In vitro activities of faropenem, ertapenem, imipenem and meropenem against Borrelia burgdorferi s.l

Int J Antimicrob Agents. 2007 Jul;30(1):83-6. doi: 10.1016/j.ijantimicag.2007.03.008. Epub 2007 May 18.


Little is known about the in vitro activity of penems and carbapenems against the spirochete Borrelia burgdorferi. Here, faropenem, ertapenem, imipenem and meropenem as well as the third-generation cephalosporin ceftriaxone and tobramycin were tested in vitro against 11 isolates of the B. burgdorferi sensu lato complex. On a microg/mL basis, ertapenem was the most potent carbapenem (minimal inhibitory concentration (MIC) range: 0.015-0.125 microg/mL), with in vitro activity comparable with that of ceftriaxone against Borrelia. These findings are supported by the results of time-kill experiments in a Borrelia afzelii skin isolate, demonstrating a >3 log10 unit (99.9%) reduction of the inoculum after 96 h of exposure to either drug at a concentration of three log2 unit dilutions above the respective MIC.

Publication types

  • Comparative Study

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Borrelia burgdorferi Group / drug effects*
  • Colony Count, Microbial
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Time Factors
  • beta-Lactams / pharmacology*


  • Anti-Bacterial Agents
  • beta-Lactams