Variable degree of slime production is linked to different levels of beta-lactam susceptibility in Staphylococcus epidermidis phase variants

Recently we demonstrated that lack of mecA transcription was responsible for the decreased methicillin resistance phenotype of strongly slime-negative Staphylococcus epidermidis phase variants [Mempel M, Feucht H, Ziehbuhr W, Endres M, Laufs R, Grüter L (1994) Antimicrob Agents Chemother 38: 1251-1255]. In the present study we compared the beta-lactam susceptibility and the slime production capacity of 60 phenotypic variants of S. epidermidis parent strain RP62A identified by their colony morphology on congo red agar. We could show that the variable degree of slime production is linked to different levels of beta-lactam susceptibility in intermediate-stage phase variants. The increased deltahemolysin production of slime-negative phase variants may indicate an accessory gene regulator-like control.