Majdani Raheleh, Shams Ghahfarokhi Elham
Department of Biology, Faculty of Basic Sciences, University of Maragheh, Maragheh, Iran.
Iran J Microbiol. 2022 Apr;14(2):203-213. doi: 10.18502/ijm.v14i2.9189.
With the emergence of antibiotic-resistant strains, using the anti-bacterial potential of bacteriophages could be an effective approach to combat bacterial infections.
In this study, after evaluation of antibiotic sensitivity of 20 clinical bacterial isolates of , isolation of lytic phages was performed against 15 isolates using double-layer agar overlay technique. Molecular analysis of isolated phages was carried out using V and III endonucleases. Then, the host range of the phages was evaluated and the phage with the broadest host range (PPaMa1/18) was selected to morphological characteristics by TEM. Also, its one-step growth curve was determined and the stability of the phage to environmental parameters (temperature and pH) was evaluated.
All isolates of were resistant to five antibiotics. In total, 15 phages were successfully isolated from the sewage sources against each of 15 used bacterial isolates. Molecular analysis of the phages showed a high rate of genomic variation. In the morphological analysis of the selected phage (PPaMa1/18) using TEM, an icosahedral head with a size of 90 nm × 75 nm and a long contractile tail (215 nm) were observed which indicated its similarity to the family. The latent period of the PPaMa1/18 was about 20 minutes and its burst size was estimated to be 58 PFU/cell. Also, the PPaMa1/18 phage antibacterial activity was not significantly affected at pH 4-10 and temperature 4-40C°.
Findings demonstrated that isolated bacteriophage (PPaMa1/18) with wide host range, strong lytic effect and high stability can be used as a promising candidate for the treatment of antibiotic-resistant infections caused by
随着抗生素耐药菌株的出现，利用噬菌体的抗菌潜力可能是对抗细菌感染的一种有效方法。
在本研究中，对20株临床分离细菌进行抗生素敏感性评估后，采用双层琼脂平板法针对15株分离菌进行裂解性噬菌体的分离。使用V和III型核酸内切酶对分离出的噬菌体进行分子分析。然后，评估噬菌体的宿主范围，选择宿主范围最广的噬菌体（PPaMa1/18）通过透射电子显微镜观察其形态特征。此外，测定其一步生长曲线，并评估噬菌体对环境参数（温度和pH）的稳定性。
所有分离菌对五种抗生素均耐药。总共从污水源中成功分离出15株噬菌体，分别针对15株所用细菌分离株。噬菌体的分子分析显示基因组变异率很高。在使用透射电子显微镜对所选噬菌体（PPaMa1/18）进行形态分析时，观察到一个大小为90 nm×75 nm的二十面体头部和一条长收缩尾（215 nm），这表明它与该家族相似。PPaMa1/18的潜伏期约为20分钟，其裂解量估计为58 PFU/细胞。此外，PPaMa1/18噬菌体的抗菌活性在pH 4 - 10和温度4 - 40°C时未受到显著影响。
研究结果表明，分离出的噬菌体（PPaMa1/18）具有广泛的宿主范围、强大的裂解作用和高稳定性，可作为治疗由……引起的抗生素耐药感染的有前景的候选药物
