Journal of Veterinary Science最新文献

Importance: Ovine pulmonary adenomatosis (OPA) and maedi-visna disease (MVD) are chronic and progressive infectious diseases in sheep caused by Jaagsiekte sheep retrovirus (JSRV) and maedi-visna virus (MVV), respectively.

Objective: To investigate the pathological changes and conduct viral gene analysis of OPA and MVD co-occurrence in Inner Mongolia, China.

Methods: Using gross pathology, histopathology, immunohistochemistry, ultrastructural pathology, PCR, and sequence analysis, we investigated the concurrent infection of JSRV and MVV in 319 Dorper rams slaughtered in a private slaughterhouse in Inner Mongolia, in 2022.

Results: Of the 319 rams included, 3 showed concurrent JSRV and MVV infection. Gross lung pathology showed diffuse enlargement, consolidation, and greyish-white miliary nodules on the lung surface; the trachea was filled with a white foamy fluid; hilar and mediastinal lymph nodes were significantly enlarged. Histopathology results revealed typical OPA and MVD lesions in the lung tissue. Immunohistochemical results were positive for JSRV envelope protein (Env) in the tumor cells and MVV CA in alveolar macrophages. Transmission electron microscopy showed several virions and autophagosomes in the lung tissue, severely damaged mitochondria, and the induced mitophagy. Nucleotide sequences obtained for JSRV env and MVV gag showed the highest homology with the Inner Mongolian strains of JSRV env (JQ837489) and MVV gag (MW248464).

Conclusions and relevance: Our study confirmed that OPA and MVD co-occurrence and identified the pathological changes in Inner Mongolia, China, thereby providing references for the identification of concurrent JSRV and MVV infections.

Importance: Despite advancements in herd management, feeding, and pharmaceutical interventions, neonatal calf diarrhea (NCD) remains a major global health concern. Bacteria, viruses, and parasites are the major contributors to NCD. Although several pathogens have been identified in the Republic of Korea (ROK), the etiological agents of numerous NCD cases have not been identified.

Objective: To identify, for the first time, the prevalence and impact of Boosepivirus (BooV) on calf diarrhea in the ROK.

Methods: Here, the unknown cause of calf diarrhea was determined using metagenomics We then explored the prevalence of certain pathogens, including BooV, that cause NCD. Seventy diarrheal fecal samples from Hanwoo (Bos taurus coreanae) calves were analyzed using reverse transcriptase and quantitative real-time polymerase chain reaction for pathogen detection and BooV isolate sequencing.

Results: The complete genome of BooV was detected from unknown causes of calf diarrhea. And also, BooV was the most frequently detected pathogen (35.7%) among 8 pathogens in 70 diarrheic feces from Hanwoo calves. Co-infection analyses indicated that most BooV-positive samples were solely infected with BooV, indicating its significance in NCD in the ROK. All isolates were classified as BooV B in phylogenetic analysis.

Conclusions and relevance: This is the first study to determine the prevalence and molecular characteristics of BooV in calf diarrhea in the ROK, highlighting the potential importance of BooV as a causative agent of calf diarrhea and highlighting the need for further research on its epidemiology and pathogenicity.

Importance: Guillain-Barré syndrome (GBS)-like neuropathy mimics the leading cause of sporadic acute nontraumatic limb paralysis in individuals from developed countries. Experimental autoimmune neuritis (EAN) is an animal model of GBS and of syndromes such as acute canine polyradiculoneuritis, seen in dogs and cats.

Objective: The involvement of glycogen synthase kinase (GSK)-3β, a pro-inflammatory molecule, in rat EAN is not fully understood. This study evaluated the potential role of GSK-3β in EAN through its inhibition by lithium.

Methods: Lewis rats were injected with SP26 antigen to induce EAN. Lithium was administered from 1 day before immunization to day 14 post-immunization (PI). Then the rats were euthanized and their neural tissues were prepared for histological and Western blotting analyses.

Results: Lithium, an inhibitor of GSK-3, significantly ameliorated EAN paralysis in rats, when administered from day 1 to day 14 PI. This corresponded with reduced inflammation in the sciatic nerves of EAN rats, where phosphorylation of GSK-3β was also upregulated, indicating suppression of GSK-3.

Conclusions and relevance: These findings suggest that lithium, an inhibitor of GSK-3β, plays a significant role in ameliorating rat EAN paralysis, by suppressing GSK-3β and its related signals in EAN-affected sciatic nerves.

Importance: Recent developments in genetic analytical techniques have enabled the comprehensive analysis of gastrointestinal symbiotic bacteria as a screening tool for animal health conditions, especially the endangered gibbons at the National Wildlife Rescue Centre (NWRC).

Objective: High-throughput sequencing based on 16S ribosomal RNA genes was used to determine the baseline gut bacterial composition and identify potential pathogenic bacteria among three endangered gibbons housed in the NWRC.

Methods: Feces were collected from 14 individuals (Hylobates lar, n = 9; Hylobates agilis, n = 4; and Symphalangus syndactylus, n = 1) from March to November 2022. Amplicon sequencing were conducted by targeting V3-V4 region.

Results: The fecal microbial community of the study gibbons was dominated by Bacteroidetes and Firmicutes (phylum level), Prevotellaceae and Lachnospiraceae/Muribaculaceae (family level), and Prevotella (and its subgroups) (genera level). This trend suggests that the microbial community composition of the study gibbons differed insignificantly from previously reported conspecific or closely related gibbon species.

Conclusions and relevance: This study showed no serious health problems that require immediate attention. However, relatively low alpha diversity and few potential bacteria related to gastrointestinal diseases and streptococcal infections were detected. Information on microbial composition is essential as a guideline to sustain a healthy gut condition of captive gibbons in NWRC, especially before releasing this primate back into the wild or semi-wild environment. Further enhanced husbandry environments in the NWRC are expected through continuous health monitoring and increase diversity of the gut microbiota through diet diversification.

Importance: Kidney disease is prevalent among veterinary species, including zoo animals; however, investigations into this condition in striped skunks (Mephitis mephitis) are scarce. Diagnostic tools for kidney diseases in this species also remain limited.

Objective: This study aimed to assess the utility of symmetric dimethylarginine as a biomarker for kidney disease in captive striped skunks in Korea.

Methods: This retrospective study analysed 11 striped skunks housed at the Everland Zoo between 2017 and 2021. Blood samples were collected during health checks. Kidney function was assessed through blood analysis and diagnostic ultrasound, with necropsies conducted on deceased animals. Symmetric dimethylarginine levels were measured in 27 plasma samples collected from 11 skunks.

Results: Over the study period, seven skunks were diagnosed with kidney disease. Analysis of 27 blood samples revealed a concurrent increase in SDMA levels with concentrations of blood urea nitrogen and blood creatinine. In 3 of the 7 skunks with kidney disease, symmetric dimethylarginine exceeded 14 µg/dL prior to the elevation of blood urea nitrogen and blood creatinine above the upper reference limit.

Conclusions and relevance: To our knowledge, this is the first study investigating symmetric dimethylarginine in captive striped skunks in Korea. Our findings suggest that symmetric dimethylarginine may serve as an early and consistent biomarker for renal dysfunction in striped skunks. Further studies with larger clinical sample size from striped skunks are needed to validate the clinical utility of blood symmetric dimethylarginine concentration.

Importance: Endochondral ossification plays an important role in skeletal development. Recent studies have suggested a link between increased intracellular reactive oxygen species (ROS) and skeletal disorders. Moreover, previous studies have revealed that increasing the levels of myeloperoxidase (MPO) and osteopontin (OPN) while inhibiting NADPH oxidase 4 (NOX4) can enhance bone growth. This investigation provides further evidence by showing a direct link between NOX4 and MPO, OPN in bone function.

Objective: This study investigates NOX4, an enzyme producing hydrogen peroxide, in endochondral ossification and bone remodeling. NOX4's role in osteoblast formation and osteogenic signaling pathways is explored.

Methods: Using NOX4-deficient (NOX4^-/-) and ovariectomized (OVX) mice, we identify NOX4's potential mediators in bone maturation.

Results: NOX4^-/- mice displayed significant differences in bone mass and structure. Compared to the normal Control and OVX groups. Hematoxylin and eosin staining showed NOX4^-/- mice had the highest trabecular bone volume, while OVX had the lowest. Proteomic analysis revealed significantly elevated MPO and OPN levels in bone marrow-derived cells in NOX4^-/- mice. Immunohistochemistry confirmed increased MPO, OPN, and collagen II (COLII) near the epiphyseal plate. Collagen and chondrogenesis analysis supported enhanced bone development in NOX4^-/- mice.

Conclusions and relevance: Our results emphasize NOX4's significance in bone morphology, mesenchymal stem cell proteomics, immunohistochemistry, collagen levels, and chondrogenesis. NOX4 deficiency enhances bone development and endochondral ossification, potentially through increased MPO, OPN, and COLII expression. These findings suggest therapeutic implications for skeletal disorders.

Importance: Feline calicivirus (FCV)-associated viral systemic disease (VSD) is a severe systemic disease caused by virulent FCV strains and has a very poor prognosis.

Objective: To evaluate the clinical characteristics of a nosocomial FCV-VSD outbreak involving 18 cats in Korea.

Methods: Medical records of cats diagnosed with FCV-VSD from March to September 2018 at a referral veterinary hospital were reviewed. The patient's signalment, history, clinical features, diagnosis, treatment, and prognosis were evaluated.

Results: Two outbreaks involving 18 cats diagnosed with FCV-VSD occurred over a 6-month period at a referral hospital in Korea. Anorexia, lethargy, fever, and limb edema were the most commonly observed clinical symptoms. Lymphopenia and macrothrombocytopenia were the most common hematological findings, and hyperbilirubinemia and increased levels of aspartate aminotransferase, creatine kinase, and serum amyloid A were the most frequent results of serum biochemistry. FCV was detected by reverse transcription polymerase chain reaction in 11 patients and the remaining 7 were suspected with FCV-VSD. The overall mortality rate was 72.2%. The hospital was closed and disinfected twice, and no additional outbreaks have occurred since the last patient.

Conclusions and relevance: The clinical and diagnostic characteristics and outcomes of FCV-VSD described in this study can be used to recognize and contain infectious diseases through quick action. To the best of the authors' knowledge, this is the first report of a nosocomial outbreak of FCV-VSD in Asia.

Importance: Bovine mastitis, predominantly associated with gram-positive Staphylococcus aureus, poses a significant threat to dairy cows, leading to a decline in milk quality and volume with substantial economic implications.

Objective: This study investigated the incidence, virulence, and antibiotic resistance of S. aureus associated with mastitis in dairy cows.

Methods: Fifty milk-productive cows underwent a subclinical mastitis diagnosis, and the S. aureus strains were isolated. Genomic DNA extraction, sequencing, and bioinformatic analysis were performed, supplemented by including 124 S. aureus genomes from cows with subclinical mastitis to enhance the overall analysis.

Results: The results revealed a 42% prevalence of subclinical mastitis among the cows tested. Genomic analysis identified 26 sequence types (STs) for all isolates, with Mexican STs belonging primarily to CC1 and CC97. The analyzed genomes exhibited multidrug resistance to phenicol, fluoroquinolone, tetracycline, and cephalosporine, which are commonly used as the first line of treatment. Furthermore, a similar genomic virulence repertoire was observed across the genomes, encompassing the genes related to invasion, survival, pathogenesis, and iron uptake. In particular, the toxic shock syndrome toxin (tss-1) was found predominantly in the genomes isolated in this study, posing potential health risks, particularly in children.

Conclusion and relevance: These findings underscore the broad capacity for antibiotic resistance and pathogenicity by S. aureus, compromising the integrity of milk and dairy products. The study emphasizes the need to evaluate the effectiveness of antibiotics in combating S. aureus infections.

Importance: Neonatal calf diarrhea is a major cause of mortality in newborn calves worldwide, posing a significant challenge in bovine herds. Group A Bovine Rotaviruses (BRVA) are the primary contributors to severe gastroenteritis in calves under two months old.

Objectives: This study examined the prevalence and molecular characterization of BRVA in neonatal calves in Gujarat, India.

Methods: Sixty-nine diarrheic fecal samples were collected and subjected to various molecular methods of BRVA detection, isolation, and characterization.

Results: The latex agglutination test (LAT), electropherotyping (RNA-PAGE), and reverse transcription polymerase chain reaction revealed positivity rates of 39.13%, 20.30%, and 37.70%, respectively. RNA-PAGE identified 11 bands with a 4:2:3:2 migration pattern, indicative of the segmented genome of BRVA. BRVA was successfully isolated from LAT-positive samples, with 26 samples exhibiting clear cytopathic effects upon passage in MA-104 cell lines. Genotyping identified G10 as the predominant G genotype, with P[11] genotypes comprising 76.92% of the isolates. The most common G/P combination was G10P[11], highlighting its zoonotic potential.

Conclusions and relevance: These findings underscore the importance of molecular detection and genotyping for effective vaccine development. This study provides crucial insights into the prevalent G and P genotypes of BRVA in Gujarat, India, aiding in the development of targeted control measures.

Importance: Over the past decade, catfish farming has increased in Southeast Asia. However, there has been no existing for pharmacokinetic data in the hybrid catfish (Clarias macrocephalus x C. gariepinus).

Objective: This study was designed to evaluate the pharmacokinetic characteristics of oxytetracycline (OTC) in the hybrid catfish, following single intravascular (IV) or oral (PO) administration at a single dosage of 50 mg/kg body weight (BW).

Methods: In total, 140 catfish (each about 100-120 g BW) were divided into two groups (n = 70). Blood samples (0.6-0.8 mL) were collected from ventral caudal vein at pre-assigned times up to 144 h (sparse samples design). OTC plasma concentrations were analyzed using high-performance liquid chromatography-photodiode array detector.

Results: The pharmacokinetic parameter of OTC was evaluated using a non-compartment model. OTC plasma concentrations were detectable for up to 144 and 120 h after IV and PO, respectively. The elimination half-life value of OTC was long with slow clearance after IV administration in hybrid catfish. The average maximum concentration value of OTC was 2.72 µg/mL with a time at the maximum concentration of 8 h. The absolute PO bioavailability was low (2.47%).

Conclusions and relevance: These results showed that PO administration of OTC at a dosage of 50 mg/kg BW was unlikely to be effective for clinical use in catfish. The pharmacodynamic properties and clinical efficacy of OTC after multiple medicated feed are warranted.