Brucella vulpis sp. nov. is attenuated in a BALB/c murine model of infection: Of mice and foxes.

Abstract

Brucellosis, caused by Brucella spp., is a zoonotic disease of global significance, affecting a wide range of animal hosts. Since the discovery of Brucella spp. in wildlife, novel bacteria belonging to the genus Brucella have been isolated across various terrestrial and aquatic animals. Among them are Brucella vulpis isolates F60and F965 cultured from two red foxes (Vulpes vulpes) tissues, classified within the Brucella genus in 2016; however, the behavior and pathogenic potential of B. vulpis in a mouse model have not been investigated yet. In this study, the virulence and serologic response of B. vulpis F60and F965 in BALB/c mice were investigated and compared using B. suis 1330, B. microti CCM 4915 and Brucella sp. 83-210 representative of phylogenetically more distant or non-core species, and previously shown to be also virulent in the mouse model. Our findings indicate that B. vulpis exhibits an attenuated infection pattern at 10CFU, with lower levels of persistence in the spleen and liver than B. suis 1330, B. microti CCM 4915, and Brucella sp. 83-210, and no associated mortality in mice. B. vulpis F60and F965 elicited a similar serologic response compared to B. suis 1330, B. microti CCM 4915, and Brucella sp. 83-210, based on an indirect enzyme-linked immunosorbent assay (iELISA). These results indicate that, in a mouse infection model, B. vulpis can replicate and is attenuated, at least for the isolates investigated, compared to the other virulent Brucella spp. studied.