Physicochemical characterization of Pseudomonas aeruginosa isolated from catering substratum surface and investigation of their theoretical adhesion

The physicochemical properties of six Pseudomonas aeruginosa isolated from catering environment surface at a health establishment and of different types of substratum surfaces were investigated. These physicochemical properties were determined by contact angles measurements via sessile drop technique. The strains of Pseudomonas aeruginosa (P3, P14, and P18) were hydrophobic, the others were hydrophilic. The results show also that all strains were predominantly electron donors (γ−) and weakly electron acceptors (γ+). Three types of marble (yellow, white and black), four types of granite (Bleu-Pearl, Rosa-Porrino, Galaxy and Green-Pinhel), corian, stainless steel 304 and polypropylene were studied. Except yellow marble and granite (Green-Pinhel) that classified as hydrophilic surfaces, the others were hydrophobic. The finding shows that yellow marble and Green-Pinhel granite were predominantly electron donating (γ−) and other substratum surfaces were weakly electron donating. Except yellow marble which has a high electron acceptor, the others have a weak electron acceptor character. The free energy of adhesion between the bacteria and substratum surface was calculated and used in this study to predict the adhesion of Pseudomonas aeruginosa on the studied substratum surface. For all studied the substratum, except P18, the adhesion of all Pseudomonas aeruginosa is thermodynamically favorable only to polyethylene. Moreover P11 has the ability to adhere to all substratum surfaces.