title: On the persistence of R factors in the gram-negative aerobic flora of the human intestine.
mesh_terms: D000362:Agar; D001419:Bacteria; D003227:Conjugation, Genetic; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000276:immunology / Q000302:isolation & purification; D005111:Extrachromosomal Inheritance; D005243:Feces / Q000382:microbiology; D005500:Follow-Up Studies; D006801:Humans; D007422:Intestines / Q000382:microbiology*
chemical_list: D000362:Agar