Construction of a slime negative transposon mutant in Staphylococcus epidermidis using the Enterococcus faecalis transposon Tn917.

The slime-producing Staphylococcus epidermidis strain sensu strictu CNS23 was transformed by protoplast transformation with the plasmid pTV1 which carries transposon Tn 917. Using this transposon mutagenesis system we obtained the Tn917-inserted mutant CT512, which has lost the ability to produce slime. A single insertion of the transposon Tn917 into the chromosome of CT512 could be detected by Southern hybridization. This mutant showed a significantly higher stability concerning its slime-negative phenotype compared with spontaneous slime-negative mutants of S. epidermidis strain CNS23. In slime-ELISA no slime-associated antigen could be detected in extracts of the transposon mutant. Compared to slime-positive S. epidermidis strains, CT512 lacked in accumulative growth in microtiter tube test.