Medicinal plants are re-emerging as an important source of novel bioactive compounds for human health. On the other hand due to the presence of structurally diverse bioactive compounds with multiple therapeutic effects medicinal plant extract/products are now standardized for use as modern phytomedicine. This book provides elaborated introduction of the bacterial drug resistance with special reference to methicillin resistant Staphylococcus aureus (MRSA) and extended spectrum beta lactamases producing strains of enteric bacteria. This monograph provides extensive research on more than fifty medicinal plants of Indian origin on antifungal, antibacterial, antioxidant and antimutagenic activities. Methodology used for microbial cultivation and various assays for detecting biological activities of plant extracts along with basic phytochemistry is explained. The works reported here also focus on synergistic interaction between plant extract and with antibiotics. This book is a useful research document for students, researchers, clinicians and herbal product formulators for developing plant based novel herbal formulation and discovery of new therapeutic compounds