Tsai Cheng-Chih, Lai Tzu-Min, Hsieh You-Miin
1Department of Food Science and Technology, HungKuang University, No. 1018, Sec. 6 Taiwan Boulevard, Shalu District, Taichung City, 43302 Taiwan, ROC.
2Department of Food and Nutrition, Providence University, Taichung City, 43301 Taiwan, ROC.
Indian J Microbiol. 2019 Mar;59(1):81-89. doi: 10.1007/s12088-018-0753-x. Epub 2018 Jul 27.
Urinary tract infections are the most common infectious diseases in babies and the elderly and are often acquired as nosocomial infections. The purpose of the present study was to identify strains of lactic acid bacteria (LAB) which could be used as alternatives to antibiotics for the treatment of urinary tract infections because of their ability to inhibit urinary tract pathogens ( BCRC 10694 and BCRC 17040). We screened 370 LAB strains using spent culture supernatants by inhibition zone assay to assess their antimicrobial effects. We studied the effect of heat, pH and enzyme treatment on the inhibitory activity of LAB strain supernatants. Anti-growth activity against urinary tract pathogens was evaluated by co-culture inhibition assay using seven LAB strains. Anti-adhesion and anti-invasion activities against urinary tract pathogens were evaluated by SV-HUC-1 uroepithelium cell culture. The results showed that the supernatants had good heat stability. However, antibacterial activity disappeared entirely at pH 7.0. After enzyme treatments, the supernatants showed first- or second-order inhibitory effects on BCRC 10694. The survival rate of urinary tract pathogens was 0-10.65% and pH of the culture medium decreased after co-culture with LAB strains for 4 h. In a competition assay, PM2 and RY2 inhibited urinary tract pathogens. PM68, PM78, PM201, PM206 and PM229 inhibited the invasion of SV-HUC-1 cells by BCRC17040. In conclusion, PM78, PM229 and RY2 showed the strongest inhibitory activity against urinary tract pathogens and could be suitable for use in the treatment of urinary tract infections.
尿路感染是婴儿和老年人中最常见的传染病，且常作为医院感染获得。本研究的目的是鉴定乳酸菌（LAB）菌株，因其具有抑制尿路病原体（BCRC 10694和BCRC 17040）的能力，可作为治疗尿路感染的抗生素替代品。我们通过抑菌圈试验使用培养后的上清液筛选了370株LAB菌株，以评估它们的抗菌效果。我们研究了热、pH和酶处理对LAB菌株上清液抑制活性的影响。使用七株LAB菌株通过共培养抑制试验评估对尿路病原体的抗生长活性。通过SV-HUC-1尿路上皮细胞培养评估对尿路病原体的抗粘附和抗侵袭活性。结果表明，上清液具有良好的热稳定性。然而，在pH 7.0时抗菌活性完全消失。酶处理后，上清液对BCRC 10694表现出一级或二级抑制作用。与LAB菌株共培养4小时后，尿路病原体的存活率为0-10.65%，培养基的pH值降低。在竞争试验中，PM2和RY2抑制尿路病原体。PM68、PM78、PM201、PM206和PM229抑制BCRC17040对SV-HUC-1细胞的侵袭。总之，PM78、PM229和RY2对尿路病原体表现出最强的抑制活性，可能适用于治疗尿路感染。
