The potential of bacteriophages as alternative treatment for multidrug-resistant (MDR) Klebsiella pneumoniae-related infections has recently gained much interest. The purpose of this research was to isolate and characterize a K. pneumoniae-specific lytic phage with the potential to treat experimental lobar pneumonia induced by K. pneumoniae in mice. A lytic phage was isolated from an urban wastewater sample in Tehran and characterized by transmission electron microscopy (TEM), thermal, pH, and chloroform stability before being employed for treatment of mice infected with K. pneumoniae in an experimental model of lobar pneumonia. BALB/C mice were challenged by intranasal inoculation with 108 colony-forming units (CFU/ml) of K. pneumoniae ATCC 10031 followed by an intraperitoneal injection of the isolated phage using 1010 and 109 plaque-forming units (PFU/ml) simultaneously or 24 h post infection. Control groups of mice received bacteria or bacteriophage alone. Mice were euthanized daily up to 7 days post infection and examined for abnormality in their lungs and livers followed by determining the number of phages and bacteria in plasma and lung homogenates. The isolated phage (vB_KpnM-Teh.1) belonged to the Myoviridae family, was stable at 37 °C, pH 7, and was resistant to chloroform. Treatment of mice with a single dose of phage simultaneously at the time of infection, or 24 h post infection, resulted in seven and five logs decrease of CFU/ml in the lung homogenates up to 3 days after phage administration, respectively. The isolated phage may have the potential as a therapeutic agent against K. pneumoniae infections.

中文翻译：

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从废水中分离的噬菌体治疗由肺炎克雷伯菌引起的小鼠大叶性肺炎感染的潜力

噬菌体作为多重耐药 (MDR) 肺炎克雷伯菌相关感染的替代疗法的潜力最近引起了人们的极大兴趣。本研究的目的是分离和表征一种肺炎克雷伯菌特异性裂解噬菌体，该噬菌体具有治疗由肺炎克雷伯菌引起的小鼠实验性大叶性肺炎的潜力。在用于治疗大叶性肺炎实验模型中感染肺炎克雷伯菌的小鼠之前，从德黑兰的城市废水样本中分离出一种裂解噬菌体，并通过透射电子显微镜 (TEM)、热、pH 和氯仿稳定性进行表征。BALB/C 小鼠通过鼻内接种 108 个集落形成单位 (CFU/ml) 的 K. 肺炎链球菌 ATCC 10031 然后同时或感染后 24 小时使用 1010 和 109 空斑形成单位 (PFU/ml) 腹膜内注射分离的噬菌体。对照组小鼠单独接受细菌或噬菌体。在感染后 7 天内每天对小鼠实施安乐死，并检查其肺和肝脏的异常情况，然后确定血浆和肺匀浆中的噬菌体和细菌数量。分离的噬菌体 (vB_KpnM-Teh.1) 属于肌病毒科，在 37 °C、pH 7 下稳定，并且对氯仿具有抗性。在感染时或感染后 24 小时同时用单一剂量的噬菌体治疗小鼠，在施用噬菌体后最多 3 天，肺匀浆中的 CFU/ml 分别下降 7 和 5 个对数。