Brucellosis of the spine with a synchronous Staphylococcus aureus pyogenic elbow infection

Staphylococcus aureus osteomyelitis and pyogenic arthritis has a different pattern in the elderly than in the young. The axial skeleton is the most frequent site of infection and treatment is usually by intravenous antibiotics. We report a case ofStaph. aureus septic arthritis of the elbow with concomitant osteomyelitis of the spine that was thought to be due toStaph. aureus, but culture of debrided material from the lesion grewBrucella in culture. We suggest that in the elderly it is advisable to obtain a tissue culture diagnosis and not to instigate therapy based on positive blood cultures or a concomitant infection.     

Detection of Brucella melitensis by the BacT/Alert automated system and Brucella broth culture

This study was conducted to evaluate the ability of the BacT/Alert automated blood culture system to detect Brucella spp. in comparison with traditional Brucella broth culture. Overall, 100 (50 bone marrow and 50 blood samples) paired cultures were obtained, and 59 were positive by at least one method. The Brucella broth culture method detected all 59 positive cultures (100%), and the BacT/Alert system detected 30 (50.8%) ( P  < 0.05). The mean detection times for B. melitensis were 4.5 days in the BacT/Alert system and 5 days in Brucella broth culture ( P  > 0.05). There is no significant difference between the two methods with respect to growth time of the microorganism, but Brucella broth culture is more sensitive than the BacT/Alert system.     

A computer-interfaced photometer and systematic spacing of duplicates to control within-plate enzyme-immunoassay variation

A Multiskan photometer for reading microtiter plate enzyme immunoassays was linked with a time sharing computer to facilitate control of assay variation and analysis of results. The interface that converted photometer output to RS-232-C format required changes to divide the output into segments short enough for input to the computer. To measure within-plate variation and investigate how the method of allocating sample duplicates to plate wells may affect the estimation of sample variance, uniformity tests were conducted with 47 plates. Coefficients of variation (CV) among wells within-plates ranged from 4.6 to 20.7% and in two-thirds of the plates exceeded 10%. Duplicates allocated to adjacent wells (method 1) gave consistently higher CV for sample means than duplicates allocated to opposite plate quadrants (method 2). In general, the CV by method 2 was about 30% smaller than that by method 1. Analysis of variance confirmed the effectiveness of the quadrant pattern of duplicate allocation as a method of controlling variation that arises from well position effects.     

Acute brucellosis as unusual cause of immune thrombocytopenia: a case report and review of the literature

A 25 year-old male patient was admitted to the causality with complaints of fever, joints pain, epistaxis and gingival bleeding, for the last week, the complete blood count revealed pancytopenia. Serological test for brucella was reported positive as 1/320, but the patient failed to respond to brucella treatment for 4 d. On day 5th the diagnosis of immune thrombocytopenia was confirmed after bone marrow aspiration. Steroid was initiated on 6th day after admission and on the 3rd day of steroid therapy thrombocytes count was raised to 55×10⁹/L and came up to 180×10⁹/L on 12th day after admission. Brucella-induced immune thrombocytopenia should be considered in patient presenting with bleeding and febrile illness especially in endemic region.     

五种布鲁氏菌核酸检测试剂盒检测性能的评价北大核心CSCD

目的比较5种布鲁氏菌核酸实时荧光PCR检测试剂盒的一致性和检出能力,为临床实验室选择检测方法和布鲁氏菌的诊断提供参考依据。方法选用经病原学检测确定为布鲁氏菌阳性的血液样本38份,健康人的血液样本24份,潘氏变形杆菌、溶藻弧菌、河弧菌、铜绿假单胞菌、肺炎克雷伯菌DNA各1份,使用5种试剂盒(编号A-E)分别进行核酸检测,比较5种试剂盒临床样本检测的一致性;选择1份阳性样本核酸用无RNA酶水梯度稀释得到5个浓度(浓度1:4453.13 fg/μL,浓度2:1113.28 fg/μL,浓度3:278.32 fg/μL,浓度4:69.58 fg/μL,浓度5:17.40 fg/μL),每个浓度使用5种试剂盒(编号A-E)分别进行3次检测,比较5种试剂盒的阳性检出率及批内重复性。结果5种试剂盒检测67份DNA样品的符合率稍有不同,试剂盒ABDE的符合率均为100%,试剂盒C的符合率为98.51%。批内重复性显示5种试剂盒在浓度1、浓度2、浓度3水平重复检测DNA的Ct值变异系数均<5%;在浓度1与浓度4梯度区间,试剂盒的阳性检出能力比较显示试剂盒A、B、D较高,为11/12,试剂盒C和E较低,为8/12。结论5种试剂盒的真实性和可靠性较好,灵敏度和符合率稍有差别,特异度均为100%;重复性较好,检测性能良好。部分试剂盒对弱阳性样本的检出能力不强,该类样本可使用多种试剂盒复核,以保障结果的准确性。     

布鲁氏菌微滴式数字PCR方法的建立与应用

目的 建立可对布鲁氏菌准确定量的微滴式数字PCR(Droplet digital PCR,ddPCR)方法。方法 使用以布鲁氏菌bscp31基因为靶标的引物和探针,摸索最佳的引物和探针工作浓度,确定反应体系和扩增条件,评价所建立方法的灵敏性、特异性及对疫情相关血液标本的检测效果。结果 ddPCR反应体系中最佳引物和探针浓度分别为0.8 μmol/L和0.4 μmol/L;最佳扩增条件:95 ℃ 10 min;95 ℃ 30 s,60 ℃ 1 min,循环40次;98 ℃酶失活10 min。布鲁氏菌核酸DNA为0.96 ng/反应~3.68 fg/反应时,ddPCR检出靶标基因拷贝数为2.00×10⁵拷贝/反应~1拷贝/反应,ddPCR测得值的对数值与DNA浓度的对数值有线性关系。在疫情相关血液标本DNA的检测中,ddPCR阳性率远高于培养法和试管凝集法;16份人血液标本中靶标基因浓度为5~65拷贝/mL血液(平均29拷贝/mL血液),5份羊血液标本中靶标基因浓度为25~245拷贝/mL血液(平均98拷贝/mL血液)。结论 ddPCR灵敏性高,可检测微量核酸DNA,适合临床血液标本的检测以及布病病原体的分子流行病学调查。     

应用CRISPR/Cas13a快速鉴定布鲁氏菌

目的 建立一种基于CRISPR/Cas13a的布鲁氏菌鉴定方法。方法 以布鲁氏菌BCSP31基因的保守区为靶标区域设计特异的引物和crRNA,建立鉴定布鲁氏菌的CRISPR/Cas13a方法。通过对纯菌株以及临床需氧血培养阳性菌液检测评价该方法的特异性和敏感性;通过梯度稀释法评估其检测下限。结果 建立了基于CRISPR/Cas13a的布鲁氏菌快速鉴定方法,其检测下限可达10 fg/μL。通过鉴定64株布鲁氏菌、56株非布鲁氏菌、人DNA以及57例临床需氧血培养阳性菌液,计算该方法的敏感性、特异性可达100%。结论 建立了一种基于CRISPR/Cas13a的布鲁氏菌鉴定方法,可用于临床需氧血培养阳性后快速鉴定布鲁氏菌。     

9例布鲁氏菌病并发感染性主动脉瘤患者临床诊治分析 临床指标及细胞因子水平变化特征

[摘要]?目的?分析布鲁氏菌病并发感染性主动脉瘤的临床特点,以提高临床医生对该疾病的认识及诊疗水平。方法?选取2002年1月1日—2022年6月1日北京安贞医院收治的9例布鲁氏菌病并发感染性主动脉瘤患者作为研究对象,收集其流行病学资料、临床表现、实验室检查结果、影像学资料、治疗及预后等情况。结果?32例血培养证实布鲁氏杆菌感染者中,9例并发主动脉瘤,发生率为28.13%。其中8例为男性,1例为女性,年龄为58～75岁。有明确牛、羊接触史者3例,有不洁羊奶饮用史者1例,有牧区旅游史者1例。所有患者均有发热,其中热型为典型波浪热者1例。患者主要症状为腰腹痛。误诊为腰椎结核者2例,误诊为腰椎管狭窄者3例。1例患者合并附睾炎。6例患者累及腹主动脉,1例累及升主动脉,2例累及主动脉弓。9例患者血清凝集试验均阳性。9例患者均接受利福平、多西环素和左氧氟沙星抗感染治疗,除1例失访外,其余8例总疗程均为3～6个月。7例手术治疗患者中,6例行主动脉替换或修补术,1例经6个月抗感染治疗后行支架植入手术,以上患者术后均随访5个月～7年（中位时间4年）,1例于术后5年死于脑血管疾病意外,其余6例均存活。2例未接受手术治疗患者中,1例出院后失访,1例随访3年存活至今。结论?布鲁氏菌病的主动脉受累较少见,且易危及生命,由于对该病认识不足,易导致漏诊、误诊。本病治疗的基石仍然是抗感染治疗联合开放性手术。血管内支架等介入手术治疗的作用尚未确定,须要考虑患者的病情和长期并发症的风险。