title: In vitro activities of erythromycin, tetracycline and levofloxacin alone and in dual combinations against ureaplasma spp.
abstract: OBJECTIVE
  It was the aim of our study to evaluate the in vitro activities of tetracycline (TET), erythromycin (ERY) and levofloxacin (LVX) alone and in dual combinations against ureaplasmas.
  
  
  METHODS
  The minimum inhibitory concentrations (MICs) of 51 ureaplasmal strains were determined by microdilution assay.
  
  
  RESULTS
  TET was the most active when the antibiotics were used alone. The combinations resulted in significantly decreased MICs for every agent compared with the use of single antibiotics (p < 0.05, respectively), except for ERY in the ERY-LVX pair (p > 0.05), and decreased the MICs more significantly in the strains with an MIC ≥4 mg/l compared with MIC <4 mg/l, except for the TET-ERY pair. The ERY-LVX pair increased ERY MICs significantly in the MIC <4 mg/l group (p < 0.05). The combinations resulted in more beneficial MICs in strains where both agents had an MIC ≥4 mg/l compared with those where either had an MIC ≥4 mg/l, as well as in strains where either agent had an MIC <4 mg/l compared with those where both had an MIC <4 mg/l.
  
  
  CONCLUSIONS
  Drugs in dual combinations always give more beneficial MICs against ureaplasmas than one agent alone. Combinational benefits prefer strains with a higher initial MIC.
authors: Department of Dermatology, Huangpu Hospital of The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China. luodq@mail.sysu.edu.cn
authors: Di-Qing
authors: DQ
authors: Luo
authors: Jing-Ye
authors: JY
authors: Liu
authors: Wei
authors: W
authors: Yang
authors: Bin
authors: B
authors: Zhang
authors: Min-Jun
authors: MJ
authors: Yu
authors: Yi-Mou
authors: YM
authors: Wu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D004917:Erythromycin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D064704:Levofloxacin; D008297:Male; D008826:Microbial Sensitivity Tests; D015242:Ofloxacin / Q000494:pharmacology*; D013752:Tetracycline / Q000494:pharmacology*; D014509:Ureaplasma / Q000187:drug effects*; D016869:Ureaplasma Infections / Q000188:drug therapy / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D004917:Erythromycin; D064704:Levofloxacin; D015242:Ofloxacin; D013752:Tetracycline