Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt.
Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia.
Front Cell Infect Microbiol. 2022 May 17;12:904531. doi: 10.3389/fcimb.2022.904531. eCollection 2022.
Accumulating evidence has denoted the danger of resistance in tenacious organisms like methicillin-resistant (MRSA). MRSA, a supple bacterium that adopts a variety of antibiotic resistance mechanisms, is the cause of multiple life-threatening conditions. Approaching a post-antibiotic era, bacteria-specific natural predators, bacteriophages, are now given the chance to prove eligible for joining the antibacterial weaponry. Considering the foregoing, this study aimed at isolating bacteriophages with promising anti-MRSA lytic activity, followed by characterization and optimization of the production of the bacteriophage with the broadest host range. Five phages were isolated from different environmental sources including the rinse of raw chicken egg, raw milk, and, remarkably, the raw meat rinses of chicken and fish. Examined for lytic activity against a set of 23 MRSA isolates collected from various clinical specimens, all five phages showed relatively broad host ranges with the bacteriophage originally isolated from raw fish rinse showing lytic activity against all the isolates tested. This phage is suggested to be a member of Siphoviridae family, order Caudovirales, as revealed by electron microscopy. It also exhibited good thermal stability and viability at different pH grades. Moreover, it showed reasonable stability against UV light and all viricidal organic solvents tested. Optimization using D-optimal design by response surface methodology was carried out to enhance the phage yield. The optimum conditions suggested by the generated model were a pH value of 7, a carbon source of 0.5% w/v sucrose, and a nitrogen source of 0.1% w/v peptone, at a temperature of 28°C and a bacterial inoculum size of 10 CFU/ml, resulting in a 2 log-fold increase in the produced bacteriophage titer. Overall, the above findings indicate the lytic ability inflicted by this virus on MRSA. Apparently, its stability under some of the extreme conditions tested implies its potential to be a candidate for pharmaceutical formulation as an anti-MRSA therapeutic tool. We hope that bacteriophages could tip the balance in favor of the human front in their battle against multidrug-resistant pathogens.
越来越多的证据表明，耐甲氧西林金黄色葡萄球菌（MRSA）等顽强生物体存在耐药危险。MRSA 是一种适应性很强的细菌，它采用了多种抗生素耐药机制，是多种危及生命的疾病的病因。在即将进入后抗生素时代之际，细菌特异性天然捕食者——噬菌体，现在有机会被证明有资格加入抗菌武器库。有鉴于此，本研究旨在分离具有潜在抗 MRSA 溶菌活性的噬菌体，然后对具有最广泛宿主范围的噬菌体进行特性描述和生产优化。从不同的环境来源（包括生鸡蛋冲洗液、生牛奶，以及令人惊讶的生鸡肉和鱼肉冲洗液）中分离出了 5 种噬菌体。对从各种临床标本中收集的 23 株 MRSA 分离株进行溶菌活性检测，所有 5 种噬菌体均显示出相对较宽的宿主范围，其中从生鱼冲洗液中分离出的噬菌体对所有测试的分离株均具有溶菌活性。通过电子显微镜观察，该噬菌体被鉴定为肌尾噬菌体科，长尾病毒目。它还表现出良好的热稳定性和在不同 pH 值下的生存能力。此外，它对紫外线和所有测试的杀病毒有机溶剂均具有合理的稳定性。通过响应面法的 D-最优设计进行优化，以提高噬菌体的产量。生成模型建议的最佳条件为 pH 值 7、0.5%w/v 蔗糖作为碳源和 0.1%w/v 蛋白胨作为氮源，温度为 28°C，细菌接种量为 10 CFU/ml，可使产生的噬菌体滴度增加 2 个对数级。总体而言，上述发现表明该病毒对 MRSA 的溶菌能力。显然，它在一些测试的极端条件下的稳定性意味着它有可能成为一种候选药物制剂，作为一种抗 MRSA 治疗工具。我们希望噬菌体能够在人类对抗多药耐药病原体的战斗中扭转局面。
