Bacterial contamination of slit lamps in veterinary ophthalmology

Abstract

Purpose: Healthcare-associated infection (HAI) is a well-known problem in human medicine. The contamination of medical devices with pathogenic organisms is less studied in veterinary medicine. The purpose of this multicenter study was to evaluate the bacterial contamination of slit lamps throughout Europe and part of the United States. The efficacy of standard cleaning was additionally investigated. Methods: Samples from adjustment wheels of slit lamps were taken by different veterinary ophthalmologists and submitted for culture (n = 29). The efficacy of cleaning protocols was evaluated by taking a second sample after routine cleaning (n = 29). Sensitivity testing was performed for pathogenic bacteria using the minimum inhibitory concentration (MIC) or disc diffusion (Kirby-Bauer) method.Statistical analysis was performed using Fisher's exact test. Results: Seventeen of 29 slit lamps were contaminated before cleaning. The most frequently cultured bacteria were Staphylococcus spp. and coliform bacteria. Twelve of 29 slit lamps showed no bacterial growth before and after cleaning. There was a significant difference before and after cleaning (P = 0.0008), with only 4/29 contaminated samples after cleaning. Conclusion: Contamination with pathogenic bacterial species is frequent in slit lamps used by veterinary ophthalmologists. A risk of cross-contamination in clinical patients has to be considered. Routine cleaning reduces bacterial contamination significantly. K E Y W O R D Santibiotic susceptibility, cross-transmission, healthcare-associated infection, hygiene, medical device, Staphylococcus spp.

Bacterial Cross-Contamination in a Veterinary Ophthalmology Setting

“…Contamination of ophthalmic equipment ranged from 41.7% (5/12) to 43.5% (10/23) in the retrospective and prospective studies, respectively, with an overall prevalence of 42.9% (15/35). These findings are fairly similar to a recent report by Casola and colleagues, who detected pathogenic bacteria in 58.6% of handheld slit lamps used in a veterinary practice (8). It would be interesting to determine whether contamination is more common in select ophthalmic equipment.…”

“…Undoubtedly, proper cleaning protocols can reduce bacterial levels in examination rooms and minimize the risk for nosocomial infections (24,25), as exemplified by a significant decrease in bacterial contamination of handheld slit lamps from 58.6 to 13.8% following disinfection (8).…”

“…In the human medicine literature, the contamination prevalence of ophthalmic materials ranges from 11.7% for ophthalmic solutions (4), 28% for ophthalmic medications (5), 54% for slit lamps (6), 76% for handheld lenses (6), and 82% for sterile ultrasound biomicroscopy probes (7). Similar information for diagnostic equipment in the veterinary field is limited to a single report describing a contamination prevalence of 58.6% (17/29) for slit lamps used in a veterinary ophthalmic practice (8).…”

Antibiotic resistance, biofilm formation, and virulence factors of isolates of staphylococcus pseudintermedius from healthy dogs and dogs with keratitis

“…Primary infectious keratitis in dogs is uncommon ( 45 ). Corneal infection is usually enhanced by disruption of the defense mechanism of the ocular surface, which includes the structural integrity and blinking action of the eyelids, and the intact epithelium of the conjunctiva and cornea ( 46 ). Microtrauma is the predominant factor contributing to the development of keratitis; other causes are tear film disturbances, disorders of the immune system (immunodeficiencies and autoimmune diseases), and corneal surgical interventions ( 2 ).…”

Case Report: The First Report on Moraxella canis Isolation From Corneal Ulcer in a Bulldog

“…In 2017, a survey about the breeding information in 2,168 brachycephalic dogs has been conducted, and the results showed that there were 15.4% of dogs had ever suffered from a bacterial corneal ulcer, and nearly one-quarter breed (22.9%) was the Pug (24). The common causes of corneal ulcers in dogs included trauma, foreign bodies, infection, and inadequate lacrimal secretion or others (25,26). A survey from 2015 to 2016 in Thailand has indicated that 32 ulcers samples, 26 (81.3%) samples yielded culturable microorganisms with 24 bacterial isolates, and 7 fungal isolates (27).…”