Phenylalanine-arginine β-naphthylamide could enhance neomycin-sensitivity on Riemerella anatipestifer in vitro and in vivo

Abstract

Riemerella anatipestifer is an important duck pathogen responsible for septicemia and infectious serositis, which has caused great economic losses to the duck industry. Phenylalanine-arginine β-naphthylamide (PAβN) is an efflux pump inhibitor, which mainly reduces the efflux effect by competing with antibiotics for efflux pump channels. Here, we found that R. anatipestifer strain GD2019 showed resistances to gentamicin, amikacin, kanamycin, and neomycin. Notably, PAβN could significantly reduce the Minimal inhibitory concentrations (MICs) of neomycin on the GD2019 strain. Moreover, PAβN combined with neomycin significantly decreased bacterial loads, relieved pathological injury and increase survival rate (p < 0.05) for the ducks lethally challenged by the GD2019 strain. Therefore, our results suggested, in vitro and in vivo, PAβN could reduce neomycin-resistant of R. anatipestifer. Importantly, finding of this study provide a new approach for treating antibiotic-resistant R. anatipestifer infection.

The GE296_RS03820 and GE296_RS03830 genes are involved in capsular polysaccharide biosynthesis in Riemerella anatipestifer

“…Only three references have been identified, indicating the involvement of specific genes in CPS biosynthesis in R. anatipestifer . These genes include a wza ‐like gene (the B739_1124 gene) of RA‐CH‐1 (corresponding to the GE296_RS03840 gene of RA‐LZ01), the M949_RS00050 gene of the CH3 strain and the G148_RS04320 gene (corresponding to the GE296_RS03845 gene) of CH‐2 6–8 . The CPS synthesis in R. anatipestifer involves multiple genes, as predicted in Figure 1.…”

“…R. anatipestifer is known to produce capsules, but the understanding of its capsular biosynthesis is limited. Previous studies have reported the presence of certain genes involved in capsule biosynthesis, such as wza ‐like, M949_RS00050 , and G148_RS04320 genes 6–8 . However, the complete mechanism of capsular biosynthesis in R. anatipestifer remains to be fully understood, as it can contribute to understanding the pathogenicity of the bacterium and provide targets for prevention and treatment.…”

“…Previous studies have reported the presence of certain genes involved in capsule biosynthesis, such as wza-like, M949_RS00050, and G148_RS04320 genes. [6][7][8] However, the complete mechanism of capsular biosynthesis in R. anatipestifer remains to be fully understood, as it can contribute to understanding the pathogenicity of the bacterium and provide targets for prevention and treatment. Therefore, it is necessary to identify the key genes related to the biosynthesis of CPS in R. anatipestifer.…”

Boosting the Antibacterial Activity of Azithromycin on Multidrug-Resistant Escherichia coli by Efflux Pump Inhibition Coupled with Outer Membrane Permeabilization Induced by Phenylalanine-Arginine β-Naphthylamide

“…In a recent study, up to 40 µg/g of PAβN combined with neomycin were injected intramuscularly into ducks infected with Riemerella anatipestifer. Treatment with PAβN coupled with neomycin significantly increased the survival rate and reduced the bacterial load and pathological changes in the heart, liver, and brain of treated animals [38]. Indeed, there is a need for more studies to confirm the safety and efficacy of PAβN in vivo before employing it for therapeutic purposes.…”

Scalable and Chromatography‐Free Synthesis of Efflux Pump Inhibitor Phenylalanine Arginine β‐Naphthylamide for Its Validation in Wild‐Type Bacterial Strains

“…While a full literature review of its use is beyond the scope of this report, we would like to highlight PAβN's recent use cases where it has been employed to inhibit efflux while other disease relevant parameters are investigated including virulence phenotypes, [16][17][18] biofilm formation and disruption, [19] the development of antibiotic resistance, [20][21][22][23] and quorum sensing; [24] it is also used as a standard for benchmarking newly developed EPIs. [25][26][27] Further, it is commonly used during the development process of new antibiotics; [28][29][30][31][32][33] indeed, our laboratory's interest in PAβN originated during our investigations of antibacterial compounds [34] and natural products [35] that lacked activity against P. aeruginosa. Additional studies show that nonspecific membrane permeabilization may be another pathway by which PAβN potentiates antibiotics, independent of their efflux inhibition, further lending credibility to its broad application as a tool compound.…”