Daisuke Todokoro1, Takashi Suzuki2, Shinichiro Kobayakawa3, Haruyoshi Tomita4,5, Yuichi Ohashi6, Hideo Akiyama7. 1. Department of Ophthalmology, Gunma University Graduate School of Medicine, Maebashi, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8511, Japan. dtodokor@gunma-u.ac.jp. 2. Ishizuchi Eye Clinic, Niihama, Ehime, Japan. 3. Department of Ophthalmology, Nippon Medical School Tama Nagayama Hospital, Tama, Tokyo, Japan. 4. Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan. 5. Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan. 6. Department of Ophthalmology, Ehime University School of Medicine, Toon, Ehime, Japan. 7. Department of Ophthalmology, Gunma University Graduate School of Medicine, Maebashi, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8511, Japan.
Abstract
Purpose Postoperative endophthalmitis caused by Enterococcus faecalis often results in poor visual outcome due to retinal destruction. We evaluated the virulence factors of Enterococcus faecalis clinical isolates and analyzed their relationship with retinal destruction and poor visual outcomes in postoperative bacterial endophthalmitis (PBE) following cataract surgery. STUDY DESIGN: Retrospective. METHODS: E. faecalis isolates from nine acute-onset PBE cases were examined using pulsed-field gel electrophoresis of genomic DNA, plasmid isolation and pheromone response experiments. Virulence determinant genes, including cytolysin (cylA), aggregation substance (asa1), enterococcal surface protein (esp), gelatinase (gelE) and adhesin of collagen from enterococci (ace), were examined by polymerase chain reaction. Expression of cytolysin and secreted protease were also tested. Retinal findings observed during vitrectomy surgery and final visual acuities were compared to obtained microbiological data. Poor visual outcome was defined as final visual acuity of less than 0.1 (decimal). RESULTS: Although nine isolates were collected, two were identical. Out of the eight different isolates, three were positive for both expressions of cytolysin and secreted proteases. Plasmid DNAs were isolated from six of eight isolates, while pheromone response was observed in five isolates. The asa1, esp and ace genes were positive in six, five and eight of the isolates, respectively. Patients with retinal destruction exhibited significantly higher prevalence of secreted protease expression versus those without (P < 0.05), and retinal destruction was related to poor visual outcome (P < 0.05). CONCLUSIONS: Our data suggest that enterococcal secreted proteases were correlated to retinal destruction, thereby fostering poor visual outcomes in eyes with enterococcal endophthalmitis.
Purpose Postoperative endophthalmitis caused by Enterococcus faecalis often results in poor visual outcome due to retinal destruction. We evaluated the virulence factors of Enterococcus faecalis clinical isolates and analyzed their relationship with retinal destruction and poor visual outcomes in postoperative bacterial endophthalmitis (PBE) following cataract surgery. STUDY DESIGN: Retrospective. METHODS:E. faecalis isolates from nine acute-onset PBE cases were examined using pulsed-field gel electrophoresis of genomic DNA, plasmid isolation and pheromone response experiments. Virulence determinant genes, including cytolysin (cylA), aggregation substance (asa1), enterococcal surface protein (esp), gelatinase (gelE) and adhesin of collagen from enterococci (ace), were examined by polymerase chain reaction. Expression of cytolysin and secreted protease were also tested. Retinal findings observed during vitrectomy surgery and final visual acuities were compared to obtained microbiological data. Poor visual outcome was defined as final visual acuity of less than 0.1 (decimal). RESULTS: Although nine isolates were collected, two were identical. Out of the eight different isolates, three were positive for both expressions of cytolysin and secreted proteases. Plasmid DNAs were isolated from six of eight isolates, while pheromone response was observed in five isolates. The asa1, esp and ace genes were positive in six, five and eight of the isolates, respectively. Patients with retinal destruction exhibited significantly higher prevalence of secreted protease expression versus those without (P < 0.05), and retinal destruction was related to poor visual outcome (P < 0.05). CONCLUSIONS: Our data suggest that enterococcal secreted proteases were correlated to retinal destruction, thereby fostering poor visual outcomes in eyes with enterococcal endophthalmitis.
Authors: Jiyeun Kate Kim; Ki Yup Nam; In Young Chung; Woo Jin Jeung; Yoon Hyung Kwon; Jung Min Park; Yong Seop Han; Ji Eun Lee; Ik Soo Byon; Sung Hu Park; Hyun Wong Kim; Kang Yun Park; Hee Sung Yoon; Indal Park; Han Woo Kim; Sang Joon Lee Journal: Emerg Microbes Infect Date: 2020-12 Impact factor: 7.163