Microbial Keratitis Isolates at a Midwestern Tertiary Eye Care Center

Area of Science:

• Ophthalmology
• Infectious Diseases
• Microbiology

Background:

• Microbial keratitis (MK) is a significant cause of vision loss.
• Understanding the causative pathogens and their antimicrobial susceptibility is crucial for effective treatment.
• Tertiary eye centers manage complex cases, providing valuable data on MK trends.

Purpose of the Study:

• To characterize the spectrum of microbial keratitis (MK) pathogens.
• To determine antimicrobial susceptibility patterns of identified microorganisms.
• To analyze temporal trends of MK incidence and types at a Midwestern tertiary eye center.

Main Methods:

• Retrospective review of electronic health records for MK patients from August 2012 to December 2021.
• Classification of laboratory-confirmed infections into bacterial, fungal, viral, Acanthamoeba, or polymicrobial categories.
• Assessment of antimicrobial susceptibility and linear regression analysis for temporal trends.

Main Results:

• Bacterial pathogens accounted for 73.5% of laboratory-positive MK cases, with gram-positive bacteria (CoNS, S. aureus) being most prevalent.
• Pseudomonas aeruginosa was the predominant gram-negative pathogen.
• Coagulase-negative Staphylococcus (CoNS) and Staphylococcus aureus (S. aureus) demonstrated universal susceptibility to vancomycin.

Conclusions:

• Bacterial infections, particularly those caused by gram-positive organisms, are the leading cause of microbial keratitis.
• Antimicrobial resistance patterns highlight vancomycin's effectiveness against common gram-positive pathogens.
• The incidence of different MK types remained stable over the study period.