Objectives: Paracoccus yeei is an environmental bacterium suspected to be responsible for ocular infections. In this study, culture-based and polymerase chain reaction (PCR) sequencing–based investigations of a corneal scraping specimen confirmed P. yeei keratitis in one contact lens wearer.
Methods: A 34-year-old male patient, who was a contact lens wearer, presented with a unilateral corneal ulcer. A corneal scraping was performed to conduct a microbiological investigation. Disease progress was favorable after a 5-week topical treatment, which combined rifampicin, ciprofloxacine, tobramycine, and dexamethasone. The final visual acuity of the right eye was 5/10 with correction, limited by a central corneal scar.
Results: Culturing the corneal scraping specimen yielded P. yeei, which was also directly detected by PCR sequencing the bacterial 16S rDNA in the presence of negative controls. The P. yeei isolate was susceptible to ticarcillin, with a minimal inhibitory concentration (MIC) of <4 mg/L of ceftazidime (MIC of 0.5 mg/L), imipenem (MIC < 0.5 mg/L), gentamycin (MIC of 0.5 mg/L), tobramycin (MIC < 0.06 mg/L), rifampicin (MIC < 0.125 mg/L), ciprofloxacin (MIC < 0.5 mg/L), and colimycin (MIC < 2 mg/L). The isolate was resistant to fosfomycine with a MIC 32 > mg/L.
Conclusions: P. yeei is a new cause of keratitis that must be diagnosed by a laboratory analysis of corneal scrapings due to the potentially poor outcome of infection.