Biofilms Research—Implications to Biosafety and Public Health

Biofilms have been implicated in a variety of nosocomial infections associated with medical devices, hospital equipment, and other hard surfaces. In addition, household and workplace surfaces such as sinks, countertops, toilets, and cutting boards can act as reservoirs. This study’s objective was to identify and evaluate literature reporting resistance to antimicrobial agents in biofilm populations. These review findings suggest that the research evaluating resistance in biofilms could be grouped into the following three mechanisms: (1) physicochemical barriers; (2) biological factors; and (3) phenotypic changes. Current research has identified potential mechanisms of antimicrobial resistance, but there is no clear evidence supporting any one mechanism. Moreover, no reported studies examine the potential impact of biofilms on biosafety practices and the public health risk of infectious diseases from biofilms in healthcare facilities and the workplace environment. Future research directions in biofilms are likely to focus on: (a) imaging of biofilms in situ, (b) in vitro and in vivo models of biofilms, (c) genetic, metabolic, and immunologic probes for real-time analysis, (d) antimicrobial resistance in multispecies biofilms, and (e) identification and characterization of phenotypic modifications. In our assessment, these studies will provide the basis to develop guidelines for biofilm-related biosafety and public health risk assessment. Introduction A biofilm is a community (population) of microorganisms that may include bacteria, fungi, yeasts, and protozoa, attached to a solid surface. Biofilms are produced by microorganisms and consist of a sticky rigid structure of polysaccharides and other organic contaminants. This slime layer is anchored to a surface and provides a protective environment in which microorganisms grow. Biofilms generally form on any surface that is exposed to nonsterile water or other liquids and are consequently found in many environmental, industrial, and medical environments. Considerable evidence exists in the scientific literature that implicates biofilms as being responsible for a variety of nosocomial infections associated with medical devices, hospital equipment, and other hard surfaces. In addition, household and workplace surfaces such as sinks, countertops, toilets, and cutting boards can act as reservoirs. There is some evidence linking biofilms to diseases such as otitis media (common ear infection), bacterial endocarditis, and Legionnaire’s disease. Biofilms have also been found in patients with cystic fibrosis. Ongoing biofilms research is primarily focused on: (a) the development of new methodologies to examine the physicochemical characteristics of biofilms, (b) identification of barriers that limit diffusion of antimicrobials, and (c) understanding antimicrobial resistance due to phenotypic and genotypic alterations. Reduced efficacy of antimicrobial agents is a major concern in the biofilm environment. Published Applied Biosafety, 10(2) pp. 83-90 © ABSA 2005 Article Biofilms Research—Implications to Biosafety and Public Health Venkat Rao, Rashmi Ghei, and Yildiz Chambers Computer Sciences Corporation, Rockville, Maryland