[Analysis of etiology and in vitro drug susceptibility of fungal keratitis in northern China].

Objective: To analyze the etiology, drug susceptibility and etiological changes of fungal keratitis so as to to provide reference for clinical diagnosis and treatment. Methods: Retrospective case series study. A total of 5 654 copies of specimens for fungal culture were collected from Outpatients suspected of fungal keratitis in Beijing Tongren Ophthalmic Center during January 2007 and December 2016. Specimens were inoculated on Potato dextrose agar (PDA) slant medium, incubated at 30℃ and 40% humidity constantly for 3 to 10 days. Filamentous fungi isolated from positive cultures were identified according to morphological traits. Yeast-like fungi were identified by API 20 C Aux. Drug susceptibility tests were performed by using ROSCO disk diffusion method, which included natamycin, terbinafine, itraconazole, fluconazole, amphotericin B, voriconazole. The Chi-square test and Spearman correlation analysis were performed using SPSS 20.0 software. Results: The positive rate of culture was 26.1%. In positive patients, the ratio of male to female was 1.77∶1, and the age range was 11 days to 95 years. The mean age was 49.0±16.9 years. Among isolated fungi, Fusarium sp. was the most common genus, accounting for 53.5% (789 strains) , followed by 17.5% of Aspergillus sp. (259 stains) and 13.8% of Alternaria sp. (203 stains). The sensitive rate of natamycin was 92.3% (410 strains) , followed by that of terbinafine as 78.5% (1 093 strains), voriconazole as 41.0% (338 strains), amphotericin B as 40.7% (553 strains). Conclusion: The predominant patients of fungal keratitis are adult and male. Fusarium sp., Aspergillus sp., and Alternaria sp. are three common species in northern china with seasonal changes in their proportion. Natamycin should be the preferred drug for empirical treatment. The preferred empirical treatment for Aspergillus sp. is terbinafine. Fluconazole should not be used alone due to the high resistant rate. (Chin J Ophthalmol, 2018, 54: 432-436).