College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of MOST, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Viruses. 2022 Mar 25;14(4):676. doi: 10.3390/v14040676.
Clostridium perfringens is an important pathogen for both humans and animals, causing human foodborne disease and necrotic enteritis in poultry. In the present study, a C. perfringens-specific phage, vB_CpeS_BG3P (designated as BG3P hereafter), was isolated from chicken farm sewage. Both electron microscopy and phylogenetic analysis suggested that phage BG3P is a novel phage belonging to Siphoviridae family. Phage BG3P exhibited a broad host range against different C. perfringens isolates (90.63% of strains were infected). Sequencing of the complete genome revealed a linear double-stranded DNA (43,528 bp) with 28.65% GC content. After sequence analysis, 73 open reading frames (orfs) were predicted, of which only 13 were annotated with known functions. No tRNA and virulence encoding genes were detected. It should be noted that the protein of orf 15 has 97.92% homology to C. perfringens-specific chloramphenicol resistance protein, which has not been reported for any C. perfringens phage. Phylogenetic analysis of the ssDNA binding protein demonstrated that this phage is closely related to C. perfringens phages phiSM101 and phi3626. In considering future use as an antimicrobial agent, some biological characteristics were observed, such as a good pH (3−11) stability and moderate temperature tolerance (<60 °C). Moreover, bacteriophage BG3P showed a good antimicrobial effect against C. perfringens liquid cultures. Thus, phage treatment with MOI ≥ 100 completely inhibited bacterial growth compared to untreated cultures. Although phage BG3P shows good lytic efficiency and broad host range in vitro, future development and application may need to consider removal of the chloramphenicol-like resistance gene or exploring its lysin for future antibacterial applications.
产气荚膜梭菌既是人类也是动物的重要病原体，可引起人类食源性疾病和禽类坏死性肠炎。本研究从鸡场污水中分离到一株产气荚膜梭菌特异性噬菌体 vB_CpeS_BG3P（简称 BG3P）。电镜观察和系统发育分析表明，噬菌体 BG3P 是一种新型的肌尾噬菌体科噬菌体。噬菌体 BG3P 具有广泛的宿主谱，可感染 90.63%的不同产气荚膜梭菌分离株。全基因组测序表明，BG3P 为线性双链 DNA，全长 43528bp，GC 含量为 28.65%。序列分析预测了 73 个开放阅读框（ORFs），其中只有 13 个具有已知功能。未检测到 tRNA 和毒力编码基因。值得注意的是，orf15 编码的蛋白与产气荚膜梭菌特异性氯霉素抗性蛋白具有 97.92%的同源性，这在任何产气荚膜梭菌噬菌体中均未见报道。ssDNA 结合蛋白的系统发育分析表明，该噬菌体与产气荚膜梭菌噬菌体 phiSM101 和 phi3626 密切相关。考虑到未来将其用作抗菌剂，观察到了一些生物学特性，如良好的 pH（3-11）稳定性和适度的温度耐受性（<60°C）。此外，噬菌体 BG3P 对产气荚膜梭菌液体培养物表现出良好的抗菌效果。因此，与未处理的培养物相比，MOI≥100 的噬菌体处理完全抑制了细菌的生长。尽管噬菌体 BG3P 在体外具有良好的裂解效率和广泛的宿主范围，但未来的开发和应用可能需要考虑去除氯霉素样抗性基因或探索其溶菌酶，以用于未来的抗菌应用。
