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Postantibiotic effects of daptomycin against 14 staphylococcal and pneumococcal clinical isolates

G A Pankuch1, M R Jacobs, P C Appelbaum

  • 1Department of Pathology, Hershey Medical Center, Hershey, Pennsylvania 17033, USA.

Antimicrobial Agents and Chemotherapy
|August 26, 2003
PubMed

Insights

Daptomycin exhibits significant postantibiotic effects (PAEs) against Staphylococcus and Streptococcus pneumoniae, lasting several hours even at sub-minimum inhibitory concentrations. These findings are crucial for optimizing daptomycin dosing regimens.

Area of Science:

  • Pharmacology and Microbiology
  • Antibiotic Resistance Studies

Background:

  • Daptomycin is a critical antibiotic for treating Gram-positive bacterial infections.
  • Understanding postantibiotic effects (PAEs) is essential for optimizing antibiotic therapy and combating resistance.

Purpose of the Study:

  • To quantify the postantibiotic effects (PAEs) of daptomycin against Staphylococcus species.
  • To determine the postantibiotic effects (PAEs) of daptomycin against Streptococcus pneumoniae.
  • To evaluate the sub-minimum inhibitory concentration (sub-MIC) effects of daptomycin on these bacteria.

Main Methods:

  • Bacterial cultures of Staphylococcus and Streptococcus pneumoniae were exposed to daptomycin.
  • Postantibiotic effects (PAEs) were measured by determining the duration of bacterial growth inhibition after antibiotic removal.
  • Sub-minimum inhibitory concentration (sub-MIC) effects were assessed at 0.4 times the minimum inhibitory concentration (MIC).

Main Results:

  • Mean staphylococcal PAEs ranged from 1.1 to 6.2 hours (mean 2.5 h).
  • Mean pneumococcal PAEs ranged from 1.0 to 2.5 hours (mean 1.7 h).
  • Sub-MIC effects for Staphylococcus and Streptococcus pneumoniae were prolonged, ranging from 3.0 to >12.0 hours and 1.9 to >12.0 hours, respectively.

Conclusions:

  • Daptomycin demonstrates substantial and prolonged postantibiotic effects against both Staphylococcus and Streptococcus pneumoniae.
  • Significant bacterial growth inhibition persists even at sub-minimum inhibitory concentrations, suggesting potential for extended dosing intervals.
  • These findings have implications for refining daptomycin treatment strategies to improve efficacy and manage bacterial resistance.

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