Bacteriology, Department of Infectious and Parasitic Diseases, FARAH and Faculty of Veterinary Medicine, ULiège, 4000 Liège, Belgium; Food Science Department, FARAH and Faculty of Veterinary Medicine, ULiège, 4000 Liège, Belgium.
Vésale Bioscience, Vésale Pharmaceutica, 5310, Noville sur Mehaigne, Belgium.
Res Vet Sci. 2021 May;136:598-601. doi: 10.1016/j.rvsc.2021.04.010. Epub 2021 Apr 15.
Pseudomonas (P.) aeruginosa is the most frequently isolated Gram-negative bacteria in dog otitis. Antimicrobial resistance is particularly prevalent in P. aeruginosa and phage therapy represents a promising alternative therapeutic strategy. The aim of this study was to assess the efficacy of the PEV2 phage against a clinical P. aeruginosa isolate from a canine otitis using a Galleria (G.) mellonella larvae model. The genomic DNA of PAV237 P. aeruginosa isolate was sequenced and analysed. In a first main experiment, the efficacy of PEV2 phage against PAV237 was assessed at different multiplicities of infection (MOI) (50,000, 5000, 500, 50) by analyzing the larvae survival rate during 4 days. In a second experiment, the bacterial and phage titer evolutions were assessed depending on two MOIs (50,000, 5000). No significant survival increase was observed with PEV2 therapy in the infected larvae groups. The generated Kaplan-Meier curves showed that the rate of alive larvae was significantly higher in the non-infected larvae compared to the infected-treated ones irrespective of phage MOIs. An increase of the phage titer was observed at 24 and 48 h post-inoculation (HPI) with both MOIs and the P. aeruginosa titers were lower with MOI 50,000 and 5000 compared to the infectivity control at 24 and 48 HPI. Even if an ineffectiveness of the PEV2 phage was observed on the larvae survival, PEV2 is active against P. aeruginosa in this model and PEV2 replication is correlated with a lower bacterial proliferation in the phage treated larvae.
铜绿假单胞菌（P. aeruginosa）是犬耳炎中最常分离到的革兰氏阴性菌。铜绿假单胞菌的抗生素耐药性尤其普遍，噬菌体治疗代表了一种有前途的治疗策略。本研究旨在使用大蜡螟（G. mellonella）幼虫模型评估 PEV2 噬菌体对犬耳炎临床分离的铜绿假单胞菌的疗效。对 PAV237 铜绿假单胞菌分离株的基因组 DNA 进行了测序和分析。在第一个主要实验中，通过分析 4 天内幼虫的存活率，评估了不同感染复数（MOI）（50,000、5000、500、50）下 PEV2 噬菌体对 PAV237 的疗效。在第二个实验中，根据两个 MOI（50,000、5000）评估了细菌和噬菌体滴度的演变。在感染幼虫组中，使用 PEV2 治疗没有观察到明显的存活率增加。生成的 Kaplan-Meier 曲线表明，无论噬菌体 MOI 如何，未感染幼虫的存活幼虫率明显高于感染治疗幼虫。在接种后 24 和 48 小时（HPI），观察到噬菌体滴度增加，两种 MOI 下的铜绿假单胞菌滴度均低于感染性对照，在 24 和 48 HPI。尽管在幼虫存活方面观察到 PEV2 噬菌体无效，但在该模型中，PEV2 对铜绿假单胞菌有效，并且 PEV2 复制与噬菌体处理幼虫中细菌增殖减少相关。
