Shaygankho Nasibeh, Jahangiri Abolfazl, Rasooli Iraj
Department of Biology, Shahed University, Tehran, Iran.
Applied Microbiology Research Center, Systems biology and poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Biomed Pharmacother. 2023 Nov;167:115583. doi: 10.1016/j.biopha.2023.115583. Epub 2023 Sep 27.
Acinetobacter baumannii is a formidable pathogen, characterized by high mortality rates and pan-drug-resistant strains. Current commercial antibiotics lack efficacy against drug-resistant variants, necessitating the search for alternative treatments. This study investigates the potential of egg yolk immunoglobulin (IgY) as a cost-effective biomolecule for passive protection against A. baumannii pneumonia. FimA (ABAYE2132), a key virulence factor involved in biofilm development and lung cell adherence, emerges as a promising antigen for triggering protective IgY production. Recombinant FimA was expressed, purified, and used for intramuscular immunization of laying White Leghorn hens. IgY antibodies were subsequently extracted from egg yolks, with their reactivity assessed through indirect ELISA. Neutropenic mice received intranasal administration of IgYs one hour prior to the challenge with a clinical A. baumannii isolate (10 ×LD). The specific anti-FimA IgYs detected recombinant FimA and provided 100% protection against bacterial infection, while non-specific IgYs prolonged survival for up to 72 h. In contrast, control mice succumbed to infection within 24 h. Analysis of bacterial loads in lungs and spleens after 16 h reveals the following order: control > non-specific IgY > anti-FimA IgY. These findings highlight FimA as a suitable antigen for the development of protective IgYs against A. baumannii.
鲍曼不动杆菌是一种可怕的病原体，其特征是死亡率高且存在泛耐药菌株。目前的商用抗生素对耐药变体缺乏疗效，因此需要寻找替代治疗方法。本研究调查了蛋黄免疫球蛋白（IgY）作为一种具有成本效益的生物分子对鲍曼不动杆菌肺炎进行被动保护的潜力。FimA（ABAYE2132）是一种参与生物膜形成和肺细胞黏附的关键毒力因子，是触发保护性IgY产生的一种有前景的抗原。表达、纯化重组FimA，并将其用于对产蛋白来航鸡进行肌肉注射免疫。随后从蛋黄中提取IgY抗体，通过间接ELISA评估其反应性。中性粒细胞减少的小鼠在受到临床鲍曼不动杆菌分离株（10×LD）攻击前1小时接受IgY的鼻内给药。特异性抗FimA IgY检测到重组FimA，并提供了100%的细菌感染保护，而非特异性IgY将存活时间延长至72小时。相比之下，对照小鼠在24小时内死于感染。16小时后对肺和脾中的细菌载量分析显示以下顺序：对照>非特异性IgY>抗FimA IgY。这些发现突出了FimA作为开发针对鲍曼不动杆菌的保护性IgY的合适抗原。
