Factor Analysis in the Evaluation of the Relationship between Bacterial Adherence to Biomaterials and Changes in Free Energy

Abstract

The relative surface charge and free energy of forty-one coagulase-negative staphylococci were found to be normally distributed; therefore, they can be considered a homogeneous group under strict statistical criteria. The adherence of these bacteria to eight different biomaterials (seven synthetic and one biologic) was found to be independent of charge and variations in free energy during adhesion. Adherence can be explained as a thermodynamic process (free energy decreased with adherence), except in the case of bovine pericardium in which free energy increases. With these biomaterials, a correlation was found between adherence and bacterial charge. Bacterial adherence and bacterial charge correlate with the surface parameters of the biomaterials. This correlation does not occur when the relationships between parameters are evaluated by means of factors analysis, thus indicating the importance of the statistical method selected for the evaluation of bacterial adherence.