ABSTRACT
Objective:To investigate the in vitro interaction between antifungals and tacrolimus against Fusarium solani. Methods:According to Clinical and Laboratory Standards Institute(CLSI) M27-Ed4 and M38-A3, 24 strains of Fusarium solani isolated from clinic were used to test the minimal inhibitory concentration (MIC) of the four antifungals.Chessboard microdilution method was used to evaluate the interaction of tacrolimus (FK506) combined with four antifungals in vitro.The study protocol was approved by the Ethics Committee of Hainan Eye Hospital (No.2017-006). Results:The MIC ranges of fluconazole, voriconazole, natamycin and amphotericin B against 24 strains of Fusarium were 64-256 μg/ml, 1-8 μg/ml, 2-8 μg/ml and 1-8 μg/ml, respectively.Tacrolimus combined with fluconazole, voriconazole, natamycin and amphotericin B had synergistic effects on 12.5% (3/24), 4.2% (1/24), 16.7% (4/24) and 29.2% (7/24) Fusarium, respectively.There were no antagonistic effect in this study. Conclusions:Fusarium is sensitive to natamycin in vitro and partly sensitive to amphotericin B and voriconazole.Synergistic effects exist in few strains of Fusarium but no antagonistic effect.
ABSTRACT
Background Hainan Island is a tropical and subtropical area in China,with a suitable climate for fungal growth and breeding.Keratomycosis occurred frequently in this area.It is essential to analyze the causative genus and investigate the sensitive drugs prior to the clinical treatment of fungal keratitis.Objective This study attempted to analyze the fungal population of fungal corneal ulcer patients in Hainan Island of China and examine the susceptibility of antifungal drugs.Methods A series cases observational study was carried out.One hundred and seventy-four eyes of 174 fungal corneal ulcer patients were enrolled in Hainan Eye Hospital from February 2014 to May 2016 based on the diagnosis criteria in Ophthalmology.The specimens at corneal lesions were collected under the aseptic conditions,and fungus was examined by KOH based smear.Mycological culture was performed with potatodextrose agar and Sabourand's agar.The 82 cultured causative strains were identified to characterize the spectrum of the species associated with keratitis infections in Hainan Province.Susceptibilities of these causative strains to ten antifungals were determined in vitro by slip diffusion method.Results By smear microscopy,fungal hyphae and spores were found in 34 specimens of 126 patients,with the positive rate 27.0％.In 174 specimens of fungal culture,82 strains of fungi were found,with the positive rate 47.1％,and typing results revealed that the isolates were distributed among species in the fusarium (47.5％),non-spore fungus (12.2％),aspergillus (9.8％) and phoma (9.8％).Nystatin was proved to be the most effective drug to 77 strains of antifungal drug susceptibility,followed by amphotericin B and terbinafine,with the susceptibility of 88.3 ％,72.7 ％,and 71.4％,respectively.Conclusions Fusarium species,non-spore fungus,aspergillus,and phoma are common pathogenic fungi of keratomycosis around Hainan Island in China,and nystatin,amphotericin B and terbinafine are efficient in the treatment of the fungal corneal ulcer.