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Effect of non-beta-lactam antibiotics on penicillin-binding protein synthesis of Enterococcus hirae ATCC 9790

A Grossato1, R Sartori, R Fontana

  • 1Institute of Microbiology, University of Padua, Italy.

The Journal of Antimicrobial Chemotherapy
|March 1, 1991
PubMed

Insights

Certain antibiotics like fosfomycin, bacitracin, and vancomycin show synergistic effects with penicillin against Enterococcus hirae. This synergy may stem from their impact on penicillin-binding proteins (PBPs) crucial for bacterial cell wall synthesis.

Area of Science:

  • Microbiology
  • Antibiotic Resistance
  • Bacterial Cell Wall Synthesis

Background:

  • Enterococcus hirae is a bacterium relevant in clinical settings.
  • Antibiotic synergy can enhance treatment efficacy and combat resistance.
  • Penicillin-binding proteins (PBPs) are essential targets for beta-lactam antibiotics.

Purpose of the Study:

  • To investigate the synergistic effects of fosfomycin, bacitracin, and vancomycin in combination with penicillin against Enterococcus hirae ATCC 9790.
  • To elucidate the impact of these non-beta-lactam antibiotics on penicillin-binding proteins (PBPs) in Enterococcus hirae.

Main Methods:

  • Testing synergistic effects of antibiotic combinations against Enterococcus hirae.
  • Incubating Enterococcus hirae with the minimum inhibitory concentration (MIC) of non-beta-lactam antibiotics.
  • Analyzing alterations in penicillin-binding protein (PBP) patterns using gel electrophoresis or similar techniques.

Main Results:

  • Fosfomycin, bacitracin, and vancomycin demonstrated synergistic activity with penicillin against Enterococcus hirae.
  • Incubation with non-beta-lactam antibiotics altered the pattern of PBPs.
  • Bacitracin and vancomycin reduced the density of all PBPs, while fosfomycin specifically reduced PBP 6 density.

Conclusions:

  • The observed synergy between fosfomycin, bacitracin, vancomycin, and penicillin against Enterococcus hirae is likely due to the inhibition of PBP synthesis.
  • These antibiotics target early stages of peptidoglycan synthesis, preceding cross-link formation.
  • Understanding PBP alterations provides insights into novel antibacterial strategies.

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