Autoradiographic Studies on Intracellular Growth of Brucella melitensis and Thymineless E. coli. ∗

Summary

Rabbit peritoneal histiocytes labelled with tritiated thymidine were infected with Brucella. No transfer of the labelled nuclear material from the host to the parasite was detected, although both types of cells multiplied during the course of the experiment. When unlabelled histiocytes ingested labelled E. coli, living or dead, label passed to the histiocyte nucleus. Uptake of tritium-labelled thymidine by peritoneal histiocytes was markedly reduced after ingestion of E. coli but not by ingestion of the attenuated strain of B. melitensis.