Essay On Biofilm

Urinary Catheter Associated Biofilms

Introduction

Biofilms are a type of complex growth that involves multiple species which specialize and carry out individual metabolic processes. A biofilm is composed of various bacterial species including multiple species of fungi, protozoans, and yeasts. These prokaryotic and eukaryotic cells attach to each other in interests of survival using an adhesive of extracellular polymeric substances (EPS). Biofilms function as a protected mode of growth for organisms, promoting their survival in unfavourable environments by enhancing colonization and the trapping of nutrients (Simões et al., 2010). Biofilms form on a variety of surfaces that are in contact with moving liquids, allowing for a constant flow of microorganisms to the biofilm site. However, biofilms can be problematic and cause disease if they form within the body on tissues or medical devices. Urinary catheters are particularly prone to biofilm accumulation, and subsequent build up of biofilm can result in catheter associated urinary tract infection (CAUTI). Currently there are various methods of controlling microbial growth, but novel therapeutic strategies are emerging to effectively eliminate biofilm formation in urinary catheters.

Characteristics of Biofilms

Biofilms are formed when bacteria recognize attachment sites, respond to nutritional cues, and face environmental stresses (Habash, 1999). Biofilm formation occurs in a step-wise fashion as seen in Figure 1. The first step consists of planktonic microorganisms reversibly attaching on to a conditioned surface through adsorption (Figure 1(a)). The organism reaches close proximity to this surface either by random flagellar propulsion or is directed to the surface by chemotax...

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...es, such as UroShield, which has been observed as promoting neutrophil killing of planktonic and biofilm Streptococcus epidermidis cells (Loike et al., 2013).

Conclusion

Biofilms are ubiquitous in nature; however, the addition of an external object further enhances biofilm formation. In the human body implantation of medical devices can foster the growth of biofilms and cause infection. A notable example of an external medical device is the conventional urinary catheter which invites biofilm formation, making the development of CAUTI inevitable. Current methods of treatment for CAUTI include use of antibiotics and a range of preventative measures. Novel therapeutic methods involve a range of strategies, such as catheter impregnation with antimicrobial agents and disruption of quorum sensing; proposing a promising future for CAUTI infected patients.