Abstract
Purpose :
Acute endophthalmitis can be a difficult disease to treat depending on the causative organism and the anti-microbial resistance characteristics of that organism. We performed a retrospective chart review to report on a series of endophthalmitis cases which were proven to be secondary to infection by Staphylococcus lugdunensis and report the microbial resistance patterns.
Methods :
There were 8 cases identified of acute endophthalmitis with culture proven Staphylococcus lugdunensis. Patients with endophthalmitis had undergone an anterior chamber tap, vitreous tap and intravitreal injection of vancomycin and ceftazidime after clinical diagnosis. Anterior chamber and vitreous chamber samples were cultured on blood agar plates. Minimum inhibitory concentration (MIC) testing was performed to identify anti-bacterial resistance patterns.
Results :
Staphylococcus lugdunensis was isolated in microbiologic cultures in all eight cases. In 63.5% (5/8) cases, oxacillin resistance was identified with MIC >4 in all cases. Of the eight cases, 87.5% were sensitive to ciprofloxacin with an MIC <0.5, however one case showed ciprofloxacin resistance with an MIC >8. Each culture showed sensitivity to levofloxacin and moxifloxacin with MIC values of <0.25 and 0.25, respectively. All isolates were sensitive to vancomycin with MIC values ranging from <0.5 to 1.
Conclusions :
Acute endophthalmitis caused by Staphylococcus lugdunensis can be confirmed by microbiologic cultures. It is important to choose an appropriate anti-microbial agent in treating Staphylococcus lugdunensis as isolates generally show sensitivity to vancomycin but can be resistant to oxacillin and rarely ciprofloxacin. In summary, we report the antibiotic resistance patterns of the largest series of acute endophthalmitis caused by Staphylococcus lugdunensis.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.