EFEK PENAMBAHAN FRAKSI SEMIPOLAR (F11-F17) Imperata cylindricaDENGAN AMOXICILLIN DAN CHLORA,PHENICOLTERHADAP DAYA HAMBAT PADA Staphylococcus aureus DAN Escherichia coli

Introduction: Infection in Indonesia is a major problem in the health sector which is characterized by an increasingly high prevalence of disease due to infection. The combination of Alang-alang herbs with antibiotics can be an alternative therapy for infection to prevent an increase in the rate of single antibiotic resistance so that the number of infectious diseases can be suppressed. This study aims to assess the inhibitory effect of the combination of the antibiotic amoxicillin or chloramphenicol with a semi-polar fraction (F11-17) on the bacteria S.aureus and E.coli.Methods: Imperata methanolic extract was obtained by maceration method followed by the fractionation process using ethyl acetate and methanol eluent. Zone of Inhibition (ZOI) test to see the inhibition through the calculation of the diameter of the clear zone which is assessed based on the Ameri-Ziaei Double Antibiotic Synergic Test (AZDAST) method. Data were analyzed using parametric test Dependent T Test followed by the Mann-Whitney test. Phytochemical test analysis using TLC sprayed with reagents and observed the color changes.Results: Phytochemical test F11-12 obtained alkaloids and F12-14 obtained phenols. The combination of Chloramphenicol with F134shows the type of antagonistic interaction in E. coli bacteria with a value of 13,3±1,5 and the significance of p = 0.046. In addition to F13, there is a type of not distinguishable interaction on antibiotics against S.aureus and E.coli.Conclusion: Single herbal F11-17 has no antimicrobial activity. In F11-12 has alkaloids and F14 has phenol content. In F13 its has an antagonistic effects with chloramphenicol in combination in E.coliKeywords: Phytochemical test, ZOI, amoxicillin, chloramphenicol, Alang-alang, combinations of herbal antibioti