Real time monitoring of biofilm formation on coated medical devices for the reduction and interception of bacterial infections

Abstract

Real time monitoring of bacterial attachment to medical devices provides opportunities to detect early biofilm formation and instigate appropriate interventions before infection develops. This study utilises long period grating (LPG) optical fibre sensors, incorporated into the lumen of endotracheal tubes (ETTs), to monitor in real time, Pseudomonas aeruginosa surface colonisation and biofilm formation. The wavelength shift of LPG attenuation bands was monitored for 24 h and compared with biofilm biomass, quantified using confocal fluorescence microscopy imaging. Biofilm formation was compared on uncoated ETTs and optical fibres, and on a biofilm resistant acrylate polymer, after challenge in an artificial sputum or minimal growth medium (RPMI-1640). The LPG sensor was able to detect a biofilm biomass as low as 81 µg cm −2 , by comparison with the confocal image quantification. An empirical exponential function was found to link the optical attenuation wavelength shift with the inverse of the biofilm biomass, allowing quantification of biofouling from the spectral response. Quantification from the sensor allows infection interception and early device removal, to reduce, for example, the risk of ventilator associated pneumonia. † Electronic supplementary information (ESI) available. See Fig. 3 Assessment of biofilm resistant polymer in situ. (a) A patient intubated with an EGDPEA:DEGMA coated ETT. (b) Bacterial attachment and biofilm formation on an uncoated ETT surface. (c) The polymer coating reduces bacterial attachment to an ETT surface.

Biofilm formation on three different endotracheal tubes: a prospective clinical trial

“…Being able to monitor or predict the grade of biofilm formation is of clinical importance, because our findings indicate that high-grade biofilm formation is associated with the development of VAP. Methods for continuous monitoring of biofilm formation on ETTs have been described in laboratory models in which optical fiber sensors are incorporated in the lumen of the ETT [28]. This approach represents an interesting tool for clinical use, although it must first be evaluated in such a setting.…”

Biofilm formation on three different endotracheal tubes: a prospective clinical trial

“…Being able to monitor or predict the grade of biofilm formation is of clinical importance, as our findings indicate that high-grade biofilm formation (not just biofilm formation at any stage) is associated with the development of VAP. Methods for continuous monitoring of biofilm formation on ETTs are described in laboratory models utilizing optical fiber sensors, incorporated into the lumen of the ETT [38]. This could be an interesting tool for clinical use, but needs clinical evaluation.…”

“…With the emergence of multiresistant bacteria and fewer choices for antimicrobial treatment of VAP, ETT routines may change [41]. Methods aimed at the continuous monitoring of biofilm formation [38] are warranted, because few predictive factors are known at the moment. Biofilm removal without ETT removal by use of tools such as the mucus shaver or photodynamic inactivation are promising but must be further evaluated [42,43].…”

Biofilm formation on three different endotracheal tubes: a prospective clinical trial

“…Being able to monitor or predict the grade of bio lm formation is of clinical importance, because our ndings indicate that high-grade bio lm formation is associated with the development of VAP. Methods for continuous monitoring of bio lm formation on ETTs have been described in laboratory models in which optical ber sensors are incorporated in the lumen of the ETT [28]. This approach represents an interesting tool for clinical use, although it must rst be evaluated in such a setting.…”