Models of experimental pseudomonas keratitis: microbiological and clinical aspects

Abstract

Annotation. Over the last ten years, there has been an increase in the incidence of bacterial keratitis caused by Pseudomonas aeruginosa, associated with contact lenses use. Certain features of the course of such keratitis, the mechanisms of corneal damage, the factors that affect the severity and depth of tissue destruction remain unclear. Therefore, the aim of our work was to model experimental pseudomonal keratitis in rabbits using different methods of infection and to investigate the microbiological and clinical aspects of keratitis depending on the method of infection. As a result of the study, we were able to reproduce superficial and deep keratitis with different methods of infection. Our proposed method cornea infection with bacterial films on a contact lens allowed to reproduce severe keratitis with a longer release of the pathogen from the surface of the affected cornea. It was also found that the results of microbiological examination of the material from the affected eye do not correlate with the course of severe keratitis: negative results of microbiological examination did not demonstrate the elimination of the pathogen from eye tissues, which deepens into corneal tissues, that was proved with microbiological examination of the cornea autopsy samples. These models of experimental keratitis can be used to study the pathomorphology, and pathophysiology of the keratitis caused by Pseudomonas aeruginosa, as well as to conduct experimental research of new antimicrobials and improve current guidelines for treatment of this pathology.

Keratitis caused by Pseudomonas aeruginosa: treatment in the experiment

“…Бактеріологічні посіви з поверхні ока показали зменшення присутності P. aeruginosa через 48 годин із 100 % до 63,9 % випадків та повне зникнення збудника через 3 Keratitis in animals was caused by applying a clinical strain of P. aeruginosa as a suspension of oneday culture of the microorganism at a concentration of 5×10 8 CFU/ml, which corresponds to the 0.5 McFarland standard, on the partially de-epithelialized (approximately 1 cm 2 ) cornea followed by coating for 24 hours with soft contact lens made of belafilcon A (water content: 36 %, oxygen permeability DK/t:110.0). In half of the cases, microbial biofilms were pre-grown on the contact lens surfaces via incubation into the broth culture of P. aeruginosa strain (concentration of cells 10 6 -10 7 per 1 ml) at a temperature of 37° C for 48 hours [19][20][21]. Keratitis was modeled on one of the eyes of each animal.…”