الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Biofilms are commonly associated with many health problems, such as endocarditis, otitis media, periodontitis, prostatitis, and urinary tract infections. Several bacteria, such as Escherichia coli, Staphylococcus aureus, Streptococcus mutans, and Pseudomonas aeruginosa, or fungal pathogen as Candida albicans, can form biofilms in the body tissues, leading to different infections.
The inherently defensive character of the biofilm is demonstrated by enhanced persistence of bacteria grown in the sessile mode respect to bacteria grown planktonically. This makes most biofilm-associated infections difficult to eradicate, thus contributing to disease chronicity. Many medical device-associated and persistent infections can be attributed to biofilm-associated microbes. To tackle the overarching public health issue of the contribution of biofilms to health care-associated infections,it was suggested that clinicians and health care workers should be more closely involved intheir detection and treatment. It was also suggested that the applied science of biofilm formation and prevention would provide greater knowledge of the contamination of medical devices. Some answers are to be found in the development of the anti-biofilm activities of beneficial microbes and/or the understanding and diversion of the anti-biofilm capacities of pathogenic bacteria. Since natural products providea diverse array of chemical structures and possess a wide variety of biological properties, natural resources are worldwide exploited in the search of new anti-biofilms.The main aim of the present study was to search for new anti-biofilm agents from somenatural compoundsisolated from natural sources and their synthetic derivativesin an attempt to combat biofilm-forming ability of some selected microorganisms.In the present work, a number of compounds of natural origins and their synthetic derivativeswere tested for their anti-microbial and potential anti-biofilm activities.
Seven of these compounds were from natural sources (catechol, chitosan, cinnamic acid, gallic acid, lactoferrin, pyrogallol and vanillin), two were of non-natural source (DMAB andPVA) and two were synthesized derivatives of chitosan (chitosan-DMAB and chitosan-vanillin).
The tested microbial reference strains were Candida albicans(ATCC 10231), Escherichia coli(ATCC 25922), Pseudomonas aeruginosa(ATCC 15442), Salmonella typhimurium(ATCC 25566) Staphylococcus aureus(ATCC 6538), and Staphylococcus epidermidis(ATCC 12228)