An overview on the phylogenetic classification of Brucella

Abstract

The genus Brucella is a globally distributed intracellular pathogen that affects animals and humans and presents low genetic variability, which is a challenge for its phylogenetic reconstruction. Genus differentiation originally occurred due to its preference for a certain host and analyses throughout the years to classify the genus Brucella and its strains, depended on the techniques used, the number of strains or the methods of phylogenetic reconstruction. Its history goes from recognizing the entire genus as unique B. mellitensis species with multiple varieties, to recognizing more than ten species. This review shows the journey through the techniques that have been used to differentiate the genus Brucella, which, although they have generated clarity in the grouping of some species, still leaves doubts in related to the oldest species, their divergence and the type of grouping of the new species discovered. The application of new technologies such as phylogenomics is contributing to solve these questions .

Molecular characterization of Brucella species detected in humans and domestic ruminants of pastoral areas in Kagera ecosystem, Tanzania

“…Various approaches have been used worldwide for identification and characterization of Brucella species; and for determination of origin and possible spillover to other species including humans. Actually, molecular and bioinformatics tools are giving to the knowledge an advance in understanding in single differences between species of Brucella evolutionary history, specificity and pathogenicity in different hosts (Vidal, Ortiz, & Olivera, 2018). Exploration of phylogenetic studies such as MLVA (Multilocus variable number of tandem repeats analysis), variable number of tandem repeats (VNTR) (Menshawy et al, 2014), single nucleotide polymorphisms (SNPs) (Wattam et al, 2014) and Multilocus sequence typing (MLST) (Shome et al., 2016) are useful for establishing relationship and grouping of Brucella species.…”