Kazunobu Asao: Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan. ORCID
Noriyasu Hashida: Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan nhashida@ophthal.med.osaka-u.ac.jp.
Kazuichi Maruyama: Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Daisuke Motooka: Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Teruhisa Tsukamoto: Biology and Translational Research Unit, Department of Medical Innovations, New Drug Research Division, Otsuka Pharmaceutical. Co. Ltd, Naruto, Tokushima, Japan.
Yoshihiko Usui: Department of Ophthalmology, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
Shota Nakamura: Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Kohji Nishida: Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
OBJECTIVE: To evaluate the usefulness of metagenomic analysis in the search for causative organisms of bacterial endophthalmitis. METHODS AND ANALYSIS: Twenty-one consecutive treatment-naïve patients (13 men and 8 women; mean age, 60.8±19.8 years) with suspected endophthalmitis were recruited. Vitrectomy was performed to diagnose and treat endophthalmitis. Bacterial culture and metagenomic analysis of the vitreous body were performed. Extracted DNA was analysed using 16S rRNA sequences, and libraries were sequenced on an Illumina MiSeq sequencer. To compare the bacterial composition in each case, α and β diversities were determined. RESULTS: Patients were categorised into three groups: endophthalmitis cases with matching predominant organisms according to metagenomic analysis and bacterial culture, those with negative results for bacterial culture and those with negative results in both cases. In 7 of 15 culture-negative cases, results from metagenomic analysis could detect pathogens. The diversity of bacterial populations was significantly lower in the group with positive results for predominant bacteria according to culture and metagenomic analysis. All patients with uveitis were included in the group for which the causative pathogen could not be determined by culture or metagenomic analysis. The structures of bacterial populations significantly differed between the positive and negative groups by culture and metagenomic analysis. CONCLUSIONS: Metagenomic analysis could be useful for prompt detection of causative pathogens, for precise diagnosis of infection, and as a marker of inflammation processes such as uveitis.
