Sensitivity of Bacteroidaceae to fosfomycin

Area of Science:

• Microbiology
• Infectious Diseases
• Pharmacology

Background:

• Bacteroides fragilis and Sphaerophorus are anaerobic bacteria that can cause infections.
• Fosfomycin is an antibiotic with broad-spectrum activity.
• Understanding bacterial susceptibility to antibiotics is crucial for effective treatment.

Purpose of the Study:

• To evaluate the in vitro sensitivity of Bacteroides fragilis and Sphaerophorus strains to fosfomycin.
• To determine if fosfomycin sensitivity can serve as a differentiating marker between these two genera.
• To assess the potential therapeutic utility of fosfomycin against infections caused by these bacteria.

Main Methods:

• Tested 116 strains of Bacteroides fragilis and 60 strains of Sphaerophorus for fosfomycin sensitivity.
• Utilized the progressive dilution method in a solid medium with surface inoculation.
• Identified bacterial strains morphologically and biochemically.

Main Results:

• None of the tested Bacteroides fragilis strains were sensitive to fosfomycin at concentrations of 200 µg/ml.
• All Sphaerophorus strains demonstrated sensitivity to fosfomycin at concentrations below 200 µg/ml, within therapeutic margins.
• Significant difference in fosfomycin susceptibility observed between the two bacterial groups.

Conclusions:

• Fosfomycin sensitivity is a reliable method for differentiating between Bacteroides and Sphaerophorus.
• Fosfomycin is not recommended for treating infections caused by Bacteroides fragilis.
• Fosfomycin shows potential as an active antibiotic against Sphaerophorus infections.