Susceptibility of bacterial endophthalmitis isolates to vancomycin, ceftazidime, and amikacin

Kuan-Jen Chen,Hung-Chi Chen,Hung-Da Chou,Wei-Chi Wu,Chiun-Ho Hou,Ming-Hui Sun,Chi-Chun Lai,Eugene Yu-Chuan Kang,Yen-Po Chen,Laura Liu,Nan-Kai Wang

doi:10.1038/s41598-021-95458-w

Abstract

Bacterial endophthalmitis is a rare intraocular infection, and prompt administration of intravitreal antibiotics is crucial for preventing severe vision loss. The retrospective study is to investigate the in vitro susceptibility to the antibiotics vancomycin, amikacin, and ceftazidime of bacterial endophthalmitis isolates in specimens at a tertiary referral center from January 1996 to April 2019 in Taiwan. Overall, 450 (49.9%) isolates were Gram positive, 447 (49.6%) were Gram negative, and 4 (0.4%) were Gram variable. In Gram-positive isolates, coagulase-negative staphylococci were the most commonly cultured bacteria (158, 35.1%), followed by Streptococci (100, 22.2%), Enterococci (75, 16.7%), and Staphylococcus aureus (70, 15.6%). In Gram-negative isolates, they were Klebsiella pneumoniae (166, 37.1%) and Pseudomonas aeruginosa (131, 29.3%). All Gram-positive organisms were susceptible to vancomycin, with the exception of one Enterococcus faecium isolate (1/450, 0.2%). Of the Gram-negative isolates, 96.9% and 93.7% were susceptible to ceftazidime and amikacin, respectively. Nine isolates (9/447, 2.0%) were multidrug-resistant Gram-negative bacteria, comprising K. pneumoniae (4/164, 2.4%), Acinetobacter baumannii (2/3, 67%), and Stenotrophomonas maltophilia (3/18, 17%). In conclusion, in vitro susceptibility testing revealed that vancomycin remains the suitable antibiotic treatment for Gram-positive endophthalmitis. Ceftazidime and amikacin provide approximately the same degree of Gram-negative coverage. Multidrug-resistant bacterial endophthalmitis was uncommon.

Highlights

Bacterial endophthalmitis is a rare intraocular infection, and prompt administration of intravitreal antibiotics is crucial for preventing severe vision loss
This study investigated the in vitro susceptibility of Gram-positive and Gram-negative bacterial endophthalmitis isolates collected over 23 years to vancomycin, ceftazidime, and amikacin
A total of 901 bacterial endophthalmitis isolates were cultured over the 23-year study period

Summary

Introduction

Bacterial endophthalmitis is a rare intraocular infection, and prompt administration of intravitreal antibiotics is crucial for preventing severe vision loss. Prompt administration of intravitreal antibiotics with or without pars plana vitrectomy is crucial for preventing severe vision loss Both the bacterial spectrum and antibiotic susceptibility patterns in bacterial endophthalmitis isolates must be considered in the context of treatment. Vancomycin is a first-line drug for managing Gram-positive bacterial endophthalmitis, whereas ceftazidime or amikacin are typically used for Gram-negative coverage. Common MDR organisms include (1) vancomycin-resistant enterococci; (2) methicillin-resistant S. aureus; (3) extended-spectrum β-lactamase (ESBL)-producing Gram-negative bacteria; (4) carbapenemaseproducing K. pneumoniae; and (5) MDR Gram-negative bacteria, such as K. pneumoniae, Enterobacter spp., Escherichia coli, A. baumannii, P. aeruginosa, and S. maltophilia. This study investigated the in vitro susceptibility of Gram-positive and Gram-negative bacterial endophthalmitis isolates collected over 23 years to vancomycin, ceftazidime, and amikacin.

Methods

Results

Conclusion