Characterization of Pseudomonas aeruginosa isolates from patients with endophthalmitis using conventional microbiologic techniques and whole genome sequencing

Purpose: To demonstrate antibiotic susceptibility and genomic virulence factor profiles of Pseudomonas aeruginosa isolates from patients with culture-confirmed endophthalmitis. Methods: Clinical isolates from patients diagnosed with pseudomonas endophthalmitis were included. Laboratory antibiotic susceptibility testing and whole genome sequencing was performed on all isolates. Results: In the current study, 8 patients had vitreous culture-confirmed endophthalmitis due to P. aeruginosa. All isolates were multi-drug resistant but sensitive to ceftazidime and each fluoroquinolone tested. Whole genome sequencing revealed a total of 179 unique genes. The most common type of virulence genes included those involved in adherence and the secretion system. Seven of 8 (88%) isolates were of the cytoinvasive phenotype (exoST) and no isolates contained exoU. Conclusions: P. aeruginosa associated endophthalmitis is often multi-drug resistant and demonstrates a variety of virulence factors with those involved in adherence and the secretion system being the most common.