title: TRANSFER OF EPISOMIC ELEMENTS TO PROTEUS. II. NATURE OF LAC+ PROTEUS STRAINS ISOLATED FROM CLINICAL SPECIMENS.
abstract: Falkow, Stanley (Walter Reed Army Institute of Research, Washington, D.C.), J. A. Wohlhieter, R. V. Citarella, and L. S. Baron. Transfer of episomic elements to Proteus. II. Nature of lac(+)Proteus strains isolated from clinical specimens. J. Bacteriol. 88:1598-1601. 1964.-Strains of Proteus mirabilis exhibiting the unusual property of utilizing lactose (lac(+)) have been reported in clinical material. A genetic examination discloses that the lac(+) determinants in these Proteus strains are associated with an infectious element, P, which is distinct from the sex factor of Escherichia coli K-12. The composite genetic element, P-lac, is readily transmissible to other enteric species and possesses properties which conform to those of an episomic element of the transfer variety. CsCl density-gradient studies of deoxyribonucleic acid (DNA) extracted from lac(+)P. mirabilis indicate that the P-lac(+) element did not arise in this species, but was acquired from an organism possessing a markedly different DNA base composition.
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D004247:DNA; D004269:DNA, Bacterial; D004926:Escherichia coli; D048168:Escherichia coli K12; D005823:Genetics; D007785:Lactose; D007930:Leucine; D008660:Metabolism; D011511:Proteus; D012106:Research; D012486:Salmonella typhimurium; D012706:Serratia marcescens; D013912:Threonine
chemical_list: D000596:Amino Acids; D004269:DNA, Bacterial; D013912:Threonine; D004247:DNA; D007930:Leucine; D007785:Lactose
keywords: AMINO ACID METABOLISM; CARBOHYDRATE METABOLISM; DNA, BACTERIAL; ESCHERICHIA COLI; EXPERIMENTAL LAB STUDY; GENETICS; LACTOSE; LEUCINE; METABOLISM; PROTEUS; SALMONELLA TYPHIMURIUM; SERRATIA MARCESCENS; THREONINE