1、检验特点检验特点 形态学检查为检测真菌的重要手段形态学检查为检测真菌的重要手段 抗原检测适合血清和脑脊液中隐球菌、抗原检测适合血清和脑脊液中隐球菌、念珠菌、荚膜组织胞浆菌。念珠菌、荚膜组织胞浆菌。血清学诊断适用于深部真菌感染血清学诊断适用于深部真菌感染。检测程序标本直接镜检抗原检出分离培养不染色乳酸酚棉蓝染色墨汁染色氢氧化钾消化后涂片镜检二相性真菌脑心浸液脑心浸液沙氏培养基病原性真菌血琼脂平板观察菌落性状和菌丝孢子形态真菌的菌落真菌的菌落-真菌分类重要的依据真菌分类重要的依据 真菌的真菌的菌落菌落一般是指在一定基质上,接种某一般是指在一定基质上,接种某种真菌的一个孢子或一段菌丝,经过培养,向种
2、真菌的一个孢子或一段菌丝,经过培养,向四周蔓延生长出丝状的群体称为真菌菌落。菌四周蔓延生长出丝状的群体称为真菌菌落。菌落呈放射状生长,因而菌落外周的生命力最旺落呈放射状生长,因而菌落外周的生命力最旺盛。在不同成分的培养基上和不同条件下培养,盛。在不同成分的培养基上和不同条件下培养,同一种真菌,形成的菌落也有差别。因此,同一种真菌,形成的菌落也有差别。因此,菌菌落的形态观察是指在固定的条件下,菌落所表落的形态观察是指在固定的条件下,菌落所表现的形状、大小、色泽和结构等。不同的真菌现的形状、大小、色泽和结构等。不同的真菌菌落所表现特征差别显著,它为真菌分类工作菌落所表现特征差别显著,它为真菌分类工
3、作提供了重要的依据。提供了重要的依据。菌落颜色菌落颜色 除酵母菌的菌落比较简单,丝状真菌的除酵母菌的菌落比较简单,丝状真菌的菌落形态各种各样。常以下述特征加以菌落形态各种各样。常以下述特征加以描述。描述。其其颜色颜色的多样很难用色泽描述,常借助的多样很难用色泽描述,常借助于色谱加以鉴别。很多真菌产生多种颜于色谱加以鉴别。很多真菌产生多种颜色的色素,使菌落的背面染有颜色,有色的色素,使菌落的背面染有颜色,有的甚至分泌可溶性色素,扩散到全部基的甚至分泌可溶性色素,扩散到全部基质中去。质中去。菌落质地菌落质地 气生菌丝构成气生菌丝构成表面表面菌丝体菌丝体质地质地。底部菌丝体埋伏于培养基。底部菌丝体埋
4、伏于培养基中或紧贴培养基表面向四周蔓延,中或紧贴培养基表面向四周蔓延,由底部体直接生出分生孢子梗,菌落外观呈由底部体直接生出分生孢子梗,菌落外观呈短茸毛短茸毛状,状,由底部菌丝体生出气生菌丝,再由它生出分生孢子梗,因由底部菌丝体生出气生菌丝,再由它生出分生孢子梗,因而往往有缠绕的气生菌丝团,一般菌落而往往有缠绕的气生菌丝团,一般菌落较厚,呈絮状较厚,呈絮状。也有部分气生菌丝扭结成绳索、还有分生孢子梗自底部菌也有部分气生菌丝扭结成绳索、还有分生孢子梗自底部菌丝成束地生长,在菌落的外观上丝成束地生长,在菌落的外观上成粒状或粉状成粒状或粉状。有些真菌产生子实体或菌核,则菌落表面呈有些真菌产生子实体或
5、菌核,则菌落表面呈颗粒结构颗粒结构。有的菌落出现有的菌落出现同心环同心环或或辐射状沟纹辐射状沟纹。有的真菌只在菌落中间区域生出分生孢子头,边缘菌丝则有的真菌只在菌落中间区域生出分生孢子头,边缘菌丝则不生育。不生育。菌落的大小也大有不同,有些种的菌落可蔓延扩展到整个菌落的大小也大有不同,有些种的菌落可蔓延扩展到整个培养基,而另一些种的菌落则局限生长。培养基,而另一些种的菌落则局限生长。真菌菌落外观结构描述真菌菌落外观结构描述 菌落表面菌落表面平滑或具皱纹、致密或疏平滑或具皱纹、致密或疏松、同心环或辐松、同心环或辐 射状沟纹等;射状沟纹等;菌落质菌落质地地绒毛状、毡状、棉絮状、羊毛状、绒毛状、毡状
6、、棉絮状、羊毛状、束状、绳索状、粉粒状、明胶状或皮革束状、绳索状、粉粒状、明胶状或皮革状等;状等;菌落的边缘菌落的边缘可呈全缘、锯齿可呈全缘、锯齿状、树枝状或纤毛状等;状、树枝状或纤毛状等;菌落高度菌落高度扁平、丘状隆起、中心部分突起或凹陷扁平、丘状隆起、中心部分突起或凹陷等。等。193 patients(392 samples);43 with ICSensitivity SpecificityMannan(ag)40%98%Antimannan(ab)53%94%ag and/or ab80%93%(一)抗原:甘露聚糖一)抗原:甘露聚糖Detection of Mannan/Antiman
7、nan in Serum of Patients with Invasive CandidiasisSendid B et al,J Clin Microbiol 1999;37:1510-7(二)抗原:半乳甘露聚糖二)抗原:半乳甘露聚糖Serial Aspergillus Galactomannan Screeningn=362 high-risk neutropenic patientsSandwich ELISA 2 times weekly,11.7%positiven=30 proven IAn=9 probable IAn=264 with no IASensitivity89.7
8、%Specificity98.1%PPV87.5%NPV98.4%Maertens J et al,Blood 2001;97:1604-10GMGM抗原检测用于侵袭性曲霉病诊断抗原检测用于侵袭性曲霉病诊断 与临床诊断和疗效反应有良好的一致性。与临床诊断和疗效反应有良好的一致性。检测方法有检测方法有ELISAELISA、放射免疫分析(放射免疫分析(RIARIA)和乳胶和乳胶凝集试验等,但敏感性低。凝集试验等,但敏感性低。ELISAELISA检测检测2424只兔只兔(王莉,等。王莉,等。2003)2003)敏感性敏感性和和特异性特异性:血清血清 95%78%95%78%尿液尿液 90%51.4%
9、90%51.4%GMGM抗原抗原ELISAELISA检测方法检测方法(PlateliaPlatelia试剂盒)试剂盒)王莉,王莉,等。临床皮肤科杂志,待发表。等。临床皮肤科杂志,待发表。(四)四)-1,3-1,3葡聚糖葡聚糖 使用仪器及配套试剂盒能快速地检测出使用仪器及配套试剂盒能快速地检测出血液和体液中真菌血液和体液中真菌-1,3-1,3葡聚糖的实际葡聚糖的实际含量,对真菌的早期诊断具有重要意义。含量,对真菌的早期诊断具有重要意义。-1,3-D-1,3-D-葡聚糖检测阴性是否需要作进一步的葡聚糖检测阴性是否需要作进一步的复查复查?FuruyaFuruya的报道即使是的报道即使是确诊确诊的深部
10、真的深部真菌感染患者菌感染患者,-1,3-D-,-1,3-D-葡聚糖检测葡聚糖检测也有可能是阴性也有可能是阴性,因此单次因此单次-1,3-1,3-D-D-葡聚糖检测阴性并不能排除深部葡聚糖检测阴性并不能排除深部真菌感染的可能真菌感染的可能,必須在必須在疾病的过疾病的过程中重复进行程中重复进行-1,3-D-1,3-D-葡聚糖检测葡聚糖检测。Furuya T et al.Usefulness of-D-glucan measurement for diagnosis of deep mycosis,Jnp J Antibiot 1993;46(6):437-443真菌分子生物学的鉴定方法 核酸碱基
11、GC比分析 限制性片段长度多态性 Southern印迹分析 脉冲场凝胶电泳(PFGE)PCR 随机扩增多态性(RAPD)DNA片段测序等真菌感染检查项目的选择和应用 浅部真菌直接显微镜检查 深部真菌标本培养、观察培养物性状并借助理化特性作鉴别。Direct Examination It is highly recommended that a direct microscopic examination be made on most this provide an immediate presumptive diagnosis for the physician,but it may als
12、o aid in the selection of an appropriate culture medium.A phase-contrast microscope is a valuable adjunct in the direct examination of specimens.The advantages include the following:1)mounts can be made and examined quickly;2)there is no need for direct staining;and3)the objects can be clearly visua
13、lized.Tests for detection of fungal antibodies(1)Determination of antibody and/or antigen titers may be useful in diagnosing fungal infections and when performed in a serial fashion also provide a means of monitoring the progression of disease and the patients response to therapy.With the exceptiono
14、f antibody tests for histoplasmosis and occidioidomycosis,however,most tests designed to detect an antibody response as a means of diagnosing invasive fungal infections lack sensitivity and specificity,are poorly standardized and are not widely availableTests for detection of fungal antibodies(2)Tes
15、ts for detection of fungal antibodies(3)Antibody tests for Candida and Aspergillus.Are often unable to distinguish active from past infection and Colonization from transient fungemiaTests for detection of fungal antibodies(4)In addition,a negative test for fungus-specific antibodies does not rule ou
16、t infection because imunocompromised patients,and some individuals with disseminated infection may not mount an antibody response to the infecting organism.Tests for detection of fungal antigens(1)Detection of fungal antigens or metabolites in serum or other body fluids represents the most direct me
17、ans of providing a serologic diagnosis of invasive fungal infection.Both the RIA and the EIA tests have been shown to be rapid,sensitive,specific,rapid,and reproducible.Tests for detection of fungal antigens(2)Although significant advances have been made in recent years,most methods for rapid detect
18、ion of fungal antigens are available only in research laboratories.Notable exceptions are the tests for detection of the polysaccharid ride antigens of C.neoformans and H.capsulatumd.Tests for detection of fungal-specific nucleic acid sequences(1)The use of the PCR to detect fungal nucleic acids dir
19、ectly in clinical material offers great promise for the rapid diagnosis of fungal infections.Tests for detection of fungal-specific nucleic acid sequences(2)In addition to detection of fungal pathogens in clinical terid,immunologic and molecular approaches have been applied successfully to the identification of fungi in culture.