Majidzadeh Mohadeseh, Heidarieh Parvin, Fatahi-Bafghi Mehdi, Vakili Mahmood
Department of Microbiology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Department of Bacteriology and Virology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran.
Mol Biol Rep. 2021 Feb;48(2):1717-1723. doi: 10.1007/s11033-021-06218-y. Epub 2021 Feb 18.
Historically, many important secondary metabolites including antibiotics used in clinic are purified from the cultural broths of Actinobacteria, which were inhabited in soil. Yazd is located in the center of Iran, the south of the Dasht-e Kavir and the west of the Dasht-e Lut; accordingly it has a hot, dry climate with long summers. In the present study, 18 strains of Actinobacteria isolated from 60 soil samples from Yazd-Iran. Pure isolates were screened for antibacterial activity against the ATCC strains by using two methods: single line streak method and spot inoculation method. ATCC strains include four antibiotic resistant ATCC strains (Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae and, Acinetobacter baumannii) and three antibiotic sensitive strains (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli) and, Bacillus subtilis. Seven isolates exhibited antimicrobial activity against the ATCC strains (38.8%). Identification of type I and type II polyketide synthases (pksI, pksII) and nonribosomal peptide synthetase (NRPS) genes were done for these 7 isolates and all of 7 strains, possessed at least one of these genes. The results of this study confirm that soil Actinobacteria bear a great ability to produce antibacterial compounds against resistant and sensitive test organisms.
从历史上看，许多重要的次生代谢产物，包括临床使用的抗生素，都是从栖息于土壤中的放线菌的培养肉汤中纯化得到的。亚兹德位于伊朗中部，卡维尔沙漠以南，卢特沙漠以西；因此，它气候炎热干燥，夏季漫长。在本研究中，从伊朗亚兹德的60份土壤样本中分离出18株放线菌。通过两种方法对纯分离株进行针对美国典型培养物保藏中心（ATCC）菌株的抗菌活性筛选：单线划线法和点接种法。ATCC菌株包括四株耐抗生素的ATCC菌株（粪肠球菌、金黄色葡萄球菌、肺炎克雷伯菌和鲍曼不动杆菌）以及三株抗生素敏感菌株（铜绿假单胞菌、金黄色葡萄球菌、大肠杆菌）和枯草芽孢杆菌。七株分离株对ATCC菌株表现出抗菌活性（38.8%）。对这7株分离株进行了I型和II型聚酮合酶（pksI、pksII）和非核糖体肽合成酶（NRPS）基因的鉴定，所有7株菌株都至少拥有这些基因中的一种。本研究结果证实，土壤放线菌具有产生针对耐药和敏感测试生物体的抗菌化合物的强大能力。
