Fluoroquinolone-resistant Streptococcus pneumoniae in Spain: activities of garenoxacin against clinical isolates including strains with altered topoisomerases.
The activity of garenoxacin was assessed against 412 Streptococcus pneumoniae isolates (49.3% from the adult population). Overall penicillin, erythromycin, and ciprofloxacin (MIC, >/=4 micro g/ml) resistance was 51.7, 35.4, and 1.5%, respectively. For all isolates, the garenoxacin MIC was </=1 micro g/ml. Amino acid replacements in GryA (Ser81-->Phe or Tyr), ParC (Ser79-->Phe or Tyr; Asp83-->Gly; Lys137-->Asn), and ParE (Ile460-->Val; Asp435-->Asn), alone or in combination, were ascribed to the reduced garenoxacin susceptibility (MIC range, 0.5 to 1 micro g/ml) found in four isolates. The low impact of these mutations on garenoxacin activity envisages the possible coverage of S. pneumoniae populations resistant to preexisting quinolones.
Morosini
María-Isabel
MI
Servicio de Microbiología, Hospital Universitario Ramón y Cajal, Madrid, Spain.
Loza
Elena
E
del Campo
Rosa
R
Almaraz
Felisa
F
Baquero
Fernando
F
Cantón
Rafael
R
D000890:Anti-Infective Agents / Q000494:pharmacology*; D027081:DNA Gyrase / Q000187:drug effects / Q000235:genetics; D026942:DNA Topoisomerases / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D008780:Methyltransferases / Q000235:genetics; D008826:Microbial Sensitivity Tests; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D011446:Prospective Studies; D015363:Quinolones / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013030:Spain / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics
D000890:Anti-Infective Agents; D004269:DNA, Bacterial; D024841:Fluoroquinolones; D007211:Indoles; D015363:Quinolones; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase; D026942:DNA Topoisomerases; D027081:DNA Gyrase; C419689:garenoxacin