Global Advanced Research Journal of Medicine and Medical Sciences (ISSN: 2315-5159) Vol. 6(10) pp. 240-244, October, 2017 Available online http://garj.org/garjmms Copyright © 2017 Global Advanced Research Journals Full Length Research Paper Antibacterial activity of crude herbal extracts of Zingiber officinale and Curcuma longa against 13 reference bacterial species Sami S. Ashgar Microbiology Department, College of Medicine, Umm Al-Qura University, Saudi Arabia. E-mail – ssashgar70@hotmail.com; Mobile: +966(0) 505 794 955 Accepted 09 October, 2017 Medicinal plants acquired great attention for their miracle properties against various human illnesses. In this laboratory-based study, Antibacterial effectiveness of Curcuma longa and Zingiber officinale (Ginger) were extracted in aqueous, 70% ethanol and ethyl acetate solvents and investigated against 13 various American type culture collection (ATCC) strains by the mean of determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results demonstrated that ethyl acetate extract of Curcuma longa was superior to other solvents versus Enterococcus faecalis, Enterococcus faecalis (VRE), Staphylococcus aureus (MRSA) and Staphylococcus epidermidis with inhibition zones range (12-19mm) and exhibited killing concentration varies between 25-50 mg/ml. Acinetobacter baumannii expressed visible sensitivity to Curcuma longa extracted in aqueous, ethanol and ethyl acetate solvents. Bactericidal activity was experimentally constant at a concentration of 50mg/ml. Ethyl acetate extract of Ginger, on the other hand, was the only extract that showed antibacterial activity against three reference bacterial strains include E. faecalis, S. aureus and Staphylococcus aureus (MRSA), with inhibition zones range (12-19mm) and MBC value of 100, 12.5 and 25 mg/ml, respectively. In conclusion, demonstrated antibacterial activity of Curcuma longa and Zingiber officinale can be further invested as potential natural antibiotics against some multi- resistant pathogens. Keywords: Curcuma longa, Zingiber officinale, MIC, MBC, ethyl acetate, ethanol, aqueous, ATCC strains. INTRODUCTION Medicinal plants considered the main source of traditional medicine almost all over the world due to their accessibility, affordability and limited side effect. For centuries, medicinal plants used to improve human health (WHO, 2002). Furthermore, estimated 60-90% of the population in some developing countries such as Uganda and Ethiopia used medicinal plants extensively as a major component of traditional medicine and part of primary health care (WHO, 2002). Herbs are still used to treat a variety of health problems. The use of traditional medicine among the local population and the tribe societies in Saudi Arabia measured as great part of the traditions. it started from ancient eras and still up to the present time (Al-Daihan et al., 2013). Medicinal plant ingredients have played an important role in traditional Western medicine, in 1984, at least 25% of the exported drugs in the United States and Canada ware derived from natural plant products (Balunas and Kinghorn, 2005). Patrons of herbal medicines showed growing interest as they see the benefit of using herbs in treating physical health problems and inspired researchers to investigate the effect of various biological activities of the medicinal