Species Identification And In Vitro Antifungal Susceptibilities Of Sporothrix Clinical Isolates In Parts Of China

PART 1 SPECIES IDENTIFICATION OF SPOROTHRIX CLINICAL ISOLATES IN PARTS OF CHINAObjective: To identify 50 Sporothrix clinical isolates in some areas of China.Methods:All isolates from patients were subcultured at 25? and morphological characteristic was analysed by microscope and visual inspection.The total genomic DNA was extracted to amplify the partial ?-tubulin gene and the internal transcribed(ITS)region by polymerase chain reaction(PCR).The phylogenetic tree was constructed by DNA sequences analyses based on datasets of ITS and a combined ITS and partial ?-tubulin region using maxium likehood(ML)and neighbor-joining(NJ)methods with Mega5 software.The Reference sequences used for phylogenetic analyses were retrieved from Gen Bank.Result:The macroscopic morphologies and microscopic features of all isolates were comformed to Sporothrix spp.The phylogenetic tree showed that all of the isolates were clustered in a distinct clade with a type of Sporothrix globosa.Conclusion:S.globosa may be the major Sporothrix existing in China,which can provide basis for the epidemiological investigation of Sporothrix.PART 2 IN VITRO ANTIFUNGAL SUSCEPTIBILITIES OF MYCELIUM PHASE OF SPOROTHRIX GLOBOSA IN PARTS OF CHINAObjective: To investigate the activities of five antifungal agents on mycelia form of Sporothrix globosa and compare the differences in antifungal susceptibilities in different areas of China.Methods: Total 100 isolates which were identified as Sporothrix globosa by molecular identification from Chongqing,Beijing and Jilin were subcultured on 2% potato-dextrose agar plates at 25? for 7d.Then according to modified CLSI microdilution method M38-A2,MICS was measured to evaluate the antifungal activities of potassium iodide(KI),itraconazole(ITC),terbinafin(TRB),fluconazole(FLC),amphotericin B(AMB)to these isolates in vitro.Candida parapsilosis ATCC22019 was used as quality control.Results: Potassium iodide showed no antifungal activity against any Sporothrix globosa isolates.TRB gave the lowest geometric mean(GM=0.14?g/m L)MIC.ITC and AMB showed almost the same activity against all strains tested and the GM was 0.79?g/m L and 0.63?g/m L respectively.FLC gave the highest GM MIC(45.89?g/m L).Seven isolates(four from Jilin,two from Chongqing,one from beijing)were found to be itraconazole-resistant,There was no difference in susceptibility according to the geographical source of the isolates(P>0.05).Conclusion:Potassium iodide showed no antifungal activities in vitro.TRB was the most active drug,followed by the ITC and AMB.FLC was the least effective drug.There was no difference in antifungal susceptibilities in different areas of China.