Genomics-Based Identification of Microorganisms in Human Ocular Body Fluid

• Published in: Scientific reports 2018-03, Vol.8 (1), p.4126-14, Article 4126
• Main Authors: Kirstahler, Philipp, Bjerrum, Søren Solborg, Friis-Møller, Alice, la Cour, Morten, Aarestrup, Frank M., Westh, Henrik, Pamp, Sünje Johanna
• Format: Article
• Language: English
• Subjects: 13; 38/22; 45/23; 631/114; 631/326/107; 631/326/2521; 631/326/2565/2142; 692/699/3161; 82/58; Antibiotic resistance; Aqueous Humor - microbiology; Bacteria - classification; Bacteria - genetics; Bacterial Typing Techniques - methods; Cataract Extraction - adverse effects; Contaminants; Deoxyribonucleic acid; DNA; DNA, Bacterial - genetics; Endophthalmitis; Endophthalmitis - etiology; Endophthalmitis - genetics; Endophthalmitis - microbiology; Female; Genomes; Genomics; Genomics - methods; Humanities and Social Sciences; Humans; Infectious diseases; Intravitreal Injections - adverse effects; Male; Mass spectroscopy; Microbiomes; Microorganisms; Middle Aged; multidisciplinary; Nucleotide sequence; Postoperative Complications - genetics; Postoperative Complications - microbiology; Science; Science (multidisciplinary); Surgery
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-22416-4

Advances in genomics have the potential to revolutionize clinical diagnostics. Here, we examine the microbiome of vitreous (intraocular body fluid) from patients who developed endophthalmitis following cataract surgery or intravitreal injection. Endophthalmitis is an inflammation of the intraocular cavity and can lead to a permanent loss of vision. As controls, we included vitreous from endophthalmitis-negative patients, balanced salt solution used during vitrectomy and DNA extraction blanks. We compared two DNA isolation procedures and found that an ultraclean production of reagents appeared to reduce background DNA in these low microbial biomass samples. We created a curated microbial genome database (>5700 genomes) and designed a metagenomics workflow with filtering steps to reduce DNA sequences originating from: (i) human hosts, (ii) ambiguousness/contaminants in public microbial reference genomes and (iii) the environment. Our metagenomic read classification revealed in nearly all cases the same microorganism that was determined in cultivation- and mass spectrometry-based analyses. For some patients, we identified the sequence type of the microorganism and antibiotic resistance genes through analyses of whole genome sequence (WGS) assemblies of isolates and metagenomic assemblies. Together, we conclude that genomics-based analyses of human ocular body fluid specimens can provide actionable information relevant to infectious disease management.