Abstract
Purpose :
To review the microbiological spectrum and susceptibility pattern of pathogens responsible for culture-positive endophthalmitis and to investigate possible trends over a 8-year period.
Methods :
Retrospective study of all cases of endophthalmitis referred to a single tertiary health center in Brazil between January 2010 and November 2018. Identification and susceptibility testing was performed by an automated broth microdilution method (bioMerieux Vitek 2, Hazelwood, MO, USA). Breakpoints were those defined by the CLSI. Analysis for trend was performed using data from consecutive 4-year intervals. The study was performed in accordance with the Ethics Committee of the Clinical Hospital of University of Sao Paulo School of Medicine.
Results :
A total of 238 cases of endophthalmitis were seen along the study period. 167 (70%) of endophthalmitis cases were postoperative, 33 (14%) were posttraumatic, 19 (8%) were endogenous, 11 (5%) were by contiguity and 8 (3%) were after intravitreal injection. Of 129 isolated obtained, 96 (74%) were gram-positive, 26 (20%) were gram-negative and 7 (5%) were fungi. The most prevalent pathogen was Staphylococcus epidermidis (25,6%), followed by Streptococcus viridans group (14,0%) and Staphylococcus aureus (10,1%). Pseudomonas aeruginosa and Enterococcus faecalis were the most frequently isolated gram-negative bacteria (4,7% each) and Candida species was the most frequently isolated fungus (3,9%). Table 1 shows a detailed overview of the isolates. We found a trend toward increasing resistance to moxifloxacin, ciprofloxacin, clindamycin, penicillin and oxacillin. Moxifloxacin-resistance strains increased from 12% to 29%, and Ciprofloxacin-resistance strains increased from 25% to 46%. See details in Table 2. All gram-positive bacteria tested were susceptible to vancomycin. Only one Enterococcus faecalis was resistant to vancomycin.
Conclusions :
Microbial spectrum is similar to previous studies and empirical therapy with vancomycin and ceftazidime remains appropriate. A trend toward increasing resistance against widely-used moxifloxacin and ciprofloxacin was observed. As antibiotic resistance can be the cause of treatment failures and may result in vision loss and blindness, surveillance remains crucial.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.