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Published on: February 6, 2021
Endophthalmitis after penetrating keratoplasty: microbiologic spectrum and susceptibility of isolates
Derek Y Kunimoto1, William Tasman, Christopher Rapuano
1Retina Service, Wills Eye Hospital, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania, USA. derek_kunimoto@yahoo.com
Purpose:
To present the microbial spectrum and susceptibilities of isolates in endophthalmitis following penetrating keratoplasty.
Design:
Interventional case series.
Methods:
The 1,074 consecutive cases of endophthalmitis presenting to Wills Eye Hospital between 1989 and 2000 were reviewed. Fourteen patients with endophthalmitis after penetrating keratoplasty were identified, and vitreous biopsy isolates from these patients were examined.
Results:
Eleven (78.6%) of 14 vitreous samples were culture-positive, and two others (14.3%) had organisms viewed on pathology specimen, for a total of 13 (92.9%) organism-proven cases of endophthalmitis. Isolates included 10 (76.9%) gram-positive cocci (six Streptococcus sp., three Staphylococcus sp., one identified on pathology specimen only) and three (23.1%) gram-negative organisms (Proteus mirabilis, Serratia marcescens, one identified on pathology specimen only). Susceptibilities to organism-appropriate antibiotic testing are reported, including cefazolin (six of eight, 75.0%), ciprofloxacin (four of seven, 57.1%), nafcillin (four of six, 66.7%), and vancomycin (seven of seven, 100.0%).
Conclusion:
This is the largest series on microbial susceptibilities in postpenetrating keratoplasty endophthalmitis. We report a high percentage of culture-positivity, and a high incidence of gram-positive species, and in particular Streptococcus species, with all tested gram-positive organisms susceptible to vancomycin.
Insights
This study analyzed microbial causes of endophthalmitis after penetrating keratoplasty. Gram-positive bacteria, especially Streptococcus species, were common, with vancomycin showing 100% effectiveness against tested gram-positive isolates.
Area of Science:
- Ophthalmology
- Microbiology
- Infectious Diseases
Background:
- Endophthalmitis is a serious complication following penetrating keratoplasty.
- Understanding the microbial spectrum and antibiotic susceptibilities is crucial for effective treatment.
Purpose of the Study:
- To determine the microbial causes and antibiotic susceptibilities of endophthalmitis after penetrating keratoplasty.
- To provide data for guiding empirical antibiotic therapy in these cases.
Main Methods:
- A retrospective review of 1,074 endophthalmitis cases was conducted.
- Fourteen patients with post-penetrating keratoplasty endophthalmitis were identified.
- Vitreous biopsy samples were analyzed for microbial isolates and their antibiotic susceptibilities.
Main Results:
- A high rate of organism detection (92.9%) was observed in vitreous samples.
- Gram-positive cocci, particularly Streptococcus species, were the most frequent isolates (76.9%).
- Vancomycin demonstrated 100% susceptibility against all tested gram-positive organisms.
Conclusions:
- This study represents the largest series on microbial susceptibilities in post-penetrating keratoplasty endophthalmitis.
- A high incidence of gram-positive pathogens, especially Streptococcus species, was identified.
- Vancomycin is a highly effective antibiotic for treating gram-positive endophthalmitis in this context.
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