The application discloses a synergistic bactericidal composition, comprising the following components: a
toona sinensis extract: 16-2048 mu g / mL; a macrolide antibiotic: 0.0625-4096 mu g / mL; the
bacteria are
staphylococcus aureus or methicillin-resistant
staphylococcus aureus, and the macrolide antibiotic is
erythromycin or
azithromycin. The application further discloses a use of the synergistic bactericidal composition in preparation of a
medicine for treating
skin and
soft tissue infections. The composition provided by the application can convert the traditional
macrolide antibiotics such as
erythromycin and
azithromycin which only have a bacteriostatic effect into a preparation which has clear bactericidal activity on
staphylococcus aureus and
drug-resistant strains thereof. After the
toona sinensis extract is combined with the antibiotic, a synergistic effect is exhibited, and the concentration of the
toona sinensis extract and the antibiotic required when the
toona sinensis extract and the antibiotic are used alone can be greatly reduced.