levoleucovorin and Psittacosis

Kajima, Masahiro (University of Notre Dame, Notre Dame, Ind.), Nehama Sharon, and Morris Pollard. Electron microscopy of latent psittacosis virus in McCoy cells. J. Bacteriol. 88:709-715. 1964.-Replication of psittacosis virus in McCoy cells was observed periodically by electron microscopy, and was correlated with the appearance of inclusion bodies in infected cells stained by acridine orange fluorochrome. Three well-defined morphological stages characterized the replication cycle: (i) noninfectious initial body, (ii) noninfectious intermediate body, and (iii) infectious mature or elementary body. When replication of virus was interrupted by aminopterin, the virus failed to develop beyond the noninfective initial body stage; however, after treatment of such cultures with folinic acid, intermediate and mature virus particles appeared in the cells. Latent psittacosis virus, as described here, represented a virus in which the replication process was interrupted at a noninfective (eclipse) stage of the developmental cycle.

Topics: Acridines; Aminopterin; Chlamydia; Chlamydophila psittaci; Electrons; Leucovorin; Microscopy; Microscopy, Electron; Psittacosis; Research

Topics: Aminopterin; Chlamydia; Chlamydophila psittaci; Leucovorin; Psittacosis; Research Design; Tissue Culture Techniques

Topics: Chlamydia; Chlamydophila psittaci; Folic Acid; Leucovorin; Psittacosis

The inhibitory action of sodium sulfadiazine on the growth of psittacosis virus (6BC) in embryonated eggs is readily reversed by citrovorum factor but not by small amounts of vitamin B(12). In embryonated eggs, the pteroylglutamic acid analogues, 9-methylpteroylglutamic acid and 4-aminopteroylaspartic acid, produced some suppression of the growth of psittacosis virus (6BC). 4-Aminopteroylglutamic add, 4-amino-N(10)-methylpteroylglutamic acid, and 4-aminopteroylaspartic acid inhibited the growth of this virus in tissue cultures at concentrations which were not toxic for the host tissue. The inhibitory action of 4-amino-N(10)-methylpteroylglutamic acid and 4-aminopteroylaspartic acid was readily overcome by addition of citrovorum factor. Growth of meningopneumonitis virus in embryonated eggs or tissue culture is suppressed by 4-aminopteroylaspartic acid. The advantages of the tissue culture technic for studies on the growth of viruses are discussed.

Topics: Chlamydophila psittaci; Folic Acid; Leucovorin; Psittacosis; Viruses; Vitamin B 12