Bovine leukemia virus (BLV) is one of the five agents considered most significant for cattle. It is important to determine the prevalence and molecular epidemiology of BLV throughout the country in order to gain a more thorough understanding of the current situation of BLV and to reveal the possibility of masked genotypes that the primers used by OIE are unable to identify. Blood samples were collected at random from 289 cows distributed in 75 farms across the country. PCR amplification of env, gag and tax gene segments was performed. The obtained amplicons were sequenced and then subjected to phylogenetic analyses. A total of 62% of the cows present at 92% of the farms were BLV-positive for gag fragment. Genotype 1 was exclusively detected by env gene segment when analyzed using previously reported primers. However, tax gene analysis revealed circulation of genotype 6 variants, which were also detected based on env gene analysis with newly designed primers. These results indicate that current genotyping approaches based on partial env sequencing may bias BLV genetic variability approaches and underestimate the diversity of the detected BLV genotypes. This report is one of the first molecular and epidemiological studies of BLV conducted in Colombia, which contributes to the global epidemiology of the virus; it also highlights the substantial impact of BLV on the country's livestock and thus is a useful resource for farmers and government entities.

Bovine leukemia virus (BLV) is the causative agent of leukemia/lymphoma in cattle. It has been found in humans and cattle-derived food products. In humans, it is described as a potential risk factor for breast cancer development. However, the transmission path remains unclear. Here, a molecular epidemiology analysis was performed to identify signatures of genetic flux of BLV among humans, animals, and food products. Sequences obtained from these sources in Colombia were used (n = 183) and compared with reference sequences available in GenBank. Phylogenetic reconstruction was performed in IQ-TREE software with the maximum likelihood algorithm. Haplotype (hap) distribution among the population was carried out with a median-joining model in Network5.0. Recombination events were inferred using SplitsTree4 software. In the phylogenetic analysis, no specific branches were identified for the Colombian sequences or for the different sources. A total of 31 haps were found, with Hap 1, 4, 5 and 7 being shared among the three sources of the study. Reticulation events among the different sources were also detected during the recombination analysis. These results show new insights about the zoonotic potential of BLV, showing evidence of genetic flux between cattle and humans. Prevention and control strategies should be considered to avoid viral dissemination as part of the One Health program policies.

The envelope glycoprotein 51 (gp51) is essential for bovine leukaemia virus (BLV) entry to bovine B-lymphocytes. Although the bovine adaptor protein 3 complex subunit delta-1 (boAP3D1) has been proposed as the potential receptor, the specific ligand-receptor interaction has not yet been completely defined and boAP3D1 receptor and gp51 3D structures have not been determined. This study was thus aimed at a functional annotation of boAP3D1 cellular adaptor protein and BLV gp51 and, proposing a reliable model for gp51-AP3D1 interaction using bioinformatics tools. The boAP3D1 receptor interaction patterns were calculated based on models of boAP3D1 receptor and gp51 complexes’ 3D structures, which were constructed using homology techniques and data-driven docking strategy. The results showed that the participation of 6 key amino acids (aa) on gp51 (Asn170, Trp127, His115, Ala97, Ser98 and Glu128) and 4 aa on AP3D1 (Lys925, Asp807, Asp695 and Arg800) was highly probable in the interaction between gp51 and BLVR domains. Three gp51 recombinant peptides were expressed and purified to validate these results: the complete domain (rgp51), the N-terminal portion (rNgp51) and the C-terminal fragment (rCgp51); and binding assays to Madin-Darby bovine kidney (MDBK) cells were then carried out with each recombinant. It was found that rNgp51 preferentially bound to MDBK cells, suggesting this domain’s functional role during invasion. The rNgp51-MDBK cell interaction was sensitive to trypsin (98% reduction) and chymotrypsin treatment (80% reduction). These results highlighted that the N-terminal portion of gp51 interacted in vitro with the AP3D1 receptor and provides a plausible in silico interaction model.

Objetivo. El objetivo de este estudio fue determinar presencia de anticuerpos y genoma viral de EHV-1 y EHV-4, como también detectar la presencia de transcriptos asociados a latencia (LATs) en una población seleccionada de caballos colombianos. Materiales y métodos. Muestras de suero, nódulos linfáticos submandibulares y ganglio trigémino se obtuvieron de 50 caballos y fueron analizadas. Los sueros se evaluaron para la presencia de anticuerpos contra EHV-1 y EHV-4 mientras que los tejidos se evaluaron inicialmente para la presencia de genoma viral por nPCR. Finalmente, las muestras se emplearon para la detección de LATs a través de RT-PCR. Resultados. En general, 6/50 muestras mostraron anticuerpos para EHV-1 y 44/50 fueron positivos para EHV-4. En cuanto a la detección del genoma viral, 10/50 muestras fueron positivas para EHV-1 y 30/50 fueron positivas para EHV-4; además, 22/35 caballos positivos para DNA de EHV fueron positivos para LATs. El empleo de estas pruebas llevó a ocho posibles combinaciones de resultados. Conclusiones. Se confirma la presencia de estos virus en la población equina colombiana. Las pruebas empleadas demuestran que los caballos pueden tener infección viral simple, co-infecciones con ambos virus, estado de latencia debido a la presencia de los LATs y presencia simultánea de LATs y de replicación de genoma viral en un momento dado. Se aporta al entendimiento del comportamiento de la enfermedad en Colombia y se llama la atención sobre la importancia de implementar diagnósticos complementarios a la serología para el control de estos virus.

Titanium alloys, particularly Ti6Al4V, are widely used in biomedical applications due to their excellent mechanical properties and inherent biocompatibility. However, enhancing their surface characteristics, such as biocompatibility and corrosion resistance, remains a key challenge for their long-term use in medical implants. In this study, we investigate the effects of rhenium–carbon coatings deposited on Ti6Al4V substrates via magnetron sputtering, incorporating a molybdenum anchoring layer. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analyses confirmed the formation of rhenium carbides, elemental rhenium, and rhenium oxides within the coatings. Despite these successful depositions, scanning electron microscopy (SEM) revealed significant delamination and poor adhesion of the coatings to the Ti6Al4V substrates. Corrosion resistance, evaluated through potentiodynamic polarization tests, showed an increase in corrosion current densities and more negative corrosion potentials, indicating a detrimental effect on the substrate’s corrosion resistance. Biocompatibility assessments using PK15 cells demonstrated a marked decrease in cell viability and metabolic activity, particularly in samples with higher surface roughness. These findings underscore the critical need for the optimization of surface preparation and deposition processes to improve both the adhesion and biocompatibility of rhenium–carbon coatings on Ti6Al4V substrates. Future research should aim to refine coating technique to enhance adhesion, explore the mechanisms of cytotoxicity related to surface roughness, and expand biocompatibility studies across different cell lines and biological environments.