Emerging isolates in postoperative endophthalmitis by selection pressure of fluoroquinolones: an 11-year multicenter and experimental study.

Postoperative endophthalmitis (PE) is the devastating complication that frequently results in vision loss. Recently, have emerged as a major cause of PE in several countries and resulted in poor visual outcome. However, the reason remains elusive. We investigate whether selection pressure of fluoroquinolone exerts effects on microorganism profiles isolated from PE. Medical records of patients who were diagnosed with PE at eight resident training institutions between January 2004 and December 2015 were reviewed. The most common isolate was (28.0%), followed by (18.6%) and other coagulase negative (7.6%). However, the rates of isolated from conjunctival microbes were 6.2% (16/257) and their resistance to fluoroquinolones was higher than those of . and co-culture models of and were established for survival assays after administration of fourth-generation fluoroquinolone. In co-culture model, the survival assay of and against the treatment of moxifloxacin showed that survived significantly better than in the presence of moxifloxacin 1 µg/mL and more. In co-culture model, survived significantly better than after topical treatment of moxifloxacin (5 mg/mL). has been the most common causative strain of PE in Korea. We suggest that the increase of in PE could be associated with the selection pressure of fourth-generation fluoroquinolone. spp. have emerged as a leading causative strain of postoperative endophthalmitis in 11-year clinical data. We suggest that the increase of spp. is associated with the selection pressure of fourth-generation fluoroquinolone.