Role for Biofilms in Infectious Disease

Garth D. Ehrlich; Fen Z. Hu; J. Christopher Post

doi:10.1128/9781555817718.ch18

Chapter 18 : Role for Biofilms in Infectious Disease

Authors: Garth D. Ehrlich¹, Fen Z. Hu², J. Christopher Post³

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Affiliations: 1: Center for Genomic Sciences, Allegheny Singer Research Institute, 320 East North Avenue, Pittsburgh, Pennsylvania 15212; 2: Center for Genomic Sciences, Allegheny Singer Research Institute, 320 East North Avenue, Pittsburgh, Pennsylvania 15212; 3: Center for Genomic Sciences, Allegheny Singer Research Institute, 320 East North Avenue, Pittsburgh, Pennsylvania 15212

Content Type: Monograph

Publication Year: 2004

Category: Environmental Microbiology; Microbial Genetics and Molecular Biology

Book DOI: 10.1128/9781555817718

Chapter DOI: 10.1128/9781555817718.ch18

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Abstract:

This chapter examines the mutualistic, commensal, and parasitic roles that biofilms play in human biology and health by using an organ system/medical specialty approach. Recently there has been a growing awareness that a number of nondevice-related chronic inflammatory conditions are, in fact, also biofilm-related. Many of these conditions, including cystic fibrosis, chronic obstructive pulmonary disease (COPD), otitis media, and prostatitis, are highly visible and prevalent diseases. Antibiotic sensitivities are generally determined by observing the zone of planktonic growth inhibition around a disc containing the antibiotic of interest. This chapter deals primarily with two topics: (i) how the phenotypic and genotypic characterization of biofilm bacteria has provided the data for the development of a new conceptual framework for the understanding of chronic infections and (ii) the medical effects of biofilm formation on host tissues and implanted medical devices. The cardinal clinical feature of bacterial biofilms is their refractoriness to nearly all host defense mechanisms and conventional therapeutics, including antibiotics. The removal of a single prosthetic joint due to biofilm infection is followed by the intravenous administration of hundreds of thousands of dollars of antibiotics. Bacterial and candidal vaginosis result when there is a disruption of the normal vaginal flora resulting in overgrowth of pathogenic bacteria and fungi.

Citation: Ehrlich G, Hu F, Post J. 2004. Role for Biofilms in Infectious Disease, p 332-358. In Ghannoum M, O'Toole G (ed), Microbial Biofilms. ASM Press, Washington, DC. doi: 10.1128/9781555817718.ch18

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Role for Biofilms in Infectious Disease

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/content/10.1128/9781555817718.chap18.fig18-1

FIGURE 1

O2 concentration measurements in a P. aeruginosa biofilm. O2 concentration is important in determining the growth rate and antibiotic susceptibility of the bacteria. (A) Oxygen concentration, measured with a microelectrode, decreases with depth into the biofilm. (B) Result of an experiment in which the electrode was left at the final depth (70 µm) where the O2 tension was low. The O2 concentration changes dramatically in response to changes in the availability of the carbon (glucose) and nitrogen (ammonium) source (denoted as C and N). The experiment shows that when the C and N sources are removed from the medium, O2 levels increase due to decreased consumption. (Provided by Phil Stewart.)

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FIGURE 1

/content/10.1128/9781555817718.chap18.fig18-2

FIGURE 2

Scanning electron micrograph of the outer surface of a ventricular-peritoneal shunt removed from a patient. Note the extensive Staphylococcus sp. biofilm present on the surface, in which bacteria can be seen embedded in a glycocalyx. The specimen was fixed and dehydrated prior to imaging, which results in a collapse of the biofilm matrix around the bacteria. The bar in the lower right indicates 1 _m. Image supplied by R. Veeh.

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FIGURE 2

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