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Nanomechanics of Drug-target Interactions and Antibacterial Resistance Detection
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Nanomechanics of Drug-target Interactions and Antibacterial Resistance Detection

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In vitro activity of LY333328, a new glycopeptide, against extracellular and intracellular vancomycin-resistant

B Al-Nawas1, J Swantes, P M Shah

  • 1Dept. of Oral and Maxillofacial Surgery, Johannes Gutenberg University, Mainz, Germany. al-nawas@mkg.klinik.uni-mainz.de

Infection
|August 29, 2000
PubMed

Insights

LY333328 shows significant activity against vancomycin-resistant enterococci, including intracellular bacteria. This new glycopeptide is effective even after the drug is removed, unlike vancomycin.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Enterococcus faecium and Enterococcus faecalis are significant pathogens, often exhibiting resistance to vancomycin.
  • Vancomycin remains a primary treatment for enterococcal infections, but resistance necessitates alternative therapies.
  • Intracellular bacteria pose a therapeutic challenge, as many antibiotics have limited efficacy against them.

Purpose of the Study:

  • To evaluate the activity of LY333328, a novel semisynthetic glycopeptide, against vancomycin-susceptible and vancomycin-resistant strains of Enterococcus.
  • To compare the efficacy of LY333328 with vancomycin against both extracellular and intracellular enterococci.
  • To assess the activity of LY333328 against intracellular bacteria, even after drug removal.

Main Methods:

  • Colony count method was used to assess bacterial viability.
  • Studies included six strains of Enterococcus faecium and Enterococcus faecalis, with four being vancomycin-resistant.
  • Bacterial activity was tested in the presence of drugs and after preincubation of polymorphonuclear leukocytes (PMN) with drug removal.

Main Results:

  • LY333328 demonstrated activity against all tested enterococci, with minimum inhibitory concentrations (MICs) of 1-2 mg/l.
  • The drug was bacteriostatic against extracellular enterococci at concentrations of 2 µg/ml and above.
  • LY333328 significantly reduced intracellular vancomycin-resistant E. faecium (55%) and E. faecalis (90%) after 4h incubation at 10 MIC.
  • Even after PMN preincubation and drug removal, LY333328 achieved a 20-30% reduction in intracellular bacteria.

Conclusions:

  • LY333328 is effective against vancomycin-resistant enterococci, including intracellular pathogens.
  • Unlike vancomycin, LY333328 retains activity against intracellular vancomycin-resistant enterococci, particularly E. faecalis, even after extracellular drug removal.
  • These findings highlight LY333328 as a promising therapeutic agent for challenging enterococcal infections.

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