Pathogens and antibiotic sensitivities in endophthalmitis

Area of Science:

• Ophthalmology
• Infectious Diseases
• Pharmacology

Background:

• Endophthalmitis following cataract surgery poses a significant risk.
• Antibiotic prophylaxis is standard to minimize post-surgical infections.
• Understanding causative organisms and resistance patterns is crucial for effective prophylaxis.

Purpose of the Study:

• To analyze pathogenic organisms and their antibiotic sensitivities in culture-proven endophthalmitis cases.
• To evaluate the effectiveness of different antibiotic prophylaxis strategies in preventing endophthalmitis.
• To identify trends in antibiotic resistance in post-cataract surgery endophthalmitis.

Main Methods:

• Retrospective analysis of 215 endophthalmitis cases post-cataract surgery (2007-2012).
• Descriptive analysis of isolated microorganisms and their antibiotic susceptibility.
• Comparison of outcomes based on antibiotic prophylaxis type (topical vs. intracameral).

Main Results:

• Gram-positive bacteria, particularly coagulase-negative Staphylococci, were the predominant pathogens (96%).
• Significant resistance to fluoroquinolones (ofloxacin, gatifloxacin) was observed in isolates from patients receiving topical prophylaxis.
• All tested isolates were sensitive to vancomycin; aminoglycosides also showed high susceptibility.
• Intracameral antibiotic prophylaxis was associated with a low incidence of culture-proven endophthalmitis.

Conclusions:

• Fluoroquinolone prophylaxis is associated with increasing bacterial resistance in endophthalmitis cases.
• Topical antibiotic prophylaxis alone resulted in a higher proportion of resistant organisms.
• Intracameral antibiotics appear more effective in preventing endophthalmitis compared to topical prophylaxis.