Dynamic models for in vitro biofilm formation

• Autor(a) principal: Pavarina, A. C. [UNESP]
• Data de Publicação: 2011
• Outros Autores: Dovigo, L. N. [UNESP], Sanitá, P. V. [UNESP], Machado, A. L. [UNESP], Giampaolo, E. T. [UNESP], Vergani, C. E. [UNESP]
• Tipo de documento: Capítulo de livro
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/227129

Since biofilms are resistant both to host defense mechanisms and to antimicrobialagents, they represent an ongoing source of infection.Investigations of natural biofilmsare restricted because of problems with access and sampling, in addition to complicationsdue to ethical aspects.In vitro biofilm models are important tools in experimental medicalscience to better understand the development and behavior of such microbialcommunities.Laboratory models that intend to mimic natural biofilms may be morecontrollable than in vivo protocols and therefore more useful to explain and predict theirbehavior.In vitro systems range from static mono-cultures to the development of diversemixed cultures growing under dynamic conditions.Given that in vivo conditions arealmost exclusively dynamic, studies evaluating biofilm formation under static conditionsmight be somewhat misleading.One of the most used dynamic models to study biofilmmode of growth is the flow cell system, which consists of a transparent chamber of fixeddepth through which the growth medium passes.In conjunction with a microscope andcamera, this method can be used to observe the early events of biofilm formation(microbial adhesion) and the interactions between microorganisms and substrata in realtime.Chemostats can also be used to study the dynamic growth of microorganismpopulations on experimental substrates submerged within the chemostat.One of the mostimportant features of chemostats is that microorganisms can be grown at a constantrate.Moreover, during biofilm formation, culture parameters such temperature and pHremain constant.Analogous to the operation of the chemostat, there is another category ofreactors in which biofilms are formed on thin filter membranes in a physiological steadystate.These systems permitanalyses of the growth rate dependence and cell-cyclespecificity of antibacterial agents by collecting the eluate passed thought the filter, whichcontains a cohort of freshly divided cells.Finally, there are constant depth reactors in which surface growth is periodically removed to maintain a constant geometry ofbiofilms.In these reactors, microorganisms can be grown in a physiological steady statewith all culture parameters constant.The system can generate large numbers of biofilmswith comparable and reproducible data from experiment to experiment and has been usedextensively to investigate factors that may influence the growth of microorganismcommunities.Considering the information presented above, this chapter will explore therange of technologies and dynamic systems available for in vitro biofilm formation, development, and maturation. © 2011 by Nova Science Publishers, Inc. All Rights Reserved.