Kazdaghli Rahma, Mourali Donia, Mora-Quilis Lucas, Domingo-Calap Pilar, Ben-Mahrez Kamel
Biochemistry and Biotechnology Laboratory LR01ES05, Faculty of Sciences of Tunis, University of Tunis El Manar, 2092 El Manar II, Tunis, Tunisia.
Institute for Integrative Systems Biology, I2SysBio, Universitat de Valencia-CSIC, 46980 Paterna, Spain.
Braz J Microbiol. 2025 Jun 6. doi: 10.1007/s42770-025-01707-9.
Phage therapy is a promising therapeutic weapon in the fight against multidrug-resistant Klebsiella pneumoniae infections. A Klebsiella phage, KpTRp1, was isolated from wastewater sample collected in Tunisia. It exhibited specific lytic activity against a reference strain of K. pneumoniae serotype K2. Phage isolation and enrichment were performed using the double-layer agar method. It was characterized by transmission electron microscopy, physiological investigation and genomic sequence analysis. Transmission electron micrographs of KpTRp1 showed a myovirus morphology. The optimal multiplicity of infection by KpTRp1 was 0.0001 with a latent period lasted for 30 min. Its rise phase showed a burst period of almost 150 min and released a small burst size of about six plaque-forming units per infected cell. KpTRp1 was stable over a broad pH and temperature range. The phage genome sequencing revealed a linear double-stranded DNA genome of 48,003 base pairs with a G + C content of 48.79%, defining a new species of Sircambvirus genus of Jameshumphriesvirinae subfamily. Among the 68 open reading frames identified, about half were hypothetical proteins with unknown functions, the others being involved in DNA replication and metabolism, phage structure, host recognition and lysis. Remarkably, lytic activity of KpTRp1 against K. pneumoniae serotype K2 was confirmed by genomic analysis of life cycle, making it suitable candidate for phage therapy, especially since no antibiotic resistance, or lysogenic genes were detected in the phage genome.
噬菌体疗法是对抗多重耐药性肺炎克雷伯菌感染的一种有前景的治疗手段。从突尼斯采集的废水样本中分离出一种肺炎克雷伯菌噬菌体KpTRp1。它对肺炎克雷伯菌血清型K2的参考菌株表现出特异性裂解活性。采用双层琼脂法进行噬菌体的分离和富集。通过透射电子显微镜、生理学研究和基因组序列分析对其进行了表征。KpTRp1的透射电子显微镜图像显示出肌病毒形态。KpTRp1的最佳感染复数为0.0001，潜伏期持续30分钟。其上升阶段显示出近150分钟的爆发期，每个感染细胞释放的爆发量较小，约为六个噬菌斑形成单位。KpTRp1在较宽的pH和温度范围内都很稳定。噬菌体基因组测序揭示了一个48,003个碱基对的线性双链DNA基因组，G + C含量为48.79%，确定为Jameshumphriesvirinae亚科Sircambvirus属的一个新物种。在鉴定出的68个开放阅读框中，约一半是功能未知的假设蛋白，其他的则参与DNA复制和代谢、噬菌体结构、宿主识别和裂解。值得注意的是，通过生命周期的基因组分析证实了KpTRp1对肺炎克雷伯菌血清型K2的裂解活性，使其成为噬菌体疗法的合适候选者，特别是因为在噬菌体基因组中未检测到抗生素抗性或溶原性基因。
