Rapid Diagnostic Work-Up of Streptococcus dysgalactiae Endophthalmitis by a Novel Culture Processing System

The diagnosis of infective endophthalmitis is supported by microbiologic work-up. Rapid work-up is critical to confirm clinical suspicion and enable appropriate antimicrobial therapy. We report the novel use of an automated liquid culture processing system (Fast System, Qvella Corporation) in a vitreous fluid culture. A 59-year-old patient with post-operative endophthalmitis presented with acute right eye pain and blurred vision. Vitreous fluid collected for microbiology culture was of limited quantity and only inoculated to thioglycolate broth. Broth culture recovered beta-hemolytic, group G Streptococcus dysgalactiae susceptible to penicillin and vancomycin. Experimental application of the Fast System to isolate and concentrate the organism from the broth culture yielded the same identification and susceptibility test results but one day sooner than the standard workflow. Despite prompt treatment with appropriate antibiotics including vancomycin and ceftriaxone, disease progressed rapidly and required enucleation to achieve a stable therapeutic outcome. Use of automated processors such as the FAST System for monomicrobial broth cultures has thus far focused on positive blood culture broths, but could potentially include other liquid-based cultures such as for sterile body fluids of critical nature.