Brucella melitensis strains from human brucellosis cases in Tunisia

Whole-genome information about Brucella melitensis in human patients from Tunisia is currently missing and for this reason, there are some gaps in the distribution of Brucella populations in the Mediterranean region. Within the framework of the German Biosecurity Programme, the Charles Nicolle Hospital of Tunis in collaboration with the Robert Koch Institute in Berlin studied 36 strains obtained from blood samples collected from patients with a clinical diagnosis of brucellosis between 2015 and 2020. The aims of this study were: 1) to characterize the genomes of Brucella melitensis strains and 2) to investigate genetic diversity and relations among Tunisian strains and other strains worldwide. All studied strains were identified as Brucella melitensis bv. 3 and mostly grouped into two new major clusters with close genetic relationships to strains from neighboring countries.