Dispersion of Pseudomonas Aeruginosa Biofilms

Suny At Binghamton, Binghamton NY

Investigators

Abstract

A grant has been awarded to Dr. David Davies of the State University of New York at Binghamton to isolate, identify and characterize a factor responsible for inducing autodispersion of Pseudomonas aeruginosa biofilms. In nature, bacteria such as P. aeruginosa often grow attached to surfaces rather than suspended in liquid (such as in a laboratory culture broth in a test tube). Surface-attached bacterial growth is known as a biofilm. The goal of the proposed work is to characterize biofilm autodispersion in order to develop novel methods for the control of bacterial biofilms. The dispersion inducing factor will be isolated from spent culture medium by solvent extraction and purified by chromatography followed by standard structural chemical analysis. This analysis will include infrared spectroscopy for functional group identification, mass spectrometry and nuclear magnetic resonance spectroscopy. The isolated factor will be tested to determine its effectiveness as a dispersion inducer throughout each stage of the isolation process. Isolated fractions containing the inducer compound(s) will be added to simulated biofilms using a rapid screening technique and these will be verified in tests with continuous culture biofilm populations. This work will incorporate undergraduate student research participation during the academic year and summer term. Student training in the departments of chemistry and biology will include laboratory sections on spectral identification of factors in spent medium and antibiotic efficacy testing of dispersion induced and non-induced bacterial biofilms. Microbial biofilms in infections and in industrial systems present significant problems due to their resistance to treatment by microbicidal agents. This resistance is due in large part to the aggregated nature of cells in biofilms. It has been discovered in Dr. Davies' laboratory that cell-free spent medium recovered from high cell density cultures of P. aeruginosa is capable of inducing biofilm autodispersion when added exogenously to growing biofilms. The proposed work is expected to provide a novel approach to control biofilm formation and persistence by P. aeruginosa and lead to the development of strategies for enhanced biofilm control and removal in industrial, household and medical applications.