Factors Related to Psittacosis Virus (Strain 6BC) Growth. V. Folic Acid-like Factor in Infected Cells.

Abstract
Growth of psittacosis virus (6BC) in L-cells in vitro was inhibited by sulfadiazine and this inhibition was reversed by addition of PABA (para-aminobenzoic acid). L-cell tissue cultures infected with the virus contained 2 or more times the amount of folic acid in noninfected cultures. The possibility of introduction into the cell or induction in the cell by the virus of enzyme or enzyme system, making the infected cell capable of folic acid synthesis, is discussed.