Effect of Soil Extracts on Ability of Clinical Isolates of Pseudomonas aeruginosa and Staphylococcus aureus to Produce Biofilm in vitro

Abstract

In present study the effect of soil extracts of different types of soil on ability of two clinical isolates, Pseudomonas aeruginosa and Staphylococcus aureus to form biofilm. The extract of soil was done by using sterile phosphate buffer saline and analyzed by Fourier Transform Infrared Spectroscopic (FTIR). Spectrophotometric method was used to check ability of the studied isolated bacteria to form biofilm on polystyrene microtiter plates. The data of FTIR showed very little difference was observed among extracts of three types of soil (soil contaminated with hydrocarbons; garden soil collected from gardens of al-jadrea, Baghdad and containers soil), but the highest difference was observed in the extract obtained from peat moss clay soil. The results of current study showed that the extracts of soil contaminated with hydrocarbons and garden soil increased the biofilm that form by P. aeruginosa (P<0.05). While, the highest level of biofilm formation by S. aureus was observed after adding the extract of container soil (P <0.05). It can be concluded from present study that the soil extracts can enhance bacteria to form biofilm in vitro but that was dependent on the kind of soil.