结核分枝杆菌对一线抗结核药物的耐药情况分析

目的了解东莞市2015-2018年结核分支杆菌对四种一线抗结核药物的耐药情况以及耐药患者人群分布特征,为制定科学的耐药结核病治疗和预防策略提供依据。方法收集东莞市2015-2018年登记的痰培养阳性的肺结核患者3975例,菌群鉴定为结核分支杆菌的标本进行药敏试验。药敏试验采用比例法,药物敏感试验药物种类包含异烟肼(INH)、利福平(RFP)、链霉素(SM)、乙胺丁醇(EMB)四种一线抗结核药物。结果3751株结核分枝杆菌对一线抗结核药物总体耐药率为25.70%(964/3751),四年间总体耐药率呈逐年增高趋势。单耐药率、耐多药率和多耐药率分别为17.41%(653/3751)、3.81%(143/3751)、4.48%(168/3751)。单耐药中耐链霉素(Sm)比例最高,耐多药中INH+RFP+EMB+Sm四种全耐的菌株比例最高。3751株结核分支杆菌对四种一线抗结核药物的耐药顺位为:Sm14.98%(562/3751)>EMB10.16%(381/3751>INH9.68%(363/3751)>RFP5.01%(188/3751)。卡方检验结果显示,年龄越大越容易耐多药(χ^2=9.27,P<0.05)和多耐药(χ^2=6.18,P<0.05)。复治患者更易患单一耐药(χ^2=11.70,P<0.05)、耐多药(χ^2=200.81,P<0.05)和多耐药(χ^2=4.66,P<0.05)。结论东莞市各耐药率水平低于全国平均水平,但呈现逐年增高水平,防控形势不容乐观。建立持续的耐药监测机制以及提供更多的标准化治疗方案并将其纳入免费治疗序列势在必行。     

新型抗真菌药物研发进展及其作用靶点机制

<正>侵袭性真菌感染(invasive fungal infection,IFI)已经成为危害人类健康的严重威胁之一。尽管IFI的流行病学在过去20年中发生了变化,广谱抗真菌预防措施降低了传统危险因素患者的发病率,提高了患者的生存率,但由于一些稀有的真菌病原体以及部分耐药菌株出现了对现有药物的抗药性,因此新型抗真菌药物的研发迫在眉睫^[1-2]。     

结核分枝杆菌216株抗结核药物耐药性监测分析

2002-01-2004—12从我院微生物实验室中分离出的216株结核分枝杆菌，对临床常用的抗结核药耐药性检测结果进行分析如下。     

佛山市顺德区肺结核耐抗结核药物分析

目的对佛山市顺德区肺结核患者耐抗结核药物的情况进行分析,为该地区开展结核病防治工作提供参考。方法收集397例涂阳肺结核患者(初治325例,复治72例)的痰标本,对分离培养获得的397株结核分枝杆菌采用浓度比例法对7种一、二线抗结核药物(包括异烟肼、利福平、乙胺丁醇和链霉素、左氧氟沙星、卡那霉素、对氨基水杨酸)进行药物敏感性试验。结果 397例患者耐药112例,耐药率为28.2%,其中链霉素和异烟肼耐药率最高,分别为20.4%(81/397)和12.6%(50/397);耐多药15例,耐多药率为3.8%。初治患者耐药率为26.2%(85/325),复治耐药率为37.5%(27/72),二者比较差异有统计学意义(χ2=5.963,P<0.05);初治耐多药率为1.8%(6/325),复治耐多药率为15.3%(11/72),二者比较差异有统计学意义(χ2=32.586,P<0.05)。结论佛山市顺德区肺结核患者耐药情况比较严重。临床治疗应根据药物敏感性试验结果选择合适药物组成有效治疗方案,以保障治疗效果,达到高治愈率的目标。 更多还原     

基于多重PCR-质谱微测序技术的结核分枝杆菌对一线治疗药物耐药性检测系统构建

目的 构建一种基于多重聚合酶链式反应-质谱微测序技术的结核分枝杆菌耐药基因多位点检测方法和检测模块,实现结核分枝杆菌对一线抗结核药物的高通量快速检测,为结核病诊疗提供一种新型技术支撑。方法 通过对5个单核苷酸多态性位点靶基因进行多重PCR扩增、单碱质量探针延伸及分子质量测定,同时完成16个突变位点、26种突变型的检测,实现结核分枝杆菌对利福平、异烟肼、吡嗪酰胺和乙胺丁醇等一线治疗药物抗性的通量检测。采用40例结核分枝杆菌样本、50例呼吸道感染患者咽拭子样本进行检测体系准确性及特异性验证。结果 本研究构建了基于5重PCR-质谱联用的结核分枝杆菌对一线治疗药物的泛耐药检测方法,并开发了质谱配套检测系统。采用该系统,结核分枝杆菌对利福平、异烟肼、吡嗪酰胺、乙胺丁醇抗性检测的准确率和特异性均为100.00%,且具有7 h内完成96个样本的检测通量。结论 本研究构建的方法有操作简便、低成本、高通量特点,耐药位点检测全面且准确,并具扩展性,可根据需要增添新突变位点,在结核分枝杆菌耐药性检测中具有良好应用前景。     

酵母双杂交系统在药物作用靶点研究中的应用进展

蛋白质-蛋白质相互作用贯穿了整个生命过程。酵母双杂交技术作为活细胞内检测蛋白质相互作用最有力的分析方法,在疾病发病机制、药物作用靶点研究和新药筛选方面显示出极大的应用潜力。本组围绕酵母双杂交系统的特点,简述了其在药物作用靶点研究中的应用进展。     

结核分枝杆菌耐药突变检测的临床研究

<正>近年来,中国的结核病发病率和耐药率均有上升趋势,每年有将近12万新发耐多药结核病患者,未来数年内可能出现耐药菌为主的流行态势[1]。耐药结核病常规的疫情监测不仅是临床用药和评价化疗方案的重要依据,也是流行病学和结核病控制工作的重要指标[2]。如何快速、准确检测结核分枝杆菌对主要一线药物的耐药性具有重要的临床意义。据报道异烟肼耐药与过氧化氢酶-过氧化物酶的编码基因Kat G有关[3],同     

非结核分枝杆菌的药物敏感试验探讨

随着非结核分枝杆菌的不断检出，由非结核分枝杆菌所致的肺病越来越引起临床关注。为了探讨有效的治疗药物，本室对13株非结核分枝杆菌进行了11种药物的药敏试验，以结核分枝杆菌H37RV参照苗株为药敏质控。材料和方法一、参照菌株结核分枝杆菌H37RV，非结核分枝杆菌；堪萨斯、瘰病、偶发、胞内、龟型各1株。二、临床菌株从病人疾标本中分离得到8株非结核分枝杆菌，其中初治病人3株（堪萨斯2株、偶发1株），复治病人5株（偶发和龟型各2株、鸟－胞1株）。三、药物种类除抗结核常用药物INH（异烟肼）、RFP（利福平）、EMB（乙胺丁醇）、…     

New structural classes of antituberculosis agents

Tuberculosis (TB), one of the deadliest diseases is shattering the health and socioeconomic status of the society. The emergence of multidrug resistant (MDR) and extremely drug resistant (XDR) strains has provided unprecedented lethal character to TB. The development of MDR and XDR strains of TB results in more deaths, longer duration of therapy, and appearance of the disease in the immunocompromised patients. Because of the development of rapid resistance by Mycobacterium tuberculosis, researchers are confronted with serious challenges in combating TB. For instance, the need for potency and specificity in therapeutic agents approaching clinics, and the increasing demand of low toxicity due to long duration of treatment. Recently, it is proposed that such challenges could be addressed by a shift from contemporary or known classes of drugs to new scaffold‐containing or entirely new structural classes of drugs that possibly act on the previously unknown targets, resulting in possibly less instances of resistance development. The exploitation of advances made in the biology of TB in the last and present decades have created opportunities to discover a large number of new structural classes that specifically targets TB by molecular mechanism of action(s) unknown earlier. We have earlier reviewed new structural classes of anti‐TB agents up to year 2005. This review covers literature reports of the subsequent 10 years on the discovery of new structural classes of synthetic anti‐TB agents. Due to the availability of large number of research reports, we have divided new compounds in 38 structural classes, 368 structures, and 307 references.     

Early bactericidal activity of antituberculosis agents

The early bactericidal activity (EBA) of an antituberculosis agent is arbitrarily defined as the fall in log₁₀ colony forming units (cfu) of Mycobacterium tuberculosis per ml sputum per day during the first 2 days of treatment. Determining the EBA is an important preliminary step in the clinical evaluation of an antituberculosis agent. We review the results of eight published studies of the EBA of different antituberculosis agents, the impact of these results on our understanding of the actions of the respective agents, the clinical characteristics and sputum findings of patients included in these studies, and explore sources of variation in the EBA results. Patients in these studies had a mean age of 31–36 years, a mean weight of 50–57 kg, 67% were male and 56% had lung involvement covering an area of more than one lung, and 90% had multicavitary disease. None of these findings were related to EBA in any study. The mean log₁₀ cfu per ml sputum in the first specimen was 6.474. This was related to radiological extent of disease and cavity size in one study (p < 0.001) and, in the case of isoniazid to EBA with a rise in EBA of 0.094 (95% CL 0.029–0.158) for each tenfold rise in cfu counts/ml sputum. The overall variation in EBA in these studies was 0.0303, that due to laboratory processing of specimens was 0.0011, and due to patient characteristics and sputum sampling 0.0212. The EBA is a reproducible investigation that has contributed significantly to our knowledge of the actions and characteristics of both established and new antituberculosis agents. The greatest source of variation in EBA results appears to be that due to interpatient variation in disease characteristics and sputum sampling.     

Early bactericidal activity of antituberculosis agents

The early bactericidal activity (EBA) of an antituberculosis agent is arbitrarily defined as the fall in log(10) colony forming units (cfu) of Mycobacterium tuberculosis per ml sputum per day during the first 2 days of treatment. Determining the EBA is an important preliminary step in the clinical evaluation of an antituberculosis agent. We review the results of eight published studies of the EBA of different antituberculosis agents, the impact of these results on our understanding of the actions of the respective agents, the clinical characteristics and sputum findings of patients included in these studies, and explore sources of variation in the EBA results. Patients in these studies had a mean age of 31-36 years, a mean weight of 50-57 kg, 67% were male and 56% had lung involvement covering an area of more than one lung, and 90% had multicavitary disease. None of these findings were related to EBA in any study. The mean log(10) cfu per ml sputum in the first specimen was 6.474. This was related to radiological extent of disease and cavity size in one study (p < 0.001) and, in the case of isoniazid to EBA with a rise in EBA of 0.094 (95% CL 0.029-0.158) for each tenfold rise in cfu counts/ml sputum. The overall variation in EBA in these studies was 0.0303, that due to laboratory processing of specimens was 0.0011, and due to patient characteristics and sputum sampling 0.0212. The EBA is a reproducible investigation that has contributed significantly to our knowledge of the actions and characteristics of both established and new antituberculosis agents. The greatest source of variation in EBA results appears to be that due to interpatient variation in disease characteristics and sputum sampling.     

Mouse model for efficacy testing of antituberculosis agents via intrapulmonary delivery

Here we describe an experimental murine model that allows for aerosolized antituberculosis drug efficacy testing. Intrapulmonary aerosol delivery of isoniazid, capreomycin, and amikacin to mice with pulmonary infection of Mycobacterium tuberculosis demonstrated efficacy in reducing pulmonary bacterial loads similar to that seen by standard drug delivery methods, even when lower concentrations of drugs and fewer doses were used in the aerosolized drug regimens. Interestingly, intrapulmonary delivery of isoniazid also reduced the bacterial load in the spleen.     

Bioterrorism: introduction and major agents

It is not if, but where and when . In light of the September 11 World Trade Center and Pentagon attacks, biological terrorist acts in the United States seem more likely than ever before. We know there are people willing to die to kill Americans and we know that nations with a history of supporting terrorism have biological warfare (BW) capability. Some of the states capable of BW include Iraq, Libya, Syria, and Iran—all of which have close ties to transnational terrorist groups such as Al-Qaeda, Armed Islamic Group of Algeria, and Al-Jihad of Egypt (Davis, 1999; McGovern, Christopher, & Eitzen, 1999; Sanger, & Kahn, 2001). The threat is not limited to these nations or groups, but all do present a clear danger. According to the U.S. Central Intelligence Agency, operatives of Al-Qaeda (the Osama bin Laden group) "have trained to conduct attacks with toxic chemicals or biological toxins" (Broad, & Peterson, 2001).     

Pharmacokinetic evaluation of the penetration of antituberculosis agents in rabbit pulmonary lesions

Standard antituberculosis (anti-TB) therapy requires the use of multiple drugs for a minimum of 6 months, with variable outcomes that are influenced by a number of microbiological, pathological, and clinical factors. This is despite the availability of antibiotics that have good activity against Mycobacterium tuberculosis in vitro and favorable pharmacokinetic profiles in plasma. However, little is known about the distribution of widely used antituberculous agents in the pulmonary lesions where the pathogen resides. The rabbit model of TB infection was used to explore the hypothesis that standard drugs have various abilities to penetrate lung tissue and lesions and that adequate drug levels are not consistently reached at the site of infection. Using noncompartmental and population pharmacokinetic approaches, we modeled the rate and extent of distribution of isoniazid, rifampin, pyrazinamide, and moxifloxacin in rabbit lung and lesions. Moxifloxacin reproducibly showed favorable partitioning into lung and granulomas, while the exposure of isoniazid, rifampin, and pyrazinamide in lesions was markedly lower than in plasma. The extent of penetration in lung and lesions followed different trends for each drug. All four agents distributed rapidly from plasma to tissue with equilibration half-lives of less than 1 min to an hour. The models adequately described the plasma concentrations and reasonably captured actual lesion concentrations. Though further refinement is needed to accurately predict the behavior of these drugs in human subjects, our results enable the integration of lesion-specific pharmacokinetic-pharmacodynamic (PK-PD) indices in clinical trial simulations and in in vitro PK-PD studies with M. tuberculosis.     

First case of pulmonary tuberculosis and visceral leishmaniasis coinfection successfully treated with antituberculosis drug and liposomal amphotericin B

Successful management of cases with visceral leishmaniasis (VL) and tuberculosis is a challenge for clinicians, because a guideline for that is currently unavailable. We report the first case in Bangladesh who developed VL during her treatment for pulmonary tuberculosis and was treated successfully with multidose liposomal amhptericin B for VL.     

Structure of the Mycobacterium tuberculosis D-alanine:D-alanine ligase, a target of the antituberculosis drug D-cycloserine

D-alanine:D-alanine ligase (EC 6.3.2.4; Ddl) catalyzes the ATP-driven ligation of two D-alanine (D-Ala) molecules to form the D-alanyl:D-alanine dipeptide. This molecule is a key building block in peptidoglycan biosynthesis, making Ddl an attractive target for drug development. D-Cycloserine (DCS), an analog of D-Ala and a prototype Ddl inhibitor, has shown promise for the treatment of tuberculosis. Here, we report the crystal structure of Mycobacterium tuberculosis Ddl at a resolution of 2.1 ?. This structure indicates that Ddl is a dimer and consists of three discrete domains; the ligand binding cavity is at the intersection of all three domains and conjoined by several loop regions. The M. tuberculosis apo Ddl structure shows a novel conformation that has not yet been observed in Ddl enzymes from other species. The nucleotide and D-alanine binding pockets are flexible, requiring significant structural rearrangement of the bordering regions for entry and binding of both ATP and D-Ala molecules. Solution affinity and kinetic studies showed that DCS interacts with Ddl in a manner similar to that observed for D-Ala. Each ligand binds to two binding sites that have significant differences in affinity, with the first binding site exhibiting high affinity. DCS inhibits the enzyme, with a 50% inhibitory concentration (IC(50)) of 0.37 mM under standard assay conditions, implicating a preferential and weak inhibition at the second, lower-affinity binding site. Moreover, DCS binding is tighter at higher ATP concentrations. The crystal structure illustrates potential drugable sites that may result in the development of more-effective Ddl inhibitors.