Choi Yoon-Jung, Kim Shukho, Shin Minsang, Kim Jungmin
Department of Microbiology, School of Medicine, Kyungpook National University, Daegu 37224, Republic of Korea.
Antibiotics (Basel). 2024 Jul 22;13(7):680. doi: 10.3390/antibiotics13070680.
is a challenging multidrug-resistant pathogen in healthcare. Phage vB_AbaSi_W9 (GenBank: PP146379.1), identified in our previous study, shows lytic activity against 26 (89.66%) of 29 carbapenem-resistant (CRAB) strains with various sequence types (STs). It is a promising candidate for CRAB treatment; however, its lytic efficiency is insufficient for complete bacterial lysis. Therefore, this study aimed to investigate the clinical utility of the phage vB_AbaSi_W9 by identifying antimicrobial agents that show synergistic effects when combined with it. The ATCC17978 strain was used as the host for the phage vB_AbaSi_W9. Adsorption and one-step growth assays of the phage vB_AbaSi_W9 were performed at MOIs of 0.001 and 0.01, respectively. Four clinical strains of CRAB belonging to different sequence types, KBN10P04948 (ST191), LIS2013230 (ST208), KBN10P05982 (ST369), and KBN10P05231 (ST451), were used to investigate phage-antibiotic synergy. Five antibiotics were tested at the following concentration: meropenem (0.25-512 µg/mL); colistin, tigecycline, and rifampicin (0.25-256 µg/mL); and ampicillin/sulbactam (0.25/0.125-512/256 µg/mL). The in vitro synergistic effect of the phage and rifampicin was verified through an in vivo mouse infection model. Phage vB_AbaSi_W9 demonstrated 90% adsorption to host cells in 1 min, a 20 min latent period, and a burst size of 114 PFU/cell. Experiments combining phage vB_AbaSi_W9 with antibiotics demonstrated a pronounced synergistic effect against clinical strains when used with tigecycline and rifampicin. In a mouse model infected with CRAB KBN10P04948 (ST191), the group treated with rifampicin (100 μg/mL) and phage vB_AbaSi_W9 (MOI 1) achieved a 100% survival rate-a significant improvement over the phage-only treatment (8.3% survival rate) or antibiotic-only treatment (25% survival rate) groups. The bacteriophage vB_AbaSi_W9 demonstrated excellent synergy against CRAB strains when combined with tigecycline and rifampicin, suggesting potential candidates for phage-antibiotic combination therapy in treating CRAB infections.
是医疗保健领域中一种具有挑战性的多重耐药病原体。我们之前的研究中鉴定出的噬菌体vB_AbaSi_W9（GenBank：PP146379.1），对29株不同序列类型（STs）的耐碳青霉烯类鲍曼不动杆菌（CRAB）菌株中的26株（89.66%）表现出裂解活性。它是治疗CRAB的一个有前景的候选者；然而，其裂解效率不足以实现细菌的完全裂解。因此，本研究旨在通过鉴定与噬菌体vB_AbaSi_W9联合使用时显示协同效应的抗菌剂，来研究该噬菌体的临床实用性。将ATCC17978菌株用作噬菌体vB_AbaSi_W9的宿主。噬菌体vB_AbaSi_W9的吸附和一步生长试验分别在感染复数（MOI）为0.001和0.01的条件下进行。使用属于不同序列类型的4株CRAB临床菌株，即KBN10P04948（ST191）、LIS2013230（ST208）、KBN10P05982（ST369）和KBN10P05231（ST451），来研究噬菌体 - 抗生素协同作用。对5种抗生素进行了如下浓度测试：美罗培南（0.25 - 512μg/mL）；黏菌素、替加环素和利福平（0.25 - 256μg/mL）；以及氨苄西林/舒巴坦（0.25/0.125 - 512/256μg/mL）。通过体内小鼠感染模型验证了噬菌体与利福平的体外协同效应。噬菌体vB_AbaSi_W9在1分钟内对宿主细胞的吸附率为90%，潜伏期为20分钟，裂解量为114个噬菌斑形成单位/细胞。将噬菌体vB_AbaSi_W9与抗生素联合使用的实验表明，与替加环素和利福平联合使用时，对临床菌株具有显著的协同效应。在感染CRAB KBN10P04948（ST191）的小鼠模型中，用利福平（100μg/mL）和噬菌体vB_AbaSi_W9（MOI 1）治疗的组实现了100%的存活率，这比仅用噬菌体治疗组（存活率8.3%）或仅用抗生素治疗组（存活率25%）有显著提高。噬菌体vB_AbaSi_W9与替加环素和利福平联合使用时对CRAB菌株表现出优异的协同作用，表明其可能是治疗CRAB感染的噬菌体 - 抗生素联合疗法的潜在候选者。
