title: Activity of the new quinolones WCK 771, WCK 1152 and WCK 1153 against clinical isolates of Streptococcus pneumoniae and Streptococcus pyogenes.
abstract: OBJECTIVE
  The new fluoroquinolones WCK 771, WCK 1152 and WCK 1153 were developed to overcome quinolone resistance in Gram-positive bacteria. The activity of these new quinolones was tested against 159 clinical isolates of Streptococcus pneumoniae and 52 clinical isolates of Streptococcus pyogenes using the microbroth dilution method.
  
  
  RESULTS
  MIC50/MIC90 values (mg/L) of WCK 771, WCK 1152 and WCK 1153 for quinolone-susceptible S. pneumoniae (n = 119; 54 penicillin G-susceptible, 53 penicillin G-intermediate, and 12 penicillin G-resistant strains) were 0.25/0.5, 0.03/0.06 and 0.016/0.03, respectively. MIC50/MIC90 values (mg/L) for quinolone-resistant pneumococci (n = 40) increased to 4/16, 0.25/1 and 0.125/0.5, respectively. Against S. pyogenes, WCK 771, WCK 1152 and WCK 1153 were also highly active with MIC50/MIC90 values (mg/L) of 0.25/0.25, 0.03/0.06 and 0.03/0.03, respectively.
  
  
  CONCLUSIONS
  Overall, WCK 771 was highly active against quinolone-susceptible, but not against quinolone-resistant S. pneumoniae, whereas WCK 1152 and WCK 1153 were more potent and were able to overcome quinolone resistance in both S. pneumoniae and S. pyogenes.
authors.affiliation: Institute of Medical Microbiology, National Reference Centre for Streptococci, University Hospital (RWTH Aachen), D-52057 Aachen, Germany.
authors.forename: Adnan
authors.initials: A
authors.lastname: Al-Lahham
authors.forename: Noel J
authors.initials: NJ
authors.lastname: De Souza
authors.forename: Mahesh
authors.initials: M
authors.lastname: Patel
authors.forename: Ralf
authors.initials: R
authors.lastname: René Reinert
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001769:Blood / Q000382:microbiology; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010612:Pharyngitis / Q000382:microbiology; D010880:Piperidines / Q000494:pharmacology*; D011008:Pneumococcal Infections / Q000382:microbiology; D013290:Streptococcal Infections / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000302:isolation & purification; D014069:Tonsillitis / Q000382:microbiology; D014947:Wounds and Injuries / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D010880:Piperidines; C508728:WCK 1152; C508727:WCK 1153; C490933:WCK 771