Transformation of ciprofloxacin-resistant Neisseria gonorrhoeae gyrA, parE and porB1b genes

Int J Antimicrob Agents. 2006 Sep;28(3):206-11. doi: 10.1016/j.ijantimicag.2006.04.003. Epub 2006 Jul 26.


In several transformation experiments, we have shown that introduction of an alteration in GyrA at position 95 of a ciprofloxacin-susceptible Neisseria gonorrhoeae strain (minimum inhibitory concentration (MIC) 0.008 mg/L) increases the MIC to 0.064 mg/L. Two alterations (positions 91 and 95) increase the MIC to 0.125-0.25 mg/L. Transformants with ciprofloxacin MICs of 0.5-16 mg/L were obtained from a moderately ciprofloxacin-resistant strain (MIC 0.25 mg/L). These transformants had alterations in the gene for PorB1b and probably other genes. In one transformant, an alteration in ParE was also introduced, which probably contributed to ciprofloxacin resistance. The ciprofloxacin-resistant transformants had the donor porB1b sequence, and most of them also had altered serovars. We conclude that alterations in N. gonorrhoeae PorB1b could be involved in ciprofloxacin resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Ciprofloxacin / pharmacology*
  • DNA Gyrase / genetics
  • DNA Topoisomerase IV / genetics
  • Drug Resistance, Bacterial / genetics*
  • Microbial Sensitivity Tests
  • Neisseria gonorrhoeae / classification
  • Neisseria gonorrhoeae / drug effects*
  • Neisseria gonorrhoeae / genetics*
  • Porins / genetics
  • Transformation, Bacterial*


  • Anti-Bacterial Agents
  • Porins
  • porin protein, Neisseria
  • Ciprofloxacin
  • DNA Topoisomerase IV
  • DNA Gyrase