Identification of Cryptococcus neoformans var.grubii, var.neoformans and Cryptococcus gattii by multiplex PCR / 中华皮肤科杂志

Objective To establish a multiplex PCR targeting the intergenic spacer regions (IGS) for the identification of Cryptococcus neoformans var.grubii,var.neoformans and Cryptococcus gattii.Methods Primers were designed by using the software ClustalW2 and Oligo 6 based on the sequence of IGS1 region,which shows high sequence variability in the genome of Cryptococcus neoformans and Cryptococcus gattii.,for the multiplex PCR.Then,the developed multiplex PCR was performed to identify 51 Cryptococcus neoformans strains representing genotypes VNI-VNIV and VNB as well as 41 Cryptococcus gattii strains representing genotypes VGI-VGIV.The identification results were compared with those from common PCR by using primers GPA1A,CLA4D and SODlgattii specific to Cryptococcus neoformans var.grubii,var.neoformans and Cryptococcus gattii,respectively,as well as with those from the canavanine-glycine-bromothymol blue (CGB) medium-based culture.Results The developed multiplex PCR successfully identified the 92 Cryptococcus neoformans and Cryptococcus gattii.strains,and yielded negative results from the other tested pathogenic yeasts,which revealed a high specificity of the designed primers.False positive results were observed in the identification of two Cryptococcus gattii strains with GPA1A primer-based PCR,one Cryptococcus gattii strain with CLA4D primer-based PCR,one var.grubii strain and one var.neoformans strain with CGB culture,while no false negative results were observed in the detection of these Cryptococcus strains by any of these methods.Conclusions The developed multiplex PCR in this study can rapidly and accurately identify Cryptococcus neoformans var.grubii,var.neoformans,AD hybrid,and Cryptococcus gattii,with superior performance in comparison with common PCR and CGB medium-based culture.

Species profiles of pathogens from 1366 superficial candidiasis cases in Shanghai / 中华皮肤科杂志

Objective To analyze the composition and distribution of pathogens from 1366 superficial candidiasis cases in Shanghai.Methods Candida species identification was carried out for 1366 adults or children with superficial candidiasis by using CHROMagar Candida plates,API20C AUX system,etc.Pal's agar,Xylose assimilation and the test for growth at 45 ℃ were utilized to differentiate Candida dubliniensis.Newly identified pathogenic Candida species including Candida orthopsilosis,Candida metapsilosis,Candida fermentati,Candida nivariensis and Candida bracarensis were differentiated by molecular biological methods.Finally,the composition and distribution of pathogens in superficial candidiasis cases were statistically analyzed.Results A total of 1366 Candida strains,included 2 Candida orthopsilosis strains and 4 Candida metapsilosis strains,were isolated from these cases.Among these isolates,Candida albicans predominated(79.0％),followed by Candida parapsilosis(9.5％),Candida tropicalis(2.9％)and Candida guilliermondii(1.9％).The composition of Candida species was significantly different between child and adult patients(x2 =196.46,P ＜ 0.01),with the isolation rate of non-albicans Candida species being 14.4％ and 45.8％ respectively in child and adult patients.Conclusions Candida albicans is still the dominant pathogen of superficial candidiasis.Candida orthopsilosis and Candida metapsilosis can cause superficial candidiasis.The isolation rote of non-albicans Candida species is higher in adult patients than in child patients.

Rapid identification and sequence typing of genotype VG Ⅱ of Cryptococcus gattii / 中华临床感染病杂志

Objective To establish a PCR method for rapid identification and sequence typing of VG Ⅱ allele of the intergenic spacer region (IGS) of Cryptococcus gattii.Methods Since IGS1 was of high sequence variation,multiple alignments were conducted by ClustalX 2 in IGS1 of Cryptococcus gattii and Cryptococcus neoformans,and then primer sets specific to genotype VG Ⅱ was designed for PCR analysis.The specificity of the primer pair was detected by amplification of the other genotypes in Cryptococcus gattii,Cryptococcus neoformans,and other pathogenic yeasts.The amplified fragments from VG Ⅱ genotype were sequenced and subtyped.Results Using the PCR analysis developed in this study,all VG Ⅱ genotype strains tested were amplified,whereas no amplification was obtained from other genotypes or yeast species involved herein.Three polymorphic nucleotide sites at 72,79 and 104 bp in the fragment amplified could be used to distinguish sub-genotypes within VG Ⅱ genotype.Conclusions The PCR analysis developed in this study can be used for rapid identification of genotype VG Ⅱ of Cryptococcus gattii.The sequence typing based on the amplified fragment from IGS1 may be performed for screening the highly virulent sub-genotype VGⅡ a.

Subgenotyping analysis of pathogenic Cryptococcus gattii isolates from China / 中华皮肤科杂志

Objective To assess the subgenotypes of pathogenic Cryptococcus gattii isolates from China and to elucidate the epidemiological links between these domestic isolates and those from other parts of the world. Methods DNA was extracted from 9 clinical isolates of Ctyptococcus gattii from China. The partially variable regions of the three unlinked loci, namely IGS1, PLB1 and GEF1, were amplified and sequenced, and the bioinformation at these loci was obtained from GenBank for multi-locus sequences alignment and phylogenetic analysis. Results Of these 9 clinical isolates, 8 were genotype VG Ⅰ and mating type α with the same sequences at the tested regions as the reference strain WM276, which was a representative isolate of an independent subgenotype; 1 was of genotype VG Ⅱ and mating type α, which was the first report in China, with the tested sequences consistent with those of the referrence strain R272. Sequencing and phylogenetic analysis of GEF1 gene, which was located at mating type locus, successfully identified the genotypes and mating types of all the Cryptococcus gattii isolates involved here. Conclusions Multi-locus sequence analysis shows that causative Cryptococcus gattii isolates of genotype VG Ⅰ in China carry similar sequences at the tested loci in IGS1, PLB1 and GEF1 genes, to a widely distributed subgenotype in the world, and the sequences of the first VG Ⅱ genotype isolate from China resemble the less virulent subgenotype VG Ⅱ b found in Vancouver islands.

In vitro antifungal susceptibility of 80 Cryptococcus neoformans isolates / 中华传染病杂志

Objective To determine in vitro drug susceptibility to five antifungal agents of clinical Cryptococcus neoformans strains isolated from different areas of China in recent ten years. Methods Eighty clinical isolates of Cryptococcus neoformans were isolated from Shanghai, Guangdong, Fujian, Beijing and some other areas of China from 1998 to 2007. The minimal inhibitory concentrations (MIC) of the isolates to five antifungal agents, including amphotericin B, fluconazole, flucytosine, itraconazole and voriconazole, were determined using broth microdilution procedure (document M27-A2) recommended by the Clinical and Laboratory Standards Institute (CLSI). Kruskal-Wallis rank sum test was employed for the statistical analysis. Results The MIC50 of the Cryptococcus neoforrnans isolates tested for amphotericin B, fluconazole, flucytosine, itraconazole and voriconazole were 0.5, 4, 2, 0.25 and ≤0.031 3 mg/L, respectively; and the MIC<,90> of the isolates tested for the above antifungal agents were 1, 8, 4, 0.5 and 0.062 5 mg/L, respectively. Among the tested isolates, 3 (3.8 %) were resistant to flucytosine, 4 (5.0 %) were resistant to itraconazole. All isolates were susceptible to amphotericin B and voriconazole. There was no significant difference in MIC of the strains isolated from any particular years to the five agents (χ2=0.500,2.687,2.211, 2.660,0.677,P>0.05). Conclusions The Cryptococcusneoformans isolates are highly susceptible to the five antifungal agents, while a few strains are resistant to flucytosine or itraconazole. The drug susceptibilities of the strains isolated from particular years are similar.

Multi-locus analysis of AD hybrid strains of Cryptococcus neoformans / 中华临床感染病杂志

Objective To identify the AD hybrid strains and its hybrid types within Cryptococcus neoformans.Methods Difierent hybrid types of AD strains were analyzed by PCR 0f STE20 and MF genes within MAT locus and CIA4 and GPal genes out of MAT locus.The PCR-RFLP analysis of g6341 gene was also performed.Results The mating types of 18 AD strains were precisely identified by PCR of STE20 gene,whereas those of H strain were not identified.CL44 gene was better than the GPal gene in PCR identification of the AD hybrids.In the RFLP analysis of g6341 gene,AD strains were grouped into 2 distinct RFLP patterns based on the mating type on serotype A allele.The mating types of AD strains were not identified by the molecular analyses based on the CL44,GPal and g6341 genes.Conclusion It is necessary to use multi-locus analyses of genes within and out of the MAT locus in precise identification of the AD strains and their hybrid types of Cryptococcus neoformans.

PCR-RFLP versus PCR fingerprinting method in the genotyping of Cryptococcus neoformans / 中华皮肤科杂志

Objective To evaluate the efficiency of PCR-restriction fragment length polymorphism (PCR-RFLP)aiming at the structure gene g6341,versus PCR fingerprinting analysis in the genotyping of Cryptococcus neoformans MethodsEight reference strains and 68 clinical and environmental isolates of C.neoformans were genotyped by PCR-RFLP and PCR fingerprinfing.In PCR fingerprinting,the minisatel lite-specific core sequence of wild-type phage M13 was used as a single primer.The structure gene g6341 was selected for PCR-RFLP analysis by sequence alignments of multiple genes,a pair of pnmers were developed based on the conserved region of g6341 gene.PCR products were digested with the appropriate restriction endonucleases,and RFLP profiles were analyzed.Partial sequence analysis of g6341 gene was performed for different genotypes of C.Neoformans.Phylogenetic analysis was done to study the relatedness between these genotypes.Results As sequence homology analysis showed,g6341 gene was suitable for RFLP analysis.In the case of enotyping of 76 C. Neoformans strains,the results obtained from PCR-RFLP were consistent with those from PCR fingerprinting.Sequence analysis of g6341 gene revealed a homology of 84%-97%among the eight genotypes as well as a consistency of 99%-100%within a same genotype.In the phylogenetic tree,genotypes VNⅠ,VNⅡ,VNⅢand VNⅣ belonged to one cluster,and genotypes VGⅠ,VGⅡ,VGⅢ and VGⅣ to another cluster.Conclusions PCR-RFLP analysis aiming at the structure gene g6341 is a useful tool to genotype C.neoformans.Sequence analysis of g6341 gene can disclose the relatedness among different molecular types of C.neoformans.

Molecular identification of species, varieties, genotypes and mating types of Cryptococcus neoformans species complex / 中华检验医学杂志

Objective To evaluate the role of Restriction fragment length polymorphism (RFLP) analysis in detection of the fragment of GEF1α/a gene which are both located at ct and a mating type loci in identification of species, varieties, genotypes and mating types of Cryptococcus neoformans species complex(Cryptococcus neoformans and Cryptococcus gattii). Methods The GEF1α/a gene was selected from 20 genes which both located at α and a mating type loci for RFLP analysis, according to the requirements of sequence similarities and primer design in PCR-RFLP analysis. Primer pair was designed from the conserved regions of GEF1α/a genes of distinct genotypes and mating types of reference strains to amplify a fragment of GEF1α/a gene from Cryptococcus neoformans and Cryptococcns gattii strains tested. Sequence alignment,restriction maps analysis, endonucleases selection and electrophoresis stimulation were conducted by using DNAMAN and Vector NTI software. EeoT14 Ⅰ and Hap Ⅱ endonucleases were selected for RFLP analysis of the GEF1α/a fragments amplified from 125 isolates of Cryptococcns neoformans and Cryptococcus gattii. Results An approximate 1 300 bp fragment was amplified from total 82 Cryptococcus neoformans and 43 Cryptoceccus gattii isolates. However, negative PCR results were found in the reference strains of Cryptococcus laurentii, Candida albicans, Candida tropicalis, Candida parapsilosis, Candida krnsei,Candida glabrata, Trichosporon asahii, Aspergillus fumigatns and Aspergillus flavus. RFLP analysis successfully identified the species, varieties, genotypes and mating types of total 125 isolates of Cryptococcus neoformans and Cryptococcns gattii tested in this study. Condusion PCR-RFLP analysis of the GEF1α/a fragment has the potential value in identification of species, varieties, genotypes and mating types of Cryptococeus neoformans species complex simultaneously and rapidly, and may be a useful tool in molecular epidemiological analysis.

Analysis of the varieties,genotypes and mating types of 110 clinical cryptococcal isolates from China / 中华微生物学和免疫学杂志

Objective To investigate the molecular epidemiology of clinical cryptococcal isolates from China by analyzing the constituents and distributions of the varieties,genotypes and mating types (MAT)of them.Methods (1)PCR fingerprinting and PCR amplification were performed by using the minisatellite-specific core sequence of wild-type phage M13 as single primer.Genotypes of the 110 cryptococcal isolates from China were assigned by comparison with the reference strains of the 8 major molecular types loaded on gel.(2)Identification of the varieties and mating types was carried out by PCR using the specific primers of the varieties and mating types.Results Of the 110 clinical cryptococcal isolates,strains of Cryptococcus neoformans var.grubii with genetype VNⅠ and mating type MATα were the most representative ones(89.1%)followed by strains of C.neoformans var.gattii(8.2%)including isolates of genotype VG I,mating type MATα(7.3%)and genotype VGⅡ,mating type MATα(0.9%);AD hybrids with the genotype VNⅢ,mating type MAT-/α and genotype VN Ⅲ,mating type MATα/-(1.8%);and isolate of C.neoformans var.neoformans with the genotype VNⅣ and mating type MATa(0.9%).Conclusion Of the clinical isolates from China,all three varieties and AD hybrids are found.The vast majority(>99%) of strains possess the α allele in MAT locus and most of them are C.neoformans vat.grubii with the genotype VN I,which accord with the data of most studies of clinical molecular epidemiology in other geographic areas.However.no genotype of VNⅡ.VGⅢ and VGⅣ isolates are found in this study.

Characterization and Sequence Analysis of 28S rDNA of Cryptococcus neoformans / 中华皮肤科杂志

Objective To investigate genetic relationships among five serotypes of two variants of Cryptococcus neoformans. Methods PCR mediated DGGE (denaturing gradient gel electrophoresis) and sequence analysis of 28S rDNA of C. neoformans were performed in ten reference strains, C. neoformans capsular-deficient strain CAP10, and nineteen clinical isolates from non-HIV patients. Results The results of DGGE and analysis of nucleotide sequences of 28S rDNA showed identical patterns and nucleotide sequences in the serotype A and D of C. neoformans var. neoformans, which were distinct from the serotye B and C of C. neoformans var. gattii. The patterns and sequences of serotype AD coincided with those of C. neoformans var. gattii. The patterns and nucleotide sequences of C. neoformans capsular-deficient strain CAP10 (serotype D) and serotype A and D were identical. Of the nineteen clinical isolates, seventeen had patterns of serotype A and D, and the others had patterns of serotype B and C. Conclusions PCR mediated DGGE integrated with sequence analysis of 28S rDNA is a valuable tool for the classification of C. neoformans. The clinical isolate of C. neoformans var. neoformans is predominant in Chinese non-HIV patients. Serotype AD is genetically close to C. neoformans var. gattii rather than C. neoformans var. neoformans. The data seem not to be in favor of previous study that serotype A, C. neoformans var. grubii, is a new variant of C. neoformans.

Study on Combination of Itroconazole and Amphotericin B Against Clinical Isolates of Cryptococcus neoformans / 中华皮肤科杂志

Objective To evaluate the sensitivity of combination of itraconazole and amphotericin B to20clinical isolates of Cryptococcus neoformans and their in vitro interactions.Methods The sensitivity of combination of itraconazole and amphotericin B and their in vitro interactions were determined with20clinical isolates of C.neoformans by a checkerboard titration broth microdilution-based method in accord with the recommendations of the National Committee for Clinical Laboratory Standards(NCCLS),USA.Results When both drugs were given in combination,there was significant reduction of geometric means of MICs for itraconazole(from0.2730to0.1195?g/mL)and for amphotericin B(from0.6830to0.2102?g/mL).Synergistic effects were found in35%of isolates,additive effects in55%of isolates,and indifferent effects in10%of isolates.Antagonistic effects were not observed.The colony formation unit(cfu)per millilitre was significantly decreased in an isolate which was treated with different concentrations of the combination of both drugs,in comparison to that with the corresponding concentrations of individual drug.Conclusion The combination of itraconazole and amphotericin B is significantly more active against C.neoformans in vitro than individual drug alone.

Genotyping of Candida albicans Isolated from Different Body Sites of Women Suffering from Candi-dal Vulvovaginitis / 中华皮肤科杂志

Objective To study the distribution of genotypes of Candida albicans isolated from different body sites of patients with candidal vulvovaginitis(CVV).Methods PCR was designed to amplify group I intron-containing region in25S rDNA of Candida albicans.The strains of Candida albicans could be classified into three genotypes:genotype A(~450bp),B(~840bp)and C(~450bp and~840bp),on the basis of different ranges of bands of amplicons.Results Sixty women with CVV were recruited,of whom54were caused by Candida albicans.Among the54patients39had non-recurrent CVV and15had recurrent CVV(RCVV).Candida albicans could be isolated simultaneously from different body sites in32of54patients,including19(19/39)with non-RCVV and13(13/15)with RCVV.A total of92strains of Candida albicans were isolated from vagina,tongue and anus in54patients with CVV.Eighty strains of genotype A,8of genotype B and4of genotype C were found.The same genotypes of Candida albicans in different body sites were identified in24patients,and the different genotypes were identified in8patients.Conclusion Genotype A is predominant in CVV.The other two genotypes(B and C)are not commonly seen,and mainly isolated from non-vaginal sites.The colonization of Candida albicans in the non-vagina sites is more frequent in RCVV than that in CVV,and the intestinal reservoir theory may play a role in the relapse of RCVV.

The EcoR V polymorphism of human monoamine oxidase A is not associated with idiopathic Parkinson's disease in a Shanghai Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the distribution of monoamine oxidase A (MOA-A) EcoRV polymorphism in Shanghai Han population and its possible role in the risk for Parkinson's disease(PD).</p><p><b>METHODS</b>The MAO-A gene EcoRV polymorphism was detected with PCR-RFLP method in 110 PD patients and 182 healthy controls, furthermore, statistical analysis was performed to investigate association between EcoR V polymorphism and PD onset.</p><p><b>RESULTS</b>(1)Remarkable difference in MAO-A EcoR V polymorphic distribution has been observed between Shanghai Han population and that in North America. (2) Neither allelic frequency nor genotypic frequency in PD cases differs significantly from that in healthy controls regardless of data from male or female subclass.</p><p><b>CONCLUSION</b>There may be racial difference in the distribution of the human MAO-A EcoR V (C/T) polymorphism, but the present research does not support the association between this variant and susceptibility to PD in Chinese Han population of Shanghai area.</p>

DNA analysis in a suspected individual with myotonic dystrophy family history and her abortus / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To observe trinucleotide repeat number, (CTG)n in the 3'-untranslated region of the myotonic protein kinase (MTPK) gene in a clinically suspected woman with myotonic dystrophy (DM) family history and her abortus, in order to confirm the necessity of exerting antenatal examination in patients or suspected individuals with DM family history.</p><p><b>METHODS</b>Long Expand Template polymerase chain reaction (PCR) system was used to analyze CTG trinucleotide repeat numbers located in the 3' untranslated region of MTPK on chromosome 19q13.2-3 in both peripheral white cells and muscles of the suspected mother and the other two DM patients in the family. The tissues of her abortus and blood of a health woman were detected, too.</p><p><b>RESULTS</b>CTG repeats in both peripheral white cells and muscles of the suspected mother and the tissue of abortus were higher than normal range of CTG repeat number. There is no significant difference between blood and muscle samples. High CTG repeats were detected in blood and muscles of the typical DM members in the family, but in the blood sample of control, CTG repeats is normal.</p><p><b>CONCLUSION</b>CTG trinucleotide analyses and antenatal examination should be done in pregnant with a DM family history, in order to reduce the birth rate of DM offspring.</p>

Immunogenicity of a multiple epitope antigen gene of hepatitis C virus in mice and rabbits / 细胞与分子免疫学杂志

Aim To explore the possibility of the multiple epitope DNA vaccines of hepatitis C virus (HCV). Methods A synthetic multiple epitope antigen gene PCX of HCV was cloned into vector pREP9(RSV promoter) and pcDNA3 (CMV promoter) to construct eukaryotic expression vectors pREP9/PCX and pcDNA3/PCX, then they were used to immunize mice and rabbits, the titer of specific humoral and cellular responses were detected and their safety were observed. Results In mice, specific anti-GZ-PCX antibody(IgG) was lower than 1∶ 1 000 and did not persist well. In rabbits, the highest titer of anti-GZ-PCX IgG reached at 1∶ 3 200 and remained for about one month. Delayed type hypersensitivity reactions (DTH)and proliferation response of peripheral lymphocytes were induced by GZ-PCX antigen. Body weights of immunized mice were normal and no obvious toxic reaction was observed. Conclusion The multiple epitope antigen gene of HCV could induce specific immune responses without obvious toxicity and it might be able to serve as an effective HCV vaccine candidate.

Synthesis, Cloning and Expression of a Multiple Epitope Antigen of BCR-ABL Fusion Gene / 中国实验血液学杂志

Chronic myeloid leukemia (CML) appears an ideal and exciting immunological target. Novel and rational immunotherapy may therefore play an important adjuvant role in the treatment of CML patients. Peptides derived from the BCR-ABL fusion region have been shown to be immunogenic and are able to stimulate the production of BCR-ABL-specific T cell lines and clones. In this study, A 280 bp multiple epitope region of BCR-ABL fusion antigen was designed and synthesized. This region contains three BCR-ABL antigen epitopes which can bind to HLA-A2, HLA-A3 and HLA-DR11 molecules, respectively, and epitopes of cholera toxin B (CTB) and tetanus toxoid (TT) which are able to elicit vigorous T cell responses. The fusion antigen gene has highly been expressed in E. coli and the purified fusion protein reserved satisfied activity and antigenicity. The results of this investigation provided a basis for further research on the developing specific T cell immunotherapy of CML.

Construction and indentification of the recombinant vaccine of Attenuated Salmonella typhimurium containing pIRES2-EGFP-4-1BBL vector / 中国免疫学杂志

0.05).The transfected HepG2 cells by infection of SL3261 containing the vector were shown with GFP and the 930 bp target expression by RT-PCR.Conclusion:Attenuated Salmonella typhimurium SL3261 containing recombined eukaryotic expressing plasmid pIRES2-EGFP-4-1BBL is successfully constructed which can deliver recombinant plasmid into HepG2 cells.