Investigation of bacterial phenotypical characteristics of respiratory infections in cystic fibrosis

Objective: The purpose of the study is determination of the changes in bacterial phenotypical structures (biofilm formation, adherence formation, growth ratio) after P.aeruginosa infection normal human epithelium and human epithelium with CF in vitro conditions.Material and Methods: In our study quantitative (fluorometric) and qualitative (fluorescent microscopic) methods have been used to determine the amount of adherence of green fluorescent protein transferred P.aeruginosa in normal and CF bronchial and, tracheal epithelium cells. Growth ratio of microorganism has been determined by using fluorometry in 37 0C incubation at 0,6,8,12,16 th hour values. Chrystal violet staining method has been used for searching slime production. T-test has been used as the statistical method. P<0.05 has been accepted as significant.Findings: Adherence of P. aeruginosa to CF bronchial epithelium was decreased compared to normal bronchial epithelium and it was statistically significant. However, P. aeruginosa adherence to CF tracheal epithelium was decreased compared to normal tracheal epithelium but it is not statistically significant. Interestingly, GFP P.aeruginosa, morphological changes have been determined in bronchial epithelium cell with CF cells. Growth ratio of all cells has been compared between control group and themselves in different time intervals, but no differences have been gathered. Conversely, statisticallysignificant increment of slime production of P. aeruginosa in CF bronchial epithelium cells has been determined compared to normal epithelium cells and control group.Result: In our study, changes in P. aeruginosa phenotypic properties such as adherence has biofilm production and morphologic changes with CF bronchial epitheliummay due to effect of structural changes on epithelial superficial structures and induction of genetic differences. It is thought that these effects directly effects bacterial phenotypic properties while infections in CF patients and these phenotypic changes may be the major determinant of the therapeutic failure of infections.Kay Words: Cystic Fibrosis, Pseudomonas aeruginosa, Adherence, Slime production