonchus contortus, Trichostrongylus spp. and Oesophagostomum spp. (unhatched eggs, larvae of the first, second and third stages (L1-L3) were determined, the proportion of L3 (the percentage of larval development - PD) was calculated and L3 were identified at the species or genus level. A five-parameter logistic curve was fitted to the observed PDs and modelled the DMSO-larval development relationship.

Results: The PD significantly decreased with increasing DMSO concentration and was significantly reduced at the 2.6% concentration. The median inhibitory concentration (IC50) was 3.79%, the concentration for 10% inhibition (IC10) was 1.75% and for 90% inhibition (IC90) was 8.20%. The percentage of L1 and L2 followed an analogical but opposite pattern to that of PD and was complementary to it at each DMSO concentration. The unhatched egg percentage was rarely >1% and showed no pattern.

Conclusion: At ≥2.6% concentration, DMSO significantly inhibited the L3 development of all three GIN species. It had a practically important inhibitory effect (IC10) at as low concentration as 1.75%. At lower concentrations, DMSO did not appear to inhibit larval development. The compound did not seem to exert an in vitro ovicidal effect regardless of the concentration.

Introduction: Grazing cattle are vulnerable to the harmful effects of gastrointestinal parasites. Organically farmed cattle are even more so because conventional antiparasitic treatments are restricted, yet parasite infection patterns in Polish organic herds remain poorly documented.

Material and methods: Imported beef cattle were studied during the pasture season in four organic herds in southern Poland. The McMaster quantitative flotation method was used to estimate infection prevalence (P, %) coproscopically and to quantify intensities of coccidia oocyst output (Ic, OPG) and nematode egg output (In, EPG) per gram of faeces. The qualitative sedimentation method was applied to assess the presence of digenean eggs. Coccidial species of the Eimeria genus were identified by sporulation, and nematodes of the Strongylida order by larvoscopy. Digenean Paramphistomatidae were identified by morphological examination of adult fluke specimens obtained at slaughter from a sick heifer in one of the studied herds and by molecular analysis of the flukes' internal transcribed spacer 2 ribosomal DNA.

Results: The prevalence of Eimeria infection was P = 28.9 (23.8-34.5)%, and the mean Ic was 287 (113-793) OPG. Calves were most heavily infected, mainly with E. bovis and E. zuernii. The prevalence of nematode infections reached P = 46.0 (40.2-51.5)%, and the mean In was 113 (88-147) EPG. Haemonchus placei dominated over Ostertagia sp. and Trichostrongylus axei, and the most infected were first-time grazing yearlings. Paramphistome eggs were confirmed in only one herd. Morphological and PCR analysis of the adult rumen flukes revealed the presence of Calicophoron daubneyi (Dinnik, 1962) in this herd.

Conclusion: This is the first Polish evidence of C. daubneyi, and it heralds an enhanced surveillance need regarding this highly pathogenic digenean.

Introduction: Enzootic nasal adenocarcinoma (ENA) is a nasal cancer that occurs in goats and sheep infected by enzootic nasal tumour virus. Pathologic examinations are useful for distinguishing tumours from inflammatory hyperplasia. The aim of this study was to describe the pathological characteristics of ENA.

Material and methods: Caprine tumour samples were collected for pathological examination. The tissue sections were stained with haematoxylin-eosin and periodic acid-Schiff (PAS) and processed for immunohistochemical staining. Tumour samples were also processed for routine transmission electron microscopy (TEM).

Results: The histopathological structure of the tumours exhibited both papillary formations in the superficial regions and tubular or acinar formations in the deeper layers, representing distinct structural patterns within the same adenocarcinoma. The tumour cells were positive for PAS, and mitotic figures were rare. Low-differentiated cancer nests and epithelial-mesenchymal transition phenomena were observed. Immunohistochemical analysis showed that the tumour cells were strongly positive for pancytokeratin and cytokeratin (CK)18, moderately positive for CK7, and did not express olfactory marker protein. The Kiel 67 labelling index was approximately 23%. Retrovirus-like particles were distributed inside and outside of acinar tumour cells in TEM.

Conclusion: The origin site of ENA is the epithelium of the nasal glandular tubules. This cancer is a low-grade adenocarcinoma with malignant potential. Cytokeratin 7 and CK18 can be considered immunophenotypes for identifying ENA tumour cells.

Introduction: Canine mammary gland cancer (CMGC) is the most common neoplastic condition in bitches and is often fatal. There are limited treatment options for CMGC. Primary cell cultures from mammary tumours are promising preclinical in vitro models in which to study personalised treatment approaches. This preliminary study aimed to establish primary cell cultures from two canine mammary gland neoplasms: a common solid adenocarcinoma and a rare carcinosarcoma.

Material and methods: Tumour masses were collected from a 13-year-old and a 16-year-old German shepherd. Tumour cells were isolated by mechanical disaggregation and enzymatic digestion of masses with 0.05% type IV collagenase. Primary cell cultures were validated by immunocytochemistry for specific markers including mucin 1 (MUC1), cytokeratin 8 and 18 (CK8/18) and Kiel 67 (Ki-67).

Results: Primary cell cultures achieved confluency by day 7 of culture, displaying polygonal cellular morphology. Cultures of both cell types exhibited strong positivity for MUC1 of >99% and high Ki-67 proliferation activity of 43.1% ± 0.5% in the solid adenocarcinoma-derived positive cells and 87.9% ± 2.7% in the carcinosarcoma-derived positive cells. Positivity was observed for CK8/18 of 98.1% ± 0.3% in cells derived from solid adenocarcinoma and 31.6% ± 1.5% in cells derived from carcinosarcoma.

Conclusion: With further characterisation, the primary cell cultures established in this study can be expected to show considerable potential as foundational in vitro models for cancer research.

Introduction: The testicular-only processing fluid (TOPF) obtained from piglet testicles after castration could be an alternative sample for porcine reproductive and respiratory syndrome (PRRS) laboratory diagnosis. If this matrix were proved useful, testing it would spare piglets the stress of blood drawing and eliminate some labour required to take blood samples. The aim of the study was to evaluate the utility of TOPF for this diagnostic purpose.

Material and methods: Serum-and-TOPF pairs from male piglets and sera from female piglets were tested using commercial ELISA and real-time RT-PCR kits. For the pooling simulation, 10 μL aliquots of TOPF separated into low-, moderately and highly positive were mixed with appropriate volumes of negative TOPF samples. This simulated pools of 5, 10, 20, 40 and 80 samples containing 1 positive for serological analyses and pools of 10, 20, 40, 80, 160 and 320 samples containing 1 positive in molecular analyses.

Results: The percentages of anti-porcine reproductive and respiratory syndrome virus (PRRSV) antibodies were statistically significantly different (P-value < 0.05) between boar sera (69.55%) and TOPF (54.49%), as well as between gilt sera (74.52%) and TOPF. However, after adjusting the cut-off value, no significant differences were noted. The RNA of PRRSV was detected in 21.26% of male sera, 15.23% of TOPFs and 17.00% of female sera. Pooled sample testing revealed discrepancies in positive results associated with the pool size and original sample positivity strength.

Conclusion: TOPF samples can be a valuable matrix for laboratory PRRS diagnosis in piglets. However, it is important to be aware of the potential for false-negative results.

Introduction: Racing pigeon competitions are a popular sport where success depends on birds' ability to return fast to their loft of origin. However, many additional factors like differences in feeding, training, everyday care and even geographical loft location influence race outcomes, which has led to the development of the One Loft Race (OLR) system. The OLR system aims to eliminate these factors by housing pigeons from various lofts in equal conditions in one facility. This in turn, however, fosters inter-individual transmission of pathogens.

Material and methods: Fifteen young racing pigeons from five different lofts, naturally infected with pigeon circovirus (PiCV) were reared in one unit for six weeks. Four uninfected birds were kept in a separate unit and were treated as controls for flow cytometry analyses (background establishment). Blood samples were collected every seven days to extract DNA for PiCV quantification using droplet digital PCR and to isolate the mononuclear cells for flow cytometry analyses. On day 42, all birds were euthanised for spleen samples to be collected for further analyses.

Results: The viraemia peak was noted on day 14 of the experiment and subsequently decreased afterwards, with a remarkable decrease noted on day 35. The percentage of IgM⁺ B lymphocytes, including apoptotic cells, in the blood was very similar throughout the experiment. The percentage of apoptotic splenic IgM⁺ B cells was approximately 40% higher in the experimental group than in the control group.

Conclusion: Study results showed that the birds' adaptation period and the specific immunity they had probably developed hindered PiCV replication. Mild PiCV infection led to a slight increase of B lymphocyte apoptosis in the spleen.

Introduction: Nematode-trapping fungi (NTFs) can produce various chitinases to degrade nematode body wall and eggshell chitin during predation. However, the regulatory mechanisms of their expression of chitinases still remain unclear. The primary objective of this study was to elucidate the differential protein profile of A. oligospora, an NTF, in response to chitin.

Material and methods: Colloidal chitin was added to induce the culture of A. oligospora, and the phenotypic differences before and after induction were observed under inverted microscope. The differential proteins before and after mycelium induction were screened by liquid chromatography-tandem mass spectrometry. The differentially expressed chitinase was expressed in Pichia yeast, and the recombinant enzyme was incubated with Caenorhabditis elegans and its egg suspension to explore its biological activity.

Results: It was found that there was a significant acceleration in the mycelial growth post chitin interaction in A. oligospora. A total of 1,124 differentially expressed proteins (DEPs) were identified between the control group (AO-c) and the experimental group (AO-e), with 183 upregulated and 941 downregulated. Gene Ontology analysis revealed that the DEPs acted in various metabolic processes with catalysis and binding functions. Kyoto Encyclopedia of Genes and Genomes analysis associated these proteins primarily with signalling pathways related to glucose metabolism. Three chitinases were significantly modulated among DEPs. Moreover, enzymatic activity assays demonstrated that one of them effectively degraded C. elegans and its eggs.

Conclusion: These findings suggest that A. oligospora can significantly alter its protein expression profile in response to chitin, thereby facilitating its sugar metabolism and mycelial development. Our study provided new insights into the regulatory mechanisms of nematode predation in A. oligospora.

Introduction: Periodontal diseases are the most frequently diagnosed problem in small animal veterinary medicine. Although their exact cause is not fully understood, bacteria play an important role in their development. Pseudomonas aeruginosa is a Gram-negative, rod-shaped, non-spore-forming bacterium. The living environment of this bacterium may be soil and water; however, it can also be found in humans and animals. Antibiotic treatment of periodontitis may be complicated by the carbapenem resistance of some P. aeruginosa strains, if these bacteria are found to be an aetiological agent. The aim of the study was to identify all bacterial strains isolated from dog with periodontitis.

Material and methods: After a clinical examination of a Schnauzer dog in the Department and Clinic of Animal Surgery in the University of Life Sciences in Lublin Faculty of Veterinary Medicine, periodontitis was diagnosed. A swab was taken from the diseased tissue and submitted for microbiological tests. Microorganisms were initially identified by colony morphology, haemolytic pattern and Gram staining, and subsequently by sensitivity tests, VITEK 2 and matrix-assisted laser desorption/ionisation-time-of-flight.

Results: Pseudomonas aeruginosa was isolated and identified as a probable aetiological factor of periodontitis in dogs.

Conclusion: In our opinion, attention should be paid to Pseudomonas aeruginosa as a possible aetiological factor of periodontal diseases in dogs.

Introduction: This study aimed to investigate the impact of perinatal body condition score (BCS) and its subsequent loss on postpartum performance and health outcomes in dairy cattle.

Material and methods: A total of 156 cows were randomly selected, and blood samples were collected at -21, 0, 7, 14, 21, 28 and 50 days relative to calving. Milk yield and disease incidence in dairy cows were recorded after calving. These cows were subsequently categorised into three groups based on BCS loss during the transition period: a no-BCS-loss (maintained BCS) group (M, 0 < BCS loss ≤ 0.25), low-BCS-loss group (L, 0.25 < BCS loss ≤ 0.5), and high-BCS-loss group (H, BCS loss > 0.5).

Results: All groups experienced a decline in BCS from 21 days prepartum through 50 days postpartum (P-value < 0.01). Cows in the H group had the highest levels of non-esterified fatty acids, beta-hydroxybutyrate, total cholesterol, aspartate aminotransferase, albumin, malondialdehyde and leptin (P-value < 0.05). Concomitantly, total antioxidant capacity, as well as the levels of insulin and glucose, were the lowest in group H (P-value < 0.05). Plasma concentrations of Ca, P, Mg and K, urea nitrogen and total bilirubin were not significantly influenced by BCS loss (P-value > 0.05). Cows in the M group were less likely to develop ketosis, mastitis, retained placenta, displaced abomasum and metritis than those in the H group, and cows in the H group produced the lowest milk yields (P-value < 0.05).

Conclusion: These observations collectively indicate that BCS loss is associated with measurable changes in energy balance, liver function, oxidative stress, daily milk production and disease incidence during the transition period.