Role of pvdE Pyoverdine Synthesis in Pseudomonas aeruginosa Keratitis. (November 2018)

• Record Type: Journal Article
• Authors: Suzuki, Takashi; Okamoto, Sayuri; Oka, Naoko; Hayashi, Naoki; Gotoh, Naomasa; Shiraishi, Atsushi
• Is Part Of: Cornea. Volume 37(2018)Supplement 1
• Publication Date: 2018-11
• Subjects: Pseudomonas aeruginosa -- keratitis -- pvdE gene -- invasion; Cornea -- Periodicals; Cornea -- Periodicals; Cornée -- Périodiques; 617.719
• DOI: 10.1097/ICO.0000000000001728
• Languages: English
• ISSNs: 0277-3740

Abstract

Abstract : Purpose: Pseudomonas aeruginosa produces pyoverdine, encoded by the pvdE gene, for high-affinity iron uptake from transferrin and lactoferrin. This study investigated the contribution of pyoverdine to P. aeruginosa keratitis pathogenesis using in vitro and in vivo models. Methods: The P. aeruginosa strains examined were parental strain PAO1 and isogenic mutant strain pvdE (Δ pvdE ) defective in pyoverdine. Bacterial growth in vitro was determined by PAO1 and Δ pvdE optical densities in Luria–Bertani (LB) broth. PAO1 or Δ pvdE (10 8 colony-forming units/mL) was inoculated onto cultured human corneal epithelial cells (HCECs) for 1 hour. The monolayers were examined for bacterial adhesion and invasion. In addition, the corneas of C57BL/6 mice were infected with PAO1 or Δ pvdE . Corneal virulence was evaluated by determining clinical scores and bacterial counts during infection. Results: The growth of PAO1 and Δ pvdE in LB broth was similar. Although adhesion of Δ pvdE onto HCECs was significantly increased compared with PAO1, the invasive capacity of Δ pvdE was significantly decreased. Clinical scores and bacterial numbers were significantly lower in Δ pvdE -infected eyes compared with PAO1-infected eyes at 6, 24, and 48 hours ( P < 0.001). Δ pvdE was not detected in mouse corneas and did not induce corneal opacity at 6, 24, or 48 hours. Conclusions: Δ pvdE lost invasive ability toward HCECs. Moreover, Δ pvdE did not cause keratitis in vivo. Thus, pvdE pyoverdine synthesis has critical roles in proliferation and invasion on ocular surfaces and could be a target for prevention of P. aeruginosa keratitis.