Work

A Putative Multicopper Oxidase Encoded by BAB2_0534 Promotes Melanin-Like Pigment Production and Intracellular Adaptation in Brucella abortus

Year: 2026

Type: article

Abstract: Brucella abortus is an intracellular pathogen that must withstand oxidative stress and other hostile conditions encountered within host cells. Here, we investigated the contribution of BAB2_0534, a gene encoding a putative multicopper oxidase, to bacterial adaptation and persistence. Deletion of BAB2_0534 impaired pigment production in the presence of the melanin precursors L-DOPA and homogentisic acid, supporting a role for BAB2_0534 in phenolic substrate oxidation and melanin-like pigment biosynthesis. The mutant also exhibited increased susceptibility to oxidative stress and reduced survival with macrophages, indicating that BAB2_0534 contribute to intracellular adaptation. In vivo, mice infected with the ΔBAB2_0534 mutant showed significantly reduced splenic bacterial burdens compared with animals infected with the wild-type or complemented strains, demonstrating impaired persistence during infection. Consistently, Fontana–Masson-positive pigment was detected in tissues from wild-type-infected animals but was markedly reduced following infection with the mutant. Collectively, these findings support a model in which BAB2_0534-associated multicopper oxidase activity and pigment production contribute to oxidative stress resistance and intracellular persistence of B. abortus. This study characterizes BAB2_0534 as a previously unrecognized component of the adaptive mechanisms underlying Brucella persistence.

Source: International Journal of Molecular Sciences

DOI: 10.3390/ijms27188105