Anaerobic 109Cd accumulation by cadmium-resistant and -sensitive Staphylococcus aureus.
Washed cells of the cadmium-sensitive Staphylococcus aureus 17810S accumulated 109Cd under anaerobic conditions via the Mn2+ porter down delta psi in 1 or 100 mM phosphate buffer, pH 7; in washed cells of the cadmium-resistant S. aureus 17810R 109Cd accumulation was highly reduced. Nigericin did not stimulate anaerobic Cd2+ accumulation by strain 17810R in 100 mM phosphate buffer, suggesting that delta psi could energize Cd2+ efflux. In 1 mM phosphate buffer nigericin restored Cd2+ accumulation via the Mn2+ porter down delta psi in strain 17810R, indicating involvement of delta pH in Cd2+ extrusion. Increase of phosphate buffer concentration from 1 to 100 mM and addition of energy source at steady-state caused delta psi-dependent Cd2+ efflux from the nigericin-pretreated cells of strain 17810R. This suggests that the Cd2+ efflux system in S. aureus may require energy of both ATP and delta mu H+.
Tynecka
Z
Z
Department of Pharmaceutical Microbiology, Medical Academy, Lublin, Poland.
Skwarek
T
T
Malm
A
A
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000693:Anaerobiosis; D002021:Buffers; D002104:Cadmium / Q000378:metabolism / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D007700:Kinetics; D013211:Staphylococcus aureus / Q000187:drug effects / Q000378:metabolism*
D002021:Buffers; D002104:Cadmium; D000251:Adenosine Triphosphatases