Elahi Yara, Mazaheri Nezhad Fard Ramin, Seifi Arash, Mahfouzi Saeideh, Saboor Yaraghi Ali Akbar
Department of Genetics, Faculty of Life Sciences, Islamic Azad University Tehran North Branch, Tehran, Iran.
Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Avicenna J Med Biotechnol. 2022 Jan-Mar;14(1):54-60. doi: 10.18502/ajmb.v14i1.8170.
Bacteriophages are viruses that infect bacteria. Bacteriophages are widely distributed in various environments. The prevalence of bacteriophages in water sources, especially wastewaters, is naturally high. These viruses affect evolution of most bacterial species. Bacteriophages are able to integrate their genomes into the chromosomes of their hosts as prophages and hence transfer resistance genes to the bacterial genomes. Enterococci are commensal bacteria that show high resistance to common antibiotics. For example, prevalence of vancomycin-resistant enterococci has increased within the last decades.
Enterococcal isolates were isolated from clinical samples and morphological, phenotypical, biochemical, and molecular methods were used to identify and confirm their identity. Bacteriophages extracted from water sources were then applied to isolated . In the next step, the bacterial genome was completely sequenced and the existing prophage genome in the bacterial genome was analyzed.
In this study, EntfacYE was isolated from a clinical sample. The EntfacYE genome was analyzed and 88 prophage genes were identified. The prophage content included four housekeeping genes, 29 genes in the group of genes related to replication and regulation, 25 genes in the group of genes related to structure and packaging, and four genes belonging to the group of genes associated with lysis. Moreover, 26 genes were identified with unknown functions.
In conclusion, genome analysis of prophages can lead to a better understanding of their roles in the rapid evolution of bacteria.
噬菌体是感染细菌的病毒。噬菌体广泛分布于各种环境中。水源,尤其是废水中噬菌体的流行率自然很高。这些病毒影响着大多数细菌物种的进化。噬菌体能够将其基因组作为前噬菌体整合到宿主染色体中,从而将抗性基因转移到细菌基因组中。肠球菌是共生细菌,对常见抗生素表现出高度抗性。例如,耐万古霉素肠球菌的流行率在过去几十年中有所增加。
从临床样本中分离出肠球菌分离株,并使用形态学、表型、生化和分子方法来鉴定和确认其身份。然后将从水源中提取的噬菌体应用于分离出的菌株。下一步,对细菌基因组进行全测序,并分析细菌基因组中现有的前噬菌体基因组。
在本研究中,从临床样本中分离出EntfacYE。对EntfacYE基因组进行分析,鉴定出88个前噬菌体基因。前噬菌体内容包括四个管家基因、与复制和调控相关的基因组中的29个基因、与结构和包装相关的基因组中的25个基因以及属于与裂解相关的基因组的四个基因。此外,鉴定出26个功能未知的基因。
总之,对前噬菌体的基因组分析可以更好地理解它们在细菌快速进化中的作用。