Can the Urine Dipstick Test Be an Alternative in the Screening of Urinary Tract Infections for Inpatients in the Context of a Low-Income Country?

Background: Urinary Tract Infection (UTI), a prevalent bacterial infection in adults, heavily relies on cytobacteriological examination of urine (CBEU) for diagnosis. However, in resource-limited countries, accessibility to CBEU remains hindered by cost and availability. This study aims to assess the utility of the Urinary Dipstick Test (UDT) in diagnosing UTIs among hospitalized patients in the context of limited resources. Methods: A cross-sectional study was conducted from February to May 2019, encompassing hospitalized patients who underwent CBEU at the bacteriology unit of Sour? Sanou University Hospital. UDT and CBEU were concurrently performed, and UDT’s analytical and diagnostic performance was evaluated against CBEU, considered the gold standard. Results: A total of 274 CBEU requests were registered, involving 274 patients (159 males) with a mean age of 45.8 ± 21.3 years (ranging from 1 to 90 years). UTI was confirmed in 90 patients, yielding a frequency of 32.85%. The UTI bacteriological profile was dominated by Enterobacteriaceae (75.23%), primarily Escherichia coli (60.55%). Nitrite and Leukocytes were positive in 54 (19.8%) and 157 (53.6%) of the samples tested. Among patients with confirmed UTI, Nitrite, and Leukocytes were positive in 30 (33%) and 71 (79%) patients respectively. UDT demonstrated variable performance based on nitrite and leukocyte combination: Sensitivity (57%-82%), Specificity (7%-98%), Positive Predictive Value (PPV) (43%-57%), Negative Predictive Value (NPV) (43%-67%). UDT performed slightly better in women (NPV = 88%) and inpatients without urinary catheters (NPV = 75% and PPV = 80%). Conclusion: This study underscores UDT’s potential utility in excluding UTIs among women, younger patients, and inpatients without urinary catheters, albeit with limited confidence. The UDT emerges as a complementary tool for UTI screening, particularly in resource-limited settings.

Use of the urinary trypsinogen-2 dipstick test in early diagnosis of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP)

Background: Acute pancreatitis is one of the most serious complications of ERCP. Early diagnosis of post ERCP pancreatitis helps physicians to provide intensive care and possible medical treatment as early as possible. Trypsinogen-2 in urine is a good diagnostic and prognostic marker of acute pancreatitis. Objectives: To evaluate the diagnostic value of urinary trypsinogen-2 dipstick test for early diagnosis of post ERCP pancreatitis. Methods: A total of 37 patients with obstructive jaundice were tested with the urinary trypsinogen-2 dipstick test and serum levels of amylase and lipase before ERCP and 6 hours after ERCP. Results: Post ERCP pancreatitis was diagnosed in 6 (16%) of 37 patients. The sensitivity, specificity, positive predictive value and negative predictive value of urinary trypsinogen-2 dipstick test at 6 hours after ERCP were 100%, 97%, 86%, 100% respectively. At the cutoff level (130 U/L) for lipase, the positive predictive value and negative predictive value all were (100%), however, the positive predictive value and negative predictive value for amylase levels at cutoff (122 U/L) were 60%, 100% respectively. Serum lipase level was the best test for diagnosing post ERCP pancreatitis followed by the urinary trypsinogen-2 dipstick test. Conclusions: The urinary trypsinogen-2 dipstick test can be used as a rapid and easy test for early diagnosis of post ERCP pancreatitis with high sensitivity and specificity.

rSj26-Sj32-Immunogold-IgG-Dipstick法用于急性日本血吸虫病患者的诊断价值

目的探讨rSj26-Sj32-Immunogold-IgG-Dipstick法用于急性日本血吸虫病患者的诊断价值。方法利用纯化的rSj26-Sj32融合蛋白和日本血吸虫成虫抗原(SjAWA)建立Immunogold-IgG-Dipstick法,检测急性日本血吸虫病患者血清,并以华支睾吸虫病、卫氏并殖吸虫病、棘球蚴病、乙型肝炎、肺结核患者和健康人血清作对照。结果 rSj26-Sj32检测急性日本血吸虫病患者血清的敏感性为96.00%,特异性为97.67%;SjAWA与华支睾吸虫病、卫氏并殖吸虫病和泡型棘球蚴病患者血清存在不同程度的交叉反应,而rSj26-Sj32则未见交叉反应。结论纯化的rSj26-Sj32融合蛋白是1种较好的免疫诊断抗原。

基于多酶恒温快速扩增-侧向流层析联用技术的肉制品真实性研究

目的:基于多酶恒温快速扩增(multienzyme isothermal rapid amplification,MIRA)与封闭式侧向流层析(lateral flow dipstick,LFD)联用技术,建立肉制品真实性快速检测方法,解决实验室方法不适于基层与现场快检需求的问题。方法:通过GenBank筛选猪、牛、羊、鸡、鸭线粒体基因的特异序列,使用DNAStar Megalign软件比对种内保守、种间特异的靶片段,依据MIRA引物探针设计原则设计靶基因引物探针组,通过阳性对照、阴性对照、空白对照等方式系统筛选引物探针,确定猪、牛、羊、鸡、鸭的专属性引物探针,并采用反应体系、反应温度、反应时间筛选,优化完善特异性检测方法。对方法进行系统的方法学考察,包括DNA提取、灵敏度、检出限、假阳性与假阴性考察等,验证方法的有效性。结果:使用建立的方法与实时荧光聚合酶链式反应检测进行比对分析,方法的平均假阳性率为3.49%、假阴性率为3.54%,符合现场快检方法的要求。结论:本研究建立了牛、羊、猪、鸡、鸭5种常见肉类的MIRA-LFD技术,并证实了其有效性和可行性,实现了肉制品真实性的现场快检。

Colorectal cancer screening: Comparison of transferrin and immuno fecal occult blood test

AIM: To evaluate the sensitivity and specificity of transfesrrin dipstick test (Tf) in colorectal cancer (CRC) screening and precancerous lesions screening. METHODS: Eight hundreds and sixty-one individuals at high-risk for CRC were recruited. Six hundreds and eleven subsequently received the three fecal occult blood tests and colonoscopy with biopsy performed as needed. Fecal samples were obtained on the day before colonoscopy. Tf, immuno fecal occult blood test (IFOBT) and guaiac fecal occult blood test (g-FOBT) were performed simultaneously on the same stool. To minimize false-negative cases, all subjects with negative samples were asked to provide an additional stool specimen for a second test even a third test. If the results were all negative after testing three repeated samples, the subject was considered a true negative. The performance characteristics of Tf for detecting CRC and precancerous lesions were examined and compared to those of IFOBT and the combination of Tf, IFOBT and g-FOBT. RESULTS: A total of six hundreds and eleven subjects met the study criteria including 25 with CRC and 60 with precancerous lesions. Sensitivity for detecting CRC was 92% for Tf and 96% for IFOBT, specificities of Tf and IFOBT were both 72.0% (95% CI: 68.2%-75.5%; χ2 = 0.4, P > 0.05); positive likelihood ratios of those were 3.3 (95% CI: 2.8-3.9) and 3.4 (95% CI: 2.9-4.0), respectively. In precancerous lesions, sensitivities for Tf and IFOBT were 50% and 58%, respectively (χ 2 = 0.8, P > 0.05); specificities of Tf and IFOBT were 71.5% (95% CI: 67.6%-75.1%) and 72.2% (95% CI: 68.4%-75.8%); positive likelihood ratios of those were 1.8 (95% CI: 1.3-2.3) and 2.1 (95% CI: 1.6-2.7), respectively; compared to IFOBT, g-FOBT+ Tf+ IFOBT had a significantly higher positive rate for precancerous lesions (83% vs 58%, respectively; χ 2 = 9.1, P < 0.05). In patients with CRC and precancerous lesions, the sensitivities of Tf and IFOBT were 62% and 69% (χ 2 = 0.9, P > 0.05); specificities of those were 74.5% (95% CI: 70.6%-78.1%) and 75.5% (95% CI: 71.6%-79.0%); positive likelihood ratios of those were 2.5 (95% CI: 2.0-3.1) and 2.8 (95% CI: 2.3-3.5). Compared to IF-OBT alone, combining g-FOBT, IFOBT and Tf led to significantly increased sensitivity for detecting CRC and cancerous lesions (69% vs 88%, respectively; χ 2 = 9.0, P < 0.05). CONCLUSION: Tf dipstick test might be used as an ad- ditional tool for CRC and precancerous lesions screening in a high-risk cohort.

Contribution of the Urine Dipstick to Urinary Tract Infection Diagnosis among Children in Two Hospitals in Cotonou-Benin

Introduction: Urinary tract infections are a daily concern in pediatric nephrology with long-term risks for high blood pressure and renal failure. The purpose of this study was to determine the contribution of a urine dipstick (UD) to the diagnosis of urinary infections among children at the CNHU-HKM and the Lagoon Mother and Child University Teaching Hospital (CHU-MEL) of Cotonou. Patients and Methods: This study is a cohort, descriptive and analytical study focused on children with suspected urinary infections in the pediatric units of the CNHU-HKM and CHU-MEL of Cotonou from March 25 to August 25, 2015. Results: Two hundred and four children out of a total of 5125 admitted children (4%) presented with at least one clinical sign of a urinary tract infection. Children under 36 months of age were predominant (41%). The main clinical signs of urinary infections were fever (60.8%) and urinary disorders (38.2%). The urinary dipstick test was positive in 145 children (71.2%). A urinary tract infection was confirmed by urine culture in 38 children (18.6%). In cases with leucocyturia- and nitrituria-positive urine dipstick tests, the sensitivity was estimated to be 13.2%, and the specificity was 95.2%, with a negative predictive value (NPV) of 82.8%. Only when the leucocyturia test was positive, the sensitivity was 76.3%, and the specificity was 31.9%. When the leucocyturia test was negative, the specificity was estimated to be 94%, and the sensitivity was 83% in the nitrituria-positive cases and 15.8% in the nitrituria-negative cases. The main isolated pathogens were Escherichia coli (n = 21) and Klebsiella pneumoniae (n = 14). Conclusion: In our environment, a negative leucocyturia test may help exclude urinary tract infections in most cases.

柑橘衰退病毒RT-RPA-LFD可视化检测方法的建立及应用

【目的】柑橘衰退病由柑橘衰退病毒(citrus tristeza virus,CTV)引起,是一种世界性的重要柑橘病害。为实现CTV的田间快速检测,建立一种准确、快速且可视化的检测方法。【方法】以CTV外壳蛋白(CP)的保守区域为靶标,设计3对特异性引物和探针,通过引物筛选,以及优化引物浓度、反应时间和反应温度等条件,建立CTV的反转录-重组酶聚合酶扩增-侧流层析试纸条(RT-RPA-LFD)快速检测方法,明确其灵敏度,并用于田间疑似样品的检测。【结果】建立了CTV的RT-RPA-LFD检测方法:最佳检测引物为RPA-1F/R,对应探针为RPA-P,最佳反应条件为40℃,25 min,且与其他5种柑橘病毒无交叉反应。该方法的灵敏度是RT-PCR的100倍,最低可检测到2.12×10^(1)拷贝·μL^(-1)的CTV核酸,与RT-qPCR相当。采用RT-RPA-LFD法在67份田间样品中检测出CTV阳性样品41份,与RT-PCR法检测结果一致。【结论】建立的CTV RT-RPA-LFD法具有操作简单、快速、结果可视等优点,适合基层植保工作者对田间样品开展快速检测。

环介导等温扩增技术与横向流动试纸条法快速检测单增李斯特菌的研究

为建立一种快速、便捷的单增李斯特菌检测方法,本研究针对单增李斯特菌hlyA基因设计了4条特异性引物和1条异硫氰酸荧光素标记的探针,采用环介导等温扩增(LAMP)与横向流动试纸条检测技术(LFD)联合应用,建立了一种快速、便捷的单增李斯特菌LAMP-LFD检测方法。通过对其反应条件进行优化,结果显示,优化后的扩增温度和时间为63℃反应50 min,完成检测全过程仅需80 min。该方法仅可以特异性地检出单增李斯特菌,而对其它6种常见食源性致病菌的检测均呈阴性。对纯细菌培养物的检测灵敏度为3.6 cfu/m L,是利用外引物建立的PCR方法的100倍。该方法重复性好。对15份牛奶和15份猪肉的细菌分离鉴定和LAMP-LFD检测表明,二者符合率为100%。研究结果表明,本研究建立的LAMP-LFD方法能够快速、特异地检测单增李斯特菌,适合基层实验室、应急检测或现场监测等使用,具有较高的推广价值。

环介导等温扩增技术与横向流动试纸条法快速检测布鲁氏杆菌

将环介导等温扩增技术(Loop-mediated isothermal amplification,LAMP)与横向流动试纸条技术(Lateral flow dipstick,LFD)联合应用,建立了一种快速、便捷的布鲁氏杆菌检测方法。针对布鲁氏杆菌OMP25基因设计4条特异性引物和1条异硫氰酸荧光素(Fluorescein isothiocyanate,FITC)标记的探针。生物素标记LAMP扩增产物能够特异性地与FITC标记的探针杂交,杂交产物经LFD检测。优化后的扩增温度和时间为63℃反应50 min,加上样品的前处理,完成检测仅需80 min。LAMP-LFD方法可特异性地检出布鲁氏杆菌,其最低检测限为5.4×100CFU/mL,是利用外引物建立的PCR方法的100倍。试验结果表明,本研究建立的LAMP-LFD方法能够快速、特异地检测布鲁氏杆菌;简单经济,不需要其他辅助仪器,结果即可直观判断;适合基层实验室、应急检测或现场监测等使用,具有较高的推广价值。

环介导等温扩增技术与横向流动试纸条法快速检测鸡贫血病毒的研究

本研究将环介导等温扩增技术(loop-mediated isothermal amplification,LAMP)与横向流动试纸条技术(lateral flow dipstick,LFD)联合应用,针对鸡贫血病毒Cux-1 VP2基因设计了4条特异性引物和1条异硫氰酸荧光素(fluorescein isothiocyanate,FITC)标记的探针,并对其反应条件进行优化,建立了一种快速、便捷的鸡贫血病毒LAMP-LFD检测方法。结果显示,优化后的扩增温度和时间为63℃反应50 min,完成检测全过程仅需80 min。该方法检测灵敏度为10 fg,是利用外引物建立的PCR方法的100倍;可特异性地检出鸡贫血病毒;重复性、稳定性好。对30份样品的病毒分离鉴定和LAMP-LFD检测表明,二者符合率为100%。本研究建立的LAMP-LFD方法能够快速、特异地检测鸡贫血病毒,并且不需要其他辅助仪器,结果可直观判断,适合基层实验室、应急检测或现场监测等使用。

快速检测沙门氏菌的荧光免疫试纸的研制

研制一种基于低噪声激发式荧光沙门氏菌免疫层析检测试纸条,用于沙门氏菌快速、高敏、兼顾定性及精准定量的检测。采用低噪声激发式荧光染料作为标记,采用免疫层析技术,制备靶向于沙门氏菌的免疫层析试纸条。检测时,采用专用便携式低噪声激发式荧光扫描仪分别扫描质控线和检测线,以检测线荧光强度检测值实现样本的定性及定量检测,并对免疫层析试纸条各项性能进行评价。低噪声激发式荧光沙门氏菌免疫层析检测试纸条制备成功,免疫层析试纸条性能检测结果显示,该试纸条特异性强、灵敏度高、检测限可达到0.5×10~3 CFU/mL,是一种新型快速高效稳定的检测方法。该免疫层析试纸条可适用于食品及病理样本中沙门氏菌初筛和即时检测。

试纸法、折射仪法、电导率法检测肾小管浓缩功能特异性的比较

目的 :比较试纸法、折射仪法、电导率法测定肾小管浓缩功能特异性。方法 :选用尿液分析仪及其配套试纸条 ,折射仪分别测试 70例标本比重 ,并用SysmexUF - 10 0测其电导率 ,然后在 70例尿标本中 15例加入酸 ,15例加入碱 ,30例加入糖 ,10例加入蛋白质 ,再用以上三种方法分析测试。结果 :试纸法测尿比重结果受尿液pH的影响而几乎不受尿中糖和蛋白质的影响。折射仪法测尿比重结果受到糖和蛋白质的影响较大 ,而几乎不受pH的影响 ,电导率不受糖和蛋白质的影响 ,受pH的影响 ,但不如试纸法显著。结论 :电导率法较试纸法、折射仪法受干扰因素少 。

不同方法检测尿红细胞的对比分析

目的探讨不同方法检测尿红细胞时的差异性,比较不同仪器检测方法对红细胞尿的携带污染率情况。方法对来自临床1 000例尿液标本分别用URISYS2400干化学分析仪、UF-500i尿有形成分分析仪、显微镜镜检进行检测。对健康成人尿标本和与之混合的不同浓度红细胞悬液交叉排列分别用干化学法和尿沉渣法进行检测。结果分别用干化学法、尿沉渣法、显微镜镜检检测尿红细胞的阳性率为41.1%(411/1 000)、22.6%(226/1 000)、19.7%(197/1 000),干化学法和尿沉渣法分别与显微镜镜检比较复合率分别是76.8%(768/1 000)、97.1%(971/1 000)。干化学和尿沉渣同时红细胞检测阴性为512例,采用显微镜复检均为阴性。携带污染率URI-SYS2400干化学分析仪为0.000%、UF-500i尿有形成分析仪为0.113%。结论干化学法、尿沉渣法检查尿红细胞可以提高检测效率,两者相互补充可以提高检测的准确度,但仍有影响因素不可避免,所以当两者检测不符时,仍然需要显微镜镜检确认。

772例妊娠期高血压孕妇尿蛋白干化学试带法的应用价值分析

目的探讨尿蛋白干化学试带法诊断孕妇子痫前期中的应用价值。方法自2014至2016年共772例孕妇纳入研究,对尿蛋白干化学试带法与24h尿蛋白定量进行相关性分析,对尿蛋白干化学试带法诊断孕妇子痫前期能力进行ROC分析,双侧P<0.05认为差异有统计学意义。结果尿蛋白干化学试带法与24h尿蛋白定量进行相关性分析(Spearman)显示,R=0.181,P=0.001。ROC分析显示,尿蛋白干化学试带法诊断孕妇子痫前期的AUC为0.683,Z=5.917,P=0.001。以cut-off值±为界时,尿蛋白干化学试带法诊断孕妇子痫前期的能力最强,敏感性为54.29%,特异性为78.26%,准确度为75.00%,Youden指数为0.33。结论尿干化学试带法诊断子痫前期的敏感性、特异性等均不理想,建议对合并妊娠期高血压的孕妇,若怀疑子痫前期的可能,直接测定24h尿蛋白定量进行确诊。

试纸法在食品及水质检测领域的应用

在食品和水质检测领域,利用试纸法能够在现场完成污染物的快速检测。基于这种情况,对试纸法进行了分析,并且对该方法在食品检测和水质检测中的应用情况展开了探讨,从而为关注这一话题的人们提供参考。

尿液分析联合检测的应用价值

目的 探讨 U F- 1 0 0尿沉渣分析与干化学分析、显微镜检查联合检测尿液的应用价值。方法 用 U F-1 0 0型尿沉渣分析仪、尿自动分析装置 US- 2 1 0 0 R、常规尿沉渣镜检分别对 5 30例随机尿液标本进行检测。结果 以镜检结果为标准 ,U F- 1 0 0与常规镜检相比 ,检测红细胞阳性符合率为 89% ,假阳性为 1 5 .1 2 % ,假阴性率为 1 1 % ;测定白细胞阳性符合率为 92 .31 % ,假阳性率为 8.2 3% ,假阴性率为 7.6 9% ;检测上皮细胞、小园上皮细胞、管型、结晶和类酵母菌阳性符合率较低 ,分别为 80 .6 %、5 0 %、6 6 .7%、6 8.89%、5 7.1 2 %。 5 30例尿标本中干化学法白细胞、红细胞、蛋白及亚硝酸盐均阴性的 2 6 7例标本中 ,UF- 1 0 0检测红细胞阳性 2 2例 ,白细胞阳性 2 5例 ,常规检查法检出红细胞阳性 7例 ,白细胞阳性 1 9例。干化学法与镜检法相比 ,测定红细胞阳性符合率为 93% ,假阳性为 1 5 .1 2 % ,假阴性为 7% ;测定白细胞阳性符合率为 5 0 .4 3% ,假阳性为 3.1 1 % ,假阴性为 4 9.5 7%。结论 UF- 1 0 0型尿沉渣分析仪与干化学分析、显微镜检查联合应用能弥补干化学法不足 ,减少漏检和误检 ,UF- 1 0 0尿沉渣分析仪还可以满足尿液检测标准化 ,而且通过对干化学与 U F- 1 0

试带法尿蛋白定性试验临床应用价值的探讨

本文测定了20例正常人、439例不同病因住院病人及24例原发性肾小球疾病病人尿蛋白含量,比较了磺柳酸法与试带法的的测定结果。试带法仅对白蛋白敏感,对其它血浆蛋白基本无反应,阳性标本尿蛋白的检出率仅64.1％。建议用磺柳酸法或其它敏感方法与试带法一起作为尿蛋白筛选试验.并讨论了两法同测的临床意义。

Usefulness of urinary trypsinogen-2 and trypsinogen activation peptide in acute pancreatitis:A multicenter study in Japan

BACKGROUND Rapid urinary trypsinogen-2 dipstick test and levels of urinary trypsinogen-2 and trypsinogen activation peptide(TAP) concentration have been reported as prognostic markers for the diagnosis of acute pancreatitis.AIM To reconfirm the validity of all these markers in the diagnosis of acute pancreatitis by undertaking a multi-center study in Japan.METHODS Patients with acute abdominal pain were recruited from 17 medical institutions in Japan from April 2009 to December 2012. Urinary and serum samples were collected twice, at enrollment and on the following day for measuring target markers. The diagnosis and severity assessment of acute pancreatitis were assessed based on prognostic factors and computed tomography(CT) Grade of the Japanese Ministry of Health, Labour, and Welfare criteria.RESULTS A total of 94 patients were enrolled during the study period. The trypsinogen-2 dipstick test was positive in 57 of 78 patients with acute pancreatitis(sensitivity,73.1%) and in 6 of 16 patients with abdominal pain but without any evidence of acute pancreatitis(specificity, 62.5%). The area under the curve(AUC) score of urinary trypsinogen-2 according to prognostic factors was 0.704, which was highest in all parameter. The AUC scores of urinary trypsinogen-2 and TAP according to CT Grade were 0.701 and 0.692, respectively, which shows higher than other pancreatic enzymes. The levels of urinary trypsinogen-2 and TAP were significantly higher in patients with extended extra-pancreatic inflammation as evaluated by CT Grade.CONCLUSION We reconfirmed urinary trypsinogen-2 dipstick test is useful as a marker for the diagnosis of acute pancreatitis. Urinary trypsinogen-2 and TAP may be considered as useful markers to determine extra-pancreatic inflammation in acute pancreatitis.

柑橘黄化脉明病毒RT-RPA检测方法的建立

【目的】利用逆转录重组酶聚合酶扩增技术(reverse transcription-recombinase polymerase amplification,RT-RPA),结合侧向流层析(lateral flow dipstick,LFD)试纸条,建立一种快速简便、特异、灵敏、裸眼可视的柑橘黄化脉明病毒(citrus yellow vein clearing virus,CYVCV)检测新方法。【方法】根据CYVCV外壳蛋白基因的保守序列设计5对引物,通过样品检测筛选出扩增效果好、特异性强的引物对。将选出的引物进行标记物修饰,并设计对应的特异性探针,分别设置6个反应时间梯度(5、10、20、30、40、50 min)和8个反应温度梯度(37、38、39、40、41、42、43、44℃),对RT-RPA反应条件进行优化,建立CYVCV的RT-RPA检测体系。分别以仅感染了CYVCV、柑橘叶斑驳病毒(citrus leaf blotch virus,CLBV)、柑橘衰退病毒(citrus tristeza virus,CTV)、柑橘碎叶病毒(citrus tatter leaf virus,CTLV)、柑橘裂皮病类病毒(citrus exocortis viroid,CEVd)、柑橘鳞皮病毒(citrus psorosis virus,CPV)、温州蜜柑萎缩病毒(satsuma dwarf virus,SDV)、柑橘黄龙病菌(Candidatus Liberibacter asiaticus,CLas)和柑橘溃疡病菌(Xanthomonas citri subsp.citri,Xcc)柑橘材料的总核酸为模板,采用所筛选的最佳引物、探针和反应条件进行检测,评价所建立RT-RPA检测体系的特异性。将感染了CYVCV的柑橘总RNA样品进行10倍梯度稀释,以原液和10~(-1)、10~(-2)、10~(-3)、10~(-4)、10~(-5)、10~(-6)、10~(-7)稀释液作为模板,平行进行RT-PCR及RT-RPA的检测,评价所建立检测方法的灵敏度。随机采集来自田间9个不同品种柑橘的叶片,同时进行RT-RPA和RT-PCR检测,检验所建立RT-RPA检测方法的适用性。【结果】建立了CYVCV的RT-RPA检测体系:最佳引物为CY1-F/R,对应探针为CY1-Probe(47 bp),最佳反应条件为39℃,30 min,特异扩增目的片段为177 bp,检测结果可通过侧向流层析试纸条直接判读。特异性检测结果显示,利用该检测体系仅对感染了CYVCV的样品检测结果为阳性,其余均为阴性;灵敏度检测结果显示,RT-RPA与RT-PCR方法均最低可检测到10~(-4)稀释液,两种方法检测灵敏度相当。随机采集的45株田间柑橘样品中,RT-PCR与RT-RPA均检测出37个阳性样品,检出率均为82.2%,表明该方法检测效果稳定可靠。【结论】建立了CYVCV的RT-RPA检测方法,该检测方法操作简单、反应快速,结果裸眼可视,适用于基层条件不足的实验室或者植检站现场快速检测。

胶体金试剂条在鼠疫监测中的应用

目的探讨鼠疫胶体金试剂条在动物鼠疫血清学监测中的应用。方法股动脉采鼠血、分离血清,同一份血清分装在两个离心管中。其中一管血清56℃30min灭活,首先进行鼠疫间接血凝(IHA)的初筛试验。初筛阳性血清,经醛化吸收后,再进行复判试验,严格按照中华人民共和国鼠疫诊断标准"GB15991-1995"执行。同时对初筛阳性的原血清样的另一管未灭活血清进行鼠疫胶体金免疫层析试剂条检测。结果在广东省鼠疫疫源地(雷州市)采集的鼠类血清799份中有7份血清发生非特异凝集,初筛假阳性率0.88%;在广东鼠疫历史疫区(佛山市南海区)采集鼠类血清601份中有31份血清发生非特异凝集,初筛假阳性率5.17%,经复判试验全部为阴性。相应的非灭活原血清样经胶体金试剂条快速检测也全部为阴性。结论鼠疫胶体金免疫试剂条检测的特异性高于间接血凝试验,可同时作为间接血凝复判中的平行试验参考。在广东不同地区来源的鼠类血清样本中,历史疫区的IHA假阳性率明显高于现在的疫源地。