Genome-sequencing of Ocular Fluid in a Patient with Syphilitic Uveitis: Strain Identification and Antimicrobial Resistance Detection

ABSTRACT

Purpose To describe an unusual case of bilateral, hypertensive uveitis in which a syphilis genome with antimicrobial resistance was identified in the aqueous humor. Methods A retrospective review of patient records was performed for clinical data. An aqueous humor sample was collected, and syphilis genomes were analyzed for phylogenetic traits and antimicrobial resistance. Results A 64-year-old male was referred to our uveitis service for an evaluation of bilateral hypertensive anterior uveitis. On examination, visual acuities were 20/80 in the right eye (OD) and 20/100 in the left eye (OS), and intraocular pressure was 57 mmHg OD and 56 mmHg OS. Ophthalmic examination revealed severe conjunctival injection, severe anterior chamber inflammation, and vitreous opacities bilaterally. A uveitis laboratory work-up revealed a reactive syphilis IgG and an elevated RPR. Because of ongoing concern of a viral process, PCR testing was performed for HSV, VZV, and CMV, which were negative. Subsequent genomic sequencing of the residual ocular fluid demonstrated Treponema pallidum species, which showed the Nichols lineage with macrolide resistance. The patient responded favorably to penicillin therapy with resolution of syphilitic uveitis and improvement in visual acuity. Conclusions and importance This case report highlights the utility of ocular fluid's genome sequencing in diagnosing ocular syphilis and detecting antimicrobial resistance. Given the resurgence of syphilis in the U.S. and globally and the shortage of penicillin worldwide, genomic sequencing of ocular fluid may also assist in antimicrobial resistance detection for syphilis, along with pathogen identification, in concert with serologic assessment.