caa a22 4500 397592817 CHVBK 20180308164943.0 cr unu---uuuuu 161202e199609 xx s 000 0 eng 10.1093/jac/38.3.349 doi (NATIONALLICENCE)oxford-10.1093/jac/38.3.349 The riminophenazines, clofazimine and B669, inhibit potassium transport in Gram-positive bacteria by a lysophospholipid-dependent mechanism [Elektronische Daten] [Engela E. De Bruyn, Helen C. Steel, Constance E. J. Van Rensburg, Ronald Anderson] The effects of the riminophenazine antimicrobial agents clofazimine and B669 as well as those of lysophosphatidylcholine (LPC), on microbial K+-transporting systems were investigated in a range of Gram-positive and Gram-negative bacteria using 42K and 36Rubidium (26Rb) as tracers. Exposing the Gram-positive bacteria to 0.1-10 mg/L of the drugs resulted in a dose-related inhibition of uptake of both radiolabelled cations due primarily to the inhibition of their influx which was prevented by pretreating the microorganisms with 25 mg/L α-tocopherol (vitamin E) which forms a complex with lysophospholipids. In contrast, Gram-negative bacteria were resistant to riminophenazine-mediated inhibition of K+-transport, with only one of four well-characterised K+-transport system mutants of Escherichia coli, namely Kup, being affected by the antimicrobial agents. The selective antimicrobial activity of riminophenazines against Gram-positive bacteria is probably achieved by lysophospholipid-mediated inactivation of K+-transport, while Gram-negative microorganisms possess several K+-transport systems which are either inaccessible and/or insensitive to lysophospholipids. Thus, K+-transport systems may represent novel targets for antimicrobial agents. © 1996 The British Society for Antimicrobial Chemotherapy Original articles nationallicence De Bruyn Engela E. MRC Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa aut Steel Helen C. MRC Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa aut Van Rensburg Constance E. J. MRC Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa aut Anderson Ronald MRC Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa aut Journal of Antimicrobial Chemotherapy Oxford University Press 38/3(1996-09), 349-362 0305-7453 38:3<349 1996 38 jac https://doi.org/10.1093/jac/38.3.349 text/html Onlinezugriff via DOI 1 other jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jac/38.3.349 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- De Bruyn Engela E. MRC Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa aut NATIONALLICENCE 700 1- Steel Helen C. MRC Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa aut NATIONALLICENCE 700 1- Van Rensburg Constance E. J. MRC Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa aut NATIONALLICENCE 700 1- Anderson Ronald MRC Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, University of Pretoria, Republic of South Africa aut NATIONALLICENCE 773 0- Journal of Antimicrobial Chemotherapy Oxford University Press 38/3(1996-09), 349-362 0305-7453 38:3<349 1996 38 jac Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford