Journal of Veterinary Research最新文献

Introduction: Endometritis is a very common pathology in animals which changes endometrial leukotriene (LT) formation and muscarinic 2 and 3 receptor subtypes (M2R/M3R) and α-7 nicotinic acetylcholine (ACh) receptor (α-7 nAChR) expression patterns. With the relationship between ACh, its receptors and LT production remaining unclear, the role of M2R, M3R and α-7 nAChR in action of ACh on the 5-lipoxygenase (5-LO), LTA4 hydrolase (LTAH) and LTC4 synthase (LTCS) protein abundances in the inflamed porcine endometrium and on the tissue secretion of LTB4 and LTC4 were studied.

Material and methods: On day three of the oestrous cycle in gilts aged 7-8 months, 50 mL of either saline solution (control group, n = 5) or an E. coli suspension at 10⁹ colony-forming units/mL (E. coli group, n = 5), was injected into each uterine horn. Endometrial explants obtained eight days later, were incubated with ACh alone, antagonists of M2R, M3R and α-7 nAChR alone, or with ACh together with particular antagonists for 16 h. Enzyme abundances in endometrial tissue were estimated by Western blotting, and LT concentrations in medium by ELISA.

Results: Severe acute endometritis developed in the E. coli group. In the endometrial explants from both groups, ACh elevated 5-LO, LTAH and LTCS protein abundances and LTB4 and LTC4 release. In the E. coli group, ACh-induced 5-LO and LTCS abundances and LTB4 release were increased versus the control group. In both groups, the M3R antagonist with ACh reduced all ACh-stimulated enzyme abundances and LT release in comparison to the abundances and release mediated by ACh alone. This effect on LTCS protein abundance and LTB4 release was also produced by the M2R antagonist with ACh in the E. coli group. Compared to the effect of ACh alone, exposure of the E. coli group endometrium to the α-7 nAChR antagonist with ACh led to a rise in LTAH and LTCS protein abundances and LTB4 and LTC4 secretion.

Conclusion: In the inflamed pig endometrium, ACh increased 5-LO, LTAH and LTCS protein abundances and LTB4 and LTC4 release by M3R, and LTCS protein abundance and LTB4 release also by M2R. By interaction with α-7 nAChR, ACh reduced LTAH and LTCS protein abundances and the release of these LTs. Thus, in an indirect manner, ACh can affect LT-controlled processes.

Introduction: Mycoplasma gallisepticum (MG) infection is a primary cause of chronic respiratory disease in poultry, threatening the economic viability of China's goose-farming industry. This study investigated the pathogenicity and drug resistance of an MG strain isolated from geese and whole-genome sequenced the strain.

Material and methods: A strain designated MG-GD01/22 was isolated from the air-sac tissues of five geese with chronic respiratory disease on a Guangdong goose farm. Its pathogenicity was assessed, antimicrobial susceptibility tests were performed using agar dilution, and its total DNA was extracted for whole-genome sequencing and gene function annotation with second- and third-generation sequencing technologies. The homology of the 16S ribosomal RNA (rRNA) region was analysed and a phylogenetic tree was constructed, as was an evolutionary tree of the mgc2 gene. Gene co-linearity analysis was performed to compare MG-GD01/22 with the strains in the GenBank database.

Results: The isolate produced "fried egg" colonies and was pathogenic to goslings. It was resistant to enrofloxacin, danofloxacin and spectinomycin and susceptible to valnemulin, tilmicosin, tylosin, acetylisovaleryltylosin tartrate and tiamulin. The genome analysis revealed 1,666 coding genes. Gene database annotation identified 25 virulence-related genes, 22 drug resistance-related genes, 13 pathogen-host-interaction genes and 9 carbohydrate-active enzyme genes. The isolate exhibited 99.9% homology to the MG S6 strain by its 16S rRNA, while the mgc2 gene typing results indicated that it differed from known MG model strains. The genome of MG-GD01/22 showed high homology but poor co-linearity with MG S6, characterised by numerous gene deletions, inversions and displacements.

Conclusion: This study offers theoretical references for the diagnosis, prevention and treatment of MG in geese in the Guangdong region.

Introduction: The grayling (Thymallus thymallus L.) has several advantages over other fish species that make it attractive for aquaculture and invest it with importance for food security. The study assessed the effects of a β-glucan-enriched diet on biomarkers of oxidative stress, energy metabolism and lysosomal function in muscle tissue of European grayling (Thymallus thymallus L.).

Material and methods: Sixty-six grayling weighing approximately 34 g were divided into equal control and experimental groups. A basal diet was fed to the control group and a β-glucan-enriched one was fed to the experimental group for 45 d. Lipid peroxidation (LP) level; oxidative protein modification (OPM); total antioxidant status (TAS); and superoxide dismutase (SOD), catalase (CAT), glutathione reductase, glutathione peroxidase (GPx), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate (LDH), succinate dehydrogenase (SDH), alanyl aminopeptidase, leucyl aminopeptidase, acid phosphatase (AcP) and β-N-acetylglucosaminidase (NAG) activities were assessed in the muscle tissue of fish euthanised after 15, 30 and 45 d of feeding.

Results: The β-glucan supplementation reduced LP, attenuated OPM and improved the TAS in muscle tissue. Increased SOD and CAT activity and maintenance of GPx activity in muscle tissue were the main mediators of these effects. They also affected energy metabolism through modulation of key enzymes and metabolites, including ALT, AST, LDH, SDH, AcP and NAG activity, and altered lactate and pyruvate levels. Multivariate analysis of variance, supported by high F-values and low P-values indicating statistical significance, highlighted the significant effect of β-glucans and feeding duration on markers of oxidative stress, antioxidant defences and TAS.

Conclusion: B-glucans altered the balance between aerobic and anaerobic metabolism, reduced OPM and modulated the transaminase response, affecting amino acid metabolism and the production of Krebs cycle intermediates.

Introduction: Campylobacter are the most common cause of food poisoning, which manifests itself in diarrhoea of varying severity. Additionally, because of the increasing number of people with immune deficiencies, more frequent serious complications of Campylobacter infections are being observed. The main source of infection is the consumption of contaminated poultry meat, which is a consequence of the insufficiency of current hygiene and biosecurity to control Campylobacter or eliminate it from the poultry food chain.

Material and methods: Two hybrid proteins, presenting selected epitopes of the Campylobacter antigens CjaD and EF-Tu, were developed based on the highly immunogenic proteins CjaA and CjaC. Four groups of chickens were vaccinated with different preparations (a mixture of both hybrid proteins encapsulated in anionic or neutral liposomes) and different doses (a single dose given on the day of hatching or two doses given on days 1 and 14 of life). The number of Campylobacter was assessed in the intestinal contents of vaccinated birds.

Results: No statistically significant differences in colonisation levels were observed between chickens immunised with neutral liposomes containing hybrid proteins and their non-immunised counterparts, regardless of dosage regimen.

Conclusion: Although immunisation of chickens did not produce the expected results, the approach used has great potential, which is worth further investigation and development.

Introduction: The enteric nervous system (ENS) in the wall of the gastrointestinal tract is complex and comprises many neurons, which are differentiated in terms of structure, function and neurochemistry. Neuregulin 1 (NRG 1) is one of the neuronal factors synthesised in the ENS about the distribution and functions of which relatively little is known. The present study is the first description of the distribution of NRG 1 in the ENS in various segments of the porcine small intestine.

Material and methods: Fragments were excised from the duodenum, jejunum and ileum of five euthanised Piétrain × Duroc sows, 18-20 kg in weight and eight weeks of age. Paraformaldehyde-fixed and dehydrated tissue was sectioned and double-labelling immunofluorescence was performed using Alexa Fluor-conjugated secondary antibodies to visualise neuregulin 1 and its colocalisation with vasoactive intestinal polypeptide (VIP), galanin (GAL), and the neuronal isoform of nitric oxide synthase (nNOS) in the myenteric and inner and outer submucosal plexuses, with PGP 9.5 serving as a pan-neuronal marker.

Results: Neuregulin 1 was observed in all enteric plexuses in each segment of the small intestine. The percentage of NRG 1-positive neurons ranged from 8.38 ± 0.55% of all neurons in the jejunal inner submucous plexus to 21.52 ± 0.98% in the duodenal myenteric plexus. Cells which were NRG 1-positive also contained VIP, GAL and nNOS in all segments of the small intestine to a degree which varied by small intestine segment and enteric plexus type.

Conclusion: The results indicate that NRG 1-positive neurons are present in the ENS of the porcine small intestine and differ significantly neurochemically, which may suggest a multifaceted role for NRG-1 in the controlling of the small intestine activity.

Introduction: Crayfish plague is considered the most important crayfish disease globally. It is caused by the fungus-like agent, Aphanomyces astaci. This study aimed to identify and determine the prevalence of A. astaci using PCR in narrow-clawed crayfish (Pontastacus leptodactylus) populations from across Türkiye.

Material and methods: A PCR was carried out with primers specific to the internal transcribed spacer region of the A. astaci pathogen on both telson and abdominal cuticle tissues from crayfish individuals from 41 different locations.

Results: Aphanomyces astaci was detected in the crayfish from 34 of the locations. Molecular diagnosis showed the prevalence rates of A. astaci to be between 0% and 68.2%. For 7 of the 34 locations, the strain of A. astaci was determined. Microsatellite analysis of tissue from individuals with positive PCR results revealed the A. astaci genotypes in seven populations. Genotype B was found to be the predominant genotype responsible for crayfish plague in Turkish crayfish populations. The Psl genotype (genotype B) was determined in six of the populations, and the As genotype (genotype A) was detected in only one.

Conclusion: Crayfish plague poses a significant threat to crayfish populations, necessitating the development of rapid, highly sensitive diagnostic methods. An understanding of the sensitivity of the PCR detection method and of the prevalence and genotyping of A. astaci in Turkish crayfish populations has been gained from this study.

Introduction: The aim of this study was to estimate the occurrence of Echinococcus spp. and other helminth infections in grey wolves in south-eastern Poland.

Material and methods: Overall, 74 samples of wolf faeces were examined with a multiplex PCR and a system of real-time quantitative PCR methods to detect and identify Echinococcus spp. The faeces were additionally examined microscopically. Also, 20 samples of wolf intestines were examined with a sedimentation and counting technique (SCT).

Results: Echinococcus multilocularis DNA was detected in 6.8% and E. granulosus s.l. (identified as E. ortleppi) in 4.1% of faeces samples. Taenia spp. DNA was found in 43.2% and Mesocestoides in 4.1%. Examination of the intestines by SCT showed E. multilocularis worms in 10%, E. granulosus s.l. (E. ortleppi) in10%, Taenia spp. in 100%, hookworms in 30%, Alaria alata in 20%, Mesocestoides sp. in 10%, Trichuris vulpis in 15%, Molineus sp. in 5% and Euryhelmis sp. in 5%. By coproscopy, Capillariidae eggs were found in 59% of faeces samples. Genetic analysis of E. multilocularis worms showed the presence of two European haplotypes previously described in Poland in red foxes and pigs. Sequences of nad1 obtained from E. ortleppi worms shared full identity with a sequence from a human case in Poland.

Conclusion: The study showed the presence of E. multilocularis in wolves for the first time in Poland and confirmed our earlier observations on E. ortleppi. This double threat from Echinococcus in this wolf population should be taken into account when assessing the epidemiological risk. The study enriched the knowledge of other helminths found in wolves, also those (Euryhelmis) that were recorded for the first time in this species.

Introduction: The aim of the study was to compare selected leukocyte subpopulations and the serum amyloid A (SAA) concentration in the peripheral blood of cows at different stages of lactation. The blood of cows receiving a probiotic as a dietary supplement was compared with the blood of cows not receiving it.

Material and methods: The research was conducted on 20 pregnant dairy cows randomly divided into two groups of 10 cows each. The experimental group consisted of cows given the probiotic as a feed supplement. The control group consisted of cows that were fed without supplementation. Blood was drawn six times for testing: 7 days before drying; 14 days before parturition; and 7, 21, 60 and 90 days postpartum. Leukocyte immunophenotyping was performed by flow cytometry.

Results: The blood of cows administered the probiotic revealed an increased percentage of forkhead box protein 3 (Foxp3)⁺, T CD4⁺ and B CD25⁺ lymphocytes and β2 CD18⁺ and αM CD11b⁺ integrins, and persistently low SAA levels at all time points.

Conclusion: The activity of the immune system in cows receiving the probiotic was higher than in control cows. However, the stabilisation of the immune system of the supplemented cows may be indicated by the persistence of a low level of SAA throughout the experiment. Therefore, it can be assumed that the immune system of cows treated with the probiotic more easily adapts to changes in conditions in particular lactation periods and that these cows become more resistant to infectious diseases.

Introduction: This study explored the effects of prenatal exposure to fumonisins B (FB) on bone innervation in newborn Wistar rats.

Material and methods: Pregnant dams (n = 6 per group) were assigned to either the control or one of two FB-exposed groups (60 mg or 90 mg/kg body weight) from the 7^th day of gestation until parturition. On the day of parturition, one male pup from each litter (n = 6 per group) was randomly selected and euthanised, and their femurs were dissected for analysis. Bone innervation was quantified by examining the morphology patterns of sympathetic, parasympathetic, sensory and cocaine- and amphetamine-regulated transcript (CART)-positive fibres. Prepared bone sections were analysed using immunohistochemistry staining for protein gene product 9.5, tyrosine hydroxylase, choline acetyltransferase, vasoactive intestinal peptide (VIP), substance P and CART-positive neurons.

Results: The group that received a higher dose of FB demonstrated an increase in both the size and complexity of the complete bone neuronal network together with heightened sympathetic and sensory innervation, and displayed a decrease in neuron density and sympathetic innervation. Fumonisin B exposure led to a decrease in galanin-positive and VIP-positive bone neuronal networks in both groups exposed to FB, while in the lower-dose group, there was also a decrease in CART-positive innervation.

Conclusion: Prenatal FB exposure significantly influences the neuronal bone network of rats, which is essential for maintaining bone homeostasis. These findings emphasise the necessity for further research to understand the lasting effects and underlying mechanisms of alterations induced by FB.

Introduction: Escherichia coli is the most common uropathogen in humans, dogs and cats. Dietary consumption of cranberry (Vaccinium macrocarpon) is known to be associated with a reduction in uropathogenic E. coli (UPEC) adhesion to human and canine urinary epithelial cell lines, but this has not been shown in cats.

Material and methods: Six neutered domestic cats, one male and five females, were randomly fed three diets successively, one containing 0.1% cranberry powder, one containing 0.3% cranberry powder, and one being the control without cranberry. Naturally emitted urine was collected on the last two days of each period of two weeks and used for bacterial growth. Adherence to Crandell-Rees feline kidney (CRFK) uroepithelial cells of the feline UPEC C571 strain (positive for the papC gene marker for P-fimbriae and the fimA marker for type 1 pili and negative for the gene of the alpha haemolysin cytotoxin hlyA, and additionally non-haemolytic in vitro on blood agar) was quantified after growth in urine samples.

Results: Significant reductions in bacterial adherence to CRFK cells were observed for 60% of cats receiving 0.1% cranberry powder supplementation and for all cats receiving 0.3% cranberry powder supplementation, compared to the same animals consuming the control diet.

Conclusion: Dietary supplementation with cranberry may provide some degree of protection to cats against adhesion of UPEC to feline uroepithelial cells.