5-FLUOROURACIL AS A SELECTIVE AGENT FOR GROWTH OF LEPTOSPIRAE.

Johnson, Russell C. (University of Minnesota, Minneapolis), and Palmer Rogers. 5-Fluorouracil as a selective agent for growth of leptospirae. J. Bacteriol. 87:422-426. 1964.-The use of 5-fluorouracil (FU) as a selective agent for the growth of leptospirae was investigated. Both the growth rate and the final cell yield of Leptospira pomona were unaltered with FU added to the medium at concentrations varying from 50 to 1,000 mug/ml. Growth of this organism was initiated with as few as five organisms per ml in the FU medium. With C(14)-FU, it was demonstrated that FU was not incorporated into L. pomona nucleic acids. Other leptospirae tested grew normally in the presence of FU. By use of the FU medium, L. canicola was successfully isolated from contaminated urine of experimentally infected dogs. Also, contaminated cultures of leptospirae were purified by passage through the FU medium.