TaqMan qPCR

TaqMan qPCR
  • 文章类型: Journal Article
    蜱传脑炎病毒(TBEV)感染导致亚洲和欧洲人类严重的中枢神经系统疾病。在中国,蜱传脑炎的病例主要由远东TBEV亚型引起,与其他广泛研究的亚型相比,它表现出不同的病程。然而,在中国,关于感染TBEV的患者的核酸和血清学诊断特征的知识有限,这是本研究的重点。
    本研究建立了一种TaqManqPCR方法,以最佳特异性检测血清中的TBEVRNA,灵敏度,和精度。用TaqManqPCR和ELISA法检测TBEVIgM,对东北地区63例被蜱叮咬的住院患者的血清样本进行了诊断特征调查。
    25例患者病毒RNA阳性;19例患者IgM阳性,9例病毒RNA和IgM阳性。通过比较分析,TBEVRNA拷贝与病毒潜伏期呈负相关。IgM水平与患者临床症状评分呈正相关。临床症状的严重程度和蜱叮咬后的长度可用于预测IgM的发生。此外,IgM水平和病毒RNA拷贝在双阳性患者中不相关。
    核酸和血清学检测方法都显示出检测TBEV感染的不同窗口,有一些重叠,并与特定的相关因素有关。这项研究为中国TBEV诱发的蜱传脑炎的诊断和病程提供了新的见解。
    UNASSIGNED: Tick-borne encephalitis virus (TBEV) infections result in severe central nervous system diseases in humans across Asia and Europe. In China, cases of tick-borne encephalitis are primarily caused by the Far East subtype of TBEV, which exhibits a distinct disease course compared to other extensively studied subtypes. However, there is limited knowledge regarding the nucleic acid and serological diagnostic characteristics of patients infected with the TBEV in China, which is the focus of investigation in the present study.
    UNASSIGNED: This study established a TaqMan qPCR approach to detect TBEV RNA in the serum with optimal specificity, sensitivity, and precision. Using TaqMan qPCR and ELISA assay for TBEV IgM detection, serum samples from 63 hospitalized patients bitten by ticks in Northeast China were investigated for diagnostic characteristics.
    UNASSIGNED: Twenty-five patients were positive for viral RNA; nineteen patients were positive for IgM, and nine were positive for both viral RNA and IgM. Through comparative analysis, TBEV RNA copies were negatively correlated with the virus incubation period. IgM levels were positively correlated with the clinical symptom scores of patients. The severity of clinical symptoms and the length after the tick bite could be used to predict the IgM occurrence. Furthermore, IgM levels and viral RNA copies were not correlated in double-positive patients.
    UNASSIGNED: Both nucleic acid and serological detection methods exhibited distinct windows for detecting TBEV infection, with some overlap, and were associated with specific correlated factors. This study provided novel insights into the diagnosis and course of TBEV-induced tick-borne encephalitis in China.
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  • 文章类型: Journal Article
    虽然水域可能被超过40种隐孢子虫的卵囊污染,只有小梭菌和人形梭菌的可行卵囊才真正对有免疫能力的人群构成主要健康风险。卵囊活力也是监测水传播寄生虫的重要但经常被忽视的危险因素。然而,水监测和调查中常用的方法不能区分物种(显微镜观察)或卵囊活力(PCR),因为水中的死卵囊可以保留数周至数月的总体结构和DNA含量。这里,我们报道了新的TaqManqRT-PCR/qPCR检测方法,用于定量检测活的细小芽孢杆菌和人形芽孢杆菌卵囊。通过靶向一个假设的蛋白质编码基因cgd6_3920,该基因在卵囊中高表达并且在物种之间可变,qRT-PCR/qPCR测定实现了优异的分析特异性和灵敏度(定量限[LOQ]=0.25和1.0卵囊/反应).使用校正曲线,可以计算标本中活卵囊的数量和比例。此外,我们还建立了TaqMan-18SqPCR,用于对泛隐孢子虫阳性标本进行经济有效的筛选(LOQ=0.1卵囊/反应).使用长春17个地点的田间水(N=43)和土壤(79)标本验证了测定的可行性,中国,它从七个地方检测到四种隐孢子虫,包括三种gp60亚型(即,小梭菌卵囊的IIdA19G1,IIdA17G1和IIdA24G2)显示出不同的生存力比率。这些新的TaqManq(RT)-PCR测定法补充了水域和其他样品调查中的当前方法(例如,表面,食品和饮料),并适用于评估卵囊失活方案的效率。
    While waters might be contaminated by oocysts from >40 Cryptosporidium species, only viable oocysts of C. parvum and C. hominis truly pose the main health risk to the immunocompetent population. Oocyst viability is also an important but often neglected risk factor in monitoring waterborne parasites. However, commonly used methods in water monitoring and surveys cannot distinguish species (microscopic observation) or oocyst viability (PCR), as dead oocysts in water could retain gross structure and DNA content for weeks to months. Here, we report new TaqMan qRT-PCR/qPCR assays for quantitative detection of viable C. parvum and C. hominis oocysts. By targeting a hypothetical protein-encoding gene cgd6_3920 that is highly expressed in oocysts and variable between species, the qRT-PCR/qPCR assays achieve excellent analytical specificity and sensitivity (limit of quantification [LOQ] = 0.25 and 1.0 oocyst/reaction). Using calibration curves, the number and ratio of viable oocysts in specimens could be calculated. Additionally, we also establish a TaqMan-18S qPCR for cost-effective screening of pan-Cryptosporidium-positive specimens (LOQ = 0.1 oocyst/reaction). The assay feasibility is validated using field water (N = 43) and soil (79) specimens from 17 locations in Changchun, China, which detects four Cryptosporidium species from seven locations, including three gp60-subtypes (i.e., IIdA19G1, IIdA17G1 and IIdA24G2) of C. parvum oocysts showing varied viability ratios. These new TaqMan q(RT)-PCR assays supplement current methods in the survey of waters and other samples (e.g., surfaces, foods and beverages), and are applicable to assessing the efficiency of oocyst deactivation protocols.
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  • 文章类型: Journal Article
    背景:建立一种通过抗生素诱导的微生物组耗竭在C57BL/6小鼠肠道中诱导空肠弯曲杆菌定植的方法。
    结果:54只雌性C57BL/6小鼠分为正常组,control,和实验组。实验组给予头孢哌酮钠舒巴坦钠(50mg/mL)灌胃2天,实验和对照小鼠胃内给药200μL空肠杆菌,2天后再重复一次。收集动物粪便,并且在建模完成后第1天至第14天使用TaqManqPCR检测空肠杆菌的HipO基因。在第14天采用免疫荧光法检测肠空肠弯曲杆菌定植,用苏木素和伊红染色观察病理变化。此外,在第14天进行肠内容物的16SrDNA分析。在实验组中,在TaqManqPCR上从第1天到第14天的粪便中检测到空肠杆菌,和免疫荧光标记的空肠弯曲杆菌在肠腔中可见。肠粘膜基本完整,没有明显的炎症细胞浸润。结肠微生物群的多样性分析显示出显著的组间差异。在实验组中,在门水平上,结肠微生物群的组成与其他两组不同,其特点是拟杆菌比例较高,厚壁菌比例较低。
    结论:头孢哌酮钠和舒巴坦钠诱导的微生物群落耗竭可促进空肠弯曲杆菌在小鼠肠道中的长期定植。
    BACKGROUND: To establish a method to induce Campylobacter jejuni colonization in the intestines of C57BL/6 mice through antibiotic-induced microbiome depletion.
    RESULTS: Fifty-four female C57BL/6 mice were divided into the normal, control, and experimental groups. The experimental group was administered intragastric cefoperazone sodium and sulbactam sodium (50 mg/mL) for 2 days; then, the experimental and control mice were intragastrically administered 200 µL C. jejuni, which was repeated once more after 2 days. Animal feces were collected, and the HipO gene of C. jejuni was detected using TaqMan qPCR from day 1 to day 14 after modeling completion. Immunofluorescence was used to detect intestinal C. jejuni colonization on day 14, and pathological changes were observed using hematoxylin and eosin staining. Additionally, 16S rDNA analyses of the intestinal contents were conducted on day 14. In the experimental group, C. jejuni was detected in the feces from days 1 to 14 on TaqMan qPCR, and immunofluorescence-labeled C. jejuni were visibly discernable in the intestinal lumen. The intestinal mucosa was generally intact and showed no significant inflammatory-cell infiltration. Diversity analysis of the colonic microbiota showed significant inter-group differences. In the experimental group, the composition of the colonic microbiota differed from that in the other 2 groups at the phylum level, and was characterized by a higher proportion of Bacteroidetes and a lower proportion of Firmicutes.
    CONCLUSIONS: Microbiome depletion induced by cefoperazone sodium and sulbactam sodium could promote long-term colonization of C. jejuni in the intestines of mice.
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  • 文章类型: Journal Article
    背景:乳腺癌是全球女性中最常见的癌症。EB病毒(EBV)在乳腺癌发病机制中的潜在参与一直是争论的主题。但其与临床结局的相关性仍不确定.方法:在本研究中,我们从麦凯纪念医院组织库和台湾国立卫生研究院收集了276例经病理证实的乳腺癌组织样本。使用QIAampDNAMini试剂盒从冷冻组织中提取DNA。Taqman定量PCR方法用于评估这些样品中每个细胞的EBV拷贝数,使用NAMALWA单元格作为参考。我们进行了统计分析,包括2×2列联表,Cox回归分析,和Kaplan-Meier存活曲线,探讨乳腺癌患者临床病理因素与生存预后的关系。我们分析了两种复发生存率,这反映了患者在治疗后仍然没有癌症复发,和总生存率,其中包括全因死亡率。结果:我们的结果显示乳腺癌患者的EBV状态与复发生存率之间存在显着关联(风险比:2.75,95%CI:1.30,5.86;p=0.008)。然而,在总体生存结局中没有发现显著相关性.此外,我们观察到ER状态和肿瘤组织学分级与总生存率和复发生存率显著相关.与EBV阴性肿瘤患者相比,EBV阳性肿瘤患者的复发率更高。此外,在我们的乳腺癌患者队列中,我们注意到EBV状态与HER-2(p=0.0005)和组织学分级(p=0.02)之间存在显著相关性.结论:乳腺癌肿瘤中EBV的存在似乎对患者预后有影响,尤其是复发率。我们的发现强调了将EBV状态视为乳腺癌患者潜在预后标志物的重要性。尽管如此,进一步的研究对于阐明潜在的分子机制和开发新的治疗方法至关重要。
    Background: Breast cancer is the most prevalent cancer among women worldwide. The potential involvement of Epstein-Barr virus (EBV) in breast cancer pathogenesis has been a subject of debate, but its correlation with clinical outcomes remains uncertain. Methods: In this study, we collected 276 pathologically confirmed breast cancer tissue samples from the tissue bank of MacKay Memorial Hospital and the National Health Research Institutes in Taiwan. DNA was extracted from frozen tissue using The QIAamp DNA Mini Kit. The Taqman quantitative PCR method was employed to assess the EBV copy number per cell in these samples, using NAMALWA cells as a reference. We performed statistical analyses, including 2 × 2 contingency tables, Cox regression analysis, and Kaplan-Meier survival curves, to explore the association between clinicopathologic factors and survival outcomes in breast cancer patients. We analyzed both relapse survival, which reflects the period patients remain free from cancer recurrence post-treatment, and overall survival, which encompasses all-cause mortality. Results: Our results revealed a significant association between EBV status and relapse survival (hazard ratio: 2.75, 95% CI: 1.30, 5.86; p = 0.008) in breast cancer patients. However, no significant association was found in overall survival outcomes. Additionally, we observed significant associations between ER status and tumor histologic grade with both overall and relapse survival. Patients with EBV-positive tumors exhibited higher recurrence rates compared to those with EBV-negative tumors. Furthermore, we noted significant correlations between EBV status and HER-2 (p = 0.0005) and histological grade (p = 0.02) in our cohort of breast cancer patients. Conclusions: The presence of EBV in breast cancer tumors appears to exert an impact on patient outcomes, particularly concerning recurrence rates. Our findings highlight the significance of considering EBV status as a potential prognostic marker in breast cancer patients. Nonetheless, further research is essential to elucidate the underlying molecular mechanisms and develop novel therapeutic approaches.
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  • 文章类型: Journal Article
    目的:从SarcoPhAge队列中鉴定与社区居住的老年人中的肌肉减少症相关的microRNA特征。
    方法:在下一代测序(NGS)的筛选阶段,我们比较了18例肌少症患者的hsa-miRome表达(79.6±6.8年,9名男性)和19名无肌少症的健康受试者(77.1±6岁,9名男性)在基线。此后,我们根据NGS结果和对以往文献进行严格评估后,选择了8个候选hsa-miRNAs.在验证阶段,通过实时qPCR,然后,我们分析了基线时这8个hsa-miRNAs的表达水平,选择了92例健康受试者(74.2±10岁)和92例肌肉减少症受试者(75.3±6.8岁).对于这两个步骤,两组的年龄和性别相匹配.
    结果:在验证阶段,血清has-miRNA-133a-3p和has-miRNA-200a-3p在肌肉减少症组和对照组中显著降低[RQ:相对定量;中位数(四分位距)]:-0.16(-1.26/0.90)vs0.34(-0.73/1.33)(p<0.01)和-0.26(-1.07/0.68)vs0.27(-0.55)Has-miRNA-744-5p降低,Has-miRNA-151a-3p升高,但这几乎没有达到显著性:+0.16(-1.34/+0.79)vs+0.44(-0.31/+1.00)(p=0.050)和+0.35(-0.22/+0.90)vs+0.03(-0.68/+0.75)(p=0.054)。
    结论:在患有肌少症的受试者中,血清hsa-miRNA-133a-3p和hsa-miRNA-200a-3p表达下调,与它们抑制肌细胞增殖和分化的潜在靶标一致。
    OBJECTIVE: To identify a microRNA signature associated to sarcopenia in community-dwelling older adults form the SarcoPhAge cohort.
    METHODS: In a screening phase by next generation sequencing (NGS), we compared the hsa-miRome expression of 18 subjects with sarcopenia (79.6 ± 6.8 years, 9 men) and 19 healthy subjects without sarcopenia (77.1 ± 6 years, 9 men) at baseline. Thereafter, we have selected eight candidate hsa-miRNAs according to the NGS results and after a critical assessment of previous literature. In a validation phase and by real-time qPCR, we then analyzed the expression levels of these 8 hsa-miRNAs at baseline selecting 92 healthy subjects (74.2 ± 10 years) and 92 subjects with sarcopenia (75.3 ± 6.8 years). For both steps, the groups were matched for age and sex.
    RESULTS: In the validation phase, serum has-miRNA-133a-3p and has-miRNA-200a-3p were significantly decreased in the group with sarcopenia vs controls [RQ: relative quantification; median (interquartile range)]: -0.16 (-1.26/+0.90) vs +0.34 (-0.73/+1.33) (p < 0.01) and -0.26 (-1.07/+0.68) vs +0.27 (-0.55/+1.10) (p < 0.01) respectively. Has-miRNA-744-5p was decreased and has-miRNA-151a-3p was increased in the group with sarcopenia vs controls, but this barely reached significance: +0.16 (-1.34/+0.79) vs +0.44 (-0.31/+1.00) (p = 0.050) and  +0.35 (-0.22/+0.90) vs  +0.03 (-0.68/+0.75) (p = 0.054).
    CONCLUSIONS: In subjects with sarcopenia, serum hsa-miRNA-133a-3p and hsa-miRNA-200a-3p expression were downregulated, consistent with their potential targets inhibiting muscle cells proliferation and differentiation.
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  • 文章类型: Journal Article
    由胞内劳森菌引起的增生性肠病是养猪业的重要经济相关疾病,但对中国猪场细胞内乳杆菌流行的认识有限。此外,来自中国的胞内乳杆菌分离株没有完整的基因组序列。在这项研究中,我们开发了一种TaqManqPCR,用于通过靶向细菌16SrDNA基因筛选细胞内乳杆菌。实验室评估显示对检测胞内乳杆菌核酸具有良好的敏感性和特异性。使用此方法,我们调查了47个农场中看似健康的猪的891个粪便样本。结果显示样本的筛查阳性率为37.3%(95%CI,34.1-40.5%),农场筛查阳性率为93.6%(95%CI,65.3-94.4%)。群体水平的筛查阳性率为6.67%(95%CI,0.2-31.9%)至40%(95%CI,38-79.6%),而在动物层面,筛查阳性率最高的是12周龄猪[85.7%(95%CI,67.3-96.0%)].对705例有症状猪的腹泻或血性粪便的调查显示,替代母猪的阳性率最高,为37.18%(95%CI,45.1-89.5%)。其次,我们通过PacBio测序对来自中国的胞内乳杆菌PPE-GX01-2022进行了全基因组测序。PPE-GX01-2022的基因组由长度为1,439,110bp的染色体和193,063,39,799和27,067bp的三个质粒组成,分别。这个基因组编码了1,428个预测的蛋白质,44个tRNA,和6个rRNA。序列比较表明,PPE-GX01-2022的基因组序列与美国两个分离株的基因组序列高度同源,这三个分离株共有1378个核心基因。筛查结果表明,中国猪场的胞内乳杆菌患病率很高。此外,中国分离株的基因组序列与美国田间分离株的基因组序列高度同源。
    Proliferative enteropathy caused by Lawsonia intracellularis is an important economic associated disease to pig industry, but the knowledge about the prevalence of L. intracellularis in pig farms in China is limited. In addition, there is no complete genome sequence available for L. intracellularis isolates from China. In this study, we developed a TaqMan qPCR for the screening of L. intracellularis by targeting the bacterial 16S rDNA gene. Laboratory evaluations revealed a good sensitivity and specificity on detecting L. intracellularis nucleic acid. Using this method, we investigated 891 fecal samples from apparently healthy pigs in 47 farms. The results demonstrated a screening positive rate of 37.3% (95% CI, 34.1-40.5%) for the samples, and a farm screening positive rate of 93.6% (95% CI, 65.3-94.4%). The screening positive rate at herd level ranged from 6.67% (95% CI, 0.2-31.9%) to 40% (95% CI, 38-79.6%), while at animal level, the highest screening positive rate was found in 12-week-old pigs [85.7% (95% CI, 67.3-96.0%)]. Investigation of 705 diarrheal or bloody feces from symptomatic pigs revealed that the highest positive rate was found in replacement gilts which was 37.18% (95% CI, 45.1-89.5%). Secondly, we conducted the complete genome sequence of a L. intracellularis PPE-GX01-2022 from China through PacBio sequencing. The genome of PPE-GX01-2022 consisted of a chromosome of 1,439,110 bp in length and three plasmids of 193,063, 39,799, and 27,067 bp, respectively. This genome encoded 1,428 predicted proteins, 44 tRNAs, and 6 rRNAs. Sequence comparisons demonstrated that the genome sequence of PPE-GX01-2022 was highly homologous to those of two isolates from US, and these three isolates shared 1,378 core genes. The screening results suggest a high prevalence rate of L. intracellularis in Chinese pig farms. In addition, the genome sequence of the Chinese isolate was highly homologous to those of the field isolates from the US.
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  • 文章类型: Journal Article
    建立了一种高灵敏度的定量PCR(qPCR)方法,用于检测和定量棉花根际中的淡黄色芽孢杆菌HMB26553。本研究旨在建立菌株HMB26553的定量检测方法,探讨其在棉花根际定殖与防治效果的关系。通过基因组测序获得菌株HMB26553的全基因组序列,并通过使用针对NCBI的高通量比对鉴定质粒plaBV2上的独特特异性序列pB-gene0026。质粒plaBV2可以稳定遗传。根据这个序列,设计了用于扩增106bp的特异性引物和用于增强灵敏度的小沟结合剂(MGB)TaqMan探针。通过内部参考引物和基于管家基因gyrB的MGBTaqMan探针证实了菌株HMB26553中的plaBV2的拷贝数为2。与传统的平板计数法相比,基于这些引物和探针建立的检测技术具有较高的特异性和敏感性,检测限为1.5拷贝基因组。使用此方法,该研究发现,用HMB26553菌株浸种和灌溉后,棉花根际定植量与根瘤菌引起的棉花衰减功效之间可能存在相关性。因此,该方法为今后菌株HMB26553的合理应用提供了科学支持。
    A highly sensitive quantitative PCR (qPCR) method was developed for detection and quantification of Bacillus velezensis HMB26553 in cotton rhizosphere. The study aimed to develop a quantitative detection method for the strain HMB26553, and explore the relationship between its colonization of the cotton rhizosphere and its control effect. The whole genome sequence of strain HMB26553 was obtained by genome sequencing and a unique specific sequence pB-gene0026 on plasmid plaBV2 was identified by using high-throughput alignment against NCBI. Plasmid plaBV2 could be stably genetically inherited. Based on this sequence, specific primers for amplifying 106 bp and a minor groove binder (MGB) TaqMan probe for enhancing sensitivity were designed. The copy number of plaBV2 in strain HMB26553, which was 2, was confirmed by internal reference primers and the MGB TaqMan probe based on housekeeping gene gyrB. The established detection technique based on these primers and probes had high specificity and sensitivity compared to traditional plate counting method, with a detection limit of 1.5 copy genome. Using this method, the study discovered a likely correlation between the quantity of colonization in cotton rhizosphere and efficacy against cotton damping-off caused by Rhizoctonia after seed soaking and irrigation with strain HMB26553. Thus, this method provides scientific support for the rational application of strain HMB26553 in the future.
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  • 文章类型: Journal Article
    随着宠物猫逐渐成为家庭成员,人类暴露于弓形虫感染,并在全球范围内代表着越来越多的公共卫生风险。弓形虫病诊断是预防和控制疾病的重要措施。在这项研究中,基于膜DNA提取方法,建立了实时荧光定量环介导等温扩增(qLAMP)和可视化LAMP检测技术,通过添加保护剂海藻糖并筛选Mg2+和dNTPs的浓度来确定最佳检测混合物。石蜡和冻干用于减少甚至去除气溶胶污染,构建详细的防污染协议。基于阳性标准质粒DNA,qLAMP和视觉LAMP的LOD分别为92拷贝/μL和92拷贝/μL,qLAMP的标准曲线为Y=2.9503X+20.8992,R2=0.99。通过评估200个临床猫粪便样品来评估qLAMP和视觉LAMP测定在疾病诊断中的适用性。化验显示出良好的诊断一致性,与TaqManqPCR相比,κ值为1.0和0.99,分别。与TaqManqPCR相比,qLAMP和视觉LAMP的诊断特异性/敏感性分别为100%/100%和100%/80%,分别。此处报告的qLAMP和视觉LAMP分析是快速简单的测试,无需大量的样品制备,并且在60分钟内具有短的周转时间,使它们适合于即时测试。
    Humans are exposed to Toxoplasma gondii infection as pet cats gradually become family members and represent an increasing public health risk worldwide. Toxoplasmosis diagnosis constitutes an important measure for disease prevention and control. In this study, real-time fluorescence quantitative loop-mediated isothermal amplification (qLAMP) and visual LAMP detection technologies were established to conduct tests of T. gondii based on the membrane DNA extraction method, and the optimal detection mix was determined by adding the protective reagent trehalose and screening the concentrations of Mg2+ and dNTPs. Paraffin and lyophilization were used to reduce and even remove aerosol pollution, constructing a detailed anti-contamination protocol. Based on the positive standard plasmid DNA, the LODs of qLAMP and visual LAMP were 92 copies/μL and 92 copies/μL, and the standard curve of qLAMP was Y=2.9503X+20.8992 with R2 = 0.99. The applicability of the qLAMP and visual LAMP assays in disease diagnosis was assessed by evaluating 200 clinical cat faeces samples. The assays showed good diagnostic consistency, with kappa values of 1.0 and 0.99 compared with TaqMan qPCR, respectively. Compared with TaqMan qPCR, the diagnostic specificity/sensitivity of qLAMP and visual LAMP were 100%/100% and 100%/80%, respectively. The qLAMP and visual LAMP assays reported here are rapid and simple tests without extensive sample preparation and have a short turnaround time within 60 min, making them suitable for point-of-care testing.
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  • 文章类型: Journal Article
    苹果斑病(AB)是亚洲苹果的主要疾病,最近在欧洲和美国出现。它是由真菌Diplocarponcoronariae(Dc)(以前是:Marssoninacoronaria;teleomorph:Diplocarponmali)引起的,并在夏末导致苹果树严重落叶,导致产量和果实质量下降。制定有效的疾病管理策略,熟悉病原体的生物学知识是至关重要的。关于疾病发展早期阶段的数据很少:没有关于欧洲孢子扩散的数据。我们开发了一种高灵敏度的TaqManqPCR方法来定量孢子陷阱样品中的Dc分生孢子。我们监测了DC分生孢子的时空分布,以及2019年和2020年瑞士广泛管理的苹果园中AB在春季和初夏的进展。我们的结果表明,落叶和孢子扩散和原发感染的Dc越冬发生在4月下旬和5月上旬。我们提供了描述Dc分生孢子早期扩散的第一个结果,which,结合观察到的疾病进展,有助于了解疾病动态,并将成为改进疾病预测模型的基础。使用新的qPCR方法,我们在芽中检测到了Dc,在树皮上,在水果木乃伊上,表明几种苹果组织可以作为真菌的越冬栖息地,除了落叶。
    Apple blotch (AB) is a major disease of apple in Asia and recently emerged in Europe and the United States. It is caused by the fungus Diplocarpon coronariae (formerly Marssonina coronaria; teleomorph: Diplocarpon mali) and leads to severe defoliation of apple trees in late summer, resulting in reduced yield and fruit quality. To develop effective disease management strategies, a sound knowledge of the pathogen\'s biology is crucial. Data on the early phase of disease development are scarce: No data on spore dispersal in Europe are available. We developed a highly sensitive TaqMan qPCR method to quantify D. coronariae conidia in spore trap samples. We monitored temporal and spatial dispersal of conidia of D. coronariae and the progress of AB in spring and early summer in an extensively managed apple orchard in Switzerland in 2019 and 2020. Our results show that D. coronariae overwinters in leaf litter, and spore dispersal and primary infections occur in late April and early May. We provide the first results describing early-season dispersal of conidia of D. coronariae, which, combined with the observed disease progress, helps to understand the disease dynamics and will be a basis for improved disease forecast models. Using the new qPCR method, we detected D. coronariae in buds, on bark, and on fruit mummies, suggesting that several apple tissues might serve as overwintering habitats for the fungus, in addition to fallen leaves. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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  • 文章类型: Journal Article
    猪乳球菌病是一种新兴的细菌性疾病,在全世界许多养殖和野生水生物种中与高经济损失有关。早期准确地检测猪乳球菌病的病原体对于养鱼场的疾病管理至关重要。在这项研究中,开发并验证了靶向16S-23SrRNA内部转录间隔区的TaqMan定量聚合酶链反应(qPCR)。qPCR的验证是使用从不同地理位置的不同水生宿主中回收的先前分型的L.petauri和L.garvieae的DNA进行的。鳟鱼水产养殖中密切相关的细菌种类和常见病原体。进一步的诊断敏感性和特异性的调查,通过筛选鱼类,水和粪便样本。开发的qPCR检测显示出高特异性,检测缺乏来自非目标病原体的信号的petauri和garvieae的敏感性和准确性,并筛选虹鳟鱼(Oncorhynchusmykiss)的后肾脏和环境样本。qPCR的检测极限是四个扩增子拷贝。此外,qPCR检测的灵敏度不受来自鱼类或环境样本的非靶DNA存在的影响.的鲁棒性,所开发的qPCR的特异性和敏感性将有助于快速准确地诊断猪乳球菌病,从而在养鱼场和水族馆中建立适当的控制措施。
    Piscine lactococcosis is an emergent bacterial disease that is associated with high economic losses in many farmed and wild aquatic species worldwide. Early and accurate detection of the causative agent of piscine lactococcosis is essential for management of the disease in fish farms. In this study, a TaqMan quantitative polymerase chain reaction (qPCR) targeting the 16S-23S rRNA internal transcribed spacer region was developed and validated. Validation of the qPCR was performed with DNA of previously typed L. petauri and L. garvieae recovered from different aquatic hosts from distinct geographical locations, closely related bacterial species and common pathogens in trout aquaculture. Further diagnostic sensitivity and specificity was investigated by screening of fish, water and faecal samples. The developed qPCR assay showed high specificity, sensitivity and accuracy in detection of L. petauri and L. garvieae with lack of signals from non-target pathogens, and in screening of rainbow trout (Oncorhynchus mykiss) posterior kidney and environmental samples. The detection limit of the qPCR was four amplicon copies. Moreover, the sensitivity of the qPCR assay was not affected by presence of non-target DNA from either fish or environmental samples. The robustness, specificity and sensitivity of the developed qPCR will facilitate fast and accurate diagnosis of piscine lactococcosis to establish appropriate control measures in fish farms and aquaria.
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