Student Research Committee, Tabriz University of Medical Sciences, Tabriz 5166616471, Iran.
Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz 5166616471, Iran.
Lett Appl Microbiol. 2024 Sep 2;77(9). doi: 10.1093/lambio/ovae084.
The antibacterial, antibiofilm, and cytotoxicity activity of cell-free supernatants (CFSs) from probiotics, including Lactobacillus plantarum, Bifidobacterium bifidum, and Saccharomyces cerevisiae against multi-drug resistant Escherichia coli evaluated in current research. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the CFSs were determined by analyzing inhibition zone formation using agar disk diffusion for antibacterial activity, microtiter plate for biofilm analysis, and auto-aggregation were done. CFSs substances were analyzed by GC-MS. The MTT assay on HEK293 cells investigated CFS's influence on cell viability. CFSs were examined for biofilm-related virulence genes, including aggR and fimH using real-time polymerase chain reaction (real-time PCR). All CFSs had bacteriostatic and bactericidal effects. The B. bifidum exhibited the highest antibiofilm activity compared to the others. Bifidobacterium bifidum, L. plantarum, and S. cerevisiae produce 19, 16, and 11 mm inhibition zones against E. coli, respectively. GC-MS indicated that Hydroxyacetone, 3-Hydroxybutyric acid, and Oxime-methoxy-phenyl-dominated CFSs from L. plantarum, B. bifidum, and S. cerevisiae CFSs, respectively. The MTT test demonstrated a cell viability rate of over 90%. Statistically, adding all CFSs lowered the relative expression of both aggR and fimH virulence genes.
本研究评估了植物乳杆菌、双歧双歧杆菌和酿酒酵母等益生菌的无细胞上清液（CFS）对多药耐药大肠杆菌的抗菌、抗生物膜和细胞毒性活性。通过琼脂平板扩散分析抑菌圈形成来确定 CFS 的最小抑菌浓度（MIC）和最小杀菌浓度（MBC），用于抗菌活性分析，微量滴定板用于生物膜分析和自动聚集。使用 GC-MS 分析 CFS 物质。MTT 测定法在 HEK293 细胞上研究了 CFS 对细胞活力的影响。使用实时聚合酶链反应（real-time PCR）检测 CFS 对生物膜相关毒力基因，包括 aggR 和 fimH 的影响。所有 CFS 均具有抑菌和杀菌作用。与其他 CFS 相比，双歧双歧杆菌表现出最高的抗生物膜活性。双歧双歧杆菌、植物乳杆菌和酿酒酵母对大肠杆菌的抑菌圈直径分别为 19、16 和 11mm。GC-MS 表明，植物乳杆菌、双歧双歧杆菌和酿酒酵母的 CFS 中分别以羟基丙酮、3-羟基丁酸和肟甲氧基苯为主导。MTT 试验表明细胞活力率超过 90%。统计分析表明，添加所有 CFS 均可降低 aggR 和 fimH 毒力基因的相对表达。
