Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic bacterium commonly found in wound infections and airways of cystic fibrosis patients. P. aeruginosa readily forms biofilms which can reduce the efficacy of antibiotics used to eradicate the pathogen. We have previously shown that a Specialized Pro-resolving Mediator (SPM), Lipoxin A4 (LxA₄) is a quorum sensing inhibitor which can reduce P. aeruginosa virulence. In this study, we examined the direct actions of LxA₄ and RvD₂ on P. aeruginosa biofilm formation and virulence gene expression. The influence of LxA₄ on antibiotic efficacy and the combined effects on biofilm formation were also investigated. LxA₄ and RvD₂ reduced P. aeruginosa biofilm formation and virulence gene expression. LxA₄ increased ciprofloxacin inhibition on biofilm formation but did not affect ciprofloxacin’s action on non-adherent bacteria. On the other hand, LxA₄ increased bacterial killing action of imipenem but did not affect imipenem’s action on biofilm. We also found that LxA₄ can increase ciprofloxacin’s bacterial killing ability in established biofilm. Together these results suggest that LxA₄ has direct effects on P. aeruginosa biofilm formation and can increase antibiotic efficacy directly.

铜绿假单胞菌 (P. aeruginosa)是一种机会性细菌，常见于囊性纤维化患者的伤口感染和气道中。铜绿假单胞菌很容易形成生物膜，这会降低用于根除病原体的抗生素的功效。我们之前已经证明，一种专门的促分解介质 (SPM)，脂氧素 A4 (LxA ₄ ) 是一种群体感应抑制剂，可以降低铜绿假单胞菌的毒力。在这项研究中，我们检查了 LxA ₄和 RvD ₂对铜绿假单胞菌生物膜形成和毒力基因表达的直接作用。LxA _4的影响还研究了抗生素功效和对生物膜形成的综合影响。LxA ₄和 RvD ₂降低了铜绿假单胞菌生物膜的形成和毒力基因的表达。LxA ₄增加了环丙沙星对生物膜形成的抑制作用，但不影响环丙沙星对非粘附细菌的作用。另一方面，LxA ₄增加了亚胺培南的杀菌作用，但不影响亚胺培南对生物膜的作用。我们还发现 LxA ₄可以增加环丙沙星在已建立的生物膜中的细菌杀灭能力。这些结果一起表明 LxA _4对铜绿假单胞菌有直接影响生物膜形成，可直接提高抗生素疗效。