DETECTION OF BIOFILM GENES AMONG CLINICAL ISOLATES OF PSEUDOMONAS AERUGINOSA RECOVERED FROM SOME EGYPTIAN HOSPITALS.

Research Abstract

Biofilm formation in Pseudomonas aeruginosa (P. aeruginosa) is controlled by about 1% of its chromosomal genes; from which four genes were selected for prospective work. The aim of this study was to determine the biofilm formation in P. aeruginosa clinical isolates and to evaluate the role of the selected genes in biofilm formation. A total of fifty isolates were recovered from different clinical samples isolated fromsome Egyptian hospitals by isolation on cetrimideagar media and then biochemically identified as P. aeruginosa. The antibiogram of the planktonic cells of all isolates was determined and showed that amikacin was the most potent antibiotic against all isolates. Quantification of biofilm formation of isolates was done by the microtiter plate method using crystal violet (CV) assay. According to the optical density (OD) readings, isolates were classified into the following categories: strong, moderate or weak biofilm producers. Screening for some selected biofilm genes as RhlI, PilA, PilT and PelB genes in some isolates using PCR, revealed the presence of these genes in both strong and weak biofilm producer isolates. These final results suggest the importance of these genes in biofilm formation and suggest the presence of other factors which may contribute in determining the degree of biofilm formation in P. aeruginosa.

Research Keywords

Pseudomonas aeruginosa - Biofilm - Genes