IDEMBRU: Identification of emerging Brucella species: new threats for human and animals
The Project #IDEMBRU
Brucellosis is a highly contagious zoonosis usually caused by ingestion of unpasteurised milk or undercooked meat from infected animals, or close contact with their secretions. Brucellosis is one of the most widespread zoonotic diseases globally, with 500,000 new human cases estimated each year. For many years six ‘classical’ Brucella species were identified but, since the late 1990’s, several new Brucella species (including B. inopinata, B. microti and B. vulpis) were isolated from humans, wild animals and/or environmental sources demonstrating a wider range of hosts and new potential zoonotic threats. Some of these species are genetically and/or phenotypically atypical in comparison to the ‘classical’ species.
In 2017, European amphibians were reported to be infected by one such recently identified species (B. microti), already reported in rodents, foxes and wild boar, thus confirming the broad host range of emerging atypical Brucella. These emerging Brucella isolates need to be further investigated to evaluate their geographical distribution and host range, to assess their zoonotic potential, and to compare their virulence and persistence markers with classical species.
Other emerging situations concern classical Brucella species, such as Brucella suis and Brucella melitensis, which circulate in wildlife reservoirs with the potential to spillover to domestic animals and humans or which are emerging in Western Europe as a result of pet movements (Brucella canis). Currently only some classical Brucella species are subject to statutory control and surveillance strategies in domestic animals in Europe. Therefore, these species are potentially underdiagnosed in wildlife. Some Brucella species are classified into biovars, and species and biovars vary in terms of pathogenicity for humans. The most studied Brucella species and biovars correspond to those presenting the known highest risk of transmission to humans while others are poorly characterised. Finally, emerging reservoirs of classical Brucella could be linked with new consumption patterns, with developing practices of organic and raw milk products, with imported animal-derived products from different origins or with emerging animal movement pathways
An exhaustive evaluation and understanding of emerging non-classical Brucella and emerging reservoirs of classical species is needed to protect people and animals from infection. This IDEMBRU project aims to develop a toolbox focusing on emerging Brucella species and reservoirs in order to ensure rapid detection, identification and characterisation. The project will include i) the detection and investigation of these pathogens from different sources under various epidemiological contexts in terms of natural landscape, livestock demographics, and wildlife populations (Mediterranean, East, North and West Europe); ii) the characterisation of the emerging Brucella species by identification of genomic and phenotypic variability via high throughput methods (NGS, molecular tests, proteomics, metabolomics) ; iii) the understanding of virulence and zoonotic potentials through in vivo and in vitro infection models ; iv) the development of a toolkit for the integration of data from emerging Brucella and as a resource to guide characterisation of emerging Brucella.