Etiology and susceptibility pattern of isolates in endophthalmitis over a 5-year period

Abstract

 

Purpose

 

Despite prompt referral and treatment just after diagnosis suspicion, endophthalmitis outcomes remain poor. Current attempts of prevention and management depend on empiric antibiotic therapy. Supervising causative agents and microbial spectrum may be important to identify trends in antibiotic susceptibility and improve guidelines. Purpose: To analyze the etiology and antimicrobial susceptibility profile of isolates in endophthalmities in a cohort of consecutive cases of patients referred to a tertiary health center.

 

Methods

 

Approval from the Ethics Committee of the Clinical Hospital of University of Sao Paulo was obtained and a retrospective study of all endophthalmities seen at a tertiary care center in Brazil between 2010 and 2014 was conducted. Samples obtained from aqueous and/or vitreous fluid were subjected to culture at the microbiological laboratory. 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.

 

Results

 

Among 91 patients diagnosed of endophthalmitis, 45 had culture-positive results (49%). The most prevalent gram-positive isolated was Staphylococcus epidermidis (19%) and viridans group streptococci (19%), followed by Staphylococcus aureus (8%) and Enterococcus faecalis (8%). Coagulase-negative staphycococcus and Streptococcus pneumoniae counted for 6% each. The most common gram-negative was Pseudomonas aeruginosa (6%). 6% of the culture-positive were fungi. Susceptibility pattern is given on table 1. Out of 3 Enterococcus faecalis tested, 1 was resistant to vancomycin. Moxifloxacin obtained only 50% susceptibility and levofloxacin, 75%. Samples tested for moxifloxacin between 2010 and 2012 had 67% susceptibility, whereas two years later it decreased to 29% susceptibility. (Graphic 1)

 

Conclusions

 

Moxifloxacin is a fourth-generation fluoroquinolone widely used in Ophthalmology as a postoperative topical antibiotic therapy. On this short series, we identified a decrease in microbial susceptibility for moxifloxacin.<br /> <br /> <br /> Miller, JJ, Scott, IU, Flynn, HW, Jr. Smiddy, WE, Newton, J, Miller, D. Acute-onset endophthalmitis after cataract surgery (2000-2004): incidence, clinical settings, and visual acuity outcomes after treatment. Am. J. Ophthalmol. 139:983-987, 2005.  

 

NT: not tested

 

 

N: number of isolates tested; S: number of isolates sensitive to the antibiotic.