In Vitro Study of the Interaction Between Spiramycin and Secnidazole with Some Disc Antibiotics Using the Decimal Assay for Addidivity (DAA) Method

Abstract

The microbiological evaluation of the interactions between spiramycin and secnidazole was evaluated using the cup plate method (CPM) and disc antibiotics against clinical isolates of Staphylococcus aureus and Escherichia coli.  Serial dilutions of both antibiotics were (5m/ml, 2.5 mg/ml, 1.25 mg/ml, 0.625 mg/ml, 0.3125 mg/ml and 0.15625 mg/ml) were used. Results show that combined spiramycin with any of the quinolones and gentamycin or erythromycin demonstrate no difference as compared to when spiramycin is used alone. Nevertheless, secnidazole demonstrates a synergistic effect when combined with penicillin or pefloxacin against E. coli 1; gentamicin or norfloxacin showed the same effect against E. coli 2. The results here suggest that a better combination should be based on the combination that achieved synergistic effect.