The impact of inoculation parameters on the pathogenesis of contact lens-related infectious keratitis.
نویسندگان
چکیده
PURPOSE Contact lens wear predisposes to Pseudomonas aeruginosa keratitis, but the mechanisms involved remain unclear. An in vivo model was used to study lens inoculation conditions enabling disease. METHODS Custom-made hydrogel contact lenses were fitted to rats after incubation in P. aeruginosa approximately 10(11) cfu/mL (3 hours) or approximately 10(3) cfu/mL (24 hours). Another group was inadvertently inoculated with a suction pen previously used with high inocula, but rinsed in ethanol and stored dry (6 months). Some corneas were tissue paper-blotted to cause fluorescein staining before lens fitting. Contralateral eyes were untreated. Twenty-four hours after disease detection, lenses were transferred to naive rats or examined by confocal microscopy before homogenization to quantify viable bacteria. After lens removal, corneas were washed to collect nonadherent bacteria and were analyzed by immunohistochemistry. RESULTS All eyes challenged with unworn contaminated lenses developed keratitis after approximately 7 to 10 days. Disease delay and severity were unaffected by inoculum parameters or tissue blotting but occurred sooner with lenses transferred from infected eyes ( approximately 2 days). Worn lenses and corneal washes contained infecting bacteria. Posterior, not anterior, lens surfaces harbored P. aeruginosa biofilms that penetrated the lens matrix. Diseased corneas showed an infiltration of phagocytes and T-lymphocytes. CONCLUSIONS P. aeruginosa induces keratitis in this lens-wearing model after a single inoculation. Delayed disease onset was interesting considering the greater keratitis risk during extended wear. Infection did not require the disruption of corneal barrier function before lens wear and occurred without exposure to lens care solutions. The data suggest that keratitis involves biofilm formation or other bacterial adaptations in vivo.
منابع مشابه
امکان استفاده از آنزیم EcoR1 در طبقه بندی سویه های اکانتامبای ایزوله شده از التهاب قرنیه
Acanthamoeba keratitis is increasingly being diagnosed among people who wear thrapeutic and cosmetic contact lenses. The chain of events is thought to begin with contamination of the contact lens storage cases with Acanthamoeba from household or mains water supplies. If bacteria contamination is also present then these amoebas can multiply by ingesting the bacteria as a food source. If the cont...
متن کاملSensitivity Pattern of Bacteria Isolated from Contact Lens Wearers in the Faculty of Pharmacy, Karachi University Student Population
Contact lens wearers are at great risk of developing microbial keratitis because of incorrect usages and unhygienic maintenance of contact lenses. Therefore, the present study was planned to provide data that will be helpful in selecting the anti-microbial to cure microbial keratitis. One hundred bacterial isolates from conjunctiva of contact lenses wearer were isolated, identified and subjecte...
متن کاملHow Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review
Contact lens wear is highly influential on the incidence of ulcerative keratitis worldwide, particularly in developed countries. The association between Acanthamoeba keratitis and contact lens wear is firmly established; it may account for up to 95% of the reported cases. Before the popularisation of soft contact lens wear, Acanthamoeba keratitis was extremely rare. In 2000 it was estimated tha...
متن کاملSensitivity Pattern of Bacteria Isolated from Contact Lens Wearers in the Faculty of Pharmacy, Karachi University Student Population
Contact lens wearers are at great risk of developing microbial keratitis because of incorrect usages and unhygienic maintenance of contact lenses. Therefore, the present study was planned to provide data that will be helpful in selecting the anti-microbial to cure microbial keratitis. One hundred bacterial isolates from conjunctiva of contact lenses wearer were isolated, identified and subjecte...
متن کاملThe pathogenesis of bacterial keratitis: studies with Pseudomonas aeruginosa.
Bacterial keratitis is a sight-threatening corneal disease that is most commonly associated with the extended wear of soft contact lenses. Over the past decade, we have investigated the pathogenesis of infectious keratitis involving the opportunistic pathogen Pseudomonas aeruginosa. Our research has focused on understanding the respective roles of bacteria and host in the establishment of this ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Investigative ophthalmology & visual science
دوره 51 6 شماره
صفحات -
تاریخ انتشار 2010