QUANTITATIVE AND QUALITATIVE ASSAYS OF BACTERIAL BIOFILM PRODUCED BY Pseudomonas aeruginosa AND Klebsiella spp.

Abstract

The aim of this study was to detect biofilm formation by study isolates of Pseudomonas aeruginosa and Klebsiella spp. qualitatively and quantitatively. Twenty-five isolates were taken from patients admitted to Ramadi General Hospital were included in this study. Qualitative biofilm formation assays (tube method and Foley-catheter assay) and quantitative assay by spectrophotometric method with ELISA reader were achieved under two experimental conditions. In tube method, the result showed that out of 8 (32%) isolates of Pseudomonas aeruginosa and 17 (68%) isolates of Klebsiella species, the biofilm were produced in 7 (87.5%), and 14(82.35%) respectively. while, in foley catheter method, the biofilm were produced on the surfaces of the catheters in all pseudomonal isolates (100%), and 15(88.23%)of klebsiella isolates respectively. In the spectrophotometric method, the results showed that out of 17 isolates of Klebsiella spp., all isolates were produced biofilm strongly in the glucose supplemented media while 15 (88.23%) of them were produced biofilm strongly in the glucose non-supplemented media and 2 (11.76%) isolates were weak biofilm producers in the glucose non-supplemented media. With regard to Pseudomonas aeruginosa, the results showed that all pseudomonal isolates, which submitted to this study, were produced biofilm strongly in the glucose supplemented and non-supplemented brain heart infusion broth. The study concluded that all isolates of Pseudomonas aeruginosa and Klebsiella spp. were produced biofilm qualitatively by both techniques. Further, the spectrophotometric method was an accurate method for detection the bacterial adherence to the surface of Microtiter plates. Further more, biofilm production was not affected by this factor in both of Pseudomonas aeruginosa and Klebsiellaspp .