阴囊孢子丝菌病1例及申克孢子丝菌基因型检测

孢子丝菌病是由申克孢子丝菌引发的一种皮肤、皮下组织和附近淋巴管的慢性感染性疾病,多发于四肢等容易暴露受伤的部位.本文报道1例发生于阴囊的固定型皮肤孢子丝菌病,并对申克孢子丝菌进行了形态学和分子生物学水平的鉴定.     

申克孢子丝菌的分子生物学研究进展

申克孢子丝菌是孢子丝菌病的致病菌，以双相致病真菌。发生孢子丝菌病是由于宿主体内酵母细胞增殖所致，同时还与宿主防御机制有关。对其基因分型、部分基因的鉴定、分子诊断方法及致病机理的分子基础等方面的研究进展进行了综述。     

发现于新疆的申克孢子丝菌新基因型

目的:利用多聚酶链反应随机扩增多态性DNA(polymerase chain reaction-random amplified polymorphic DNA,PCRRAPD)法对新疆地区固定型和皮肤淋巴管型孢子丝菌病致病菌进行基因分型,并与北京和哈尔滨的菌株基因型比较,探讨新疆地区申克孢子丝菌的基因特点.方法:采用...     

申克孢子丝菌基因型与临床表现型关系研究

目的了解申克孢子丝菌的基因学特征，探索其基因型特征与临床表现型的关系。方法收集不同临床型别孢子丝菌病的申克孢子丝菌分离株并提取DNA，再用随机扩增DNA多态性方法（RAPD）进行PCR扩增。结果①共选用10个随机引物进行扩增，筛选出4个具有较好扩增片段的引物。②不同菌株同-引物扩增均见-共有DNA片段。③不同临床型孢子丝菌病的申克孢子丝菌分离株带型有差异。结论随机扩增DNA多态性研究发现申克孢子丝菌具有一定的种内差异，其DNA带型与菌株的临床型有关。     

不同地区申克孢子丝菌基因分型研究

目的:探讨申克孢子丝菌基因分型特征与菌种来源的关系。方法:采用随机扩增DNA指纹方法(RAPD)对来源于不同地区的31株申克孢子丝菌临床分离株进行DNA多态性分析。结果:①筛选出4个具有较好扩增片段的引物。②31株菌的DNA带型不完全相同,具有一定的遗传变异性,与菌株的地区来源有关。③同一患者不同部位取材的菌株间DNA型可不同。结论:随机扩增DNA多态性方法可用于申克孢子丝菌的DNA分型,其DNA带型与菌株的地区来源有关。     

申克孢子丝菌chs1基因生物信息分析

目的:对申克孢子丝菌几丁质合成酶基因(chs1)及其编码蛋白的结构和特性进行分析和预测。方法:利用NCBI网站、Ex PASy和CBS等工具预测申克孢子丝菌chs1基因及编码蛋白的结构和功能。结果:chs1 mRNA全长2 745 bp,编码914个氨基酸。BLAST分析显示,申克孢子丝菌与巴西孢子丝菌、蓝菌属真菌、足马杜拉分枝菌等真菌chs氨基酸序列一致性达到99%,且有保守域。预测chs1蛋白相对分子量为102 714.7,理论等电点为6.71。预测chs1编码蛋白ɑ螺旋、β折叠、β转角、无规则卷的比例分别是38.40%、17.94%、10.39%、33.26%。chs1蛋白是一种疏水蛋白,包含9个跨膜区,未发现信号肽。结论:成功预测了chs1基因及编码蛋白质的生化性质及结构特征,为下一步对其进行克隆、表达和敲除奠定基础。     

“ITS/CAL"靶位分子鉴定结合表型分析确诊狭义申克孢子丝菌致淋巴管型孢子丝菌病一例

患者女,54岁,农民.左上肢近手腕部外伤后出现豌豆大小的单一红色结节15d,后肿大、破溃,并在30 d内发展为多个成串状分布的结节.皮肤科检查:患者左上肢可见多个呈线性排列的紫红色结节,质硬;部分结节破溃,伴少许脓性分泌物.组织病理提示,感染灶呈混合炎性细胞浸润为主的化脓性肉芽肿炎症;过碘酸雪夫染色阴性,未见真菌孢子、菌丝及星状体.活检组织真菌培养阳性.根据培养物形态学分析和内部转录间隔区(ITS)及钙调蛋白(CAL)编码区靶位的分子生物学鉴定结果,确诊该病例为狭义申克孢子丝菌致淋巴管型孢子丝菌病.给予患者10％碘化钾溶液10 ml/次每日3次口服;治疗2个月后,患者自觉症状明显改善,后失访.本例报道提示联合应用表型鉴定和“ITS/CAL”靶位的基因分析能够准确将孢子丝菌复合体鉴定到种水平.     

应用PCR-RFLP进行申克孢子丝菌的分子生物学鉴定

目的　探索一种简单、快速的申克孢子丝菌的鉴定方法。方法　应用真菌通用引物ITS1和ITS4对来源于不同地区及不同临床型别孢子丝菌病的 2 8株申克孢子丝菌以及 9种其他临床上重要的真菌进行PCR扩增 ,利用限制性内切酶HaeⅢ对PCR产物进行酶切分析鉴定。结果　所有 2 8株申克孢子丝菌和其他 9种真菌均扩增出一条约 3 5 0bp的片段 ,其中 2 8株申克孢子丝菌RFLP带型一致 ,与 9种其他临床上重要的真菌RFLP带型差异较明显。 结论　PCR RFLP可以为建立一种简单、快速鉴定申克孢子丝菌的方法提供依据。     

一株引起皮肤播散性孢子丝菌病的孢子丝菌临床分离株的基因型鉴定

孢子丝菌病是由申克孢子丝菌引起的常见深部真菌病,临床多见于淋巴管型及固定型,播散性孢子丝菌病少见.孢子丝菌进入人体后引起不同临床类型的孢子丝菌病与机体免疫状态有关^[1],但是否与菌型有关尚无定论.为此,我们从一皮肤播散性孢子丝菌病患者皮损中分离1株孢子丝菌菌株,利用常规真菌学和分子生物学方法对其进行鉴定,并探讨该菌株与皮肤淋巴管型孢子丝菌在基因水平上的异同.     

种特异性引物鉴定申克孢子丝菌

目的 研究申克孢子丝菌的分子鉴定方法,为孢子丝菌感染的分子诊断奠定基础.方法 对22株申克孢子丝菌和12种12株暗色真菌临床分离株的核糖体DNA(rDNA)内转录间隔区(ITS)进行聚合酶链反应扩增.对10株来源于中国不同地区及1株来源于美国的申克孢子丝菌的扩增产物测序并进行分析,以获得的ITS2区序列为靶序列设计出申克孢子丝菌的种特异性引物(SSP),并用该引物扩增全部受试菌株.结果 序列分析显示,申克孢子丝菌rDNA的ITS2区相当保守,特异性引物对22株申克孢子丝菌可扩增出一条300bp的片段,其他受试菌株均为阴性.结论 应用设计出的种特异性引物,结合PCR方法,鉴定申克孢子丝菌特异、敏感、可靠,可用于临床诊断.     

Rapid identification of Sporothrix schenckii in biopsy tissue by PCR

Background The dimorphic fungus Sporothrix schenckii is the etiological agent of sporotrichosis, an important cutaneous mycosis with a worldwide distribution. At present, it is challenging to rapidly discover and identify Sporothrix schenckii in biopsy tissues nowadays. Aims To explore new methods for rapid diagnosis of sporotrichosis. Materials and Methods We screened specific primers for Sporothrix schenckii using 50 clinical isolates from patients with sporotrichosis. DNA was extracted from the lesions of 30 cases of clinically suspected sporotrichosis using the Graham s method of CTAB and amplified by PCR using the screened specific primers. Results The primer S2‐R2 was applicable for the identification of S. schenckii from different geographic areas and clinical types with high specificity and sensitivity. Twenty‐five out of the thirty cases (83.3%) amplified using the primer S2‐R2 showed positive bands. Further positive bands were observed in 95.6% of cases tested positive by fungal culture. Conclusions Using the PCR technique and specific primers, we developed a new diagnostic method that can rapidly diagnose sporotrichosis with tissues obtained from clinical biopsies.     

Galactose-reacting agglutinins to Sporothrix schenckii

Agglutinins to Sporothrix schenckii were produced in rabbits by immunization with Aspergillus fumigatus. Agglutination of S. schenckii cells was inhibited by D-galactose but not by D-mannose. Indirect immuno-scanning electron microscopy using rabbit anti-A. fumigatus serum and ferritin conjugated goat anti-rabbit IgG serum showed considerable labelling of ferritin particles at the cell surface of S. schenckii; this behavior was inhibited by D-galactose but not D-mannose. These results suggested that galactose determinants were present at the cell surface of S. schenckii and that agglutinins to S. schenckii were divided into two groups, galactose-reacting antibodies as well as the already recognized rhamnose-reacting ones.     

Unusual fatty acid in Sporothrix schenckii

Sporothrix schenckii was isolated from a specimen from a 75-year-old woman with lymphatic sporotrichosis on the left forearm. A mass of fungi was cultured in liquid Sabouraud dextrose broth for three months. Crude lipids were extracted from the cultured fungal mass. Total fatty acids and free fatty acids were isolated, purified, and then analyzed using thin-layer chromatography, gas liquid chromatography, and mass spectrometry. Total fatty acid composition consisted of seven molecular species of C15:0 (2.5%), C16:1 (2.5%), C16:0 (64.5%), 2-Me-C16:0 (5.1%), C17:0 (2.0%), C18:1 (18.0%) and C18:0 (5.3%). Free fatty acid composition consisted of eight species of C14:0 (2.0%), C15:1 (4.1%), C16:1 (7.5%), C16:0 (68.5%), C17:0 (0.6%), C18:2 (2.0%), C18:1 (14.5%) and of C18:0 (0.9%). 2-Me-C16:0 was detected in the fungus for the first time.     

申克孢子丝菌双相体外药物敏感试验研究

目的：研究双相真菌申克孢子丝菌分别在菌丝相和酵母相两种形态下对常用抗真菌药物的敏感性。方法：分别采用Roseo纸片扩散法及微量液基稀释法对临床分离的4株申克孢子丝菌的两种形态（菌丝相及酵母相）进行体外药敏试验。测定的抗真菌药物为：两性霉素B、伊曲康唑、氟康唑、特比萘芬。结果：除AMB二者一致外，其余各抗真菌药的MIC，菌丝相30℃孵育比酵母相35℃孵育高。结论：申克孢子丝菌的生长形态（菌丝相或酵母相）及孵育温度（30℃或35℃）对其药敏试验MIC值有明显影响。     

孢子丝菌超微结构观察

我们用透射电镜观察了在真皮和培养的申克氏孢子丝菌,后者见孢子和菌丝,二者都有正常的细胞壁,孢子直径在3.0~5.4μm范围内,菌丝平均直径4.5μm,在孢子胞浆中见糖原颗粒、线粒体、空泡、脂滴、核蛋白体、内浆膜系统、同心膜系统、中心无定形物质及核.前者见直径0.9~4.0μm的缩小孢子,胞浆中可见糖原颗粒、空泡.脂滴、线粒体及核.并讨论了真皮中孢子丝菌与孢子丝菌病的关系.     

Rapid and specific identification of Sporothrix schenckii by PCR targeting the DNA topoisomerase II gene

BACKGROUND: In order to study the genotype variation of Sporothrix schenckii, we previously analyzed the genomic sequences of the DNA topoisomerase II genes of this fungus and S. schenckii-related species, such as S. schenckii var. luriei and Ceratocystis stenoceras. OBJECTIVE: To develop a PCR-based identification system that can distinguish S. schenckii from its related species for clinical diagnosis of sporotrichosis. METHODS: Based on the nucleotide sequences of the DNA topoisomerase II genes of S. schenckii, S. schenckii var. luriei and C. stenoceras, three gene-specific primers (SSHF31 and SSHR97 for S. schenckii, and SSLF64 for S. schenckii var. luriei) were designed and evaluated for their specificities in PCR amplifications. RESULTS: The primer set SSHF31/SSHR97 amplified PCR products of 663-817 bp from S. schenckii and approximately 660 bp from S. schenckii var. luriei, while SSLF64/SSHR97 exclusively amplified a major product of 305 bp from S. schenckii var. luriei. CONCLUSION: PCR targeting the DNA topoisomerase II gene specifically and rapidly distinguished S. schenckii from its related species.     

申克孢子丝菌4Hppd基因结构功能的生物信息学分析

 目的:初步预测及分析申克孢子丝菌(Sporothrix schenckii，Ss.)对羟苯基丙酮酸双加氧酶基因（4Hppd）编码蛋白的结构和生物学功能特征。方法：应用生物信息学在线工具预测分析Ss.4Hppd编码蛋白的理化性质及功能特征。结果：Ss.4Hppd基因编码蛋白含对羟苯基丙酮酸双加氧酶保守域，由477个氨基酸构成，理论分子量为52.0 kD，等电点为5.98，半衰期较长，该蛋白为非分泌蛋白，定位于线粒体中。其二级结构以无规则卷曲及α-螺旋为主，另外还存在乙二醛酶功能域及丰富的磷酸化位点，与其他致病真菌同源蛋白有较高的相似度。结论：预测Ss.4HppD位于线粒体中，具有乙二醛酶功能域结构功能特点及丰富修饰位点，可为其表达、晶体结构分析及小分子抑制剂开发提供参考。