Paper Title
The Effect of Dimethyl Sulfoxide on Growth of Pseudomonas Aeruginosa

Abstract
Dimethyl sulfoxide (DMSO) is a commonly used solvent for synthetic and natural antibacterial compounds. Experiments that use DMSO to determine Minimal inhibitory concentration (MIC) must take into account that the solvent can have an effect upon bacterial growth. The aim of this study was to explore how the growth of Pseudomonas aeruginosa (PA) was affected by different concentrations of DMSO. Six PA clinical isolates and ATCC PA strain 27853 were used. MIC assays were conducted using the microtiter broth dilution method. DMSO at concentration of 1%–8% v/v were used to evaluate the impact of DMSO upon the growth and bio film formation using microtiter-plate test. The results were analyzed using an ANOVA. The statistical significance was set as P < 0.05. The MIC and minimal bacteriostatic concentration (MBC)for PA were 25% and 50% respectively. There was a significant decline in the growth of PA and development of biofilms when the concentration of DMSO at was 4%, 6% and 8%. Growth and biofilm formation inhibition was also detected at lower concentrations of DMSO (1% and 2%. Studies into antimicrobial susceptibility should consider the effect ofthis common solvent have upon compounds that are being tested, such as traditional antibiotics and novel antimicrobials. Keywords - Cystic Fibrosis CF, Pseudomonas aeruginosa, DMSO, Solvents, Growth, Biofilm.