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Antistaphylococcal activity of pentamidine
M D Libman1, M A Miller, G K Richards
1McGill University, Montreal General Hospital, Quebec, Canada.
Antimicrobial Agents and Chemotherapy
|September 1, 1990
Summary
Pentamidine isethionate demonstrates bacteriostatic effects against various bacteria and Candida albicans. It inhibits Staphylococcus aureus at concentrations of 16-64 µg/ml and kills it at higher doses, with enhanced efficacy in the presence of cations.
Area of Science:
- Microbiology
- Antimicrobial Agents
Background:
- Pentamidine isethionate is an antimicrobial compound with a history of use in treating certain infections.
- Understanding its spectrum of activity and factors influencing its efficacy is crucial for potential therapeutic applications.
Purpose of the Study:
- To evaluate the bacteriostatic and bactericidal activity of pentamidine isethionate against a panel of relevant microorganisms.
- To investigate the influence of cations and methicillin resistance on the antimicrobial efficacy of pentamidine isethionate against Staphylococcus species.
Main Methods:
- Broth microdilution assays were performed to determine the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs).
- Antimicrobial activity was assessed in the presence and absence of various cations.
- Susceptibility testing included methicillin-susceptible and methicillin-resistant strains of Staphylococcus aureus.
Main Results:
- Pentamidine isethionate exhibited bacteriostatic activity against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus sanguis, Micrococcus sp., and Candida albicans.
- Staphylococcus aureus was inhibited at concentrations ranging from 16 to 64 µg/ml and killed at concentrations from 64 to ≥128 µg/ml.
- Staphylococcal killing was significantly enhanced in the presence of cations and was not affected by methicillin resistance.
Conclusions:
- Pentamidine isethionate possesses broad-spectrum bacteriostatic activity against Gram-positive bacteria and yeast.
- The presence of cations potentiates the bactericidal effect of pentamidine isethionate against staphylococci.
- Methicillin resistance does not alter the susceptibility of Staphylococcus aureus to pentamidine isethionate.