Biotechnology Unit, Center of Technological Development, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil.
Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, CEP 96010-900, Pelotas, RS, Brazil.
Microbes Infect. 2024 Jul-Aug;26(5-6):105347. doi: 10.1016/j.micinf.2024.105347. Epub 2024 Apr 27.
Acinetobacter baumannii is an opportunistic bacterium that causes infection in several sites. Carbapenem-resistant A. baumannii strains (CRAb) lead the World Health Organization's list of 12 pathogens considered a priority for developing new antimicrobials. The pathogenicity of A. baumannii is related to the different virulence factors employed in the colonization of biotic and abiotic surfaces, biofilm formation and multidrug resistance. We analyze the outer membrane protein FilF from A. baumannii in silico and produce it in recombinant form (rFilF). rFilF protein was successfully expressed in Escherichia coli BL21 Star in an insoluble form. Immunization with rFilF induced significant anti-rFilF IgG antibody production in mice, detected by indirect enzyme-linked immunosorbent assay, since the first evaluation until 49th. On the last experimentation day, the predominant immunoglobulin found was IgG1 followed by IgG2a, IgG2b, IgM, IgG3, and IgA. We observe that interleukins 4 and 10 show significant production after the 28th day of experimentation in mice immunized with rFilF. Anti-rFilF pAbs were able to inhibit biofilm formation in nine CRAb strains evaluated, and in the standard strain ATCC® 19606. These results demonstrate the anti-biofilm activity of anti-rFilF antibodies, promising in the development of a non-antibiotic approach based on the control of CRAb strains.
鲍曼不动杆菌是一种机会致病菌，可在多个部位引起感染。耐碳青霉烯鲍曼不动杆菌（CRAb）菌株在世界卫生组织列出的 12 种被认为优先开发新抗菌药物的病原体中位居榜首。鲍曼不动杆菌的致病性与生物和非生物表面定植、生物膜形成和多药耐药性中使用的不同毒力因子有关。我们对鲍曼不动杆菌的外膜蛋白 FilF 进行了计算机分析，并以重组形式（rFilF）生产。rFilF 蛋白在大肠杆菌 BL21 Star 中以不溶性形式成功表达。用 rFilF 免疫小鼠可诱导显著的抗 rFilF IgG 抗体产生，通过间接酶联免疫吸附试验检测，从第一次评估到第 49 次均如此。在最后一次实验日，发现主要免疫球蛋白是 IgG1，其次是 IgG2a、IgG2b、IgM、IgG3 和 IgA。我们观察到，用 rFilF 免疫的小鼠在第 28 天之后白细胞介素 4 和 10 的产生显著增加。抗 rFilF pAb 能够抑制 9 株 CRAb 菌株和标准菌株 ATCC®19606 的生物膜形成。这些结果表明抗 rFilF 抗体具有抗生物膜活性，有望开发出一种基于控制 CRAb 菌株的非抗生素方法。
