To Biofilm or Not to Biofilm ? 1

Material and methods: 30 strains of Pseudomonas aeruginosa and 30 strains of Staphylococcus aureus obtained from clinical specimens were used. After preparing the suspensions of bacteria inoculated on broths, they were set on microtiter plates and the biofilm production was measured using the spectrophotometric reader on 550 nm. Strains were classified into four categories: nonproducing, weak producers, moderate and strong producers, based on the comparison of optical density of samples and negative control.