鸡毒支原体与鸡滑液囊支原体双重PCR检测方法的建立

为建立能同时检测鸡毒支原体(Mycoplasma gallisepticum, MG)和鸡滑液囊支原体(Mycoplasma synoviae,MS)的双重PCR诊断方法,该研究根据GenBank中登录的MG gapA基因序列和MS heat shock ATP-dependent protease基因序列,设计2对特异性引物,通过对PCR扩增条件的优化,建立了能够同时检测MG和MS的双重PCR诊断方法。特异性检测结果显示,该方法能够扩增出729 bp的MG和309 bp的MS特异性片段,对禽巴氏杆菌、大肠杆菌、鸡白痢沙门菌、副鸡禽杆菌核酸扩增均为阴性;敏感性检测结果显示,对MG和MS DNA的最低检出量均为5×10^-2 ng/μL;临床样品的检测结果显示,所建立的双重PCR方法可同时有效地检测出MG、MS混合感染和单独感染。该研究建立的鸡毒支原体与鸡滑液囊支原体双重PCR方法具有良好的特异性、敏感性、重复性,为快速、高效检测MG和MS提供了技术支持。     

鸡毒支原体PCR检测方法的建立

根据已发表的鸡毒支原体种特异性序列fMG-2设计1对引物,建立检测鸡毒支原体的PCR方法.该法对鸡毒支原体能特异性扩增726 bp的目的片段,而对其他禽病原DNA模板的扩增结果为阴性.建立的PCR方法对鸡毒支原体的最少检出量为3 Pg.用建立的PCR方法对临床采集的样品进行检测,同时对相应的样品进行细菌分离,结果临床样品PCR的阳性检出率为20.5%,细菌分离培养的阳性率为0.9%,表明PCR的敏感性高于细菌分离鉴定.     

应用多重聚合酶链式反应检测鸡毒支原体、鸡滑液囊支原体和禽衣阿华支原体的研究

根据鸡毒支原体 (MG)、禽衣阿华支原体 (MI)、鸡滑液囊支原体 (MS)的基因文库 ,设计了 3对分别与MG、MI、MS某段基因序列互补的引物。用这 3对引物对同一样品中的MG、MI、MSDNA模板进行多重聚合酶链式反应 (PCR)扩增 ,结果均同时得到了 3条特异性的大小与实验设计相符的 732bp (MG)、 2 99bp (MI)、 2 0 7bp (MS)多重的PCR扩增带 ,而对其他 6种禽病病原的PCR扩增结果均为阴性 ;敏感性测定结果能同时检出 1pg的MG、MI和MSDNA模板     

鸡毒支原体PCR检测试剂盒的研制与应用

根据基因库中鸡毒支原体 1 6SrRNA的序列研制PCR检测试剂盒 ,用于检测鸡毒支原体 (MG)。结果表明该MG PCR检测试剂盒对不同MG参考菌株和地方分离株均能特异性地扩增出 732bp条带 ,而对其他禽支原体和禽病病原体的扩增结果为阴性。该MG PCR试剂盒最低能检测出 1 0 0fg的MGDNA模板。保存期测定结果表明 ,该MG PCR试剂盒在 - 2 0℃条件下保存至 1 ,3 ,6和 9个月时 ,其敏感性无明显变化 ,仍能检测到 1 0 0fg至 1pg的MGDNA模板。保存至 1 2个月时其敏感度虽降低了 1个滴度 ,但仍能 1 0 0 %检出人工感染鸡的临床样品     

鸡传染性喉气管炎病毒、鸡毒支原体、鸭源鸡杆菌混合感染病例的病原学诊断

为确诊贵州省六盘水市某养殖场蛋鸡群发病死亡的原因,采集病料进行新城疫病毒、鸡传染性喉气管炎病毒、鸡毒支原体、滑液囊支原体核酸检测,以及细菌分离培养、鉴定和药敏试验。结果:(1)鸡传染性喉气管炎PCR试验扩增出大小为537 bp目的基因条带,鸡毒支原体PCR试验扩增出大小为636 bp目的基因条带,呈阳性;其余病毒核酸检测均呈阴性。(2)分离菌在血液琼脂培养基上生长呈白色半透明状、可溶血的小菌落,经革兰氏染色镜检为革兰氏阴性杆菌,分子生物学鉴定为鸭源鸡杆菌;对硫酸安普霉素、氟本尼考、延胡索酸泰妙菌素高度敏感,对硫酸粘菌素、盐酸多西环素、替米考星中度敏感,对酒石酸泰乐菌素低度敏感,对盐酸大观霉素、盐酸林可霉素、磺胺间甲氧嘧啶、阿莫西林耐药。结论:确诊病例为鸡毒支原体、鸡传染性喉气管炎病毒、鸭源鸡杆菌混合感染。     

鸡毒支原体与滑液囊支原体双重PCR检测方法的建立与应用

为建立鸡毒支原体(MG)与滑液囊支原体(MS)双重PCR检测方法,一次反应即可诊断鸡毒支原体与滑液囊支原体感染情况。根据GenBank公开的MG和MS基因序列,设计了2对质粒构建引物和2对检测引物,优化检测反应体系与条件,进行灵敏性试验、特异性试验和临床检测应用。结果显示,该方法对MG和MS阳性质粒的最低检测限为10拷贝/μL;与常见的H9禽流感病毒、新城疫病毒、传染性支气管炎病毒、Ⅰ群禽腺病毒4型、副鸡嗜血杆菌和鸡大肠埃希氏菌6种病原无交叉反应;应用该方法检测335份样品,MG单阳性率为7.8%,MS单阳性率为31.3%,MG和MS双阳性率为17.0%,两种支原体总的感染率为56.1%。成功建立了检测MG和MS的双重PCR检测方法,为流行病学调查和诊断提供了可靠的技术手段。     

鸡滑液囊支原体的分离和鉴定研究

从河南某肉种鸡场疑似鸡滑液囊支原体感染的病鸡跗关节样品进行病原的分离与鉴定.分离菌经瑞氏染色,在油镜下呈球形或椭圆形.在固体培养基上表现为细小、光滑、致密的小菌落,菌落形态为“煎蛋状”.L型细菌鉴定发现菌体仍保持原有形态.菌体能够吸附红细胞,分解葡萄糖,但不能分解精氨酸和尿素,还可致SPF鸡胚死亡,说明该分离菌为支原体.进一步的血清学试验结果表明,该分离菌为鸡滑液囊支原体,而不是鸡毒支原体.根据已发表的鸡滑液囊支原体血凝素基因序列vlhA设计合成一对引物,经PCR扩增,该菌体能够扩增出鸡滑液囊支原体(773 bp)的特异性片段.人工感染试验结果显示,SPF鸡能够复制出自然病例.     

牛支原体、无乳支原体和丝状支原体丝状亚种小克隆三重PCR检测方法的建立及初步应用

本研究旨在建立一种可一次性区分牛支原体、丝状支原体丝状亚种小克隆和无乳支原体的三重PCR诊断方法,为临床诊断和流行病学调查提供可靠检测技术.根据GenBank发表的上述3种病原的基因组序列保守区域设计3对特异性引物建立三重PCR方法;确定其检测敏感性,以猪支原体、鸡支原体、无乳支原体和丝状支原体丝状亚种小克隆基因作模板检验其特异性;同时和病原分离鉴定结果对比其准确性.结果表明在优化体系和条件下能够同时得到扩增长度为448、549、375 bp 3条特异性片段,未扩增出猪、鸡支原体模板特异性片段;其敏感性(可检测到的最小模板DNA含量)为0.8 ng·μL-1;36份临床样品检测结果显示,三重PCR检测结果与分离培养鉴定方法一致,均能鉴定出牛支原体阳性病料.本研究建立的三重PCR诊断方法能够一次性鉴别3种支原体,具有高敏感性、特异性和准确性,可用于临床诊断和流行病学调查.     

以鸡毒支原体pvpA基因序列建立的套式PCR检测方法

本试验以GenBank中登录的鸡毒支原体(Mycoplasma gallisepticum,MG)的特异性黏附蛋白pvpA基因序列为目标,用两对引物对鸡毒支原体DNA进行套式PCR扩增,建立套式PCR扩增体系,并进行了套式PCR的敏感性和特异性试验。结果显示,应用该PCR方法对MG DNA的检出限为0.18 pg/μL;以鸡常见细菌、病毒DNA为模板进行PCR扩增,均未扩增出条带,说明该方法特异性强,适用于临床对MG早期感染的检测。     

鸡毒支原体PCR检测方法的建立

目前临床上常见的支原体主要为鸡毒支原体（MG）和鸡滑液囊支原体（MS）。由于MG和MS经常发生混合感染，给临床诊断和治疗带来极大的困难。为了快速诊断MG，特别是致病性鸡毒支原体，本研究针对MG的pvpA基因设计特异性引物，通过优化反应条件，进行灵敏性试验、特异性试验和重复性试验，建立快速高效检测MG的PCR方法。结果表明，该检测技术具有较好的灵敏性、特异性强且CV<3%，具有很好的符合性。     

Monitoring Mycoplasma gallisepticum and Mycoplasma synoviae infection in breeder chickens after treatment with enrofloxacin.

Three experimental strains of breeder chickens were accidentally exposed to Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS), presumably from a newly introduced group of leghorn-type pullets. The experimental strains subsequently became infected and were diagnosed positive for MG and MS by the serum plate agglutination (SPA) test and confirmed by the hemagglutination inhibition (HI) test and the polymerase chain reaction (PCR) of tracheal swabs. Treatment with 10 mg/kg enrofloxacin via drinking water for 14 days was elected. Before and after initiation of treatment, MG and MS were monitored for changes by SPA, HI, PCR, and culture, with sampling intervals ranging from 1 wk to 7 wk. MG and MS SPA, HI, PCR, and culture were performed at each sampling period, with the exception of weeks 1.0 and 6.5. Week 1.0 included SPA and His for MG and MS. Week 6.5 included PCR and culture for MG and MS. The MG and MS SPA results were positive throughout the 29-wk trial period. MG HI titers declined until the last sampling, whereas the MS HI titers did not decline significantly. PCR for MG yielded only one positive result, which occurred before treatment. MS PCR remained positive throughout the trial period. MG was never isolated from any sample; however, one MS organism was isolated during treatment. The treatment regimen was effective for MG on the basis of PCR results. Treatment with enrofloxacin did not eliminate SPA reactions during the 29-wk trial period. MG HI titers remained in the suspicious range throughout the remainder of the trial period. Four weeks after the treatment ended, MG HIs were reduced by approximately 40%, with MS HIs remaining high throughout the 29-wk period. PCR appeared to be a sensitive and specific test on the basis of correlation with HIs. On the basis of the isolation of MS during treatment and continued subsequent PCR positive reactions, the treatment for MS with enrofloxacin was not as efficacious as for MG.     

用探针杂交法检测鸡毒支原体和滑液囊支原体

根据鸡毒支原体(MG)和滑液囊支原体(MS)的16SrRNA基因序列，设计并合成了探针MG和MS共同目的基因，跨幅为580bP的一对引物。用这对引物对2个标准的MG和1个标准的Ms菌株DNA模板进行聚合酶锭反应(PcR)，结果得到了预期大小约580bP的PcR产物。回收纯化琼脂糖电泳凝肢中的MG扩增产物克隆至T载体中，DIG随机引物法合成核酸探针，斑点杂交试验对MG和MS均呈阳性，检测灵敏度分别为2ng和3ng，其它对照菌(毒)株为阴性。     

Development and Application of a Duplex PCR Assay for Detecting Mycoplasma ovipneumiae and Mycoplasma arginini

In order to establish a duplex PCR method for simultaneous detection of Mycoplasma ovipneumiae and Mycoplasma arginini, specific primers of Mycoplasma ovipneumiae and Mycoplasma arginini were designed, and evaluated its sensitivity and specificity after optimizing the reaction conditions of PCR.Then, a total of 40 nasal swabs were tested by duplex PCR.The assay could specifically amplify PCR fragments of 545 and 806 bp from Mycoplasma ovipneumiae and Mycoplasma arginini, respectively.While no PCR products were detected for other pathogens.The detection limits of the assay were determined to be 100 pg/μL for Mycoplasma ovipneumiae and 10 pg/μL for Mycoplasma arginini.The duplex PCR could detect Mycoplasma ovipneumiae and Mycoplasma arginini, and the coincidence rate could reach as high as 92.5% with enrichment culture about the 40 nasal swabs.The results suggested that the duplex PCR could be useful for clinical detection of Mycoplasma ovipneumiae and Mycoplasma arginini.     

绵羊肺炎支原体和精氨酸支原体双重PCR检测方法的建立及应用

为建立绵羊肺炎支原体和精氨酸支原体的双重PCR检测方法,本试验分别设计了绵羊肺炎支原体和精氨酸支原体的特异性引物,优化反应条件后对其特异性和敏感性进行评价,并对40份鼻拭子进行了检测。结果显示,该方法能同时扩增出绵羊肺炎支原体545 bp和精氨酸支原体806 bp的特异性片段,而对其他病原的DNA扩增均为阴性。该双重PCR方法对绵羊肺炎支原体和精氨酸支原体的最低检测限分别为100和10 pg/μL。40份鼻拭子检测结果显示,双重PCR检测方法与分离培养法符合率高达92.5%,均能鉴定出绵羊肺炎支原体和精氨酸支原体。结果表明,本研究建立的双重PCR方法可用于绵羊肺炎支原体和精氨酸支原体的临床快速诊断。     

3种禽支原体多重PCR检测方法的建立及应用

从鸡毒支原体、鸡滑液囊支原体和火鸡支原体 3种致病性支原体液体培养物中提取DNA,用特定引物分别和组合进行PCR,均得到了特异性扩增产物,片段大小分别为732、207和850 bp。直接用液体培养物进行PCR亦得到了一致的电泳条带。试验结果表明,建立的PCR方法可用于上述3种支原体临床感染的鉴别诊断。ELISA血清学检测和气管拭子PCR检测的比较结果表明,该PCR方法可用于临床MG检测。     

Evaluation and comparison of various PCR methods for detection of Mycoplasma gallisepticum infection in chickens

Four genetic Mycoplasma gallisepticum (MG) polymerase chain reactions (PCRs) (16s rRNA PCR, three newly developed PCR methods that target surface protein genes [mgc2, LP (nested) and gapA (nested)]) were compared for analytical specificity and sensitivity and for diagnostic sensitivity (Se) and specificity of detection from tracheal swabs. The licensed MG DNA Test Kit Flock Chek test (IDEXX, Laboratories, Inc., Westbrook, ME) was as well evaluated for the diagnostic specificity and sensitivity of detection from tracheal swabs. Analytical specificity was evaluated for the four generic PCR methods using a panel of DNA samples from microorganisms that may be isolated from the trachea of commercial poultry and other fowl. PCR methods mgc2, nLP, and ngapA only amplified DNA from MG, whereas 16S rRNA PCR amplified DNA from MG and Mycoplasma imitans. The analytical sensitivity of the four generic PCR methods expressed in color-changing units (CCU)/amplification reaction was estimated for each PCR method and ranged from 4 to 400 CCU/reaction; the sensitivities of single PCR methods 16S rRNA and mgc2 were estimated at 40 CCU/reaction, the nLP at 400 CCU/reaction, and the ngapA at 4 CCU/reaction. The diagnostic sensitivity and specificity of MG detection from tracheal swab pools, as compared to isolation from choanal cleft swabs, was evaluated for the five PCR methods using three groups of birds exposed to vaccine strains ts-11 and 6/85 and to challenge strain R. All PCR methods were able to detect the vaccine strains and the challenge strain R directly from tracheal swabs, indicating that PCR primers from the different methods amplified divergent MG strains. Isolation and PCR results correlated satisfactorily among the three experimentally infected groups, with agreement values (k) ranging from 0.52 to 1.00. The ngapA, IDEXX, and mgc2 PCRs showed the best sensitivity (Se) ratios for detection of M. gallisepticum strains as compared to isolation. Compared to the ngapA and IDEXX PCR methods, the mgc2 PCR has a faster turnaround time, since this test consists of a single amplification reaction and the amplification product is detected by gel electrophoresis. Therefore, among the PCR methods evaluated in this study, the mgc2 PCR is the method of choice to further validate in the field.     

Mycoplasma gallisepticum in house finches (Carpodacus mexicanus) and other wild birds associated with poultry production facilities.

Since 1994, an epidemic of conjunctivitis caused by Mycoplasma gallisepticum (MG) has spread throughout the eastern population of house finches (Carpodacus mexicanus). The adaptation of MG to a free-flying avian species presents potential problems for the control of mycoplasmosis in commercial poultry. To evaluate risks associated with this emerging problem, a field survey was conducted to assess prevalence of MG infection in house finches and other passerine birds associated with poultry farms. Between November 1997 and March 1999, 1058 birds were captured by mist net or trap at 17 farms and at 10 feeder stations in northeast Georgia. Birds were bled and screened by serum plate agglutination (SPA) for antibodies to MG. Birds with negative or weak positive SPA results were released at capture sites, and those with strong positive SPA reactions were kept for further evaluation. Necropsies were performed on selected house finches and individuals of 11 other passerine species, and samples were collected for MG testing by culture, polymerase chain reaction (PCR), hemagglutination inhibition, and histopathology. Testing revealed 19.1% of 671 birds caught at farms and 11.6% of 387 birds caught at feeder sites were SPA positive for MG. Three house finches captured on farms were positive for MG by culture and PCR, whereas three from feeder sites were positive only by PCR. No MG isolates were made from tufted titmice (Baeolophus bicolor), but 40% were positive by PCR. Individuals from 10 additional species were SPA positive only. Results suggest that MG persists at low levels in house finches in northeast Georgia and that tufted titmice may be nonclinical carriers of MG or a related mycoplasma. Positive SPA reactions in other species may be caused by nonspecific reactions or contact exposure. Current biosecurity recommendations should be sufficient to minimize risks of transmission between wild and domestic birds.