Clinical and Experimental Ocular Trauma and Infection (Aug 2020)
Does Staphylococcus lugdunensis pose any infection risk after a cataract surgery ?
Abstract
Purpose: The purpose of this study is to present the current risk and to examine the biofilm formation ability and the antibiotic sensitivity of S. lugdunensis that were isolated from the cataract surgeries and to minimize the risks that are likely to occur due to S. lugdunensis following cataract surgeries. Material and Methods: The bacteria that had been isolated from previous cataract surgeries and stored at the Microbiology Laboratory of Eskisehir Technical University, Faculty of Science, Department of Biology were used for the study. The isolates grown on blood agars were tested with gram stain, catalase, coagulase and oxidase tests. The strains were identified with ID 32 Staph and VITEK II system (BioMerieux). The RiboPrinter® Microbial Characterization System (Dupont Qualicon) and the standard EcoRI DNA preparation kit were used for Automated EcoRIRibotyping. The isolates were assessed for biofilm production according to a modified microtiter plate method and cultivation on Congo Red Agar (CRA) plates. The antibiotic sensitivity of the isolates was tested by the disc diffusion method. Vancomycin and methicillin were assessed by microdilution method. Results: We identified 12 S. lugdunensis isolates from ocular surface of patients who underwent cataract surgery. They all produced beta hemolytic rough white colonies in the blood agar. Regarding antibiotic sensitivity results, all of the tested isolates were found to be sensitive to vancomycin and levofloxacin. Cefuroxime resistance was found in two third of the strains. While 1 isolate produced strong biofilm, 4 isolates produced a moderate biofilm, with CRA method. Six isolates did not produce any biofilm. As for microtitration method, 3 isolates produced strong biofilm, while 5 isolates did not produce any biofilm. Conclusion: Vancomycin provided a consistent coverage for S. lugdunensis and should be selected as the first line of treatment for acute endophthalmitis caused by coagulase-negative staphylococcus. In our study, two thirds of the S. lugdunensis isolates were multi drug resistant, and these isolates were resistant to cefuroxime which is used as intracameral antibiotic. This should be kept in mind in endophthalmitis in vulnerable patients.
