title: The product of the qacC gene of Staphylococcus epidermidis CH mediates resistance to beta-lactam antibiotics in gram-positive and gram-negative bacteria.
abstract: We have characterized a natural isolate of Staphylococcus epidermidis resistant to heavy metals that carries a small 2391-bp plasmid, pSepCH, encoding the qacC gene. The S. epidermidis qacC gene confers resistance to a number of beta-lactam antibiotics and to ethidium bromide in its natural host and in Escherichia coli K12 and Salmonella enterica sv. Typhimurium. This is the first communication of a small multidrug resistance (SMR) pump involved in resistance to beta-lactam antibiotics. Experiments using tolC, ompW and ompD mutant strains of S. Typhimurium demonstrated that the beta-lactam antibiotic resistance conferred by this pump does not depend on these outer membrane proteins.
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Ciencias Biológicas, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile.
authors.forename: Derie E
authors.initials: DE
authors.lastname: Fuentes
authors.forename: Claudio A
authors.initials: CA
authors.lastname: Navarro
authors.forename: Juan C
authors.initials: JC
authors.lastname: Tantaleán
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Araya
authors.forename: Claudia P
authors.initials: CP
authors.lastname: Saavedra
authors.forename: José M
authors.initials: JM
authors.lastname: Pérez
authors.forename: Iván L
authors.initials: IL
authors.lastname: Calderón
authors.forename: Phil A
authors.initials: PA
authors.lastname: Youderian
authors.forename: Guido C
authors.initials: GC
authors.lastname: Mora
authors.forename: Claudio C
authors.initials: CC
authors.lastname: Vásquez
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017920:Antiporters / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D029968:Escherichia coli Proteins; D004996:Ethidium / Q000494:pharmacology; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D012486:Salmonella typhimurium / Q000187:drug effects / Q000254:growth & development; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D018440:beta-Lactam Resistance / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D017920:Antiporters; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D047090:beta-Lactams; C075436:EmrE protein, E coli; D004996:Ethidium