Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 2386-2398 2386 Original Research Article https://doi.org/10.20546/ijcmas.2019.803.282 Interaction between some Plant Extracts with some Antibiotics against Staphylococcus aureus from Chickens Ashraf, A. Abd-El Tawab 1 , Ahmed A. Ammar 2 , Ahmed M. Hamouda 3 , Wafaa A. EL Sebaey 4 , Salma S. El-Deen 4 and Safinaz A.M. Elhawary 5* 1 Department of Bacteriology, Immunology and Mycology, Faculty of Veterinary Medicine, Benha University, Moshtoher, Qalyubiyagovernate, Egypt 2 Department of Bacteriology, Immunology and Mycology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Sharkiagovernate, Egypt 3 Animal Health Research Institute Zagazig, Sharkiagovernate, Egypt 4 Animal Health Research, Dokki, Giza, Egypt 5 Faculty of Veterinary Medicine, Benha University, Qalyubiyagovernate, Egypt *Corresponding author ABSTRACT Introduction The incorrect and overuse of existing antimicrobials was becoming a formidable threat in the fight against disease due to the emergence of multi-drug resistant strains (Lambert, 2000; Van Vuuren et al., 2009). Drug synergism between known antimicrobial Multidrug-resistant bacterial strains are becoming a serious problem. Therefore, the application of natural antimicrobial agents from plant extracts combined with antibiotics to overcome this problem is of major importance. The antimicrobial activity of five plants(geranium, turmeric, thyme, ginger and green tea)methanol extract prepared by ultrasonic-assisted (UAE) combined with antibiotics (amoxicillin, doxycycline, gentamicin and difloxacin) against 16 Staphylococcus aureus chickens isolates was tested using in vitro methods. The interactions between plant extracts and antibiotics are known to be either additive or synergistic or antagonistic. The mean zones of inhibition (mm) and the minimum inhibitory concentration (MIC) of plant extracts and of antibiotics and combination between them was determined. The total phenolic content (TPC) and the antioxidant activity (DPPH) of plant extracts were evaluated. Methanol extracts had high total phenolic compounds which used as a source of natural antioxidants. The results revealed that synergistic effects appear thyme with amoxicillin and gentamicin and difloxacin. Turmeric had synergistic effect with amoxicillin, doxycycline, and difloxacin. Synergistic activity against Gram-positive bacteria demonstrated that extracts could be a source of bioactive substances with a broad spectrum of antibacterial activity especially when combined with antibiotics. In addition, extracts are potential safe sources of bioactive compounds, antioxidants, antibacterial agents which might be applied in different foods and pharmaceutical products. Keywords Decimal Assay for Additivity (DAA), Antiradical, Antimicrobial, Amoxicillin, Doxycycline, Gentamicin, Difloxacin Accepted: 20 February 2019 Available Online: 10 March 2019 Article Info International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 8 Number 03 (2019) Journal homepage: http://www.ijcmas.com