Objective To study the in vitro
antibacterial activities of Fructus forsythiae, Folium isatidis, Spica prunellae, dried root-bark of Rhus chinensis,
volatile oil of Herba scutellariae barbatae against 139 strains of
bacteria commonly encountered in the clinic. Methods Decoctions of the 5 traditional Chinese
medicines at specified concentrations were prepared and the in vitro antibacterial activities of the 5 traditional Chinese medicines and 3 of these drugs in combination with levoflacin against 139 strains of bacteria were determined according to the K-B methods. Results Folium Isatidis, root-bark of Rhus chinensis and volatile oil of Herba scutellariae barbatae were shown to exert definite bacteriostatic effects on the 139 strains of bacteria while Fructus forsythiae and Spica Prunellae had little effect on these bacteria. The bacteriostatic effects of Folium isatidis, root-bark of Rhus chinensis and volatile oil of Herba scutellariae barbatae on these 139 strains of bacteria were enhanced when they were separately combined with levoflacin. Conclusion Better antibacterial activities against bacteria commonly encountered in the clinic may be achieved by the combined application of traditional Chinese medicines and antibiotics.