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Comparison of intravitreal vancomycin and daptomycin application in experimental methicillin-resistant Staphylococcus
Erol Coskun1, Seydi Okumus, Bulent Gurler
1Department of Ophthalmology, School of Medicine, University of Gaziantep, Gaziantep, Turkey.
Purpose:
To compare bactericidal activities of daptomycin and vancomycin in an experimental rabbit model of methicillin-resistant Staphylococcus aureus (MRSA) endophthalmitis.
Methods:
The right eyes of 19 New Zealand rabbits weighing 2 to 2.5 kg were used. Each eye was inoculated with 1000 colony-forming units (cfu) of MRSA into the vitreous cavity. 24 h after the inoculation, the rabbits were randomly distributed into three groups: control group (n = 5) was given 0.1 ml of balanced saline solution, daptomycin group 2 (n = 7) was given 0.2 mg/0.1 ml daptomycin and vancomycin group 3 (n = 7) was given 1 mg/0.1 ml vancomycin intravitreally. Clinical examination scores were recorded and vitreous aspirates were obtained for microbiological analysis on days 2 and 3 after MRSA inoculation. Rabbits were sacrificed, and the eyes were enucleated for histopathological examination.
Results:
There was no difference between the daptomycin group, vancomycin group and control in terms of the clinical grading of endophthalmitis 24 h after the inoculation. In all treatment groups, mean number of cfu and histopathological scores were significantly lower compared to the control group. There was no difference between the daptomycin and vancomycin group in terms of the histopathological and clinical examination scores. Culture negativity achieved on day 3 was 71.4% and 57.1% in the daptomycin treatment group and the vancomycin treatment group, respectively.
Conclusions:
Although both daptomycin and vancomycin are effective in treatment of experimental MRSA endophthalmitis, daptomycin has superior bactericidal activity 72 h after inoculation.
Insights
Daptomycin and vancomycin effectively treat experimental methicillin-resistant Staphylococcus aureus (MRSA) endophthalmitis in rabbits. Daptomycin demonstrated superior bactericidal activity 72 hours post-treatment.
Area of Science:
- Ophthalmology
- Infectious Diseases
- Pharmacology
Background:
- Endophthalmitis is a severe intraocular infection.
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant treatment challenge.
- Novel therapeutic strategies are crucial for managing MRSA-related ocular infections.
Purpose of the Study:
- To compare the bactericidal efficacy of daptomycin and vancomycin.
- To evaluate treatment outcomes in an experimental rabbit model of MRSA endophthalmitis.
Main Methods:
- New Zealand rabbits with induced MRSA endophthalmitis were treated with intravitreal daptomycin, vancomycin, or saline.
- Clinical examinations, microbiological analyses (cfu counts), and histopathological assessments were performed.
- Treatment groups were compared to a control group.
Main Results:
- Both daptomycin and vancomycin significantly reduced MRSA burden and inflammation compared to controls.
- No significant differences in clinical or histopathological scores were observed between daptomycin and vancomycin groups at 24 hours.
- Higher culture negativity rates were achieved with daptomycin (71.4%) versus vancomycin (57.1%) by day 3.
Conclusions:
- Daptomycin and vancomycin are effective treatments for experimental MRSA endophthalmitis.
- Daptomycin exhibits superior bactericidal activity compared to vancomycin at 72 hours post-inoculation.
- Further investigation into daptomycin for MRSA endophthalmitis is warranted.
