Antimicrobial activity biofilms with

The increasing occurrence of microbial and nosocomial infection has stimulated research activities into antimicrobial polymers and textiles [19, 25, 34]. Most medical textiles and polymeric materials used in hospitals are conductive to crosstransmission of diseases, as most microorganisms can survive on these materials for hours to several months [17, 26]. Thus, it would be advantageous for polymeric surfaces and textile materials to exhibit antibacterial properties so as to reduce and prevent disease transmission and cross-contamination within and from hospitals. N-halamines exhibit a similar antimicrobial potency to chlorine bleach, one of the most widely used disinfectants, but they are much more stable, less corrosive and have a considerably reduced tendency to generate halogenated hydrocarbons, making them attractive candidates for the production of antimicrobial polymeric materials. N-halamine compounds are currently used as antimicrobial additives to produce polymers with antimicrobial and biofilm-limiting activities. 

It is important to note that antimicrobial and biofilm resistance are two different characteristics though some materials show both properties at the same time. Antimicrobial materials do not automatically prevent biofilm formation and vice versa. Antimicrobial surfaces could kill bacteria on contact but if dead bacteria cell debris blocks the active biocidal surface, biofilm formation could eventually occur. For example, quaternary anunonium polymers can effectively kill bacteria but when the surface is fouled with dead bacteria debris, biofilm formation is inevitable [188]. Materials with antibiofilm properties will repel the bacterial adhesion very effectively but may not kill the bacteria when they do colonize the surface. PEG surfaces are well known to repel bacteria adhesion. However, PEG surfaces show little antimicrobial activity. Quantitative antibiofilm efficacy tests can be divided into two categories static (minimum biofilm eradication concentration assay, MBEC) and dynamic (flow cell assay). In addition, SEM is a semiquantitative assay, which is discussed in Section 2.5. 

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