Bevilacqua Lorella, Ovidi Monia, Di Mattia Elena, Trovatelli Luigi Daniele, Canganella Francesco
Department of Agrobiology and Agrochemistry, University of Tuscia, via C. de Lellis, 01100 Viterbo, Italy.
Microbiol Res. 2003;158(2):179-85. doi: 10.1078/0944-5013-00192.
As probiotic bacteria, strains belonging to the genus Bifidobacterium colonise the gastro-intestinal tract of humans and animals at the time of birth, and they are found in young as well as in adult individuals in great numbers. Moreover, they can interact with the development of enteric infections by the production of antimicrobial metabolites. In this work 281 strains of bifidobacteria were anaerobically isolated from human faecal samples, supplied by volunteers of different ages (youngs, adults, elders), and preliminarly described by microscopic observation. All strains were screened by the fructose 6-phosphate phosphoketolase (F6PPK) test in order to confirm their classification within the genus Bifidobacterium. Selected strains were used to evaluate their antagonistic activities against Escherichia coli, Salmonella thyphimurium, Staphylococcus lentus, Enterococcus faecalis, Acinetobacter calcoaceticus, Sphingomonas paucimobilis, Listeria monocytogenes, Yersinia enterocolitica, Bacillus cereus, Clostridium sporogenes. Experiments were performed in vitro by different methods based on the observation of growth inhibition in Petri dishes. The strains that showed the highest inhibiting activities were compared by SDS-PAGE for total cell proteins, using type strains of human origin as references. Representative isolates were metabolically characterised by the BIOLOG system; a specific database was created with strains obtained from our collection and a statistical evaluation for metabolic patterns was carried out.
作为益生菌，双歧杆菌属的菌株在人类和动物出生时就定植于胃肠道，在年轻人和成年人中都大量存在。此外，它们可通过产生抗菌代谢产物来影响肠道感染的发展。在这项研究中，从不同年龄段（年轻人、成年人、老年人）志愿者提供的人类粪便样本中厌氧分离出281株双歧杆菌，并通过显微镜观察进行初步描述。所有菌株均通过6-磷酸果糖磷酸酮醇酶（F6PPK）试验进行筛选，以确认它们在双歧杆菌属内的分类。选择的菌株用于评估其对大肠杆菌、鼠伤寒沙门氏菌、缓慢葡萄球菌、粪肠球菌、醋酸钙不动杆菌、少动鞘氨醇单胞菌、单核细胞增生李斯特菌、小肠结肠炎耶尔森菌、蜡样芽孢杆菌、产芽孢梭菌的拮抗活性。通过基于观察培养皿中生长抑制的不同方法在体外进行实验。以人类来源的模式菌株为参照，通过SDS-PAGE对总细胞蛋白进行分析，比较显示出最高抑制活性的菌株。通过BIOLOG系统对代表性分离株进行代谢特征分析；利用从我们的菌株库中获得的菌株创建一个特定数据库，并对代谢模式进行统计评估。
