[ODP22] 5. Pathogenicity -b. Toxins, effectors and physically active substances

[ODP-111] Role of extracellular vesicles from Staphylococcus aureus on pathogenicity of Pseudomonas aeruginosa

Phawinee Subsomwong¹, Kouji Narita^1,2, Noriaki Kawai¹, Akio Nakane^3,4, Krisana Asano^1,3 (¹Dept. Microbiol. Immunol., Hirosaki Univ. Grad. Sch. Med., ²Inst. Anim. Exp., Hirosaki Univ. Grad. Sch. Med., ³Dept. Biopolym. Health Sci., Hirosaki Univ. Grad. Sch. Med., ⁴Hirosaki Univ. Health Welf.)

Staphylococcus aureus (Sa) and Pseudomonas aeruginosa (Pa) are prevalent pathogens found in chronic wounds and lungs with cystic fibrosis. Co-infection of these bacteria, especially antibiotic-resistant strains, becomes a serious problem in hospitals. Therefore, a clear understanding of their interactions, in particular synergistic virulence mediated by extracellular vesicles (EVs), is essential for establishment of novel preventive and therapeutic strategies. Here, we investigated the effect of EVs from Sa (SaEVs) on pathogenicity of Pa. SaEVs were purified from Sa culture supernatant (average size 149 nm). Forty-three proteins in SaEVs were identified by LC-MS/MS analysis, and several virulence factors were detected including transcriptional regulators, and signal transduction proteins. Fusion of R18-labled SaEVs with Pa was observed by fluorescence microscopy. The SaEVs did not alter the antibiotic susceptibility and biofilm formation of Pa. By using human lung carcinoma cells (A549) and keratinocytes (HaCaT), we found that SaEVs promoted Pa invasion into HaCaT cells. In addition, SaEV-pretreated Pa induced cytotoxicity of Pa to A549 and HaCaT cells. The results suggest the role of SaEVs as the mediator that induces the pathogenicity of Pa. This finding prompts us to further develop SaEVs as vaccine or drug transporter for prevention and treatment of Sa-Pa co-infection.