Maliheh Shokouhfard - Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
Rouha Kasra Kermanshahi - Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
Roya Vahedi Shahandashti - Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
Mohammad Mehdi Feizabadi - Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Shahram Teimourian - Department of Medical Genetics, Iran University of Medical Sciences, Tehran, Iran

Objective(s):Serratia marcescens is one of the nosocomial pathogen. The ability to form biofilm is an important feature in the pathogenesis of S. marcescens. The aim of this study was to determine the anti-adhesive properties of a biosurfactant isolated from Lactobacillus acidophilus ATCC ۴۳۵۶, on S. marcescens strains. Materials and Methods: Lactobacillus acidophilus ATCC ۴۳۵۶, was selected as a probiotic strain to produce biosurfactant. Anti-adhesive activities was determined by pre-coating and co- incubating methods in ۹۶-well culture plates. Results: The FTIR analysis of derived biosurfactant revealed the composition as protein component. Because of the release of such biosurfactants, L. acidophilus was able to interfere with the adhesion and biofilm formation of the S. marcescens strains. In co- incubation method this biosurfactant in ۲.۵ mg/ml concentration showed anti-adhesive activity against all tested strains of S. marcescens (P<۰.۰۵). Conclusion: Our results show anti-adhesive properties of L. acidophilus biosurfactant will be useful against microorganisms responsible for infections in the urinary, vaginal and gastrointestinal tracts, as well as skin, making it a suitable alternative to conventional antibiotics.

Anti-adhesive, biofilm formation, Biosurfactant, Co-incubation, Pre-coating, Lactobacillus acidophilus