Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Pritzel, V.
Laboratory diagnosis in infectious keratitis and corneal ulcer.
A hospital-based study.
Humanmedizin; [ Diplomarbeit ] Medizinische Universität Graz; 2022. pp. 115
[OPEN ACCESS]
FullText
- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Horwath-Winter Jutta
- Nitsche-Resch Marianne
- Altmetrics:
- Abstract:
- Background: Knowledge of the pathogens responsible for infectious keratitis and corneal ulcers and the resistances of the causative germs to antibiotics is the basis for adequate therapeutic measures in the treatment of these diseases. The germ spectrum of keratitis or corneal ulcer is also characteristic for different geographical locations. In this retrospective study, the germ spectrum of infectious keratitis or corneal ulcers and the resistances of the bacterial isolates for the care area of the University Eye Hospital Graz (parts of Styria, Burgenland and Carinthia) are presented. Methods: A retrospective (single-centre) study design was chosen for the present research project. The data required for the study are extracted from data sets of the University Hospital of Ophthalmology, Graz. All patients who were treated for infectious keratitis or ulcer at the University Hospital of Ophthalmology, Graz in 2018, were included in the study. Corneal scrapes and direct smears taken from cornea (n=100) and conjunctiva (n=62) and sediments of contact lenses container’s liquids (n=23) were examined for pathogen detection. Pathogen detection was performed by direct microscopy, microbial culture and polymerase chain reaction (PCR). When bacterial pathogens were detected, antimicrobial resistance screenings were conducted. Data management and statistical analysis were carried out with MS Excel and SPSS. Results: 100 eyes of 100 patients were included in the study (56 male 44 female, mean age: 49±21 years; range from 16 to 93 years, 51 contact lens wearers, 8 cases after trauma, 9 cases after eye related surgery). Bacteria were detected in 100 patients, fungi in 25 patients, Acanthamoeba in 12 patients, and viruses in 8 patients. Regarding the cornea, 84 bacterial isolates were detected in total. Koagulase-negative staphylococci (40.5%) showed the largest category. The most common bacterial isolate was Propionibacterium acnes (28.6%). vi Overall, resistances to 24 antibiotic agents were detected in the corneal isolates. Regarding the conjunctiva, 19 bacterial isolates were detected in total. Coagulase-negative staphylococci (36.8%) showed the largest category as well. The most common bacterial isolate was Staphylococcus aureus (26.3%). Overall, resistances to 17 antibiotic agents were detected in the conjunctival isolates. Regarding contact lens cases’ sediments, 45 isolates were detected in total. Gram-negative bacilli (33.3%) showed the largest category. The most common bacterial isolate was Pseudomonas aeruginosa (15.6%). In addition, bacterial cultures detected 2 fungal isolates (4.4%). Overalll, resistances to 27 antibiotic agents were detected in the isolates of the contact lens cases’ sediments. The proportion of patients with visual acuity ≥ 0.5 increased significantly during the treatment (from initially 28.8% to 49.3% during follow-up). Conclusion: In our study, bacterial pathogens were identified as the most frequent pathogens of infectious keratitis. Differences in the expression and frequency of bacterial colonization of the cornea, conjunctiva, and contact lens cases were demonstrated. Resistances of the presented bacterial isolates to antibiotic agents were summarized for the cornea and conjunctiva scrapes/smears and for the contact lens cases’ sediments. Contact lenses, trauma, and eye related surgeries are potential risk factors for infectious keratitis. Improvement in visual acuity could be achieved in many cases with the applied therapy. The collected data can be used for further statistical analysis or comparisons with other geographic regions.