There are a few studies which mention that CWD-forms were seen, but in recent years I have only seen studies mentioning the spirochete form and the cyst form were seen. Also, some studies (posted below) speak of "cysts (spheroplast L-forms)" and "Cystic forms (also called spheroplasts or starvation forms)".
Therefore, I suspect that the CWD-forms that were seen, were actually the same forms as the cyst forms, so not a distinct form.
My 2 cents.
Infection. 1998 May-Jun;26(3):144-50.
In vitro conversion of Borrelia burgdorferi to cystic forms in spinal fluid, and transformation to mobile spirochetes by incubation in BSK-H medium.
Brorson O, Brorson SH.
Dept. of Microbiology, Vestfold Sentralsykehus, Tønsberg.
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.
PMID: 9646104 [PubMed - indexed for MEDLINE]
APMIS. 2001 May;109(5):383-8.
Conversion of Borrelia garinii cystic forms to motile spirochetes in vivo.
Gruntar I, Malovrh T, Murgia R, Cinco M.
Institute of Microbiology and Parasitology, Veterinary Faculty, Ljubljana, Slovenia. email@example.com
Cystic forms (also called spheroplasts or starvation forms) and their ability to reconvert into normal motile spirochetes have already been demonstrated in the Borrelia burgdorferi sensu lato complex. The aim of this study was to determine whether motile B. garinii could develop from cystic forms, not only in vitro but also in vivo, incyst -inoculated mice. The cysts prepared in distilled water were able to reconvert into normal motile spirochetes at any time during in vitro experiments, lasting one month, even after freeze-thawing of the cysts. Motile spirochetes were successfully isolated from 2 out of 15 mice inoculated intraperitoneally with cystic forms, showing the infectivity of the cysts. The demonstrated capacity of the cysts to reconvert into motile spirochetes in vivo and their surprising resistance to adverse environmental conditions should lead to further studies on the role and function of these forms in Lyme disease.
PMID: 11478686 [PubMed - indexed for MEDLINE]