Microbial biofilms and gastrointestinal diseases

Abstract

The majority of bacteria live not planktonically, but as residents of sessile biofilm communities. Such populations have been defined as ‘matrix-enclosed microbial accretions, which adhere to both biological and nonbiological surfaces’. Bacterial formation of biofilm is implicated in many chronic disease states. Growth in this mode promotes survival by increasing community recalcitrance to clearance by host immune effectors and therapeutic antimicrobials. The human gastrointestinal (GI) tract encompasses a plethora of nutritional and physicochemical environments, many of which are ideal for biofilm formation and survival. However, little is known of the nature, function, and clinical relevance of these communities. This review summarizes current knowledge of the composition and association with health and disease of biofilm communities in the GI tract.

Amyloid-DNA Composites of Bacterial Biofilms Stimulate Autoimmunity

“…We think that the difference in the polymerization rates is due to the DNA fragment size in each DNA source. Since enteric bacterial biofilms form in the gastrointestinal tract of humans (Bollinger et al, 2007; Macfarlane et al, 2011; Macfarlane and Dillon, 2007; von Rosenvinge et al, 2013), we also asked whether this acceleration also occurred with eukaryotic DNA. We used salmon sperm DNA and found that it also accelerated curli polymerization by shortening the time in lag phase of polymerization by an average of 155 minutes (Figure 2F–G).…”

Extracellular matrix structure governs invasion resistance in bacterial biofilms

“…Biofilmdwelling cells secrete extracellular substances, including nutrient-sequestering compounds, digestive enzymes and structural matrices composed of proteins, DNA and polysaccharides (Arvidson, 2000;Visca et al, 2007;Stewart and Franklin, 2008;Flemming and Wingender, 2010;Stewart, 2012). The strain composition and spatial arrangement of bacteria in biofilm communities strongly influence the course of bacterial infections, the functioning of our resident microbiota, bacterial contributions to biogeochemical cycling and industrial bioremediation (Nicolella et al, 2000;Costerton, 2001;Oggioni et al, 2006;Arnosti, 2011;von Rosenvinge et al, 2013). Analysis of bacterial communities in spatial detail poses a challenging problem (Nadell et al, 2013), and thus we are only at the early stages of discovering the ecological and evolutionary principles that underlie the dynamic nature of biofilm composition and development.…”

Biofilms associated with bowel necrosis: A newly recognised phenomenon in infants

“…[3,7] Although K. pneumoniae is present as a saprophyte in the gastrointestinal tract, the identification of intramural Klebsiella biofilms has not been published in the English paediatric litera ture. [5,10] The question of whether Klebsiella-associated biofilms were direct aetiological factors in causing bowel necrosis and the death of the patients reported on cannot be proven, but their presence satisfies all four of the Parsek and Singh postulates. [6] We postulate that this sole offending organism shielded from environmental defence mechanisms could have played a part in the unfolding pathogenesis, either as a direct pathogen or promoter thereof.…”

“…[4] The pathogenic role of biofilms has been established for oral infections, chronic wounds, indwelling medical and surgical devices, and implants. [1,3,5] Currently, the link between gastrointestinal infections and biofilms in infants is less clear. [6] We encountered three infants with necrotic small bowel in whom special staining techniques on histological specimens of their resected bowel revealed an abundance of Klebsiella-associated intramural biofilm formations.…”