Abstract This work investigated chloroform extracts from culture supernatants of two human probiotic bacteria, Lactobacillus casei CRL 431 and Lactobacillus acidophilus CRL 730 for the production of virulence factors and quorum sensing (QS) interference against three Pseudomonas aeruginosa strains. Both extracts inhibited biofilm biomass (up to 50%), biofilm metabolic activity (up to 39%), the production of the enzyme elastase (up to 63%) and pyocyanin (up to 77%), and decreased QS, without presenting any antibacterial acgivity. In addition, the chloroform extracts of both strains disrupted preformed biofilms of the three strains of P. aeruginosa analyzed (up to 40%). GC-MS analysis revealed that the major compounds detected in the bioactive extracts were four diketopiperazines. This study suggests that the metabolites of L. casei and L. acidophilus could be a promising alternative to combat the pathogenicity of P. aeruginosa.

中文翻译：

---

人类益生菌通过群体感应抑制减弱铜绿假单胞菌生物膜和毒力

摘要 本工作研究了来自两种人类益生菌、干酪乳杆菌 CRL 431 和嗜酸乳杆菌 CRL 730 的培养物上清液的氯仿提取物，用于产生毒力因子和群体感应 (QS) 对三种铜绿假单胞菌菌株的干扰。两种提取物都抑制了生物膜生物量（高达 50%）、生物膜代谢活性（高达 39%）、弹性蛋白酶（高达 63%）和绿脓素（高达 77%）的产生，并降低了 QS，而没有呈现任何抗菌活性。此外，两种菌株的氯仿提取物都破坏了所分析的三种铜绿假单胞菌菌株的预先形成的生物膜（高达 40%）。GC-MS 分析表明，在生物活性提取物中检测到的主要化合物是四种二酮哌嗪。该研究表明，干酪乳杆菌和干酪乳杆菌的代谢物。