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Merozoite surface antigen-1 is a glycoprotein expressed by Babesia bovis and is considered a vaccine candidate given that antibodies against it are able to partially block in vitro invasion of bovine erythrocytes. Despite this, no study to date has confirmed the target cell binding properties of the full MSA-1 or its fragments. This research has thus been focused on identifying protein regions playing a role in erythrocyte attachment, based on genetic diversity and natural selection analysis. Two regions under functional constraint (nucleotides 134–428 and 464–629) having a preponderance of negatively-selected signals were identified in silico. Three non-overlapping peptides derived from functionally constraint regions (42422 (39PEGSFYDDMSKFYGAVGSFD58), 42424 (91NALIKNNPMIRPDLFNATIV110) and 42426 (150TDIVEEDREKAVEYFKKHVY169)) were able to specifically bind to a sialoglycoprotein located on the bovine erythrocyte surface as confirmed by sensitive and specific peptide-cell interaction competition assays using both enzymatically treated and untreated red blood cells. Interestingly, it was predicted that peptides 42422 and 42426 have a helical structure and conserved motifs in all strain/isolates. These findings provide evidence, for the first time, related to B. bovis MSA-1 short regions used by the parasite in erythrocyte binding which could be predicted using natural selection analysis. Future work focused on evaluating these peptides’ antigenic ability during natural infection, and their ability to induce protection in immunisation assays are needed to confirm their usefulness as synthetic vaccine candidates. Incluye referencias bibliográficas

Artículo digital., The objective of the study was to determine the presence of Mycobacterium avium subsp. paratuberculosis (MAP) in cattle faeces from the municipality of Sincelejo, Sucre, Colombia. A direct bacteriological study was performed by microscopy techniques and polymerase chain reaction (PCR) for pools of faeces with two molecular markers, one specific for MAP (IS900) and another based on 16S of the genus Mycobacterium. The presence of acid-fast bacilli occurred in 21.1% of the faecal samples stained with Ziehl Neelsen. Three pools were positive with IS900 and three with 16S. The sequencing indicated the presence of three species of bacteria: MAP, Mycobacterium abscessus and Dietzia timorensis. The presence of MAP in the department of Sucre is identified for the first time., El objetivo del estudio fue determinar la presencia de Mycobacterium avium subspecie paratuberculosis (MAP) en heces de bovinos del municipio de Sincelejo, Sucre, Colombia. Se realizó un estudio bacteriológico directo por técnicas de microscopía y reacción en cadena de la polimerasa (PCR) para pooles de heces con dos marcadores moleculares, uno específico para MAP (IS900) y otro basado en 16S del género Mycobacterium. La presencia de bacilos ácido-alcohol resistentes (BAAR) se dio en el 21.1% de las muestras de heces teñidas con Ziehl Neelsen. Tres pooles resultaron positivos con IS900 y tres con 16S. La secuenciación indicó la presencia de tres especies de bacterias: MAP, Mycobacterium abscessus y Dietzia timorensis. Se identifica por primera vez la presencia de MAP en el departamento de Sucre.