Iranian Biomedical Journal

en Evaluation of Anti-Bacterial and Anti-Biofilm Activity of Native Probiotic Strains of Lactobacillus Extracts Pharmaceutical Biotechnology Pharmaceutical Biotechnology مقاله کامل Full Length/Original Article <div style="text-align: justify;">Background: <a name="_Hlk166400247">Lactic acid bacteria </a>produce various beneficial metabolites, including antimicrobial agents. Owing to the fast-rising antibiotic resistance among pathogenic microbes, scientists are exploring antimicrobials beyond antibiotics. In this study, we examined four Lactobacillus strains, namely L. plantarum 42, L. brevis 205, L. rhamnosus 239, and L. delbrueckii 263, isolated from healthy human microbiota, to evaluate their antibacterial and antifungal activity. Methods: Lactobacillus strains were cultivated, and the conditioned media were obtained. The supernatant was then used to treat pathogenic bacteria and applied to the growth media containing fungal and bacterial strains. Additionally, the supernatant was separated to achieve the organic and aqueous phases. The two phases were then examined in terms of bacterial and fungal growth rates. Disk diffusion and MIC tests were conducted to determine strains with the most growth inhibition potential. Finally, the potent strains identified through the MIC test were tested on the pathogenic microorganisms to assess their effects on the formation of pathogenic biofilms. Results: The organic phase of L. rhamnosus 239 extracts exhibited the highest antibacterial and antibiofilm effects, while that of L. brevis 205 demonstrated the most effective antifungal impact, with a MIC of 125 µg/mL against Saccharomyces cerevisiae. Conclusion: This study confirms the significant antimicrobial impacts of the lactic acid bacteria strains on pathogenic bacteria and fungi; hence, they could serve as a reliable alternative to antibiotics for a safe and natural protection against pathogenic microorganisms.  </div> Biofilms, Lactobacillus, Drug resistance 102 112 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-4579-2&slc_lang=en&sid=1 Elmira Karimzadeh Barenji elmira.karimzade1373@gmail.com 0000-0003-2383-2013 No Department of Biology, Science and Research branch, Islamic Azad University, Tehran, Iran Shokufeh Beglari shokufehbeglari@gmail.com 0000-0002-5636-532 No Department of Biology, Science and Research branch, Islamic Azad University, Tehran, Iran Azar Tahghighi atahghighi2009@gmail.com 0000-0002-1221-4490 No Medicinal Chemistry Laboratory, Department of Clinical Research, Pasteur Institute of Iran, Tehran, Iran Parisa Azerang p.azerang@gmail.com 0000-0002-9851-2658 Yes Medicinal Chemistry Laboratory, Department of Clinical Research, Pasteur Institute of Iran, Tehran, Iran Mahdi Rohani* m_rohani@pasteur.ac.ir 0000-0001-8956-5072 No Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran