基于MALDI-TOF MS和二代测序的VGⅠ型格特隐球菌的鉴定与基因组学分析OA

Objective To investigate the genomic characteristics of Cryptococcus gattii VGⅠ genotype and provide assistance in exploring its pathogenic mechanisms.Methods MALDI-TOF MS was used for the identification and genotyping of Cryptococcus strains,and multilocus sequence typing(MLST)was performed via PCR.Illumina next-generation sequencing(NGS)was applied to analyze genomic features,virulence genes,and gene database annotation.Results Among the 20 Cryptococcus strains,two study strains were identified as C.gattii VGⅠ genotype(scores 2.01～2.21).Their mass spectra lacked the specific peaks of C.neoformans(6686、8633 Da)or C.gattii VGⅡ-type(9611 Da),and principal component analysis(PCA)clustering clarified their evolutionary relationships.The MLST types of the two C.gattii strains were ST565 and ST57.Their genomes ranged from 18 Mb to 20 Mb in size with a GC content of 47.85%～47.86%,and contained multiple virulence genes.Subtypes VGⅠa/Ib were distinguishable by mutations in the URA5 gene(C→A at position 469,T→G at 547,G→A at 562)and SOD2 gene(A→G at position 136).KEGG analysis showed significant enrichment in metabolic pathways,secondary metabolite,biosynthesis,amino acids biosynthesis,and oxidative phosphorylation.GO analysis indicated differential proteins were enriched in Golgi apparatus-related structures.Conclusion MALDI-TOF MS enables rapid identification and typing of C.gattii genotype VGⅠ.Next-generation sequencing and genomic analysis reveal its omics characteristics,providing support for genetic research and pathogenic mechanism exploration of this fungus.