title: [Effect of combination of sub-MIC sodium houttuyfonate and erythromycin on biofilm of Staphylococcus epidermidis].
abstract: OBJECTIVE
  To observe the effect of the combination of sub-MIC sodium houttuyfonate and erythromycin on biofilm of Staphylococcus epidermidis.
  
  
  METHODS
  The serial dilution method was adopted to determine MIC of the combination of sodium houttuyfonate and erythromycin on S. epidermidis; the checkerboard method was used to evaluate the combination of sodium houttuyfonate and erythromycin on suspended bacteria of S. epidermidis; S. epidermidis biofilm was built in vitro, and XTT reduction assay was used to evaluate the effect of the combination of sub-MIC sodium houttuyfonate and erythromycin on the adhesion of S. epidermidis and bacterial metabolism inside the biofilm. Microscope was applied to observe the impact the single administration and combination of the two medicines under sub-MIC on biofilm morphology of S. epidermidis.
  
  
  RESULTS
  The MIC of sodium houttuyfonate and erythromycin were 62.5, 7.812 5 mg x L(-1), respectively. The combination of 1/8MIC sodium houttuyfonate and 1/2MIC erythronmycin showed a synergistic effect on S. epidermidis. Sodium houttuyfonate, erythromycin and their combination had an inhibitory effect on the adhesion and metabolism of S. epidermidis biofilm bacteria, and made impact on the morphology of S. epidermidis biofilm.
  
  
  CONCLUSIONS
  The sub-MIC sodium houttuyfonate and erythromycin have an inhibitory effect on S. epidermidis biofilm. The combination of sodium houttuyfonate and erythromycin shows a synergistic effect in inhibiting suspended bacteria and biofilm of S. epidermidis, particularly in inhibiting the metabolism of S. epidermidis biofilm bacteria and impacting the morphology of biofilm.
authors.affiliation: Anhui University of Traditional Chinese Medicine, Hefei 230038, China. guanyan0726@sina.com
authors.forename: Yan
authors.initials: Y
authors.lastname: Guan
authors.forename: Chun
authors.initials: C
authors.lastname: Li
authors.forename: Jing-Jin
authors.initials: JJ
authors.lastname: Shi
authors.forename: Hua-Na
authors.initials: HN
authors.lastname: Zhou
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Pu
mesh_terms: D000473:Alkanes / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004917:Erythromycin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000502:physiology*; D013447:Sulfites / Q000494:pharmacology*
chemical_list: D000473:Alkanes; D000900:Anti-Bacterial Agents; D013447:Sulfites; C473296:sodium houttuyfonate; D004917:Erythromycin