Genomic characterization of clinical Borrelia burgdorferi sensu lato isolates in the Netherlands over a thirty-year period

Background Lyme borreliosis (LB), the most common vector-borne disease in the Northern Hemisphere, is caused by a multitude of pathogenic Borrelia burgdorferi sensu lato (sl) species endemic to northern, western, and central regions of Europe. We utilized whole genome sequencing (WGS) to characterize the genetic diversity of 130 clinical B. burgdorferi sl isolates collected from LB cases in the Netherlands between 1988 and 2023, the majority of which were B. afzelii . Results WGS analysis revealed significant diversity, including 29 different multi-locus sequence types (MLSTs) across four genospecies. Plasmids from B. garinii and B. bavariensis were found to exhibit greater sequence diversity than those from B. burgdorferi sensu stricto and B. afzelii . We further characterized the Borrelia membrane protein antigens OspA, OspC and DbpA for sequence diversity and correlation with LB disease state. Conclusions This large-scale genomic analysis of clinical Dutch B. burgdorferi sl isolates furthers our understanding of LB and may indicate potential coverage for LB vaccine candidates in clinical development.