Background: Lumpy skin disease (LSD) is a re-emerging transboundary viral disease of cattle and buffaloes, causing significant economic losses and classified as a notifiable disease by the WOAH. Mass vaccination of susceptible animals is the principal strategy for disease control. Live attenuated Goatpox vaccine of Uttarkashi strain is authorized by the government for control of LSD as an emergency measure in India during 2022. Methods: A vaccination trial was undertaken to determine the optimum dose of Goatpox vaccine for LSD prevention in cattle. Randomly selected heifers were allocated into four groups (A, B, C and D), each containing eight animals. Group A served as the unvaccinated control, while groups B, C and D received 1 mL, 2 mL and 3 mL doses, respectively, of the Goatpox vaccine containing 1 × 103.0 TCID50 per dose. Result: Group D, vaccinated with three times the dose used in goats (3 mL), exhibited the highest and most persistent humoral immune responses, which continued through day 35 post-vaccination (p greater than 0.05). Results indicated that an increased dose provided better and sustained protection in cattle across the trial period.
Introduction:Bluetongue virus (BTV) is a species of genus Orbivirus belonging to the Sedoreoviridae family. Bluetongue (BT) is endemic in India and responsible for causing significant economic losses to livestock farmers. In India, antibodies to BTV serotype 24 (BTV-24) have been reported in 2005; it was first isolated in 2010, and it caused several outbreaks in sheep during 2012-2014. The in vivo studies investigating the pathogenetic potential of various BTV serotypes in the susceptible host sheep are scarce. Furthermore, detailed investigations to elucidate the pathogenetic mechanisms of BTV-24 under experimental conditions in sheep are not available. Because of its impact on the livestock economy, the present study was undertaken for the first time to explore the infection kinetics, pathology, pathogenesis, and immune responses against the Indian isolate of BTV-24 in sheep under experimental conditions. Methods:Six native sheep were infected intradermally with BTV-24 at 106 TCID50/mL concentration, and six sheep were inoculated with uninfected cell culture fluid. Animals were euthanized at 4, 7, 11, 16, 45, and 60 days post-inoculation (DPI). The sequential pathology, BTV localization by immunohistochemistry, BTV quantification by quantitative PCR (qPCR), immune cell kinetics [CD4+ and CD8+ T lymphocytes in peripheral blood mononuclear cells (PBMCs), prescapular lymph node (PSLN), and spleen] by fluorescence-activated cell sorting (FACS), and cytokine estimation by qRT-PCR were studied. Results:The BTV-24-infected animals showed pyrexia, conjunctival and oral mucosal congestion, cyanosis of tongue, serous to catarrhal nasal discharge, and viremia. Gross pathological lesions were observed in the lymph nodes, lungs, and kidneys, with the lymph nodes being enlarged, edematous, and hemorrhagic. Subintimal hemorrhage at the base of the pulmonary artery (pathognomonic lesion of BT) was observed at 7 DPI. Histopathological lesions were prominent in lymph nodes, spleen, heart, lungs, and cerebral endothelium. Severe hemosiderosis in spleen, and hemorrhages and hyalinization of tunica media in pulmonary artery at 7 DPI were observed. Development of clinical signs and gross and histopathological lesions in BTV-24-infected animals emphasized the moderate progression of disease and enhanced virulence of the serotype. Humoral immune response was significantly high at 5, 11, 16, 21, 45, and 60 DPI. Cell-mediated immune response-like kinetics of CD4+ and CD8+ T lymphocytes showed a sharp decline during the early stage and an increase of CD8+ T lymphocytes during later stages of infection. BTV antigen was detected consistently in tongue, thymus, trapezius muscle, heart, and pulmonary artery by immunohistochemistry and qPCR. Significant changes in the levels of cytokines [interferon-alpha (IFN-α), IFN-β, IFN-γ, interleukin-2 (IL-2), IL-12, and tumor necrosis factor-alpha (TNF-α)] and upregulated expression of apoptotic markers, B-cell lymphoma-2 (Bcl-2), and caspase-3 in the spleen and lymph nodes were correlated with peak viremia. Conclusion:The results of this study can be used to formulate effective preventive and control measures and to develop a suitable vaccine against BTV-24 to minimize economic losses.
This study investigated the nematode population in 140 commercial banana plants in Tamil Nadu, India, focusing on identifying the most common plant parasitic nematodes (PPNs) associated with bananas. The prevalent nematode species were P. coffeae, M. incognita, H. multicinctus in major banana belts. Morphological characteristics were employed to describe the plant parasitic nematode P. coffeae, revealing features such as flat lips, a thin stylet with well-developed knobs, and an esophagus that ventrally overlapped the intestine. Meloidogyne incognita exhibited a lengthy vermiform appearance in the male nematode, while the spiral nematode Helicotylenchus sp. displayed a hemispherical lip with conspicuous, broad stylet knobs. These nematodes were found throughout the sample areas, leading to gall formation and necrotic lesions on the surface and cortical tissues of banana roots. The highest prevalence rates were recorded for H. multicinctus (70.4
ABSTRACT Senecavirus A (SVA) is a causative agent of vesicular disease in pigs and has gained global attention in recent years. SVA infection leads to vesicular lesions and hoof deformities in pigs, posing a significant threat to the swine industry. The VP4 protein is a crucial component of the SVA capsid, located on the inner surface of the virus particle, and plays a key role in the viral life cycle. However, its exact function and immunological characteristics remain poorly understood. Additionally, the VP4 protein of picornaviruses is known to form antigenic epitopes during viral infection, providing potential targets for antibody development and vaccine design. Nevertheless, due to the unique location of VP4, these epitopes remain largely unexplored. In this study, a monoclonal antibody (mAb) 4E4 was successfully generated by immunizing mice with purified SVA VP4 protein. The mAb 4E4 specifically recognizes recombinant VP4 protein and the SVA‐infected cells. Further epitope mapping using truncated VP4 proteins detected with Western blotting defined a key B‐cell epitope, 7 SKDNFD 12 , which is exposed on the surface of VP4 protein and is highly conserved among different SVA strains. Additionally, mAb 4E4 showed neutralizing activity against SVA. This study provides the first identification of a conserved antigenic epitope on the SVA VP4 protein. This finding provides valuable tools for further investigation of VP4 protein function and lays the foundation for developing novel diagnostic and vaccine strategies.
African swine fever (ASF), caused by African swine fever virus (ASFV), has resulted in significant economic impacts on the global swine industry. Currently, there is no safe and effective commercial vaccine available for ASFV. Thus, the development of effective and readily available therapeutics for ASF is urgently needed. To conduct high-throughput screening (HTS) for anti-ASFV drugs, we initially developed a recombinant dual-reporter virus (rASFV-Gluc/EGFP) using the virulent strain ASFV HLJ/18 (ASFV-WT). The enhanced green fluorescent protein (EGFP)- and Gaussia luciferase (Gluc)-encoding genes were incorporated downstream of the ASFV MGF300-4L gene without disrupting viral genes. The growth kinetics, hemadsorption, and transmission electron microscopy analysis of rASFV-Gluc/EGFP in primary porcine alveolar macrophages (PAMs) revealed that rASFV-Gluc/EGFP exhibits similar biological characteristics to ASFV-WT. Furthermore, analysis of Gluc activities, fluorescence, and next-generation sequencing indicated that rASFV-Gluc/EGFP maintains good genetic stability after 20 consecutive passages in PAMs. Using the HTS platform established with rASFV-Gluc/EGFP, we screened and identified phenazine-1-carboxylic acid (PCA) as an effective inhibitor of ASFV replication from 246 small molecule compounds in PAMs. Importantly, PCA was found to reduce ASFV replication by as much as 100-fold at a concentration of 25 μM. Overall, this study suggests that rASFV-Gluc/EGFP is suitable for rapid screening of anti-ASFV drugs. Importantly, we showed that PCA has significant anti-ASFV activity in PAMs.
