Search Results (5)

Bubaline alphaherpesvirus 1 (BuHV-1) is a virus that belongs to the Varicellovirus genus within the Alphaherpesvirinae subfamily. While BuHV-1 infections in water buffaloes (Bubalus bubalis) are often subclinical, clinical manifestations have been reported. This study provides complete genome sequences of five BuHV-1 strains isolated in Argentina, marking the first genomic characterization of BuHV-1 from the Americas. Phylogenetic reconstructions based on whole-genome and coding sequences, along with analyses of glycoproteins C, D, and E, identified a distinct clade and divergent strains. Comparative genomic analyses with publicly available BuHV-1 and Bovine alphaherpesvirus 5 (BoHV-5) sequences showed nucleotide divergence of up to 1.3% among BuHV-1 strains, indicating significant intraspecific genetic diversity. Cross-neutralization assays revealed variable relationships between BuHV-1 and BoHV-5 strains. Some Argentinian BuHV-1 strains exhibited significant antigenic subtype differences compared to Bovine alphaherpesvirus 1 (BoHV-1). Recombination analyses uncovered events between BuHV-1 and bovine herpesviruses, suggesting a complex evolutionary history within mixed farming systems. The findings indicate that the monophyletic BuHV-1 clade, including the reference BuHV-1 isolate, is representative of the BuHV-1 species. The remaining strains, provisionally classified as BuHV-1 indeterminate (BuHV-1i), can be categorized based on specific clinical and antigenic properties. The identified heterogeneity has significant implications for diagnostic accuracy, vaccine development, and disease management strategies in buffalo populations worldwide. Full article

Bovine alphaherpesvirus 1 (BoAHV1) is prevalent in cattle throughout the world, whereas bovine alphaherpesvirus 5 (BoAHV5) prevalence seems restricted to some countries in South America, Australia, and other regions, mainly in the Southern Hemisphere. BoAHV5 infections occur where water buffalo (Bubalus bubalis) farming is practiced, often close to cattle (Bos taurus) farms. Bubaline alphaherpesvirus 1 (BuAHV1), a virus whose natural host is believed to be the water buffaloes, usually causes asymptomatic infections in that species. Here, evidence is provided confirming the close relationship between BuAHV1 and BoAHV5. Phylogenetic and recombination analyses were used to reveal the evolutionary relationship between all whole-genome sequences of BoAHV1 (n = 52), BoAHV5 (n = 7), and BuAHV1 (n = 6) available to date. It is proposed here that BoAHV5 most likely resulted from multiple recombination events between a BuAHV1-like ancestor and BoAHV1-like viruses. The BoAHV5 whole unique short (US) region and most of the unique long (UL) genomic regions seem to have been derived from a BuAHV1-like parental genome, whereas at least six small segments of the UL (corresponding to nucleotides 8287 to 8624; 10,658 to 14,496; 48,013 to 48,269; 71,379 to 71,927; 81,426 to 85,003; and 94,012 to 96,841 of the BoAHV5 genome) and two small segments of the US (corresponding to nucleotides 107,039 to 107,581 and 131,267 to 131,810) have been derived from a BoAHV1-like parental genome. The hypothesis that the BoAHV5 species may have originated following a series of recombination events between BuAHV1 and BoAHV1 variants is consistent with the geographical distribution of BoAHV5, which seems to be prevalent in the regions where cattle and water buffalo farming overlap. Full article

Herpesviruses are significant pathogens of ruminants. In water buffaloes (Bubalus bubalis), however, herpesviruses have not been thoroughly studied. Although bubaline alphaherpesvirus 1 (BuAHV1) and bovine alphaherpesvirus 1 (BoAHV1) have already been recovered from water buffaloes, to date, no reports on the occurrence of bovine alphaherpesvirus 5 (BoAHV5) in these animals have been published. Therefore, the aim of this study was to search for BuAHV1, BoAHV1, and BoAHV5 in palatine tonsils of apparently healthy water buffaloes from the Pará state, Northern Brazil. Tissue samples of tonsils (n = 293) were screened by a nested PCR (nPCR) targeting a region of UL44 (gC coding gene), followed by sequencing, to detect and differentiate between the viral types. Viral genome segments were detected in 18 out of 293 (6.1%) of the palatine tonsil samples. Two animals carried genomes of BoAHV1 only, eleven animals carried BoAHV5 genomes only, and four animals carried BuAHV1 only. Another animal had both BoAHV1 and BoAHV5 genomes in its tonsils. No infectious virus could be recovered from any of the samples. The BuAHV1 sequences identified here were more closely related to BuAHV1 genomes identified in India. Phylogenetic analyses suggested a closer relationship between the recovered BoAHV5 and BuAHV1 genomes. Therefore, evidence is provided here to confirm that not only BoAHV1 and BuAHV1, but also BoAHV5, can infect water buffaloes. This report highlights (i) the first detection of BoAHV5 in water buffaloes and (ii) the occurrence of coinfections with BoAHV1 and BoAHV5 in that species. Such findings and the similarity of BoAHV5 to Indian herpesvirus genomes suggest that the origin of type 5 may be linked to recombinations between bovine and bubaline herpesviruses within bubalines, since the scenario for generation of recombinants in buffaloes is potentially present. Full article

European regulations on the control of infectious diseases provide measures to control Bovine alphaherpesvirus 1 (BoHV-1) infection in both cattle and buffalo. Owing to the reported serological cross-reactivity between BoHV-1 and Bubaline alphaherpesvirus 1 (BuHV-1), we hypothesized a new immunization protocol using BoHV-1 gE-deleted marker vaccines could protect water buffalo against BuHV-1. Five water buffaloes devoid of BoHV-1/BuHV-1-neutralizing antibodies were immunized with two commercial BoHV-1 gE-deleted marker vaccines at 0, 30, 210, and 240 post-vaccination days (PVDs). Five additional water buffaloes were used as controls. At 270 PVD (0 post-challenge days (PCDs), all animals were challenged intranasally with wild-type (wt) BuHV-1. The vaccinated animals produced humoral immunity (HI) as early as PVD 30 whereas, in control animals, antibodies were detected on PCD 10. After challenge infection, HI significantly increased in vaccinated animals compared to that in controls. Real-time PCR for gB revealed viral shedding in vaccinated animals from PCDs 2 to 10. In contrast, positive results were observed from PCDs 2 to 15 in the unvaccinated control group. Although the findings indicated the possible protection capabilities of the tested protocol, these findings did not support its protective roles in water buffaloes against wt-BuHV-1. Full article

Bovine alphaherpesvirus 1 (subtypes 1.1, 1.2a, and 1.2b), type 5 (subtypes 5a, 5b, and 5c), and bubaline herpesvirus 1 (BuHV-1) induce highly, though not fully cross-reactive serological responses. Most types and subtypes of these viruses circulate particularly in countries of the southern hemisphere, notably Brazil and Argentina. Therefore, the detection of infected animals is important in defining prevention and control strategies, particularly when flocks are destined for international trade. Identification of infected herds is most often achieved by assays that detect antibodies, such as enzyme immunoassays (ELISAs). However, to date, no ELISA has been evaluated in its capacity to detect antibodies to these alphaherpesviruses. Here, an ELISA was developed to detect antibodies to all currently recognized BoAHV-1, BoAHV-5, and BuAHV-1 types/subtypes, and its sensitivity and specificity were determined. Six hundred bovine sera were screened in serum neutralization tests (SN) against the seven viruses. ELISAs prepared with each of the viruses were compared to SN. Subsequently, a combined assay with multiple antigens LISA was prepared by mixing five viral antigens, chosen for their highest sensitivity in the preparative assays. In comparison to SN, the mAgELISA sensitivity was 96.5% with 96.1% specificity (κ = 0.93; PPV = 95.0%; NPV = 97.3%). The findings reveal that the mAgELISA developed here is highly suitable for the detection of antibodies, comparable in sensitivity and specificity to that of SN when performed with all known types and subtypes of bovine and bubaline alphaherpesviruses. Full article