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In Vitro Conversion of Borrelia burgdorferi to Cystic Forms in Spinal
Fluid, and Transformation to Mobile Spirochetes by Incubation in BSK-H
Medium
Date of Publication: May-Jun, 1998 Source: Infection,
26(3):144-50 Authors: Brorson O; Brorson S. Institution: Dept. of Microbiology,
Vestfold Sentralsykehus, Tonsberg
Abstract
The purpose of this study was to examine the structural alterations of
Borrelia 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 that B. 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 to B. burgdorferi.
Quotation From The Full-Text Article “It is not known whether cystic forms
of B. burgdorferi can be detected by PCR, but if we assume that cysts cannot
be detected by PCR, this may explain why PCR on spinal fluid is negative
even when the patient has the diagnosis of neuroborreliosis.” |
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Serum Starvation-Induced Cyst Formation in Borrelia burgdorferi Under
Defined Conditions Paper confirming the Brorsons’ work on cystic forms
of Borrelia burgdorferi. Alban PS; Nelson DR. University
of Rhode Island, Kingston, RI 02181 Presented at the 1999 International
Conference on Lyme Disease in Munich, Germany. Subsequently published
in Microbiology, Jan 2000;146 (Pt 1):119-27.
It has recently been demonstrated that cells of
Borrelia burgdorferi transform from mobile spirochetes into nonmotile
cysts when cultured for several weeks in BSK medium lacking rabbit serum
(BSKrs-) or within 24 h in cerebrospinal fluid. Additionally,
cyst forms of B. burgdorferi can successfully convert back to the motile
vegetative form when incubated for 6 wk in BSK medium containing 6% rabbit
serum (BSKrs+). The aim of this study was to investigate cyst formation
by B. burgdorferi cells under defined conditions in order to understand
the physiological basis of this transformation and to identify proteins
involved in cyst formation. We confirmed that motile B. burgdorferi cells
transform into cysts after a 30 d incubation in BSKrs-.
Quotations From The Full-Text Article (Microbiology, Jan 2000) “...Western
blots displayed consistent differences between the protein antigens recognized
in vegetative cells and cysts. ...both the 46 kDa and 41 kDa (flagellin)
protein bands exhibited less reactivity to sera from humans or monkeys
in blots prepared from cysts, suggesting that both proteins were present
in decreased amounts in cysts.” (pp.123-4) “By forming cysts, it is also
conceivable that B. burgdorferi cells evade detection by the immune system.”
(p. 125)
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