Quaternary Ammonium Compounds (QACs) induced inactivation of Pseudomonas spp.: Effect of material surface

• Adaptation of cells to QACs was performed by serial cell exposure QACs.
• The affinity of cells to treated and not treated surfaces was investigated.
• Surface treatment with QAC enhanced cell affinity to stainless steel.
• Higher water contact angle and energy of adhesion resulted in more cell inactivation.
• Results can be used for facility hygiene manufacture and appropriate sanitation.

In this study, we investigated the adaptation of selected Pseudomonas spp. to QACs and monitored the changes in susceptibility to these compounds after serial exposure to QACs. Additional study was performed on the QACs efficacy on cells on different types of surfaces and the data were correlated to surface properties. Results showed that wild type Pseudomonas fluorescens and Pseudomonas fragi exhibited more susceptibility to QACs in comparison with Pseudomonas putida. In addition, the investigations carried out on the adhesion of both wild and adapted strains to different types of surface materials using thermodynamic approaches showed that hydrophilic Pseudomonas strains exhibited highest adhesion to the tile surface, while least adhesion was observed on the stainless steel surface material. A diverse relationship was detected between the thermodynamic affinity of cells to the surfaces (higher water contact angle and energy of adhesion) and cell inactivation. The results can be useful to the hygiene manufacture of food processing facilities or to choose appropriate sanitation strategies for the existing plants.