Nami Yousef, Haghshenas Babak, Yari Khosroushahi Ahmad
Department of Food Biotechnology, Branch for Northwest & West Region, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran.
Regenerative Medicine Research Center (RMRC), Kermanshah University of Medical Sciences, Kermanshah, Iran.
Adv Pharm Bull. 2018 Nov;8(4):683-695. doi: 10.15171/apb.2018.077. Epub 2018 Nov 29.
The increased demand for probiotics because of their health purposes provides the context for this study, which involves the molecular identification of lactic acid bacteria (LAB) obtained from the vaginal microbiota of healthy fertile women. The isolates were subjected for examination to prove their probiotic potential. In particular, the isolates were subjected to various tests, including acid/bile tolerance, antimicrobial activity, antibiotic susceptibility, Gram staining, and catalase enzyme activity assessment. Several methods were utilized for the molecular identification of the isolates, including ARDRA, (GTG)5-PCR fingerprinting, and the PCR sequencing of 16S-rDNA amplified fragments. Disc diffusion and well diffusion methods were used to assess antibiotic susceptibility and antibacterial activity of isolates. Tolerance to acid and bile was performed at pH 2.5 and 0.3% bile oxgall. A total of 45 isolates of 88 separate organisms was selected. All of the isolates demonstrated an antibacterial effect on the exploited indicator microorganisms. All selected strains also maintained their viability at low-pH and high-bile salt conditions and exhibited abroad variation in their survival. Only the Enterococcus avium strain showed resistance to all 9 tested antibiotics. Based on the molecular identification and clustering, the 45 isolated bacteria were classified into three major groups of LAB: Enterococcus, Lactobacillus and Lactococcus. LAB are microorganisms that have a particularly important function in maintaining the health of the vaginal and gastrointestinal tract and in protecting it from infection by other pathogenic organisms. The isolates found to be a promising probiotic candidate by showed desirable characteristics. Therefore, strain DL3 can be used as natural food preservative with some more potential investigations.
由于益生菌具有健康功效，其需求不断增加，这为本研究提供了背景。本研究涉及对从健康育龄妇女阴道微生物群中分离出的乳酸菌（LAB）进行分子鉴定。对分离株进行检测以证明其益生菌潜力。具体而言，对分离株进行了各种测试，包括耐酸/耐胆汁性、抗菌活性、抗生素敏感性、革兰氏染色和过氧化氢酶活性评估。采用了多种方法对分离株进行分子鉴定，包括ARDRA、（GTG）5-PCR指纹图谱分析以及16S-rDNA扩增片段的PCR测序。采用纸片扩散法和打孔扩散法评估分离株的抗生素敏感性和抗菌活性。在pH 2.5和0.3%胆盐条件下进行耐酸和耐胆汁性检测。从88个不同的生物体中总共选择了45个分离株。所有分离株均对所使用的指示微生物表现出抗菌作用。所有选定菌株在低pH和高胆盐条件下也保持了活力，并且在存活率方面表现出广泛差异。只有鸟肠球菌菌株对所有9种测试抗生素均有抗性。根据分子鉴定和聚类分析，45株分离细菌被分为乳酸菌的三大类：肠球菌、乳杆菌和乳球菌。乳酸菌是在维持阴道和胃肠道健康以及保护其免受其他致病生物体感染方面具有特别重要功能的微生物。通过检测发现具有理想特性的分离株有望成为益生菌候选菌株。因此，菌株DL3在经过更多潜在研究后可作为天然食品防腐剂使用。
