EXAMINATION OF PHYSICOCHEMICAL CHARACTERIZATION OF CELL SURFACES PROPERTIES OF STAPHYLOCOCCUS AUREUS

Background and Aim:Bacterial attachment to inert surfaces is influenced by the properties of both, substratum and bacterial cell, such as charge, hydrophobicity surface rough ness, the presence of fimbriae, flagella and production of exopolysaccharids (EPS). The properties of the bacterial cells are affected by the environmental conditions (temperature, PH or composition of the culture medium), hence, alterations in these conditions can affect the bacterial adhesion. The adhesion process of bacterial to the surfaces include interactions, such as van der waals, Lewis acid-base, hydrophobic and electrostatic interactions. Staphylococcus areus is a human phatogen that causes both chronic and nosocomial infection many of wich are mediated by their ability to adhere to medical devices and to form biofilms.Methods:The MATS test (microbial adhesion to solvents) was performed to evaluate the Lewis acid-base properties and the hydrophilic / hydrophobic nature of bacterial surfaces under different percentages of serum of human blood (growth media). The pairs of solvents used were: chloroform (an acidic solvents) and hexadecane (apolar), ethylacetate (a basic solvent) and hexane (apolar). The percentage of bound cells to each solvent was calculated by the equation: % Adh = (1-A/A0)×100 where A0 was the absorbance of the bacterial suspension before mixing and A was the absorbance after mixing.Results:This study has shown that under different percentage of serum of human blood staphylococcus aureus (ATCC 25923) has different interactionsConclusion:The cells were grown on BH1 (BRAIN HEART INFUSION) include 10% serum of human blood have Low characteristic of electron-donor.

Keywords:

Bacterial adhesion.hydrophobicity