Clutivation of Borrelia buttonii in tissue culture (sequel)

Burrelia buttonii strain 406K which has been maintained in our laboratory in mice did not grow in both Kelly and BSK LL media which were reported as the growth media of B. duttonii. In the orevious report of this series, one of the authors, K. Sugiyama, attempted to obtain survival or replication (or both ) of strain 406K in vitro and succeeded to cultivate it on conventional monolayer cultures of SflEp cells. In the oresent studies, we examined several factors which have not been incestigated by K. Sugiyama. The optimum temperature for growth was 34℃. The strain grew also at 30℃ but slower than at 34℃. The optimum concentrations of untreated and heat-inactivated fetal calf sera(FCS) supplemented for replication of the strain were 10% and 30%, respectivey. Commercial lots of FCS varied greatly in their ability to support growth of B. duttonii.