Journal of Veterinary Science最新文献

Importance: In human medicine, research using magnetic resonance imaging (MRI) has shown that an increase in the vertebral body fat signal fraction (FSF) is associated with the severity of intervertebral disc (IVD) degeneration. Nevertheless, veterinary medicine has limited information on the relationship between the vertebral body FSF and IVD degeneration.

Objective: This study evaluated the relationship between IVD degeneration and the vertebral body FSF in dogs and compared these factors between chondrodystrophic (CD) and non-chondrodystrophic (NCD) dogs.

Methods: IVD degeneration in dogs was classified morphologically using the Pfirrmann grade, and the vertebral body FSF was evaluated quantitatively.

Results: The vertebral body FSF showed a statistically significant difference among the age groups. The vertebral body FSF was significantly higher in Pfirrmann grades 3-5 than in grades 1 and 2. The mean Pfirrmann grade of CD dogs was higher than that of NCD dogs in the four-to-six-year-old group. The mean vertebral body FSF of CD dogs was higher than that of NCD dogs in the group of seven years and above.

Conclusions and relevance: In dogs, the vertebral body FSF increased significantly with age and Pfirrmann grade. The CD dogs showed a higher degree of IVD degeneration at a younger age than the NCD dogs. CD dogs appeared to experience more severe fat deposition of the vertebral body in old age than NCD dogs. MRI examinations are helpful for evaluating IVD degeneration and vertebral body fat deposition.

Importance: Porcine circovirus (PCV) is a global concern due to its financial impact on the pig industry. Molecular epidemiology of PCV2 and PCV3 in wild boars is essential for understanding viral dispersal and evolution in the wild boar population.

Objective: This study aimed to assess the prevalence and genotypic traits of PCV2 and PCV3 in wild boars in the Gyeongnam region.

Methods: Serum samples from wild boars in Gyeongnam Province were screened for PCV2 and PCV3, and polymerase chain reaction-positive samples were further subjected to genotyping and whole-genome sequencing of PCV2 and PCV3.

Results: Thirty-eight samples tested positive for PCV2, 7 for PCV3, and 2 for PCV2 and PCV3 (coinfection). PCV2d and PCV3b are the dominant genotypes, causing PCV2 and PCV3 coinfections. Wild boar PCV2 and PCV3 viruses closely resemble their corresponding genotypic strains circulating in South Korea.

Conclusions and relevance: The circulation of PCV2 and/or PCV3 in wild species poses an additional challenge for commercial pig farming due to potential contact with infected wild boars. Our findings highlight the necessity for active monitoring and surveillance of wild boars and the enforcement of stringent biosecurity measures on commercial swine farms to mitigate the risk of PCV spillover to the domestic pig population.

Importance: Mesenchymal stem cells (MSCs) used to treat inflammatory diseases in humans show improved clinical outcomes compared to other treatments. On the other hand, feline MSCs have limited therapeutic effects because of their low bioactivity. Successful clinical treatment requires enhancing the anti-inflammatory ability of feline adipose-derived MSCs (fAdMSCs).

Objective: To enhance the anti-inflammatory activity of fAdMSCs.

Methods: fAdMSCs were treated with the toll-like receptor 3 (TLR3) ligand poly (I:C) and aggregated. Indoleamine 2,3-dioxygenase-1 (IDO-1) expression and kynurenine production were measured to evaluate the anti-inflammatory activity. Anti-inflammatory effects were assessed by culturing fAdMSCs with rat macrophages and transplanting them into the kidney capsules of rats.

Results: IDO-1 expression and kynurenine production in fAdMSCs were increased significantly by a poly (I:C) treatment and enhanced using a basic fibroblast growth factor (bFGF) treatment. The level of fAdMSC aggregation increased IDO-1 expression significantly compared to the monolayer. These effects were enhanced by pretreatment with bFGF and poly (I:C). The bFGF and poly (I:C)-pretreated fAdMSC aggregates suppressed tumor necrosis factor-α expression in rat macrophages. During transplantation, the pretreated fAdMSC aggregates avoided leakage, survived in aggregate form, and induced anti-inflammatory macrophages.

Conclusions and relevance: TLR3-stimulated, bFGF-pretreated fAdMSC aggregates increase the anti-inflammatory activity significantly, providing a potential therapeutic approach for inflammatory diseases in felines.

Importance: Understanding the microbial diversity within the gastrointestinal tract of wild Korean water deer (KWD; Hydropotes inermis argyropus) is essential for gaining insights into their health and ecological interactions.

Objective: This study aims to isolate and identify aerobic and anaerobic bacterial species in the feces of wild KWD.

Methods: Fecal samples were collected from 55 wild KWD of varying age and sex. Aerobic bacteria were cultured at 37°C for 24-48 h under standard conditions, whereas anaerobic bacteria were cultured at 37°C for 48-72 h in an anaerobic environment. Bacterial identification was conducted using DNA extraction and polymerase chain reaction amplification targeting the 16S rRNA gene.

Results: The predominant aerobic bacteria identified belonged to the Firmicutes (58.18%) and Proteobacteria (41.82%) phyla, with Escherichia coli (31.82%) and Bacillus cereus (31.82%) being the most common species. Among anaerobic bacteria, most belonged to the Firmicutes (71.03%), Proteobacteria (27.10%), and Fusobacteriota (1.87%) phyla, with Paraclostridium bifermentans (28.97%) and E. coli (22.43%) being the most prevalent species. Other frequently identified anaerobic species were Fusobacterium varium, Lactococcus garvieae, Terrisporobacter glycolicus, Enterococcus faecalis, and Clostridium sporogenes.

Conclusions and relevance: Our findings indicate a diverse microbial community in the feces of water deer, offering valuable insights into their gut microbiota and its potential implications for health and ecology.

Importance: Equine behavioral traits are important criteria to assess the suitability of retired Thoroughbred racehorses for equestrian sports.

Objective: This study aims to develop a practical procedure to assess retired Thoroughbreds for their suitability for equestrian sports or leisure purposes and to assess if horses identified as having reactive temperaments in response to a standardized startle test, will have improved test results following a period of transition training.

Methods: Behavioral reactivity data and cardiac autonomic responses to a startle test (comprising of a plastic bag applied to the neck area) were collected from twelve retired Thoroughbred racehorses (6 males and 6 females; average age: 4.33 ± 0.89 years old; average body weight 465.17 ± 25.33 kg), before and after the three-month transition training for equestrian sports. A priori power calculation indicated a requirement of 12 individuals for a power of 80%.

Results: Following the training, there was a significant reduction in the behavioral score (BS), peak heart rate (HR), and response duration (RD) of all horses compared to their pre-training scores. However, 25% of horses (3/12) retained a BS of 2 or above post-training, exhibiting significantly higher peak HR and longer RD compared to those with a BS below 2. Post-training, the females demonstrated a significant increase in the root mean square of the successive differences between normal heartbeats compared to their pre-training levels.

Conclusions and relevance: Transition training of retired Thoroughbreds can assist in improving horses' suitability for equestrian sports, based on their successive responses to a novel startle test.

Importance: The porcine reproductive and respiratory syndrome virus (PRRSV) poses a significant threat to swine production, particularly with emerging strains such as the highly virulent NADC30-like strain.

Objective: This study examined the impact of PRRSV NADC30-like strains on pig farms in Fujian, China.

Methods: The effectiveness of strategic management protocols, including herd closure, medication programs, monitoring of processing fluids (pig testicular fluid), and collection of production data, were analyzed. The prevalent strain in the pig farm was identified as a NADC30-like strain of the PRRSV through genetic sequencing comparison analysis.

Results: The quantitative real-time reverse-transcription polymerase chain reaction results showed that the PRRSV cycle threshold (Ct) values of the processing fluid samples were relatively low from September to early October 2021. After implementing the intervention measures (October 2021), the Ct value increased gradually and reached a negative in March 2022, lasting six months. In addition, the average survival rate of the pigs before the intervention was 84.1%, while the average survival rate after the intervention was 93.1%.

Conclusions and relevance: The use of 12-month intervals for pig herd closure, drug planning, and other strategic management agreements (multi-point production and active monitoring of production data, McREBEL) helped stabilize the subsequent pig farm production, providing a basis for clinical disease prevention and control.

Importance: A relatively new therapeutic agent for osteoarthritis (OA), polydeoxyribonucleotide (PDRN), shows potential in treating human OA due to its regenerative and anti-inflammatory effects. However, studies on PDRN for canine OA are limited, and no study has investigated their use with mesenchymal stem cells (MSCs) conventionally used for OA treatment.

Objective: This study aimed to evaluate the potential of PDRN and explore its combined effect with adipose tissue-derived MSCs (AdMSCs) in treating canine OA.

Methods: To study the impact of PDRN, canine chondrocytes, synoviocytes, and AdMSCs were exposed to various PDRN concentrations, and viability was assessed using cell counting kit-8. The OA model was created by treating chondrocytes and synoviocytes with lipopolysaccharide, followed by treatment under three different conditions: PDRN alone, AdMSCs alone, and a combination of PDRN and AdMSCs. Using real-time quantitative polymerase chain reaction, the anti-inflammatory effects and mechanisms were investigated by quantitatively assessing pro-inflammatory cytokines, collagen degradation markers, adenosine A2a receptor (ADORA2A), and nuclear factor-kappa B.

Results: PDRN alone and combined with AdMSCs significantly reduced the expression of pro-inflammatory cytokines and collagen degradation markers in an OA model. PDRN promoted AdMSC proliferation and upregulated ADORA2A expression. AdMSCs exhibited comprehensive anti-inflammatory effects through paracrine effects, and both substances reduced inflammatory gene expression through different mechanisms, potentially enhancing therapeutic effects.

Conclusions and relevance: The results indicate that PDRN is a safe and effective anti-inflammatory material that can be used independently or as an adjuvant for AdMSCs. Although additional research is necessary, this study is significant because it provides a foundation for future research at the cellular level.

Importance: Porcine epidemic diarrhea virus (PEDV) binds to particular cell surface receptors to penetrate cells. The virus specifically identifies certain carbohydrate structures present on the surface of the cell to facilitate the binding process. Nevertheless, the influence of viral infections on specific alterations of glycoconjugates in the small intestines remains unexplored.

Objective: This work aimed to examine the alterations in glycoconjugates in the small intestines of piglets naturally infected with PEDV using lectin histochemistry.

Methods: Six piglets including three PEDV-infected and three non-infected piglets were evaluated. Small intestinal samples were histopathologically examined, and lectin histochemistry was performed.

Results: Piglets infected with PEDV had significant histological abnormalities in their small intestines, such as pronounced villous atrophy, varying degrees of villous fusion, and diverse mucosal alterations. Specific regions of the duodenum, jejunum, and ileum showed discernible variations in glycoconjugate distribution, as determined by lectin histochemistry. Compared with the controls, the PEDV-infected piglets showed significant changes in N-acetylglucosamine- and galactose-binding lectins (particularly wheat germ agglutinin and Arachis hypogaea (peanut) agglutinin) in multiple intestinal regions.

Conclusions and relevance: These findings can enhance understanding of how viruses such as PEDV impact the glycoconjugate composition of the small intestines and emphasize the potential connection between the pathogenesis of PEDV and glycoconjugate.

Importance: Carbapenem-resistant Enterobacteriaceae are emerging as a global public health risk. Therefore, assessing the prevalence of carbapenem-resistant Escherichia coli (CRE) in both humans and animals is important.

Objective: We aimed to ascertain the occurrence and characteristics of CRE isolated from companion animals, dogs and cats.

Methods: E. coli strains were tested for antimicrobial susceptibility using the broth microdilution technique. Antimicrobial resistance genes were detected by polymerase chain reaction and sequencing analysis. The molecular characteristics of CRE were determined using multi-locus sequence typing, replicon typing, and pulsed-field gel electrophoresis (PFGE).

Results: In total, 13 CRE isolates (0.13%) were identified from dogs possessing bla_NDM-5 along with β-lactamase genes, mostly bla_CMY-2 (92.2%) and bla_TEM-1 (53.8%). The commonly observed mutations were S83L and D87N in gyrA, S80I in parC, and S458A in parE. CRE carried non-beta-lactam resistance genes, with the majority being tet(B) (100%), sul (84.6%), and aac(3)-II (53.8%). Nine different PFGE patterns (P1-P9), IncX3-type plasmids (69.2%), and ST410 (84.6%) were predominantly detected.

Conclusions and relevance: This investigation provides significant insight into the prevalence and molecular characteristics of bla_NDM-5-carrying E. coli in dogs. The co-existence of bla_NDM-5 and other antimicrobial resistance genes in E. coli potentially poses severe health hazards to humans.

Importance: Glutamic acid decarboxylase 67 (GAD67) is a gamma-aminobutyric acid (GABA) synthesis enzyme associated with the function of other neurotransmitter receptors, such as the N-methyl-D-aspartate (NMDA) receptor and cannabinoid receptor 1. However, the role of GAD67 in the development of different abused drug-induced reward behaviors remains unknown. In order to elucidate the mechanisms of substance use disorder, it is crucial to study changes in biomarkers within the brain's reward circuit induced by drug use.

Objective: The study was designed to examine the effects of the downregulation of GAD67 expression in the dorsal striatum on reward behavior development.

Methods: We evaluated the effects of GAD67 knockdown on depression-like behavior and anxiety using the forced swim test and elevated plus maze test in a mouse model. We further determined the effects of GAD67 knockdown on ketamine- and JWH-018-induced conditioned place preference (CPP).

Results: Knockdown of GAD67 in the dorsal striatum of mice increased depression-like behavior, but it decreased anxiety. Moreover, the CPP score on the NMDA receptor antagonist ketamine was increased by GAD67 knockdown, whereas the administration of JWH-018, a cannabinoid receptor agonist, did not affect the CPP score in the GAD67 knockdown mice group compared with the control group.

Conclusions and relevance: These results suggest that striatal GAD67 reduces GABAergic neuronal activity and may cause ketamine-induced NMDA receptor inhibition. Consequently, GAD67 downregulation induces vulnerability to the drug reward behavior of ketamine.