The tetAB genes of the Corynebacterium striatum R-plasmid pTP10 encode an ABC transporter and confer tetracycline, oxytetracycline and oxacillin resistance in Corynebacterium glutamicum

The tetracycline resistance region of the 50-kb R-plasmid pTP10 from the clinical isolate Corynebacterium striatum M82B was analyzed in Corynebacterium glutamicum ATCC 13032 and confined to a 4.4-kb SphI-Sa/I DNA fragment. Nucleotide sequence analysis revealed two open reading frames, termed tetA and tetB, specifying proteins of 513 and 528 amino acids, respectively. The deduced amino acid sequences of tetAB displayed similarity to ATP-binding cassette transporters including StrV and StrW of Streptomyces glaucescens which are proposed to play a role in the export of streptomycin-like aminoglycosides. An antibiotic susceptibility screening in C. glutamicum showed that the tetAB genes confer resistance to tetracycline, oxytetracycline and to the structurally and functionally unrelated beta-lactam antibiotic oxacillin.