Investigation of Biofilm Related Antibiotic Susceptibilities

Biofilms can be seen in human bodies in many non-living and live surfaces such as in catheters, prosthetic heart valves, cardiac pacemakers, intra uterine devices, lung tissue. Biofilms formed by microorganisms are responsible for a significant part of the nosocomial infections and that this increases the treatment costs. When a microorganism transforms to sessile cell in biofilm environment, minimal inhibitor concentration and minimal bactericidal concentration values of antibiotics change for sessile cells. The purpose of this study is to research the susceptibility of methicillin resistant Staphylococcus aureus, coagulase negative staphylococcus and Pseudomonas aeruginosa strains, produced as an infection factor in different catheter types, to various antibiotics and antibiotic combinations in planktonic cell phase and then in vitro conditions after biofilm is formed. Our experiments with antibiotics both single and combinations showed a significant decrease in the sensitivities of sessile cells. As a result, the data of our study suggest that combined treatment is preferable in the treatment of biofilm related infections and double combinations could be a wise treatment method.