Whole genome sequencing for tracing genetic diversity and virulence genes of Brucella abortus and Brucella melitensis isolated from livestock in Egypt.

Brucellosis is a highly contagious zoonosis worldwide with high economic and public health impacts. Whole-genome sequencing (WGS) using next-generation sequencing (NGS) technology has become a widely accepted molecular typing method for outbreak tracing and genomic epidemiology of brucellosis. This investigation aimed to assess genetic diversity, antibiotic resistance genes and virulence genes of Brucella (B.) abortus and B. melitensis isolates from different animal species located in different governorates in Egypt. In total, 34 suspected Brucella isolates were recovered from lymph nodes, milk, and fetal abomasal contents of infected cattle, buffaloes, sheep, and goats originating from nine districts in Egypt. Of these, 29 Brucella isolates (eight B. abortus biovar 1 and 21 B. melitensis biovar 3) were sequenced and genotyped.