Ahmadbeigi Yasaman, Soleimani Neda, Azizmohseni Farzaneh, Amini-Bayat Zahra
Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran.
BMC Microbiol. 2025 Jun 7;25(1):357. doi: 10.1186/s12866-025-04074-5.
The rising occurrence of antibiotic resistance in Staphylococcus aureus significantly complicates its treatment. Endolysins are now recognized as a promising substitute for antibiotics in combating multidrug-resistant bacteria. In this research, a novel chimeric endolysin named ZAM-CS was engineered and assessed to achieve enhanced stability, solubility, and rapid bactericidal activity. This was accomplished by combining the catalytic domain of the SAL-1 endolysin with the peptidoglycan binding domain of lysostaphin.
Expression and purification outcomes indicated that ZAM-CS exhibited significant solubility, with a yield of approximately 23 mg/L. ZAM-CS demonstrated high stability under various temperature conditions and retained most of its activity in both acidic and alkaline pH. The results of turbidity reduction assay showed a 50% decrease in the initial OD600 within 10 min at a minimum concentration of 2 µg/mL. The minimum inhibitory concentration and the minimum bactericidal concentration values of ZAM-CS are identical in the methicillin-resistant Staphylococcus aureus strain, indicating the strong bactericidal properties of this endolysin. Antimicrobial tests showed ZAM-CS was also effective against coagulase-negative Staphylococci, Streptococcus agalactiae, and Enterococcus faecalis.
The rapid and dynamic action and high stability of ZAM-CS compared to other recombinant endolysins make it a suitable candidate for development to replace antibiotics targeting harmful Staphylococci, including MRSA.
金黄色葡萄球菌中抗生素耐药性的不断增加使其治疗变得极为复杂。内溶素现已被认为是对抗多重耐药菌的一种有前景的抗生素替代品。在本研究中，设计并评估了一种名为ZAM-CS的新型嵌合内溶素，以实现更高的稳定性、溶解性和快速杀菌活性。这是通过将SAL-1内溶素的催化结构域与溶葡萄球菌素的肽聚糖结合结构域相结合来实现的。
表达和纯化结果表明，ZAM-CS具有显著的溶解性，产量约为23 mg/L。ZAM-CS在各种温度条件下均表现出高稳定性，在酸性和碱性pH条件下均保留了大部分活性。浊度降低试验结果表明，在最低浓度为2 µg/mL时，初始OD600在10分钟内降低了50%。ZAM-CS在耐甲氧西林金黄色葡萄球菌菌株中的最低抑菌浓度和最低杀菌浓度值相同，表明该内溶素具有强大的杀菌特性。抗菌试验表明，ZAM-CS对凝固酶阴性葡萄球菌、无乳链球菌和粪肠球菌也有效。
与其他重组内溶素相比，ZAM-CS具有快速动态作用和高稳定性，使其成为开发替代针对包括耐甲氧西林金黄色葡萄球菌在内的有害葡萄球菌的抗生素的合适候选物。
