Sabour Sahar, Arzanlou Mohsen, Jeddi Farhad, Azimi Taher, Hosseini-Asl Saied, Naghizadeh-Baghi Abbas, Peeri Dogaheh Hadi
Department of Microbiology, School of Medicine, Ardabil University of Medical Science, Ardabil, Iran.
Department of Genetics and pathology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran.
J Microbiol Methods. 2020 Aug;175:105982. doi: 10.1016/j.mimet.2020.105982. Epub 2020 Jun 13.
This study aims to evaluate the efficiency of the TaqMan real-time PCR and serological methods in detecting Brucella spp. in clinical specimens that have been collected from suspected patients in Ardabil, Iran.
In this cross-sectional study, a total of 113 consecutive patients suspected of brucellosis who were referred to the three hospitals in Ardabil province were selected. In the first step, the diagnosis of brucellosis was performed by serological methods including the Rose Bengal slide agglutination test, Wright test, 2-ME test, and BrucellaCapt test. In the next step, TaqMan real-time PCR with primer and probe targeting the bcsp31 gene was used for the detection of Brucella spp. Specificity, sensitivity, and positive and negative predictive values of the TaqMan real-time PCR assay were calculated.
Among 113 suspected patients with different clinical manifestations, the Rose Bengal slide agglutination test, Wright test, and 2-ME test were positive in 60 cases; however, the BrucellaCapt test titer was 1:160 for one patient. Six patients had high initial serum antibody titers; 2-ME titers of ≥1:640; STA titers of ≥1:1280; BrucellaCapt titers of ≥ 1:2560. Among positive cases, no correlation was observed among gender, age, and life (residence) in urban or rural areas. The TaqMan real-time PCR was positive in 35% of all 60 positive cases. The comparison of the results of the BrucellaCapt and TaqMan real-time PCR methods revealed that 19 out of 54 (35.2%) and 2 out of 6 (33.4%) BrucellaCapt positive cases with titers of >1:320 and ≤ 1:320 were positive, respectively. The sensitivities and specificities of the TaqMan real-time PCR assay were 49.1% and 100% respectively.
The sensitivity of the TaqMan real-time PCR assay was low in the diagnosis of brucellosis, while the BrucellaCapt test turned out to be a very valuable, sensitive, and specific test for the diagnosis of brucellosis in suspected patients and, thus, can provide reliable results in medical laboratories.
本研究旨在评估TaqMan实时荧光定量PCR和血清学方法在检测从伊朗阿尔达比勒疑似患者采集的临床标本中布鲁氏菌属的效率。
在这项横断面研究中，共选取了113例连续转诊至阿尔达比勒省三家医院的疑似布鲁氏菌病患者。第一步，采用血清学方法，包括虎红平板凝集试验、Wright试验、2-巯基乙醇试验和布鲁氏菌捕获试验进行布鲁氏菌病诊断。第二步，使用针对bcsp31基因的引物和探针的TaqMan实时荧光定量PCR检测布鲁氏菌属。计算TaqMan实时荧光定量PCR检测方法的特异性、敏感性以及阳性和阴性预测值。
在113例有不同临床表现的疑似患者中，虎红平板凝集试验、Wright试验和2-巯基乙醇试验有60例呈阳性；然而，有1例患者的布鲁氏菌捕获试验效价为1:160。6例患者初始血清抗体效价较高；2-巯基乙醇试验效价≥1:640；STA试验效价≥1:1280；布鲁氏菌捕获试验效价≥1:2560。在阳性病例中，未观察到性别、年龄以及城乡生活（居住地）之间存在相关性。在所有60例阳性病例中，TaqMan实时荧光定量PCR有35%呈阳性。布鲁氏菌捕获试验和TaqMan实时荧光定量PCR方法结果的比较显示，效价>1:320和≤1:320的54例和6例布鲁氏菌捕获试验阳性病例中，分别有19例（35.2%）和2例（33.4%）呈阳性。TaqMan实时荧光定量PCR检测方法的敏感性和特异性分别为49.1%和100%。
TaqMan实时荧光定量PCR检测方法在布鲁氏菌病诊断中的敏感性较低，而布鲁氏菌捕获试验对于疑似患者布鲁氏菌病的诊断是一种非常有价值、敏感且特异的检测方法，因此，可在医学实验室提供可靠结果。
