Drug efflux and parC mutations are involved in fluoroquinolone resistance in viridans group streptococci.
Nine ciprofloxacin-resistant viridans group streptococci isolated from asymptomatic carriers were analyzed. Identification to the species level by using three different commercial systems and a PCR-based approach was inconsistent. The nucleotide sequences of fragments of the parC, parE, gyrA, and gyrB genes showed considerable intra- and interspecies variations, and these variations mainly involved silent mutations. Three isolates had changes in Ser-79 of ParC (to Phe or Tyr). Phenotypic characterization indicated that eight of the nine isolates had a putative efflux mechanism that would confer low-level resistance to ciprofloxacin.
Ferrándiz
M J
MJ
Unidad de Genética Bacteriana (Consejo Superior de Investigaciones Científicas), Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Majadahonda, 28220 Madrid, Spain.
Oteo
J
J
Aracil
B
B
Gómez-Garcés
J L
JL
De La Campa
A G
AG
D000890:Anti-Infective Agents / Q000378:metabolism / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D027081:DNA Gyrase; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004352:Drug Resistance, Microbial / Q000235:genetics; D024841:Fluoroquinolones; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D013291:Streptococcus / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D024841:Fluoroquinolones; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase; D004250:DNA Topoisomerases, Type II