山东兔场皮肤真菌病病原rDNA-ITS区序列测定及分析

利用皮肤真菌核糖体内转录间隔区（Internal transcribed spacer,ITS）序列通用引物,对采自山东地区主要兔场的皮肤真菌病的16株分离菌进行了PCR扩增,ITS区的克隆、测序、序列变异及遗传进化关系分析。经与Gen-Bank核酸序列数据库数据比对结果表明：16株病菌分别为须癣毛癣菌（12/16,75%）、犬小孢子菌（2/16,12.5%）、石膏样小孢子菌（2/16,12.5%）;不同病原菌的5.8SrDNA序列高度保守,而ITS区的变异性则较高;对该区序列的聚类分析表明,不同种菌株ITS1比ITS2在碱基构成和序列长度上有更大变异;而种内各菌株的ITS1和ITS2在长度上均没有变异,碱基构成上存在微小的变异,可基于该区进行兔皮肤真菌的分类鉴定。该研究确定了兔皮肤病原PCR检测特异引物的靶序列,为兔皮肤真菌病病原的特异性分子鉴定提供了可靠的靶标,为兔皮肤真菌的科学分类提供了分子依据。     

基于几丁质酶基因序列分析鉴定兔源须癣毛癣菌

利用几丁质酶基因(CHS1)序列分析和形态学方法对兔源须癣毛癣菌分离株(31株)进行鉴定和分型。从患兔采集病料,在沙保弱培养基进行分离培养,观察菌落和菌丝、孢子的形态及尿素酶、毛发穿孔等生理试验表现;提取病料和分离株DNA,扩增目的基因,通过序列分析,结合形态学方法对分离株进行鉴定,根据分离株序列同源性差异进行基因分型。结果显示,分离株的菌落多数为颗粒型和粉末型,占87.09%(27/31),背面有黄褐色素沉着,有大量葡萄状小分生孢子、螺旋菌丝、梳状菌丝及棒状大分生孢子,尿素酶试验和毛发穿孔试验阳性;CHS1序列比对显示分离菌株与须癣毛癣菌复合体的指间须癣毛癣菌有99.2%~95.4%相似性。根据CHS1序列比对结果,结合分离株的形态学特征,将该菌株鉴定为亲动物指间须癣毛癣菌。基于CHS1序列同源性差异,将分离株分成5种基因类型,其中Ⅰ型和Ⅱ型是优势菌株,占54.84%(17/31),提示CHS1序列分析可以用于须癣毛癣菌的鉴定和基因分型。     

河北兔场皮肤病原真菌rDNA-ITS序列分析

利用皮肤真菌核糖体内转录间隔区（ITS）序列通用引物,对采自河北省兔场的5种皮肤真菌病进行了PCR扩增,ITS区的克隆、测序、序列变异及遗传进化关系分析。经与GenBank核酸序列数据库数据比对和形态学观察结果表明：有4种真菌被鉴定,分别为须毛癣菌、多聚曲霉、球孢白僵菌和产黄青霉,1种未鉴定;不同病原菌的5.8SrDNA序列高度保守,而ITS区的变异性则较高。该研究确定ITS区序列分析可用于兔皮肤病原真菌的分离。     

兔皮肤真菌病病原PCR快速诊断技术研究

兔皮肤真菌病近年来在我国各地流行严重,其病原菌靠传统的表型特征鉴定难以区分,本文从浙江、江苏等各地发病的21个兔场各品种兔中通过培养分离纯化出17株真菌,在培养特性等表型特征初步鉴定的基础上,进一步建立了PCR快速诊断技术,通过基因扩增和序列测定,能够正确作出鉴别诊断,分别鉴定出须癣毛癣菌10株、犬小孢子菌5株和趾间毛癣菌2株,其扩增的基因片段大小分别为692bp、741bp和708bp。     

犬小孢子菌、石膏样小孢子菌、须毛癣菌多重PCR检测方法的建立及初步应用

宠物浅表皮肤真菌病主要由犬小孢子菌、石膏样小孢子菌、须毛癣菌感染引起。本研究根据3种真菌基因内转录间隔区(internal transcribed spacer,ITS)区域的序列差异设计4条引物,通过优化多重PCR反应条件,建立了一种可同时快速检测这3种真菌的多重PCR,同时对其特异性、灵敏性、重复性进行分析。结果显示,建立的多重PCR方法对犬小孢子菌、石膏样小孢子菌、须毛癣菌基因组DNA均可扩增出特异性预期片段,条带大小分别为286、596、188 bp;最低检测限(灵敏性)分别为12.6、8.8、13.6pg/μL;被检测的6份人工模拟样品扩增结果准确。应用该多重PCR方法检测27份人临床皮屑样品和43份宠物犬、猫毛发样品,结果显示阳性检出率分别为74.07%(20/27)和83.72%(36/43);采用常规真菌分离培养法从阳性样品中获得10株致病性真菌,分离率为17.86%(10/56);两种检测方法的种属鉴定结果表明多重PCR法优于常规方法。本研究建立的多重PCR检测方法简便、特异、灵敏,可同时对宠物浅表真菌病原作出快速诊断与鉴别。     

兔皮肤病原真菌的分离及其ITS序列的分析鉴定

【目的】分离发病兔场皮肤真菌病的病原,并对其ITS序列进行分析鉴定。【方法】采集病兔患病部位的皮屑、结痂进行培养,并根据形态学的特点进行鉴定;然后采用真菌ITS区通用引物对其ITS区进行PCR扩增测序,并将其ITS区序列与Gen Bank中的核酸数据库进行比对分析,确定病原真菌的生物学分类,最后对其亲缘关系进行系统发育分析。【结果】分离得到的病原真菌经形态学初步鉴定为小孢子菌属;序列比对和系统发育分析表明,该菌与Microsporum gypseum strain WCH-MG001(序列号:GU348990.1)的ITS序列具有99%的同源性,在系统发育树上也属于同一分支,从而确定该菌为石膏样小孢子菌。     

兔皮肤病原真菌的分离及其ITS序列的分析鉴定

本试验的目的是分离发病兔场皮肤真菌病的病原,并对其ITS序列进行分析鉴定。采集病兔患病部位的皮屑、结痂进行培养,并根据形态学的特点进行鉴定;然后采用真菌ITS区通用引物对其ITS区进行PCR扩增测序,并将其ITS区序列与GenBank中的核酸数据库进行比对分析,确定病原真菌的生物学分类,最后对其亲缘关系进行系统发育分析。结果显示:分离得到的病原真菌经形态学初步鉴定为小孢子菌属;序列比对和系统发育分析表明,该菌与Microsporum gypseum strain WCH-MG001(序列号:GU348990.1)的ITS序列具有99%的同源性,在系统发育树上也属于同一分支,从而确定该菌为石膏样小孢子菌。     

犬皮肤病常见病原真菌多重PCR检测方法的建立

根据相关文献以及Gen Bank设计真菌的特异性引物,通过引物、退火温度及时间的优化,建立犬小孢子菌(Mc)、石膏样小孢子菌(Mg)和厚皮马拉色菌(Mp)的多重PCR检测方法,用于犬皮肤病病原真菌的快速检测。经特异性和灵敏性检测后,对浦东地区宠物医院采集到的38份疑似病例样品通过真菌培养后提取DNA进行检测。结果:所建立的多重PCR方法稳定性好,可有效区分3种常见的犬皮肤病原真菌,扩增出290 bp(Mc)、460 bp(Mg)和582 bp(Mp)的目的片段,最低检测限分别为4.1、2.0和5.1 pg/μL。检测的38份临床样品中,犬小孢子菌有7例,石膏样小孢子菌2例,马拉色菌2例,经测序均验证扩增正确。由此表明,本文建立的犬皮肤病常见病原真菌多重PCR检测方法为犬真菌性皮肤病的快速检测提供了技术支持。     

6株副猪嗜血杆菌基因组DNA的PCR指纹图谱研究

根据肠道菌基因闻重复一致序列，设计了一对特异性引物，采用ERIC-PCR和RAPD技术，研究了副猪嗜血杆菌6个分离菌株的指纹图谱和DNA多态性。结果表明，6个分离株的PCR指纹图谱与15个标准血清型指纹图谱相比较可分辨出4种血清型；6个分离株的RAPD研究结果均表现出多态性。有意义的是，6个菌株的多态性DNA片段也能明显将其分为4种类型的副猪嗜血杆菌，与特异性引物PCR结果相一致。该研究可作为流行病学调查和该菌的分子分型快速诊断方法的基础。     

PCR法检测犬常见皮肤致病真菌的试验研究

利用PCR检测方法可对犬临床疑似真菌性皮肤病样本进行诊断。笔者选用真菌通用引物,对已知标准菌株及不同微生物进行特异性检测,并对其敏感性进行检测。采用该方法对临床30份疑似为真菌性皮肤病犬病料进行检测并克隆测序,同时对30份病料进行表型分析。结果表明,3种常见皮肤致病真菌(犬小孢子菌、石膏样小孢子菌、须毛癣菌)PCR扩增条带为310 bp;特异性检测结果,该方法检测其他微生物和犬体细胞均为阴性;采用该方法进行PCR检测真菌核酸检测限可以达到100 pg/m L。采用该方法对30份临床病料进行检测,检出12份阳性,经测序7份为犬小孢子菌,4份为石膏样小孢子菌,1份为须毛癣菌。采用传统培养法检测出阳性样本10份,其中6份为犬小孢子菌,4份为石膏样小孢子菌。通用PCR方法与传统培养法相比,检出率无显著差异。与传统的培养鉴定方法相比,PCR检测方法操作简便、特异性和敏感性比较理想,符合率较高,可用于临床犬皮肤真菌病检测和流行病学调查,并具有重要的公共卫生意义。     

Dermatophytes from skin lesions of domestic animals in Nsukka,Enugu State,Nigeria

Background – Dermatophytes are well‐recognized cutaneous fungi with public health implications. In Nigeria, several studies have been carried out on dermatophytosis in humans; however, data on dermatophytes in animals are lacking. Objectives – This study was conducted to determine the occurrence and species of dermatophytes in skin lesions in domestic animals in Nsukka Agricultural Zone of Enugu State, Nigeria. Animals – Forty‐six domestic animals (dogs, goats, sheep and pigs) presented for sale in the local markets in the study area and with suspected lesions of dermatophytosis were used for the study. Methods – Plucked hairs and epidermal scales from the skin lesions of affected animals were inoculated on Sabouraud dextrose agar slants containing 0.05 mg/mL of chloramphenicol and 0.5 mg/mL of cycloheximide. Inoculated slants were incubated at room temperature (27°C) for up to 4 weeks and examined at 2–3 day intervals for fungal growth. Laboratory identification of the fungal isolates was based on their colonial, microscopic and biochemical characteristics. Results – Of the 46 animals with suspected lesions of dermatophytosis, six (13.0%) were positive for a dermatophyte, and the following dermatophytes were identified: Microsporum gypseum, two of 12 sheep; Microsporum audouinii, one of 16 dogs; Trichophyton mentagrophytes, one of 16 dogs and one of 12 sheep; and Trichophyton schoenleinii, one of 13 goats. Conclusions and clinical importance – Anthropophilic dermatophytes are among the fungal agents associated with dermatophytosis in animals in Nsukka Agricultural Zone. These dermatophytes could constitute health risks to humans in contact with the animals.     

Detection and identification of Mycoplasma conjunctivae in infectious keratoconjunctivitis by PCR based on the 16S rRNA gene.

A specific PCR assay based on unique sequences of the rrs genes (16S rRNA) of Mycoplasma conjunctivae was developed for direct detection and identification of this pathogen from clinical material. DNA from eye swabs was amplified after a simple lysis step by either a single PCR with the M. conjunctivae specific primer pair McoR1 and McoF1, or by a nested PCR with the Mycoplasma genus specific primer pair MOLIGEN1-L and 16UNI-R in the first step and McoR1 and McoF1 in the second step. The specificity of the primer pair McoR1 and McoF1 was verified with purified DNA from the type strain, from 17 field isolates of M. conjunctivae and from several Mollicutes which are phylogenetically related to M. conjunctivae or which can be isolated from the same host animals. This method identified mycoplasma isolates from goat, sheep, ibex and chamois originating from different countries as M. conjunctivae. No cross amplifications with other mycoplasmas which are related to M. conjunctivae were observed. Eye swab samples containing known numbers of M. conjunctivae cells were analysed after direct lysis of the material. The detection level was estimated to be 20 cells per swab when the nested PCR procedure was used and 2 x 10(5) by the single PCR method. In an experimental infection model of sheep, the nested PCR method for detection of M. conjunctivae gave results which were comparable to mycoplasmal culture. These are the implications for diagnostic purposes: M. conjunctivae isolates can be identified by the one-step PCR method, whereas for detection and identification of M. conjunctivae in clinical material the two-step method should be used (higher sensitivity).     

Evaluation of Pasteurella multocida isolated from rabbits by capsular typing, somatic serotyping, and restriction endonuclease analysis.

The goal of this study was to characterize Pasteurella multocida isolated from rabbits. Five hundred and fifty-three apparently healthy rabbits were sampled for this study. Nasal swabs were collected from each rabbit for P. multocida isolation and identification. Isolates were further characterized by capsular and somatic antigens and genomic DNA fingerprinting. Thirty-nine P. multocida isolates were recovered from 553 rabbits (7%). Capsular typing was done by depolymerization of P. multocida capsule by Staphylococcus aureus hyaluronidase and by disc diffusion with mucopolysaccharidase enzymes (heparinase III, chondroitinase AC, and hyaluronidase). Thirty-one (79%) of the isolates were capsular type A, and 8 isolates (21%) had untypable (UT) capsules. The gel-diffusion precipitin test was used to determine the somatic type of P. multocida isolates. Nineteen isolates were somatic serotype 3 (49%), 12 were serotype 1 (31%), 1 was serotype 2, 2 were serotype 5, 2 were serotype 12 with a weak reaction to antiserum raised against serotype 7 (5%), and 1 was serotype 4. Two of the isolates (5%) were UT. Restriction endonuclease analysis of the DNA of the isolates revealed 7 distinct profiles by digestion with HindIII, and 12 profiles were obtained with HpaII, whereas digestion with EcoRI did not differentiate between any of the P. multocida DNA isolates studied. The DNA restriction endonuclease enzyme HpaII was found more useful for differentiating between DNA fingerprints of P. multocida rabbit isolates. However, no correlation between capsular type, somatic serotypes, and DNA fingerprints was seen in this study.     

Single primer polymerase chain reaction fingerprinting for Pasteurella multocida isolates from laboratory rabbits

OBJECTIVE: To evaluate a rapid polymerase chain reaction (PCR) fingerprinting technique for discriminating among Pasteurella multocida isolates from laboratory rabbits. SAMPLE POPULATION: 33 P multocida isolates from rabbits with clinical pasteurellosis. PROCEDURE: PCR assays were conducted with 2 minisatellites (core sequence and modified core sequence of phage M13) and 2 microsatellites ([GTG]5 and [GACA]4). Each bacterium was assigned to a PCR type for each of the primers used. Boiled bacterial extracts and purified genomic DNA were compared by use of PCR assays for phage M13 and (GACA)4. Plasmids were isolated from each bacterium, and their influence on PCR fingerprint was determined, using boiled extracts as a DNA source. RESULTS: M13 core sequence and M13 modified core sequence yielded 5 and 8 PCR types, respectively. The microsatellites (GTG)5 and (GACA)4 yielded 4 and 9 PCR fingerprint types, respectively. Fingerprint patterns obtained by use of isolated DNA differed from those obtained by use of boiled extracts, although discrimination among P multocida isolates was similar. The presence or absence of plasmids did not affect PCR fingerprints. CONCLUSION: Single primer PCR fingerprinting with minisatellite and microsatellite primers is an efficient and reproducible method for the discrimination of P multocida isolates from rabbits and can be performed directly, using boiled bacterial extracts as a source of template, although more bands were obtained from pure genomic DNA.     

兔奇异变形杆菌的分离鉴定及耐药性分析

为了解拉萨市一种兔场种兔腹泻死亡的病因,本试验从一只种兔的肠道内容物中分离出一株细菌,通过革兰氏染色、生化鉴定、16S rRNA PCR扩增和序列比对、动物回归试验及药敏试验进行了分析。结果显示,分离菌株为单个或成对的短杆状的革兰氏阴性菌;分离菌与GenBank中奇异变形杆菌的同源性为73.5%～99.8%,采用Mega 7.0软件将分离菌株与11株参考菌株的16S rRNA序列进行同源性比对分析,并构建系统进化树,综合分析后确定分离菌株为奇异变形杆菌,命名为T2018。在动物回归试验中有3只试验兔出现了腹泻,但均未死亡,剖检结果显示,空肠、回肠肠壁薄而透明,内有半透明胶冻样物;结肠和盲肠黏膜充血,浆膜上有出血斑点。药敏试验显示,分离菌株仅对阿莫西林/克拉维酸、庆大霉素和喹诺酮类的氧氟沙星、环丙沙星、诺氟沙星5种抗菌药表现出高度敏感,对哌拉西林表现为中介,对其他24种抗生素均表现为耐药。上述结果表明该种兔场种兔腹泻死亡的病原为奇异变形杆菌。     

PCR-based identification of serotype 2 isolates of Actinobacillus pleuropneumoniae biovars I and II

A genetic typing method utilizing PCR for the identification of Actinobacillus pleuropneumoniae serotype 2 isolates has been developed based on the in vitro amplification of a 1.4 kb DNA segment of the serotype 2 capsular polysaccharide genes cps2AB. The assay was tested with all serotype reference strains and a collection of 92 different A. pleuropneumoniae strains of all 15 serotypes of both biovars I and II, originating from 18 different countries worldwide. The cps2 based PCR identified the serotype 2 reference strain and all 12 serotype 2 collection strains contained in this set. DNA was not amplified from the remaining A. pleuropneumoniae reference and collection strains, indicating the PCR assay was highly specific. Furthermore, the PCR method detected all 31 A. pleuropneumoniae serotype 2 field isolates from diseased pigs that were identified in parallel as serotype 2 by agar gel diffusion. The serotype 2 PCR assay proved to be highly specific and reliable for the identification of serotype 2 isolates of A. pleuropneumoniae.     

Detection and genotyping of porcine circovirus in naturally infected pigs by oligo-microarray

A rapid and reliable method for the identification of porcine circovirus (PCV) genotypes based on oligonucleotide microarray hybridization has been developed. The genotype-specific oligonucleotides (22-30 mer) immobilized on the surface of glass slides were selected to bind to the multiple target sites within the replication gene that are conserved among individual PCV genotypes. Cy5-labeled DNA targets were amplified in a PCR with primers common to both genotypes. The identification of PCV genotype was based on hybridization with several individual genotype-specific oligonucleotides. This approach combines the high sensitivity of PCR with the selectivity of DNA-DNA hybridization. The utility and feasibility of oligonucleotide microarray hybridization was evaluated by testing standard and 87 clinical isolates. Analysis of the specimens showed that this microarray-based method is capable of unambiguous identification of both genotypes and fivefold more sensitive than gel electrophoresis. Our results indicated that the oligonucleotide array is useful for the identification and discrimination of PCV from clinical isolates and specimens in a clinical laboratory.     

猪伪狂犬病毒的分离鉴定及其部分毒力基因序列遗传变异分析

为了解吉林省猪伪狂犬病毒（PRV）的遗传变异情况,本研究将采集自吉林省疑似发生猪伪狂犬病的临床样品,通过细胞传代、PCR检测和测序分析进行病毒分离鉴定。TCID₅₀法测定分离毒株的病毒滴度,通过家兔感染试验测定分离毒株对家兔的致病性。对TK、gB、gC、gD和gE基因进行PCR扩增和测序,分析其遗传变异情况。结果表明,临床样品经PK15细胞传代后,有3份样品出现细胞病变,经PCR鉴定和测序分析表明,分离获得3株PRV,分别命名为PRV JL03、JL12和JL15株。通过PK15细胞测定分离毒株的病毒滴度分别为10^6.5、10^6.5和10^7.5TCID₅₀/mL。6只家兔分别接种3株分离毒株（10^3.5TCID₅₀/只）后均表现为体温升高、注射部位奇痒和四肢麻痹等症状,且于病毒接种后3~4 d全部死亡。3株分离病毒TK、gB、gC、gD和gE基因推导氨基酸序列分析结果表明,与参考毒株相比,分离株TK基因未发生氨基酸变异;gB、gC、gD和gE基因部分位点发生氨基酸缺失、插入或突变,其中gE基因在第48和496位分别存在1个天冬氨酸的插入,与国内报道的流行毒株变异特征一致。遗传进化树分析结果表明,3株分离毒株TK、gB、gC、gD和gE基因与国内2012年以后分离的参考毒株JS-2012和ZJ01等的上述基因均表现出较高的同源性,说明毒株间亲缘关系较近,位于同一分支;与国外分离毒株NIA3和Becker等亲缘关系较远,位于不同的分支;而与国内早期流行的毒株SC和Ea等亲缘关系介于二者之间。本研究成功分离鉴定了3株PRV变异株,分离毒株对家兔具有较强的致病性,该结果为吉林省PRV流行病学研究提供了新的数据,并为相关后续研究奠定基础。     

家兔皮癣病原菌的分离鉴定及致病性研究

从发病家兔的皮屑、被毛分离到两种病原真菌,通过培养特性、菌落性状、菌丝形态、孢子形状特征等一系列鉴定,确定为絮状表皮癣菌和石膏样小孢子菌.该菌通过皮肤涂擦法感染家兔,4天后均发病,产生以面部、头顶等处出现丘疹、瘙痒,继而皮损、流微黄色渗出液,日久结痂或鳞屑,逐渐消瘦为主要特征的一种皮癣病,与自然病例症状相同.     

Detection and identification of the Candida species by 25S ribosomal DNA analysis in the urine of candidal cystitis

Candida species in clinical urine samples were identified directly by the newly developed method of PCR analysis on 25S ribosomal DNA (rDNA). Two dogs were referred to the Animal Medical Center, Nihon University School of Veterinary Medicine, Fujisawa, Kanagawa, Japan for the examination of chronic cystitis. Microscopic examination of urine samples from these dogs revealed yeast cells. Urine culture on Sabouraud's dextrose agar at 27 degrees C for 5 days produced white to cream colored colonies. The isolates were identifical to Candida albicans and C. parapsilosis by mycological examination, respectively. The nucleotide sequences of 25S ribosomal DNA from these urine isolates showed 99% similarity to those of a reference strain of Candida albicans or C. parapsilosis. The nucleotide sequences of 25S rDNA obtained directly from urine samples were also identical to C. albicans and C. parapsilosis, respectively. Confirming the results on the isolates cultured from the same urine samples. This PCR analysis method could be available for the direct identification of Candida species in urine samples within 2 days.