الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Escherichia coli (E. coli) is a common constituent of the gastrointestinal flora of most vertebrates, including humans, and may be isolated from a variety of environmental sources. Fluoroquinolones (FQs) are broad-spectrum antibiotics that are used to treat several Gram negative (GN) and Gram-positive (GP) bacterial infections. Furthermore, FQ resistance has become a public health concern since it may lead to limitation of available agents in the treatment of many types of infection .FQ resistance usually occurs mainly due to specific point of mutations within the quinolone resistance-determining regions (QRDRs) of either DNA gyrase (gyrA and gyrB) or topoisomerase IV (parC and parE) genes leading to target alterations that decrease the binding affinity of the FQs. many efforts have been made to explore new sources of active antibacterial compounds of plant origin to combat the diseases. Normally during their life cycle, plants encounter various infectious agents’ viz. viruses, bacteria, fungi and other parasites and synthesize a variety of secondary metabolites, which provide protection against infectious agents. So far studies have been done on a number of antibacterial extracts and bioorganic compounds have been identified from so many plants which have shown very good fighting potential against different drug resistant pathogens.