Thermal mitigation of Pseudomonas aeruginosa biofilms

Abstract

Bacterial biofilms infect 2–4% of medical devices upon implantation, resulting in multiple surgeries and increased recovery time due to the very great increase in antibiotic resistance in the biofilm phenotype. This work investigates the feasibility of thermal mitigation of biofilms at physiologically accessible temperatures. Pseudomonas aeruginosa biofilms were cultured to high bacterial density (1.7 × 10⁹ CFU cm⁻²) and subjected to thermal shocks ranging from 50°C to 80°C for durations of 1–30 min. The decrease in viable bacteria was closely correlated with an Arrhenius temperature dependence and Weibull-style time dependence, demonstrating up to six orders of magnitude reduction in bacterial load. The bacterial load for films with more conventional initial bacterial densities dropped below quantifiable levels, indicating thermal mitigation as a viable approach to biofilm control.

Keywords:

• Pseudomonas aeruginosa
• biofilm
• infection
• heat shock
• implanted medical device

Acknowledgements

The content of this material is solely the responsibility of the authors and does not necessarily represent the official views of the supporting agencies.

Disclosure statement

The authors declare that they have no conflict of interest related to this work.

Supplemental material

The supplemental material for this paper is available online at http://dx.doi.org/10.1080/08927014.2015.1083985.

Additional information

Funding

The authors gratefully acknowledge support from the American Heart Association [11SDG7600044] and the National Science Foundation [CBET-1133297]. E. Ricker was supported by the Predoctoral Training Program in Biotechnology from the National Institute for General Medical Sciences of the National Institutes of Health [5T32GM008365]. A. O’Toole was supported by a training grant from the Iowa Center for Biocatalysis and Bioprocessing, also associated with the above NIGMS NIH Predoctoral Training Program in Biotechnology.