Coinfection withBorrelia turicataeSerotype 2 Prevents the Severe Vestibular Dysfunction and Earlier Mortality Caused by Serotype 1

Relapsing fever (RF) is a multisystemic spirochetal infection caused by different Borrelia species. Studies in our laboratory have shown that disease severity varies depending on the infecting serotype. However, the relative contribution of each serotype to pathogenesis during mixed infections is not known. To investigate this, we compared the outcome of infection with isogenic serotypes 1 (Bt1) or 2 (Bt2) of the RF agent B. turicatae alone or in combination.