• Norris, Steven J, (PI)

Project: Research projectResearch Project


The basic goals of this proposal are to achieve continuous in vitro culture
of Treponema pallidum and to characterize the proteins associated with the
structural components of the organism. Of highest priority will be the
attempted continuous passage of T. pallidum in vitro utilizing the tissue
culture system developed by Fieldsteel et al. The approach to extending
the limited multiplication obtained in this system will be: 1) to identify
the nutritional and environmental requirements for T. pallidum growth, and
use this information to optimize culture conditions; and 2) to maintain
optimal conditions through subcultivation, continuous flow, or chemostatic
techniques. Because of our recent success in achieving significant
multiplication in secondary cultures, subcultivation as a means of
prolonging in the in vitro growth of T. pallidum will be investigated.
Stabilization of culture conditions by continuous flow medium replacement
or chemostatic techniques will eliminate the depletion of nutrients and
accumulation of toxic products as possible causes of the cessation of
growth. High density tissue culture techniques utilizing hollow fiber
perfusion cultures, sepharose microcarriers or collagen matrices will be
used in combination with continuous flow medium replacement to determine
whether these 'tissue-like' conditions will enhance treponemal growth. In defining the nutritional requirements of T. pallidum, the
growth-promoting factors present in serum and tissue extracts will be
purified and characterized. Because the requirement for serum is
associated with serum proteins, it will be determined whether albumin
complexed with lipids and other compounds is capable of replacing the serum
requirement, as it is for other parasitic spirochetes. The medium
currently used for cultivation studies could be deficient in required
compounds; therefore, the effects of supplementation with fatty acids and
vitamins required by related bacteria will be assessed. Monitoring of
numerous cultural parameters during in vitro cultivation of T. pallidum
will be used as a means for identifying changes leading to the cessation of
treponemal growth. Identification of the proteins associated with the outer membrane,
cytoplasmic membrane, flagella, and cytoplasm of T. pallidum will aid in
understanding their functional properties and their potential roles as
protective immunogens. Therefore, the structural distribution of the major
polypeptides of T. pallidum will be determined by structural fractionation
and immunoelectron microscopy techniques.
Effective start/end date8/1/8211/30/93


  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $132,672.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $143,741.00


Treponema pallidum
Globus Pallidus
Hydrophobic and Hydrophilic Interactions
Sexual Behavior
Nucleic Acids
Culture Media
Acquired Immunodeficiency Syndrome
Fatty Acids
Cell Culture Techniques


  • Medicine(all)
  • Immunology and Microbiology(all)