Clinical and Epidemiological Studies Originalia


, Volume 26, Issue 3, pp 144-150

First online:

In vitro conversion ofBorrelia burgdorferi to cystic forms in spinal fluid, and transformation to mobile spirochetes by incubation in BSK-H medium

  • Ø. BrorsonAffiliated withDept. of Microbiology, Vestfold Sentralsykehus
  • , S. H. BrorsonAffiliated withDept. of Pathology, Ulleval University Hospital

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


The purpose of this study was to examine the structural alterations ofBorrelia burgdorferi when exposed to spinal fluid. Normal, mobile spirochetes were inoculated into spinal fluid, and the spirochetes were converted to cysts (spheroplast L-forms) after 1–24 h. When these cystic forms were transferred to a rich BSK-H medium, the cysts were converted back to normal, mobile spirochetes after incubation for 9 to 17 days. The cultures were examined by dark field microscopy (DFM), interference contrast microscopy (ICM) and transmission electron microscopy (TEM). When neuroborreliosis is suspected, it is necessary to realize thatB. burgdorferi can be present in a cystic form, and these cysts have to be recognized by microscopy. This study may also explain why cultivation of spinal fluid often is negative with respect toB. burgdorferi.