[Cloning and expression of the determinant for resistance to a new class of tetracycline in Escherichia coli strains].

Tetracycline-resistance determinant of the plasmid pBS221 isolated from a Pseudomonas aeruginosa strain has been cloned on pUC19 vector plasmid. The determinant is expressed under aerobic and anaerobic conditions coding for two proteins: a 36 Kd protein conferring antibiotic resistance and 27 Kd repressor protein. The determinant is not homologous to tet-determinants of the known classes as shown by blot hybridization experiments. The determinant represents a new class--G. Determinants of the new class are widespread among Serratia marcescens strains.