Comparison of redox and D29 phage methods for detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis

Rapid, accurate and inexpensive methods are essential to detect drug-resistant Mycobacterium tuberculosis and allow timely application of effective treatment and precautions to prevent transmission. The proportion method, the MTT and Alamar Blue redox methods, and the D29 mycobacteriophage assay, were compared for their ability to detect resistance to isoniazid and rifampicin. When tested against a panel of known M. tuberculosis strains, the redox methods and the D29 assay showed good sensitivity and specificity compared to the proportion method, suggesting that they could be useful alternatives for identifying multidrug resistance in M. tuberculosis.     

Mycobacterium Tuberculosis Infection Incidence in Hospitalized Renal Transplant Patients in the United States, 1998–2000

The incidence, risk factors, and prognosis for Mycobacterium tuberculosis (MTB) infection have not been reported in a national population of renal transplant recipients. We performed a retrospective cohort study of 15,870 Medicare patients who received renal transplants from January 1, 1998 to July 31, 2000. Cox regression analysis derived adjusted hazard ratios (AHR) for factors associated with a diagnosis of MTB infection (by Medicare Institutional Claims) and the association of MTB infection with survival. There were 66 renal transplant recipients diagnosed with tuberculosis infection after transplant (2.5 cases per 1000 person years at risk, with some falling off of cases over time). The most common diagnosis was pulmonary TB (41 cases). In Cox regression analysis, only systemic lupus erythematosus (SLE) was independently associated with TB. Mortality after TB was diagnosed was 23% at 1 year, which was significantly higher than in renal transplant recipients without TB (AHR, 4.13, 95% CI, 2.21, 7.71, p < 0.001). Although uncommon, MTB infection is associated with a substantially increased risk of mortality after renal transplantation. High-risk groups, particularly those with SLE prior to transplant, might benefit from intensified screening.     

PCR-SSCP法检测结核分枝杆菌耐药性

目的：探讨耐多药结核分枝杆菌耐药基因突变与耐药性的关系以及聚合酶链反应-单链构象多态性分析(poly merase chain reaction-single strand cinfomlation polymorphism，PCR-SSCP)方法的临床应用价值。方法：用PCR-SSCP方法检测58株结核分枝杆菌临床分离株katG，rpoB，rpsL基因突变并与常规药敏试验检测结果进行对比。结果：经常规药敏试验检测，58株结核分枝杆菌临床分离株中共有41株耐药，其中，耐异烟肼(INH)为35株，高耐药株27株；耐利福平(RFP)为31株，高耐药株24株；耐链霉素(SM)有31株，高耐药株26株。同时耐3种药物的有21株(51．2％)，耐2种药物的14株(34．1％)，单耐药株6株(14．6％)．PCR-SSCP方法对58株临床分离株katG，rpoB，rpsL基因突变的检测率为40％(23／58)，45％(26／58)，38％(22／58)，其中检出3个基因同时突变的有13株(32％)，2种基因突变的12株(29％)，1种基因突变的有10株(23．8％)．常规药敏试验与PCR-SSCP法检出结核分枝杆菌同时耐3种药物的符合率为61．9％(13／21)，检出耐2种药物的符合率为85．70k，(12／14)，检出耐1种药物的符合率为50％(3／6)．高耐药株中突变率为80．5％(62／77)，低耐药株中突变率为60％(12／20)．结论：PCR-SS-CP方法对耐2种以上药物的结核杆菌检出率较高，且耐药基因突变率随着耐药浓度增高而增高。将PCR-SSCP法与药敏试验联合应用可互相弥补，已成为临床指导用药的好方法。     

病灶清除一期植骨内固定治疗脊柱结核

目的探讨脊柱结核病灶清除手术后内固定方式的选择。方法对35例脊柱结核患者采用3种不同术式：16例前路病灶清除、植骨,一期前路钢板或钉棒内固定;14例前路病灶清除、植骨,一期后路经弓根钉棒内固定;5例前路病灶清除、植骨,一期前路钢板、后路钉棒联合内固定。结果35例均获随访,时间18-24个月。X线显示病灶静止,植骨融合,内固定无松动断裂,后凸畸型改善,其中合并脊髓损害15例,按Frankel分级,C级3例、D级12例术后全部恢复到E级。结论病灶清除一期植骨内固定有利于重建脊柱稳定性,纠正和预防脊柱后凸畸形,可避免或减少结核复发。     

肾结核90例临床分析

目的 探讨肾结核的临床特征及有效治疗方法。方法 回顾性分析90例肾结核患者的临床资料。结果 近年来肾结核病例仍较多见，早期诊断困难，单纯药物治疗可治愈者约16％，手术切除仍是主要治疗方法。结论 不典型肾结核的发病率仍较高。尿常规、B超、静脉肾盂造影为主要诊断方法，诊断性治疗仍是确诊的重要依据。     

核素全身骨显像在脊柱结核诊治中的临床价值

[目的]评价核素全身骨显像在脊柱结核诊治中的价值。[方法]对175例脊柱结核采用99Tcm—MDP（亚锡亚甲基二膦酸盐）核素全身骨显像，了解脊柱病灶的显影情况和全身其他骨关节是否并存病灶的情况。[结果]175例患者全部显像为阳性，其中伴有多节段椎体结核者146例，其中2个椎体者78例，3个椎体者26例，4个椎体以上者42例。伴有四肢骨关节结核者22例，伴骶髂关节结核者29例。[结论]核素全身骨显像在脊柱结核诊治中有重要价值，可以发现全身骨与关节多个结核病灶，对制定脊柱结核的治疗方案有指导作用。     

Comparison of Quantiferon-TB Gold With Tuberculin Skin Test for Detecting Latent Tuberculosis Infection Prior to Liver Transplantation

Screening for latent tuberculosis infection (LTBI) is recommended prior to organ transplantation. The Quantiferon-TB Gold assay (QFT-G) may be more accurate than the tuberculin skin test (TST) in the detection of LTBI. We prospectively compared the results of QFT-G to TST in patients with chronic liver disease awaiting transplantation. Patients were screened for LTBI with both the QFT-G test and a TST. Concordance between test results and predictors of a discordant result were determined. Of the 153 evaluable patients, 37 (24.2%) had a positive TST and 34 (22.2%) had a positive QFT-G. Overall agreement between tests was 85.1% (kappa= 0.60, p < 0.0001). Discordant test results were seen in 12 TST positive/QFT-G negative patients and in 9 TST negative/QFT-G positive patients. Prior BCG vaccination was not associated with discordant test results. Twelve patients (7.8%), all with a negative TST, had an indeterminate result of the QFT-G and this was more likely in patients with a low lymphocyte count (p = 0.01) and a high MELD score (p = 0.001). In patients awaiting liver transplantation, both the TST and QFT-G were comparable for the diagnosis of LTBI with reasonable concordance between tests. Indeterminate QFT-G result was more likely in those with more advanced liver disease.     

内固定技术在脊柱结核外科治疗中的应用

内固定技术的应用是脊柱结核外科治疗的新发展,其目的是充分发挥内固定即刻重建脊柱稳定性的作用,促进局部结核控制和骨性融合达到结核病灶的静止与修复。临床实践证明在结核病灶局部植入组织相容性好、耐腐蚀性强的钛合金材料不会增加术后感染及结核扩散的发生率。内固定应用的适应证:①脊柱结核造成椎体破坏明显,在病灶清除或切除后必须用植骨来修复骨缺损及恢复椎间高度者;②病灶清除或切除后对脊柱的稳定性有明显损害者;③脊柱后凸畸形需矫正者。采用内固定时,须根据患者的具体病情,选择前路或后路内固定方法,采用Ⅰ期或Ⅱ期手术。应该明确,脊柱结核外科治疗只是辅助治疗方法,有效的抗结核化疗才是脊柱结核治疗的基础。     

结核分枝杆菌Rv1009基因蛋白的克隆和表达

目的 克隆表达结核分枝杆菌促Rv1009基因,序列测定正确后进行融合、表达.方法 采用热启动聚合酶链反应（Polymerase Chain Reaction,PCR）从结核分枝杆菌H37Rv基因组中扩增出Rv1009编码基因,用限制性内切酶消化后插入pGEX 4T-2载体中,将重组质粒转化大肠杆菌BL21（DE3）,目的基因经IPTG诱导,表达Rv1009基因蛋白.结果 经PCR扩增在1300bp处发现一条目的片段,获得了结核分枝杆菌H37Rv株Rv1009基因蛋白,经诱导后高效表达分子量为64KD的外源蛋白,与预期分子量大小一致,凝胶自动扫描分析,在A600值为0.6,IPTG终浓度为0.3 mmol/L,诱导表达3 h时融合蛋白表达量即达峰值,占菌体总蛋白的22.8%.结论 构建了结核分枝杆菌Rv1009基因重组表达载体,获得了RPF样融合蛋白的高效表达,为今后深入研究奠定了基础.