Characterizing the microbiota of instrumentation in ophthalmology clinics during and beyond the COVID-19 pandemic

Purpose Increased ophthalmology-specific risk of novel coronavirus 2019 (SARS-CoV-2) transmission is well-established, increasing the fear of infection and causing associated decreased rates of procedures known to save vision. However, the potential transmission from exposure to clinic instrumentation is unknown, including which additional pathogens may be spreading in this context. This study seeks to fill this gap by characterizing the microbiota of instrumentation in ophthalmology clinics during the COVID-19 pandemic and identifying potential sources of pathogenic spread encountered by patients and healthcare workers. Methods Thirty-three samples were captured using standard cultures and media. Ten positive and negative controls were used to confirm proper technique. Descriptive statistics were calculated for all samples. Samples were collected from the retina (N=17), glaucoma (N= 6), cornea (N= 6), and resident (N=4) clinics with rigorous disinfection standards at a tertiary academic medical center. Standard media cultures and/or polymerase chain reaction (PCR) was performed for each sample. Results From 33 samples, more than half (17/33, 51.5%) yielded bacterial growth. Using two different molecular methods, three samples (3/33, 9%) tested positive for SARS-CoV-2 (cycle thresholds 36.48, 37.14, and 37.83). There was no significant difference in bacterial growth (95% confidence interval [95% CI]: - 0.644-0.358, p = 0.076) among different clinics (retina, glaucoma, cornea, resident). Staphylococcus (S.) epidermidis grew most frequently (12/35, 34%), followed by S. capitis (7/35, 20%), Micrococcus luteus (2/35, 5.7%), Corynebacterium tuberculostearicum (2/35, 5.7%), and Cutibacterium ([C.], Propionibacterium) acnes (2/35, 5.7%). C. acnes growth was more frequent with imaging device forehead rests (2/7, 28.6%) than other surfaces (0/26, 0%, 95% CI: 0.019-0.619, p = 0.040). No samples isolated fungus or adenovirus. Conclusions Most samples across subspecialty clinic instrumentation grew bacteria, and several tested positive for SARS-CoV-2. Many isolated pathogens have been implicated in causing infections such as endophthalmitis, conjunctivitis, uveitis, and keratitis. The clinical implications of the ophthalmology microbiome for transmitting nosocomial infections warrant optimization of disinfection practices, strategies for mitigating spread, and additional study beyond the pandemic.