Journal Article

Disruption of Erythritol Catabolism via the Deletion of Fructose-Bisphosphate Aldolase as a Strategy to Improve the Brucella Rev1 Vaccine

Zúñiga-Ripa, Amaia, Elizalde-Bielsa, Aitor, de Miguel, María Jesús, Muñoz, Pilar M, Lázaro-Antón, Leticia, Conde-Álvarez, Raquel

2024

Overview

Brucellosis is a bacterial zoonosis caused by the genus Brucella , which mainly affects domestic animals. In these natural hosts, brucellae display a tropism towards the reproductive organs, such as the placenta, replicating in high numbers and leading to placentitis and abortion, an ability also exerted by the B. melitensis live-attenuated Rev1 strain, the only vaccine available for ovine brucellosis. It is broadly accepted that this tropism is mediated, at least in part, by the presence of certain preferred nutrients in the placenta, particularly erythritol, a polyol that is ultimately incorporated into the Brucella central carbon metabolism via two reactions dependent on transaldolase (Tal) or fructose-bisphosphate aldolase (Fba). In the light of these remarks, we propose that blocking the incorporation of erythritol into the central carbon metabolism of Rev1 by deleting the genes encoding Tal and Fba may impair the ability of the vaccine to proliferate massively in the placenta. Therefore, a Rev1Δfba Δtal double mutant was generated and confirmed to be unable to use erythritol. This mutant exhibited a reduced intracellular fitness both in BeWo trophoblasts and THP-1 macrophages. In the murine model, Rev1Δfba Δtal provided comparable protection to the Rev1 reference vaccine while inducing fewer adverse reproductive events in pregnant animals. Altogether, these results postulate the Rev1Δfba Δtal mutant as a reproductively safer Rev1-derived vaccine candidate to be studied in the natural host.

• Publisher: MDPI AG
• Subject: Brucellosis / Care and treatment / Composition / Diagnosis / Disease transmission / Dosage and administration / Erythritol / Inflammation / Prevention