Subinhibitory Concentrations of Biogenic Silver Nanoparticles Affect Motility and Biofilm Formation in Pseudomonas aeruginosa

Frontiers in Cellular and Infection Microbiology

Heloísa Moreira Martins¹  Renata Katsuko Takayama Kobayashi¹  Gerson Nakazato¹  Laís Anversa²  Doroti de Oliveira Garcia³  Erika Kushikawa Saeki⁴  Amanda Yaeko Yamada⁴  Larissa Amianti de Araujo⁴  Renan Luiz Barros de Souza⁵ 

[1] Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil;Regional Laboratory of Bauru, Adolfo Lutz Institute, Bauru, Brazil;Regional Laboratory of Marília, Adolfo Lutz Institute, Marília, Brazil;Regional Laboratory of Presidente Prudente, Adolfo Lutz Institute, Presidente Prudente, Brazil;University of Western São Paulo, UNOESTE, Presidente Prudente, Brazil;

关键词: antibiofilm;    antivirulence;    virulence factor;    metal nanoparticle;    quorum sensing;   

DOI  :  10.3389/fcimb.2021.656984

来源: Frontiers

【 摘 要 】

Biogenic silver nanoparticles (bio-AgNPs) are increasingly recognized as an antibiofilm and antivirulence strategy against P. aeruginosa, a bacterium that causes chronic infections in immunocompromised and cystic fibrosis patients. This study aimed to investigate the effects of subinhibitory concentrations of bio-AgNPs on motility and biofilm formation in P. aeruginosa. Bio-AgNPs were synthesized via reduction of ionic silver catalyzed by cell-free culture filtrate from Fusarium oxysporum. A total of 17 P. aeruginosa isolates and strains were evaluated for swarming, swimming, and twitching motility in the presence and absence (control) of bio-AgNPs, including 10 clinical isolates from patients with and without cystic fibrosis, 5 environmental isolates obtained from the public water supply system, and 2 reference strains (PAO1 and PA14). Isolates were identified by biochemical and molecular methods. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. Swarming, swimming, and twitching motility assays were performed in Petri dishes. Biofilm formation capacity was assessed quantitatively by the crystal violet method. MIC values ranged from 15.62 to 62.50 µM. The results showed that subinhibitory concentrations of bio-AgNPs (½ MIC, 7.81–31.25 µM) significantly increased (p < 0.05) swarming, swimming, and twitching motility in 40.0, 40.0, and 46.7% of isolates, respectively. Subinhibitory bio-AgNP treatment enhanced (p < 0.05) biofilm formation capacity in PA14 and a cystic fibrosis isolate (P11). It is concluded that subinhibitory concentrations of bio-AgNPs increased biofilm formation and swarming, swimming, and twitching motility in PA14 and some P. aeruginosa isolates. These virulence factors are directly involved with quorum-sensing systems. Further research should investigate the effects of AgNPs on P. aeruginosa quorum sensing to help elucidate their mechanism of action at subinhibitory concentrations.

【 授权许可】

CC BY