Atomic force microscopy and hydrodynamic characterization of the adhesion of staphylococcus aureus to hydrophilic and hydrophobic substrata at different pH values

Abstract

Understanding the mechanism of the bacterial cell adhesion to solid surfaces is of great medical and industrial importance. Bacterial adhesion to inert surfaces, such as a catheter, and other indwelling devices can form biofilm, consequently cause severe morbidity and often fatal infections. Initial bacterial adhesion to the material surfaces is a complicated process that is affected by various physicochemical properties of both bacterial cells and substratum surfaces. The surface properties of the cells were characterized by the sessile drop technique. Moreover, the interfacial free energy of Staphylococcus aureus adhesion to the supporting materials was determined. The results showed that S. aureus examined at different pH levels could be considered hydrophilic. We noted hat the electron-donor character of S. aureus was important at intermediate pH (pH 5, pH 7, and pH 9) and it decreased at both limits acidic and basic conditions. In addition, the adhesion of Staphylococcus aureus ATCC 25923 to the hydrophilic glass and hydrophobic indium tin oxide (ITO)-coated glass surfaces at different pH values (2, 3, 5, 7, 9 and 11) was investigated using atomic force microscopy (AFM) and image analysis was assessed with the Mathlab Ò program. The data analysis showed that cells (number of adhering cells to glass and ITO-coated glass surface) adhered strongly at acidic pH and weakly at alkaline pH. Also, S. aureus has the ability to attach to both hydrophobic and hydrophilic surfaces, but the adhesion was higher on hydrophobic surface.

Chloroform extract of turmeric inhibits biofilm formation, EPS production and motility in antibiotic resistant bacteria

“…It has been reported that adhesion of microorganisms to various surfaces also involves a physico-chemical process that can efficiently mask the role of cell surface hydrophobicity in adhesion. Numerous studies have explored the belief of the absence of a direct relationship between adhesion to hydrophobic/hydrophilic surfaces and cell surface hydrophobicity in a number of pathogens such as S. epidermidis (Cerca et al, 2005) and S. aureus (Zmantar et al, 2011). Moreover, a critical element contributing to reduced adherence could be the destruction of an EPS matrix of bacteria by the chloroform extract.…”

Bacterial Extracellular Polysaccharides in Biofilm Formation and Function

“…(A) PS intercellular adhesion producing Staphylococcus aureus . Reprinted from World Journal of Microbiology and Biotechnology (214) with permission from the publisher. (B) Pel producing Pseudomonas aeruginosa (Δ wspF Δ psl ).…”

Effects of Piper cubeba L. essential oil on methicillin‐resistant Staphylococcus aureus: an AFM and TEM study

“…PES are hydrophobic membranes widely used in bioseparation, because of their specific chemical and physical features . Staphylococcus aureus attach to both hydrophilic and hydrophobic surfaces, with stronger adhesion to hydrophobic surface …”