Hosseini Bafghi Mahdi, Ghanipour Farangis, Nazari Razieh, Aghaei Seyed Soheil, Jafari Parvaneh
Department of Laboratory Sciences, Faculty of Paramedical and Rehabilitation Sciences, Mashhad University of Medical Sciences, 91779-48564 Mashhad, Iran.
Department of Microbiology, Faculty of Basic Sciences, Qom Branch, Islamic Azad University, 3749113191 Qom, Iran.
Front Biosci (Landmark Ed). 2024 Apr 30;29(5):171. doi: 10.31083/j.fbl2905171.
The antibiotic resistance of microorganisms is escalating rapidly. Infections caused by opportunistic pathogens in immunocompromised individuals have prompted researchers to seek for potent and safe antibacterial agents. The purpose of this investigation was to explore the suppression of virulence gene expression, specifically the operon genes responsible in biofilm formation in , through the utilization of metabolites obtained from probiotic bacteria.
To assess the antimicrobial properties, standard strains of five probiotic bacteria were tested against a standard strain of multidrug-resistant (MDR) employing the agar gel diffusion technique. Following the identification of the most potent probiotic strain (), the existence of its and genes was confirmed using the polymerase chain reaction (PCR) test. High-performance liquid chromatography (HPLC) and fourier-transform infrared spectroscopy (FTIR) techniques were employed to identify the intended metabolite, which was found to be a lipopeptide nature. The minimum inhibitory concentration (MIC) values and anti-biofilm activity of the targeted metabolite were determined using a dilution method in 96-well microplates and field emission scanning electron microscopy (FE-SEM). Real-time PCR (qPCR) was utilized for comparing the expression of operon genes, including , in pre- and post-exposure to the derived lipopeptide.
The MIC results indicated that the probiotic product inhibited the growth of at concentrations lower than those needed for conventional antibiotics. Furthermore, it was observed that the desired genes' expression decreased due to the effect of this substance.
This research concludes that the probiotic product could be a viable alternative for combating drug resistance in .
微生物的抗生素耐药性正在迅速升级。免疫功能低下个体中由机会性病原体引起的感染促使研究人员寻找强效且安全的抗菌剂。本研究的目的是通过利用从益生菌获得的代谢产物来探索对毒力基因表达的抑制作用，特别是对负责生物膜形成的操纵子基因的抑制作用。
为评估抗菌特性，采用琼脂凝胶扩散技术，对五种益生菌的标准菌株针对一株多重耐药（MDR）标准菌株进行测试。在鉴定出最有效的益生菌菌株（）后，使用聚合酶链反应（PCR）测试确认其和基因的存在。采用高效液相色谱（HPLC）和傅里叶变换红外光谱（FTIR）技术鉴定目标代谢产物，发现其具有脂肽性质。使用96孔微孔板中的稀释法和场发射扫描电子显微镜（FE-SEM）测定目标代谢产物的最低抑菌浓度（MIC）值和抗生物膜活性。利用实时PCR（qPCR）比较在暴露于衍生脂肽之前和之后中操纵子基因（包括）的表达。
MIC结果表明，益生菌产品在低于传统抗生素所需的浓度下就能抑制的生长。此外，观察到由于该物质的作用，所需基因的表达下降。
本研究得出结论，益生菌产品可能是对抗耐药性的一种可行替代方案。
