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LY146032: activity and resistance development in vitro

R P Mouton1, S L Mulders

  • 1Department of Medical Microbiology, University Hospital Leiden, The Netherlands.

The Journal of Antimicrobial Chemotherapy
|October 1, 1987
PubMed

Insights

LY146032, a novel lipopeptide antibiotic, demonstrated broad-spectrum activity against Gram-positive bacteria, including resistant strains. While resistance developed to all tested antibiotics, LY146032 showed promising bactericidal effects against specific pathogens.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Antibiotic resistance is a growing global health threat, necessitating the development of new antimicrobial agents.
  • Gram-positive bacteria, including Staphylococcus spp. and Streptococcus faecalis, are significant causes of hospital-acquired infections.
  • Existing antibiotics like vancomycin and teicoplanin face challenges with emerging resistance.

Purpose of the Study:

  • To evaluate the in vitro activity of LY146032, a novel lipopeptide antibiotic, against a panel of clinical isolates.
  • To compare the efficacy of LY146032 with established antibiotics: vancomycin, teicoplanin, cefamandole, and ciprofloxacin.
  • To assess the potential for resistance development to LY146032 and other agents.

Main Methods:

  • Antimicrobial susceptibility testing was performed on 107 clinical isolates, including methicillin-susceptible and methicillin-resistant Staphylococcus spp., Streptococcus faecalis, and Corynebacterium spp.
  • Bactericidal activity was assessed for LY146032 and ciprofloxacin against Streptococcus faecalis.
  • Resistance development was studied through serial transfer experiments with ten selected strains to determine minimum inhibitory concentration (MIC) changes.

Main Results:

  • All tested staphylococci were susceptible to LY146032, vancomycin, teicoplanin, and ciprofloxacin. Some methicillin-resistant strains showed resistance to cefamandole.
  • LY146032 and ciprofloxacin exhibited bactericidal activity against Streptococcus faecalis.
  • A stable, greater than or equal to eight-fold increase in MIC was observed against all tested agents, indicating variable resistance development. Simultaneous resistance to other antibiotics occurred in 11/200 tests.

Conclusions:

  • LY146032 demonstrates potent in vitro activity against a range of Gram-positive bacteria, including resistant strains.
  • The lipopeptide antibiotic shows bactericidal potential against Streptococcus faecalis.
  • While resistance can develop to LY146032, its profile warrants further investigation as a potential therapeutic agent.

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