Tn1525, a kanamycin R determinant flanked by two direct copies of IS15.

We have isolated plasmid pIP112 (IncI1) from Salmonella panama and characterized by restriction endonucleases analysis and by recombinant DNA techniques a transposable element designated Tn1525. This 4.44 kilobase (kb) transposon confers resistance to kanamycin by synthesis of an aminoglycoside phosphotransferase (3') (5") type I and contains two copies of IS15 (1.

Transposition of a tetracycline-resistance determinant (Tn1523) and cointegration events mediated by the pIP231 plasmid in Escherichia coli.

A 10.8-kb transposable DNA sequence conferring resistance to tetracycline resides on the IncY Escherichia coli plasmid pIP231. This sequence, designated Tn1523, was shown to insert into different sites of the replicons of the IncY prophage P1Cm c1.

Curing of P1 prophage from Escherichia coli K-12 recA(P1) lysogens superinfected with P1 bacteriophage.

Curing of the P1 plasmid prophage in recA(P1) lysogens by superinfection with another P1 phage was specific and independent of immunity and incompatibility expression.