Veterinary Quarterly最新文献

Infectious bronchitis virus (IBV) presents a major threat to global poultry production, necessitating a thorough understanding of its evolutionary relationships for effective control measures. This study presents a novel distance-based Minimum Span Clustering (MSClustering) method to cluster 311 IBV strains, with a comparison of its results to the established IBV classification. Phylogenetic network and recombination analyses were employed to investigate IBV evolutionary relationships and transmission pathways. The phylogenetic network revealed distinct clusters reflecting relationships between IBV strains. Importantly, these network patterns, combined with recombination event analysis, suggest an unrecognized role for migratory birds in IBV dissemination, highlighting potential transmission pathways beyond established poultry trade routes. These findings contribute to advancing our understanding of IBV evolution and support the development of targeted strategies for controlling viral outbreaks in poultry populations. While statistical limitations may affect threshold estimation for smaller networks, our MSClustering method significantly accelerates processing speeds-approximately 100,000 times faster than PhyML when analyzing the dataset-enabling comprehensive-scale phylogenetic analysis of viruses.

This study aimed to classify the Feline leukaemia virus (FeLV) infection outcomes in domestic cats in Thailand and determine the accuracy of conjunctival swabs for FeLV proviral DNA detection by comparing results to PCR testing of blood samples. Whole blood and conjunctival swabs were collected from 126 cats with and without clinical signs. Blood specimens were evaluated for p27 FeLV antigen using the SNAP Feline Immunodeficiency Virus (FIV)/FeLV Combo Test, IDEXX Laboratories. The 3'-LTR region of the proviral FeLV was amplified from both blood and conjunctival samples. The prevalence rates of progressive and regressive FeLV infections in this study were 14.3% (95% CI: 8.69-21.63) and 36.5% (95% CI: 28.12-45.55), respectively. Cats older than 12 months of age had a higher probability of being regressively infected than cats younger than 1 year (p-value = 0.039, OR =0.294, 95% CI: 0.092-0.942). Conjunctival swabs used for detecting FeLV proviral DNA demonstrated a sensitivity of 95.3% (95% CI: 86.91-99.02) and a specificity of 100% (95% CI: 94.22-100.00) compared to conventional blood samples. The observed kappa value of 0.956 indicates that conjunctival swabs are reliable and can be used as an alternative to blood venipuncture.

Salmonella Typhimurium (ST) is an important food-borne pathogen, particularly in chicken meat, making its rapid detection essential for food safety. Conventional detection methods are slow and equipment-intensive, creating the need for sensitive and portable alternatives. We developed a rapid, ultrasensitive, and portable electrochemical aptasensor platform for detecting ST in samples extracted from chicken meat. The sensor employed graphene oxide-bovine serum albumin (GO-BSA) nanocomposite to enhance electrode biocompatibility, stability, and aptamer immobilization. A specific NH₂-modified DNA aptamer targeting ST allowed direct binding without prior extraction. Fabrication steps included GO-BSA drop-casting, aptamer immobilization, and BSA blocking before ST binding. The sensor operates on a signal-off mechanism, measured via differential pulse voltammetry (DPV), where the aptamer-ST complex formation reduces the redox signal of [Fe(CN)₆]³^-/^4- due to insulation and electrostatic repulsion. The aptasensor demonstrated excellent sensitivity (limit of detection 3 CFU/mL) and high specificity. Performance validation using spiked samples extracted from chicken meat confirmed the effective detection of ST in a complex matrix, aligning with the results obtained through culture-based methods. The sensor also maintained good stability for up to 28 days at 4 °C. These results showed that aptasensors can be a rapid, cost-effective, and field-deployable tool for monitoring foodborne pathogens.

Weaning stress-induced diarrhea is a serious issue in pig production. This study aimed to evaluate the potential of glucose oxidase (GOD) as an antibiotic substitute to alleviate diarrhea and improve gut health in weaned piglets. According to a randomized complete block design, 250 piglets weaned around 21 d of age were allocated into 5 groups (5 replicates/group), which received a basal diet without or with supplemental 200 mg/kg antibiotic, 500, 1000 and 2000 U/kg GOD, respectively. Dietary treatments did not affect (p > 0.05) growth performance of piglets. However, supplemental all doses of GOD were equivalent or superior to antibiotic to reduce (p < 0.05) diarrhea as well as increase (p < 0.05) thymus index, hepatic and colonic antioxidant properties. GOD addition at 1000 and 2000 U/kg reduced (p < 0.05) cecal and rectal pH value, respectively. They also displayed similar or superior efficacy to antibiotic in improving (p < 0.05) duodenal and jejunal morphology along with certain tight junction proteins expression of jejunum and colon. Collectively, GOD represents an antibiotic alternative to reduce diarrhea of weaned piglets through associating with ameliorations of intestinal structure and functions.

The African swine fever virus (ASFV) surveillance strategies, including the early diagnosis, are key for prevention and control of African swine fever (ASF). This work studies the effects of different doses of ASFV Georgia strain: high dose (10⁴ HAU); moderate dose (10^2.5 HAU) and low dose (10 HAU), inoculated intranasally in three groups with 20 pigs each. The qPCR was used to follow the infection dynamics in a wide sample panel (clinical, tissues, non-invasive and environmental), together with LAMP, serological tests and cytokine detection. After inoculation, the Georgia strain was lethal for all animals that resulted infected, including those in the low-dose group, where such low ASFV doses, as used in this study, have rarely been tested before. However, in the low dose group only one pig developed the ASF, while the rest remained negative despite being in contact with the infected one. Here, blood was confirmed as the gold standard sample but other matrices such as serum, spleen, tonsils, bone marrow, ear tip and tongue could be useful for the early ASFV diagnosis. We also showed the air and non-invasive samples as helpful monitoring tools for ASFV. No ASFV-specific antibodies were detected in most of the animals. Our data support the relevance of both molecular and serological diagnostic strategies for ASF control. The rapid detection together with strict biosecurity measures can efficiently minimize the ASFV dissemination.

Canine atopic dermatitis (cAD) is a chronic inflammatory skin condition associated with T helper 2 (Th2)-type immune responses, and recent evidence suggests that periostin, an extracellular matrix protein, may play a role in its pathogenesis. To investigate the significance of serum periostin concentrations in dogs with cAD, this study examined their relationship with disease severity and laboratory parameters, including eosinophil counts and Th2 cytokines such as interleukin (IL)-4 and IL-13. A total of 68 dogs diagnosed with cAD and 21 healthy controls were included, with serum periostin, IL-4, and IL-13 levels measured. Disease severity was assessed using the Canine Atopic Dermatitis Extent and Severity Index (CADESI-04) and the Pruritus Visual Analog Scale (PVAS). The results showed that serum periostin concentrations were significantly higher in dogs with cAD compared to healthy controls and exhibited a positive correlation with CADESI-04 scores, reflecting disease severity. Treatment with prednisolone or oclacitinib led to a significant reduction in serum periostin, IL-4, and IL-13 levels, along with a decrease in eosinophil counts. These findings highlight the potential of serum periostin as a valuable biomarker for assessing cAD severity and monitoring treatment response, emphasizing its clinical relevance as an objective measure.

The aim of this study was to assess the beneficial effects of oral supplementation of Lepidium meyenii (Maca) on improving and keeping sperm quality in dogs during storage, and to investigate its effect on changes in testosterone concentrations. Forty male dogs were enrolled in the study and divided into four groups of ten dogs each: two subfertile (control and treatment) and two normofertile (control and treatment) groups. The dogs in the treatment groups received Maca in a capsule formulation (75 mg/kg), while the control groups received placebo. The spermiogram and testosterone levels were assessed at three times of the sperm cycle: 0 (T0), 31 (T31), and 62 (T62) days. Ejaculates were processed for storage at 5 °C and evaluated for total and progressive motility and membrane integrity at 3 (T3h), 24 (T24h), 48 (T48h), and 72 h (T72h) post storage. The oral supplementation of 75 mg/kg of Maca extract in dogs can improve sperm parameters and increase serum testosterone concentrations, leading to improved reproductive capacity. The semen of subjects treated with oral Maca supplementation maintained its parameters stable for a longer period when stored compared to the semen of control subjects, demonstrating the beneficial effect of the use of this extract on male fertility.

Pond sliders (Trachemys scripta) is a common pet and invasive species in many countries. Its ability to thrive and reproduce in Mediterranean climates necessitates population control to prevent overpopulation. Ovariectomy is considered as a preventive strategy to limit reproduction and protect local biodiversity. This study compares two spaying techniques in Trachemys scripta: electrosurgery using the EnSeal^® tissue sealer (group E) and a conventional approach with manual ligation of blood vessels (group C). Statistical tests evaluated procedural differences, including ANOVA for duration (factoring in follicular stage, surgery type, and their interaction) and Chi-squared tests for the likelihood of single surgical access via the prefemoral fossa and post-surgical feeding. Pearson's Chi-squared test with Yates' correction was used to assess complications by surgery type and follicular stage. ANOVA assessed the effect of follicular stage on surgery time, with follicles classified as Class I (n = 17), Class II (n = 12), and Class III (n = 7). Both follicular stage and surgery type significantly impacted surgery time, while their interaction was not significant, indicating independent effects. The likelihood of single-access procedures was significantly linked to surgery type, with EnSeal^® procedures being faster and associated with earlier post-surgical feeding. Complications were not significantly linked to surgery type or follicular stage.

Bovine mammosphere-derived epithelial cell (MDEC) cultures are heterogeneous and enriched for stem and progenitor cells. We previously reported that the bovine MDEC secretome, comprised of all bioactive factors secreted by the cells, displays regenerative properties, exerts antimicrobial effects, and modulates neutrophil activity, positioning it as a promising non-antibiotic biologic therapy for infectious diseases important to the dairy industry, like mastitis. Mastitis is defined as inflammation of the udder, and it is typically caused by bacterial infection. The effect of the MDEC secretome on macrophages, a first line of defense against bacterial infections in the udder, is unknown and could impact the utility of the secretome as a therapy for mastitis. To address this, we isolated bovine monocytes from peripheral blood and maintained them as an unpolarized (M0) population or polarized them into M1 or M2 phenotypes. Macrophages cultured with the secretome of bovine MDECs were assessed for their ability to phagocytose labeled bacterial particles and accumulate reactive oxygen species (ROS). We used single-cell RNA sequencing (scRNA-seq) and fluorescence-activated cell sorting (FACS) to isolate a subpopulation of MDECs that exert enhanced effects on macrophages. We found that the secretome of MDECs that do not express cluster of differentiation (CD) 73, a cell surface enzyme used as a marker for mesenchymal stromal cells, most strongly increased macrophage phagocytosis and ROS accumulation. These findings will help optimize the generation of the bovine MDEC secretome as a suitable treatment option for mastitis.

The emergence of multidrug-resistance (MDR) in Pasteurella multocida, a major contributor to bovine respiratory disease (BRD) is being increasingly reported, often linked to the carriage of antimicrobial resistance genes (ARGs) on integrative and conjugative elements (ICEs). The resistance phenotype for 19 antimicrobials was determined using broth microdilution in 75 Pasteurella multocida isolates from healthy and BRD-affected cattle from five feedlots. The genomes of 32 isolates were sequenced to identify ARG) and mobile genetic elements (MGEs) and assess their genetic diversity. MDR isolates (with phenotypic resistance to aminoglycosides, macrolides, fluoroquinolones and/or tetracyclines) were primarily found among BRD-affected compared to healthy animals. Non-susceptible isolates, belonging to ST79 and ST13, harbored point mutations and four to nine ARGs, including rarely reported mechanisms in Europe (mph(E), msr(E) and aadA31 ARGs and newly described mutations in the gyrA/parC genes). All ARGs were linked to the presence of MGEs including two ICEs, Tn7407 and the novel Tn7809, a prophage and a putative composite transposon. Clonally related isolates were found in different batches from the same feedlot, suggesting maintenance of MDR strains. Our findings demonstrate the diverse genetic basis of AMR in P. multocida from BRD-affected cattle in Spain, emphasizing the role of MGEs in the ARG dissemination.