Genomic analysis of Brucella isolates from animals and humans, Türkiye, 2010 to 2020

BackgroundBrucellosis is a bacterial zoonosis causing severe illness in humans and animals and leading to economic losses in the livestock production in Türkiye and other endemic countries.AimWe aimed at investigating genomic differences of <i>Brucella</i> isolates from animals and humans in Türkiye.MethodsWe used whole genome sequencing (WGS) to assess the genetic diversity of <i>Brucella</i> isolates from 41 provinces in Türkiye and compared with isolates from other countries. We applied allele-based typing and core genome single nucleotide polymorphism (cgSNP) determination.ResultsOf the 106 Turkish <i>Brucella</i> isolates included, 57 were <i>B. abortus</i> and 49 were <i>B. melitensis</i>. One <i>B. melitensis</i> and two <i>B. abortus</i> isolates were identified as vaccine strains. Most (n = 55) <i>B. abortus</i> isolates clustered in three major branches, with no spatial discernible pattern. Of the <i>B. melitensis</i> isolates<i>,</i> 48 were assigned to the Eastern Mediterranean lineage with no discernible patterns between host species, location and sampling date. The Turkish isolates clustered with isolates from neighbouring countries such as Greece and Syria, but some also with isolates from human patients in European countries, like Germany, Norway and Sweden, suggesting that the source may be travel-related.ConclusionSeveral <i>B. melitensis</i> and <i>B. abortus</i> lineages are circulating in Türkiye. To decrease the prevalence and prevent brucellosis in animals and humans, stricter control measures are needed, particularly in areas where humans and animals have close contact. Furthermore, illegal transportation of animals across borders should be more closely controlled and regulated.