ABSTRACT
Objective To analyze the genomic sequences of Cryptococcus neoformans var grubii strains of two genotypes with different virulence and to screen out the virulence-associated genes. Methods A clinical strain (IFM56800) with the strongest virulence and an environmental strain (IFM56731) with the weakest virulence were screened out for whole genome sequencing analysis. The results of sequencing analy-sis were comprehensively analyzed by using the method of comparative genomics. Genetic variations were ex-tensively screened by using the strategies of non-synonymous single nucleotide polymorphisms ( nsSNPs), nonsense SNPs and the insertions or deletions ( InDels) causing frameshift mutations. The filtered genes were sequenced in 20 experimental strains. The whole RNAs were extracted and then the full-length cDNAs were sequenced by using the rapid amplification of 5′ and 3′ cDNA ends (RACE) method. Results By whole genome sequencing, valid data with high coverage (127 times and 111 times) was obtained in both the environmental strain IFM56731 and the clinical strain IFM56800. The data of InDels and SNPs were statisti-cally analyzed, respectively. Six genes were chosen for further analysis based on the strategies of nonsense SNPs and the InDels causing frameshift mutations. The six genes were amplified and sequenced in all of the experimental strains, three of which were further analyzed with cDNA sequencing. Ultimately, the location and structure of CNAG_01032 gene were determined. The predicted nonsense mutation locus was verified to present in the actual mRNA. Conclusion The strategies of nonsense SNPs and the InDels causing frame-shift mutations showed high-efficiency in screening potential virulence-associated genes. The CNAG_01032 gene was screened out as a novel virulence-associated gene.
ABSTRACT
Objective To investigate the genotype distribution of microsatellite locus CAI among Candida albicans ( C.albicans ) strains and to evaluate its relationship with the epidemic of vulvovaginal candidiasis ( VVC) in Guizhou region .Methods Ninety independent C.albicans strains isolated from pa-tients with VVC in Guizhou were investigated based on single-strand conformation polymorphisms ( SSCP ) and GeneScan analysis .The genotypes of C.albicans strains were identified by microsatellite locus CAI pol-ymorphism analysis .The gene polymorphism and the cluster of C.albicans strains were analyzed by using software SPSS 19.0.A logistic regression model was used to analyze the relationship between genotype distri -bution of CAI microsatellite among C.albicans strains and VVC infection .Results Twenty-seven distinct CAI genotypes with various patterns were identified from 90 C.albicans strains by GeneScan analysis .Clus-ter analysis showed that the C.albicans strains were classified into three clusters ( ClusterⅠto Cluster Ⅲ) . Three predominant genotypes including 30-45, 32-46 and 30-46 and other 7 highly similar genotypes be-longed to clusterⅡthat accounted for 70.0%(63 strains) in all strains.The odds ratio for the predominant genotypes associated with VVC infection was 4.3.Conclusion The predominant distribution of genotypes was observed among the isolated C.albicans strains.The predominant genotypes of C.albicans were highly associated with the occurrence of VVC .
ABSTRACT
Clinical training together emphasized the combination of theory and practice. It not only improved students'clinical thinking and skills and enhanced their communication skills and medical treatment writing skills but also demanded the teachers to have higher sense of responsibility and teaching skills.