Sevilla-Navarro Sandra, Otero Jennifer, López-Pérez Júlia, Torres-Boncompte Jan, Prucha Tiago, De Gussem Maarten, Silva Daniela, Burgan Julia, Catalá-Gregori Pablo, Cortés Pilar, Llagostera Montserrat
Centro de Calidad Avícola y Alimentación Animal de la Comunidad Valenciana (CECAV), 12539 Alquerias NP, Castellón, Spain.
Molecular Microbiology Group, Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain.
Animals (Basel). 2024 Aug 14;14(16):2352. doi: 10.3390/ani14162352.
serovar Infantis (. Infantis) poses a growing issue in the poultry sector, with phage-based products emerging as a safe and effective control measure. This study investigated the emergence of reduced-phage-susceptibility variants (RPSV) of . Infantis in PhagoVet-treated broilers, given that RPSV could undermine phage treatment efficacy. The bacteriophages in the PhagoVet product were characterized using transmission electron microscopy (TEM), genome sequencing, and infection profiling. Furthermore, two broiler trials were conducted: a challenge group (T1) and a challenge-and-treated group (T2). The . Infantis infective dose was set at 10 and 10 colony-forming units (CFUs) per animal, with PhagoVet administration at 10 and 10 plaque-forming units (PFUs) per animal, in Trials 1 and 2, respectively. The results revealed that the four PhagoVet bacteriophages belonged to different genera. PhagoVet evidenced broad-spectrum efficacy against 271 strains representing 18 serovars. In Trial 1, PhagoVet reduced bacterial counts in feces to nearly undetectable levels by day 42, with no RPSV detected. However, in Trial 2, three and five RPSVs were detected in feces and ceca, respectively. Consequently, PhagoVet demonstrated efficacy against . Infantis in broilers, and the potential impact of RPSV is deemed unlikely to compromise its efficacy.
婴儿血清型（.Infantis）在家禽行业中成为一个日益严重的问题，基于噬菌体的产品成为一种安全有效的控制措施。鉴于噬菌体敏感性降低变体（RPSV）可能会削弱噬菌体治疗效果，本研究调查了在接受PhagoVet治疗的肉鸡中. Infantis的RPSV的出现情况。使用透射电子显微镜（TEM）、基因组测序和感染谱分析对PhagoVet产品中的噬菌体进行了表征。此外，进行了两项肉鸡试验：一个挑战组（T1）和一个挑战与治疗组（T2）。在试验1和试验2中，. Infantis的感染剂量分别设定为每只动物10和10个菌落形成单位（CFU），PhagoVet的给药剂量分别为每只动物10和10个噬菌斑形成单位（PFU）。结果表明，四种PhagoVet噬菌体属于不同的属。PhagoVet对代表18个血清型的271株菌株具有广谱疗效。在试验1中，到第42天时，PhagoVet将粪便中的细菌数量降低到几乎检测不到的水平，未检测到RPSV。然而，在试验2中，分别在粪便和盲肠中检测到3个和5个RPSV。因此，PhagoVet在肉鸡中对. Infantis显示出疗效，并且RPSV的潜在影响被认为不太可能损害其疗效。
