N.F. Gamaleya Federal Research Centre for Epidemiology and Microbiology, Ministry of Health of the Russian Federation, 123098 Moscow, Russia.
Lomonosov Moscow State University, 119991 Moscow, Russia.
Viruses. 2019 Mar 21;11(3):284. doi: 10.3390/v11030284.
The extremely rapid spread of multiple-antibiotic resistance among Gram-negative pathogens threatens to move humankind into the so-called "post-antibiotic era" in which the most efficient and safe antibiotics will not work. Bacteriophage lysins represent promising alternatives to antibiotics, as they are capable of digesting bacterial cell wall peptidoglycans to promote their osmotic lysis. However, relatively little is known regarding the spectrum of lysin bactericidal activity against Gram-negative bacteria. In this study, we present the results of in vitro activity assays of three putative and newly cloned bacteriophage endolysins (LysAm24, LysECD7, and LysSi3). The chosen proteins represent lysins with diverse domain organization (single-domain vs. two-domain) and different predicted mechanisms of action (lysozyme vs. peptidase). The enzymes were purified, and their properties were characterized. The enzymes were tested against a panel of Gram-negative clinical bacterial isolates comprising all Gram-negative representatives of the ESKAPE group. Despite exhibiting different structural organizations, all of the assayed lysins were shown to be capable of lysing , , , , and strains. Less than 50 μg/mL was enough to eradicate growing cells over more than five orders of magnitude. Thus, LysAm24, LysECD7, and LysSi3 represent promising therapeutic agents for drug development.
革兰氏阴性病原体对抗生素的多重耐药性迅速传播，这有可能使人类进入所谓的“后抗生素时代”，在这个时代，最有效和最安全的抗生素将不再起作用。噬菌体裂解酶是抗生素的有前途的替代品，因为它们能够消化细菌细胞壁肽聚糖，促进其渗透裂解。然而，对于裂解酶对革兰氏阴性细菌的杀菌活性的范围，相对知之甚少。在这项研究中，我们介绍了三种假定的和新克隆的噬菌体内溶素（LysAm24、LysECD7 和 LysSi3）的体外活性测定结果。选择的蛋白质代表具有不同结构域组织（单结构域与双结构域）和不同预测作用机制（溶菌酶与肽酶）的裂解酶。对这些酶进行了纯化，并对其特性进行了表征。对这些酶进行了测试，以评估包含 ESKAPE 组所有革兰氏阴性代表的一组革兰氏阴性临床细菌分离株。尽管表现出不同的结构组织，但所有测试的裂解酶都能够裂解 、 、 、 和 菌株。少于 50 μg/mL 的浓度就足以消灭超过五个数量级的生长细胞。因此，LysAm24、LysECD7 和 LysSi3 代表了药物开发有前途的治疗剂。
