Microbial Surveillance of Commonly Encountered Clinical Surfaces Within a Veterinary Ophthalmology Service

To establish surveillance of organisms found on high-touch clinical surfaces within a veterinary teaching hospital ophthalmology service and record trends that may foster additional studies investigating links between environmental microbiota and pathogenic bacteria affecting the ocular surface.

Samples from 17 high touch surfaces in the ophthalmology department of a veterinary teaching hospital were collected over four consecutive Monday mornings, with additional samples taken 9 months later on a Monday morning and Thursday afternoon of the same week. Samples were processed using standard culture methods, with additional specific testing for Salmonella species, carbapenemase-producing Enterobacteriaceae (CRE), and methicillin-resistant Staphylococcus (MRSsp).

Out of 102 samples collected for aerobic bacterial culture, 11 (11%) showed no growth and 91 (89%) yielded positive results. Of the 211 total isolates found, all exhibited a low colony count. Of the isolates identified, 66/211 (31%) were Staphylococcus spp., followed by 45/211 (21%) Bacillus spp. Exam tables (25/211, 11.8%) and countertops (24/211, 11.4%) had the highest number of isolates. There was no clinically significant difference in the number of isolates found between Monday morning and Thursday afternoon of the same week.

All isolates were considered incidental environmental findings and cultured in low numbers. When routine cleaning and disinfection procedures are maintained, common surfaces and equipment of ophthalmology departments are unlikely to be pathogenic reservoirs, posing minimal risk to patients. Further studies are recommended to explore correlations between environmental microbiota and pathogenic bacteria affecting the ocular surface in patients.