Evaluation of the activity of ertapenem against gonococcal isolates exhibiting a range of susceptibilities to cefixime.

Abstract

OBJECTIVES:

There is a need for new or alternative antimicrobial agents for the treatment of gonorrhoea as antimicrobial resistance emerges to current therapies. The aim was to investigate the activity of ertapenem against isolates of Neisseria gonorrhoeae with decreased susceptibility to cefixime.

METHODS:

A panel of 52 clinical isolates and 10 control strains of N. gonorrhoeae were selected to represent a range of susceptibilities to cefixime. Susceptibility testing was performed using the methodology used for the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP). The isolates were typed by N. gonorrhoeae multi-antigen sequence typing (NG-MAST).

RESULTS:

The isolates comprised 42 different molecular types as defined by NG-MAST. The susceptibility of the clinical isolates to ertapenem was similar to that of cefixime, with a Pearson's correlation coefficient of R = 0.89. The MIC90 and MIC50 values of ertapenem were 0.25 and 0.12 mg/L, respectively, while those of cefixime were 0.12 and 0.06 mg/L, respectively. However, these isolates were more susceptible to ceftriaxone than ertapenem, with a Pearson's correlation coefficient of R = 0.65 and ceftriaxone MIC90 and MIC50 values of 0.03 and 0.016 mg/L, respectively. The isolates that were least susceptible to ertapenem were all non-producers of penicillinase. However, one isolate that was highly resistant to cefixime and ceftriaxone was more susceptible to ertapenem than either cefixime or ceftriaxone.

CONCLUSIONS:

This study has shown that ertapenem is not a suitable alternative for first-line treatment for gonorrhoea but that it may be useful for the treatment of highly resistant infections.

• Authors: Nerteley Quaye, Michelle J Cole, Catherine A Ison
• Journal: The Journal of antimicrobial chemotherapy (J Antimicrob Chemother) Vol. 69 Issue 6 Pg. 1568-71 (Jun 2014) ISSN: 1460-2091 [Electronic] England
• PMID: 24492260 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: [email protected].

Chemical References

• Anti-Bacterial Agents
• beta-Lactams
• Cefixime
• Ertapenem

Topics

• Anti-Bacterial Agents (pharmacology)
• Cefixime (pharmacology)
• Ertapenem
• Gonorrhea (microbiology)
• Humans
• Inhibitory Concentration 50
• Microbial Sensitivity Tests
• Multilocus Sequence Typing
• Neisseria gonorrhoeae (classification, drug effects, genetics, isolation & purification)
• beta-Lactams (pharmacology)