It's snot impossible to break down biofilms

Chronic Rhinosinusitis is one of the most common respiratory tract disorders in Europe, affecting 10% of the population. This disease is characterised by inflammation of the paranasal sinuses and nasal airway and is classified as chronic if it lasts for 12 consecutive weeks or more. Current therapy involves topical steroids and nasal douching for chronic disorders and antibiotics for acute, however these methods have been criticised as ineffective and in some exacerbated cases surgery may be warranted to remove mucin build up and nasal blockage. This recalcitrance to medical therapy is due to the biofilm forming capabilities of the bacteria responsible (mostly Staphylococci spp.) which enables a 1000fold increase in resistance to antibiotics. Several novel methods have been proposed for treating biofilms, most predominant of which involves degrading the extracellular DNA (eDNA) which provides stabilisation of the biofilm structure, enhanced adhesion capabilities and enhanced exchange of genetic material. Extracellular deoxyribonucleases (eDNAses) exist which catabolise the eDNA, thus disrupting the existing biofilm.

The authors of this study collected mucin from patients suffering from Chronic Rhinosinusitis and applied the afore mentioned eDNAse, called NucB, isolated from a marine strain of the gram positive bacterium Bacillus licheniformis. Confirmation of biofilm formation and structure was obtained using transmission electron microscopy. The authors applied the NucB to the infected mucus and observed the subsequent degradation of the biofilm. The results of this study show no extracellular biofilm observed in the treated samples.

The authors conclude that this test shows a novel therapeutic methodology which shows promising prospects for the future and whilst I agree with this, I can’t help but point out that this study is only in vitro and clinical trials are a very lengthy and very costly process, often ending prematurely and in disappointment. Nevertheless, ultimately all medical therapies must start somewhere and this study shows that NucB undoubtedly has potential for the control of biofilms. It will be interesting to see the results of the in vivo study on the same enzyme, which is currently being undertaken by the same research group in Newcastle (this is stated in the paper and as far as I know is still underway). 

REF: Shields, R.C., Mokhtar, N., Ford, M. et al (2013) Efficacy of a Marine Bacterial Nuclease against Biofilm Forming Microorganisms Isolated from Chronic Rhinosinusitis. PLoS One, 8 (2), e55339. (Published online)

Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3575374/