Institute of Medical Microbiology, RWTH Aachen University Hospital, 52074 Aachen, Germany.
Department of Infection Control and Infectious Diseases, RWTH Aachen University Hospital, 52074 Aachen, Germany.
Viruses. 2017 Oct 27;9(11):315. doi: 10.3390/v9110315.
In this study, we characterize three phages (SL1 SL2, and SL4), isolated from hospital sewage with lytic activity against clinical isolates of multi-drug resistant (MDR-PA). The host spectrum ranged from 41% to 54%, with all three phages together covering 79% of all tested clinical isolates. Genome analysis revealed that SL1 (65,849 bp, 91 open reading frames ORFs) belongs to PB1-like viruses, SL2 (279,696 bp, 354 ORFs) to phiKZ-like viruses and SL4 (44,194 bp, 65 ORFs) to LUZ24-like viruses. Planktonic cells of four of five selected MDR-PA strains were suppressed by at least one phage with multiplicities of infection (MOIs) ranging from 1 to 10 for 16 h without apparent regrowth of bacterial populations. While SL2 was most potent in suppressing planktonic cultures the strongest anti-biofilm activity was observed with SL4. Phages were able to rescue bacteria-infected wax moth larvae () for 24 h, whereby highest survival rates (90%) were observed with SL1. Except for the biofilm experiments, the effect of a cocktail with all three phages was comparable to the action of the best phage alone; hence, there are no synergistic but also no antagonistic effects among phages. The use of a cocktail with these phages is therefore expedient for increasing host range and minimizing the development of phage resistance.
在这项研究中，我们从医院污水中分离出了三个噬菌体（SL1、SL2 和 SL4），它们对具有抗药性的临床分离株具有裂解活性。宿主范围从 41%到 54%不等，三种噬菌体一起覆盖了 79%的所有测试临床分离株。基因组分析表明，SL1（65849 bp，91 个开放阅读框 ORFs）属于 PB1 样病毒，SL2（279696 bp，354 个 ORFs）属于 phiKZ 样病毒，SL4（44194 bp，65 个 ORFs）属于 LUZ24 样病毒。五种选定的多药耐药性（MDR-PA）菌株中的四个浮游细胞至少被一种噬菌体抑制，感染复数（MOI）范围为 1 到 10，持续 16 小时，而细菌种群没有明显的再生长。虽然 SL2 在抑制浮游培养物方面最有效，但 SL4 表现出最强的抗生物膜活性。噬菌体能够拯救感染蜡蛾幼虫（）24 小时，其中 SL1 观察到的存活率最高（90%）。除了生物膜实验外，含有三种噬菌体的鸡尾酒的效果与单独使用最佳噬菌体的效果相当；因此，噬菌体之间没有协同作用，也没有拮抗作用。因此，使用这种噬菌体的鸡尾酒可以扩大宿主范围，最大限度地减少噬菌体耐药性的发展。
