title: R factors from Proteus mirabilis and P. vulgaris.
abstract: Eighty-nine R factors were transmitted by conjugation to Escherichia coli K12 from isolates of Proteus hauseri (P. mirabilis  plus P vulgaris). More than half were non-selftranmissible. The remainder included plasmids assigned to the previously defined groups FII,A-C complex, J, N and P, as well as some not belonging to any knwon compatibility groups. R factors from strains isolated in India, Thailand and Japan carried plasmids whose inheritance was extremely unstable in E. coli K12. All belonged to a new compatibility group, V.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003227:Conjugation, Genetic; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects; D005111:Extrachromosomal Inheritance; D011513:Proteus mirabilis / Q000187:drug effects*; D011514:Proteus vulgaris / Q000187:drug effects*; D011995:Recombination, Genetic
chemical_list: D000900:Anti-Bacterial Agents