GI FeGSH : A New Genomic Island Might Explain the Differences in Brucella Virulence

An imported dog was confirmed to be positive withcanine brucellosis in Sweden in 2010. The whole genome of Brucella canis SVA10 was subjected to phage analysis (WGS-PA) andwas assigned to the Asian B. canis cluster. Further analysis indicated that the genomeof B. canis SVA10 is smaller compared to genomes of the samespecies. A 35,781 bp genomic island (GI) was found to be absent instrain SVA10 which was detected by read mapping the paired reads to the genomeof B. canis ATCC 23,365T. The lacking genes of genomic island GIFeGSH are mainly coding for iron uptake enzymes and partsof the glutathione pathway. A screening of all available whole genome sequencesof Brucella strains confirmed that GIFeGSH is also missing in four more strains of B. canis but present in several strains of B. abortus, B. melitensis, B. suis, B. ovis, B. microti, B. pinnipedialis, and B. ceti. Parts of the GI were present, but scattered in twoother B. canis strains. The aim of this study was to finddifferences in the genomes of Brucella which might explain former described differences invirulence. The analysis was extended to all available Brucella genomes after the detection of a genomic island instrain SVA10.