Aazami Nazila, Salehi Jouzani Gholamreza, Khodaei Zohreh, Meimandipour Amir, Safari Mohammad, Goudarzvand Mahdi
Microbial Biotechnology & Biosafety Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Karaj, Iran; Department of Food Science, Engineering and Technology, Faculty of Agricultural Engineering and Technology, College of Agriculture & Natural Resources, University of Tehran.
J Gen Appl Microbiol. 2014;60(6):215-21. doi: 10.2323/jgam.60.215.
The objective of the present study was to isolate, identify and characterize new LAB strains with high probiotic potentials from Iranian (Isfahan) indigenous chickens. From 90 isolated LABs, 11 isolates had high growth rate under different stress conditions, including acid (pH 2.5), bile (0.5% oxgall), salt (6-15%) and temperatures 15 and 45°C, and their aggregation time was less than 120 min. Based on the molecular identification using 16S rDNA sequencing and phylogenetic analysis, the isolates belonged to two Lactobacillus salivarius and L. reuteri species. The isolates showed different tolerance to 16 clinically and veterinary relevant antibiotics, and most of them were resistant to or semi-tolerant of 7-15 different studied antibiotics. The Es11, Es12, Es3 and Es13 strains with resistance to or semi-tolerance of 15, 14 and 13 different antibiotics, respectively, were the most tolerant strains. The selected isolates showed a wide range of antimicrobial activity against 7 different pathogenic strains. All the isolates exhibited antagonistic activity against E. coli, Enterococcus hirae, Salmonella enterica and Staphylococcus aureus. The isolates Es6 and Es11 with high antagonistic activity and resistance against 6 of the studied pathogens were the most powerful antagonistic isolates. The values and types of adhesion to the Caco-2 cell cultures were significantly different (0-40 bacteria/Caco-2 cell), and the maximum adhesion was observed for the isolates Es6 and Es13 with 35 and 40 bacteria adhesion/cell, respectively. Finally, based on all the experiments, 7 strains, including Es1, Es6, Es7, Es11, Es12 and Es13, were selected for the further in vivo assays and possible use in the poultry industry.
本研究的目的是从伊朗（伊斯法罕）本土鸡中分离、鉴定和表征具有高益生菌潜力的新型乳酸菌菌株。在90株分离出的乳酸菌中，有11株在不同应激条件下具有高生长速率，这些条件包括酸性（pH 2.5）、胆汁（0.5%牛胆汁）、盐（6 - 15%）以及15和45°C的温度，并且它们的聚集时间小于120分钟。基于使用16S rDNA测序的分子鉴定和系统发育分析，这些分离株属于唾液乳杆菌和罗伊氏乳杆菌两个物种。这些分离株对16种临床和兽医相关抗生素表现出不同的耐受性，其中大多数对7 - 15种不同的研究抗生素具有抗性或半耐受性。分别对15、14和13种不同抗生素具有抗性或半耐受性的Es11、Es12、Es3和Es13菌株是耐受性最强的菌株。所选分离株对7种不同的致病菌株表现出广泛的抗菌活性。所有分离株均对大肠杆菌、平肠球菌、肠炎沙门氏菌和金黄色葡萄球菌表现出拮抗活性。具有高拮抗活性且对6种研究病原体具有抗性的分离株Es6和Es11是最强大的拮抗分离株。对Caco - 2细胞培养物的黏附值和类型存在显著差异（0 - 40个细菌/Caco - 2细胞），分别观察到分离株Es6和Es13的最大黏附，黏附细菌数分别为35和40个/细胞。最后，基于所有实验，选择了7株菌株，包括Es1、Es6、Es7、Es11、Es12和Es13，用于进一步的体内试验以及可能在家禽行业中的应用。
