Synergistic antimicrobial effects of ethanol extracts of Rubus corchorifolius L.f leaves and antibiotics

The minimum inhibitory concentration（MIC）of RE and antibiotics on Escherichia coli，Shigella dysenteroae，and Salmonella were measured by Kirby-Bauer text（K-B）. Then Rubus corchorifolius L.f leaves（RE） was used to combine with antibiotics. Fractional inhibitory concentration（FIC） was measured by checkerboard microevolutio and K-B method. The results showed that E. coli，S. dysenteroae and Salmonella were used as microbial strains to test the antibacterial activity，the MICs of RE were 6.250 mg/mL，6.250 mg/mL，3.125 mg/mL，respectively. The minimum FICs of combined use of RE and aureomycin were 0.313，0.375，0.313，and the best ratios were 1/8MIC1∶1/2MIC2， 1/4MIC1∶1/2MIC2，1/8MIC1∶1/2MIC2，respectively. The minimum FICs of combined use of RE and Jingqiusan were 0.375， 0.313，0.375，and the best ratios were respectively. When theconcentration of RE was 1/4~1/8MIC1，and the concentrations of aureomycin and Jingqiusan were 1/2MIC2，the synergistic antimicrobial effects on E. coli，S. dysenteroae and Salmonella were strong.