Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 5 5-6 2017 02 02 1 12 EN Laila Goudarzi Department of Microbiology, Faculty of Sciences, Alzahra University, Tehran, Iran. AND Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, Iran. Rouha Kasra Kermanshahi Department of Microbiology, Faculty of Sciences, Alzahra University, Tehran, Iran. Zahra Mousavinezhad Department of Microbiology, Faculty of Sciences, Alzahra University, Tehran, Iran. Mohammad Mehdi Soltan Dallal Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, Iran. AND Division of Food Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 2017 02 01 2017 02 01 Background:   Proteus spp. belongs to the family of Enterobacteriaceae. These bacteria are Gram-negative and motile microorganisms and known as the third most common causes of urinary tract infections. The aim of the current study was to investigate the effects of some secondary metabolites from probiotic strains of Lactobacillus spp. on swarming and growth of Proteus mirabilis and P. vulgaris.  Methods:   After determination of optimal conditions for the growth and production of antimicrobials, bacteriocins and biosurfactants were partially purified from Lactobacillus culture supernatants. Then, effects of the purified compounds on growth and swarming migration of Proteus spp. were examined in the presence of various concentrations of semi-purified compounds.  Results:  Results showed that the partially purified bacteriocins inhibited Proteus spp. swarming distance and had a significant reduction on the bacterial growth curves. Biosurfactants in a solvent form did not have any considerable effects on factors produced by Proteus spp.  Conclusion:  According to the results, the secondary metabolites, especially bacteriocins or bacteriocin-like substances derived from Lactobacillus strains, can inhibit or reduce growth and swarming migration of Proteus spp. which are considered as the bacteria major virulence factors. https://jmb.tums.ac.ir/index.php/jmb/article/view/268 https://jmb.tums.ac.ir/index.php/jmb/article/download/268/195