Elephant endotheliotropic herpesvirus (EEHV) is one of the most devastating viral infectious diseases in elephants worldwide. To date, it remains unclear how elephants get infected by the virus, where the virus persists, and what mechanisms drive the pathogenesis of the disease. The present study was aimed to develop an antibody against glycoprotein B (gB) of EEHV, investigate the EEHV tissue tropisms, and provide the possible routes of EEHV transmission in Asian elephants. Samples from elephant organs that had died from EEHV1A and EEHV4 infections, peripheral blood mononuclear cells (PBMC) from EEHV4- and non-EEHV-infected calves were used in this study. The results of western immunoblotting indicated that the antibody can be used for detection of gB antigens in both EEHV1A- and EEHV4-infected samples. Immunohistochemical detection indicated that the EEHV gB antigens were distributed mainly in the epithelial cells of the salivary glands, stomach and intestines. Immunofluorescence test of PBMC for EEHV gB in the EEHV4-infected calf indicated that the virus was observed predominantly in the mononuclear phagocytic cells. The findings in the present study unveil tissue tropisms in the EEHV1A- and EEHV4-infected calves and point out that saliva and intestinal content are likely sources for virus transmission in EEHV-infected Asian elephants.

Understanding molecular epidemiology is essential for the improvement of lumpy skin disease (LSD) eradication and control strategies. The objective of this study was to perform a molecular characterization and phylogenetic analysis of lumpy skin disease virus (LSDV) isolated from dairy cows presenting LSD-like clinical signs in northern Thailand. The skin nodules were collected from 26 LSD-suspected cows involved in six outbreaks during the period from July to September of 2021. LSDVs were confirmed from clinical samples using the polymerase chain reaction (PCR). The PCR-positive samples were subsequently amplified and sequenced using a G-protein-coupled chemokine receptor (GPCR) gene for molecular characterization and phylogenetic analyses. All 26 samples were positive for LSDV by PCR. A phylogenetic analysis indicated that the 24 LSDV isolates obtained from cattle in northern Thailand were closely related to other LSDV sequences acquired from Asia (China, Hong Kong, and Vietnam). On the other hand, two LSDV isolates of the cows presenting LSD-like clinical signs after vaccination were clustered along with LSDV Neethling-derived vaccines. The outcomes of this research will be beneficial in developing effective control strategies for LSDV.

Recombinant outer membrane protein H (rOmpH) is a potential fowl cholera vaccine candidate. The present study was aimed at developing rOmpH formulations for intranasal administration. The rOmpH was purified and formulated with either Escherichia coli enterotoxin B (LTB) or CpG oligodeoxynucleotides (ODN) as an adjuvant. Antibody responses in chickens intranasally immunized with rOmpH in combination with 2 different adjuvants were significantly increased (P<0.05) post immunization. Chicken survival rates showed that rOmpH formulated with ODN and LTB elicited 90% and 70% protection, respectively. Our findings indicated that rOmpH formulated with ODN elicited protection better than that formulated with LTB. Therefore, the vaccines formulations in the present study can be considered new intranasal vaccine formulations for fowl cholera in chickens.

Lumpy skin disease (LSD) is a contagious disease among cattle and buffalo worldwide. Currently, an enzyme-linked immunosorbent assay (ELISA) has been recognized as an efficient diagnostic tool that is less time-consuming and easier than the viral neutralization test to measure the antibody levels. In the present study, an in-house method of indirect ELISA was developed to detect the bovine antibodies against Lumpy skin disease virus (LSDV) and its performance was assessed using field samples. This in-house method has been compared with the commercial ELISA test kit for detection of bovine antibodies against LSDV. The sensitivity (Se) and the specificity (Sp) of the test were estimated using a Bayesian latent class model. Checkerboard titration was performed using the naturally LSDV-infected bovine sera and colostrum-deprived calf sera. The LSDV antigen concentrations (1 TCID₅₀/mL), the sample serum (1:500), and goat anti-bovine immunoglobulin G (IgG) labeled with horseradish peroxidase (HRP) (1:10,000) were determined to be optimal for this assay. The calculated cut-off value was 0.067, and there were no differences in the results of tests that utilized positive and negative sera (p < 0.05). The characteristics of two diagnostic tests were evaluated using a conditional dependent and one-population Bayesian model. The Se value of an in-house indirect ELISA were almost similar to ELISA test kit. On the other hand, the Sp value of the in-house ELISA test was lower than that of the commercial ELISA test with the median values of 89% (95% PPI = 75.9-99.3%) and 91.4% (95% PPI = 85.3-95.5%), respectively. A posterior estimate for the prevalence was 66.9% (95% PPI = 60.8-83.3%) and higher than initially expected.