The DosR antigen Rv1737c from Mycobacterium tuberculosis confers inflammation regulation in tuberculosis infection

There is an urgent need to identify the potential risk factors for activating latent Mycobacterium tuberculosis infection. In this study, we evaluated the immune function of Rv1737c, which is a latency‐associated antigen of dormancy survival regulator (DosR) of M. tuberculosis in a mouse model. Our data showed that mice pretreated with recombinant Rv1737c (rRv1737c) exhibited higher levels of antigen‐specific antibodies (IgG, IgM and IgA) than sham‐treated mice. Following Bacilli Calmette‐Guerin (BCG) challenge, rRv1737c adjuvanted with cholera toxin subunit B (CTB) induced diffuse lung inflammation and fibrosis compared to the control mice. The inflammatory pathogenesis due to rRv1737c pre‐exposure was associated with a switch in the macrophage phenotype from M1 to activated M2 and was characterized by IL‐10 production. Intracellular cytokine analysis further showed that the rRv1737c‐pretreated mice exhibited an increased frequency of Th2 cells in the lungs, lymph nodes and spleen after BCG challenge. Furthermore, IFN‐γ expression increased in the lungs after rRv1737c pretreatment compared to that in the sham mice. Accordingly, lung cells from rRv1737c‐immunized mice stimulated with killed BCG produced higher levels of multiple cytokines, such as IFN‐γ, IL‐10 and IL‐6. The results confirmed that the pathological features of rRv1737c promoted inflammation. Overall, our findings provide direct evidence of the pro‐inflammatory function of rRv1737c in a murine model of BCG infection, indicating that Rv1737c is a pathogenic antigen of M. tuberculosis and may be key to the recurrence of latent infection.     

Novel vaccination strategies and approaches against human tuberculosis

Tuberculosis (TB) remains one of a major health problem worldwide. Tuberculosis vaccine research has made an extraordinary progress over the past few years. However, there is still no replacement for the Bacillus Calmette‐Guérin vaccine, the only TB vaccine licensed for human use. Therefore, the discovery and development of new TB vaccines remains a priority. This article discusses current strategies used to diversify TB vaccines and includes discussion of the status of efforts to improve protection against Mycobacterium tuberculosis (M tb) infection or TB disease by developing new and safe TB vaccines. This article also highlights the current research efforts in immune‐enhancing approaches to improve vaccination efficacy. The development of more effective TB vaccines might have significant impact on global TB control.     

Coinfection by Talaromyces marneffei and Mycobacterium abscessus in a human immunodeficiency virus-negative patient with anti-interferon-γ autoantibody: a case report

Patients with anti-interferon (IFN)-γ autoantibodies have weakened immune defenses against intracellular pathogens. Because of its low incidence and non-specific symptoms, diagnosis of anti-IFN-γ autoantibody syndrome is difficult to establish during the early stages of infection. Here, we report a patient with high titers of serum anti-IFN-γ autoantibodies suffering from opportunistic infections. The patient presented with intermittent fever for 2 weeks. During his first hospitalization, he was diagnosed with Talaromyces marneffei pulmonary infection and successfully treated with antifungal therapy. However, multiple cervical lymph nodes subsequently became progressively enlarged. Mycobacterium abscessus infection was confirmed by positive cervical lymph node tissue cultures. High-titer serum anti-IFN-γ antibodies were also detected. Following anti-M. abscessus therapy, both his symptoms and lymph node lymphadenitis gradually improved. Anti-IFN-γ autoantibody syndrome should be considered in adult patients with severe opportunistic coinfections in the absence of other known risk factors.     

糖尿病合并初治肺结核患者结核分枝杆菌耐药性分析

目的 分析糖尿病合并初治肺结核患者对一线、二线抗痨药耐药情况,以及不同糖化血红蛋白（HbA1c）水平时的耐药率。方法 收集2017年1~12月安徽省胸科医院住院患者中痰培养阳性初治肺结核患者296例,按是否患糖尿病分为单纯初治肺结核（对照组）170例和糖尿病合并初治肺结核（观察组）126例。比较两组患者对4种一线药物异烟肼（H）、利福平（R）、乙胺丁醇（E）、链霉素（S）和5种二线药物丁胺卡那（Am）、卷曲霉素（Cm）、左氧氟沙星（Lvfx）、对氨基水杨酸钠（Pas-Na）、丙硫异烟胺（Pto）的耐药率。同时,观察组患者按照HbA1c值不同分为3组：HbA1c < 7%组、7%≤HbA1c < 9%组、HbA1c≥9%组,比较观察组不同HbA1c水平时对上述4种一线药物和5种二线药物的耐药率。结果 观察组患者总耐药率、单耐药率、任一耐异烟肼率高于对照组,差异有统计学意义（P<0.05）;观察组患者耐多药率、多耐药率和任一耐R、S、E、Am、Cm、Lvfx、Pas-Na、Pto率均高于对照组,但差异无统计学意义（P>0.05）;观察组中,不同HbA1c水平下的耐药率分别为13.79%、34.15%、85.19%,差异有统计学意义（P<0.05）。结论 糖尿病合并初治肺结核患者耐药率高;HbA1c水平越高,耐药率越高。     

艾滋病病毒与结核分枝杆菌双重感染对死亡的影响

目的 了解广西壮族自治区（广西）HIV及结核分枝杆菌（Mycobacterium tuberculosis,MTB）双重感染对死亡的影响,为有效控制HIV/MTB双重感染提供依据。方法 利用中国疾病预防控制信息系统的艾滋病综合防治信息系统和结核病防治数据系统,收集整理2011年广西HIV/MTB双重感染患者,采用跨系统和大数据串联分析方法,交叉核对艾滋病治疗、随访、综合信息以及结核病患者登记报告基本信息,明确HIV/MTB双重感染患者;用描述性流行病学方法、χ²检验以及Cox比例风险回归模型描述、分析资料。结果 HIV感染者及艾滋病患者登记队列（HIV/AIDS队列）感染MTB比例为17.72%（2 533/14 293）;结核病患者登记队列（结核病队列）感染HIV比例5.57%（2 351/42 205）;随访1年内HIV/AIDS队列发现的HIV/MTB双重感染患者病死率为15.16%（384/2 533）,高于单纯感染HIV者随访1年的病死率（13.63%,1 603/11 760）（P<0.000 1）;19.33%（384/1 987）当年登记、当年死亡的HIV/AIDS由感染MTB引起。HIV/AIDS队列和结核病队列发现的双重感染分别有60.05%（1 521/2 533）、47.90%（1 126/2 351）开始抗病毒治疗;HIV/AIDS队列发现的结核病患者结核病治愈率为15.48%（392/2 533）,完成疗程比例为27.48%（696/2 533）;结核病队列发现的HIV/AIDS其结核病治愈率为19.70%（463/2 351）,完成疗程比例为37.26%（876/2 351）;64.13%（785/1 224）HIV/MTB双重感染报告时CD4⁺T淋巴细胞计数（CD4）<200个/μl。与单纯感染HIV者相比,HIV/MTB双重感染患者5年死亡风险增高1.17倍,和单纯感染MTB者相比,HIV/MTB双重感染者12个月死亡风险增加25.68倍。结论 广西HIV/MTB双重感染死亡、发病占报告艾滋病患者比例较高,病死率及死亡风险明显高于单纯感染HIV者及单纯感染MTB者;应该尽快提高抗病毒治疗覆盖率和抗结核治愈率;针对HIV感染者,应加强早发现和早治疗MTB感染。     

Early ancient sublineages of Mycobacterium tuberculosis Beijing genotype: unexpected clues from phylogenomics of the pathogen and human history

ObjectiveThe Mycobacterium tuberculosis Beijing family is an epidemiologically important lineage subdivided into large-scale phylogenetic sublineages: ancient, endemic in East Asia, and global modern. Here, we analysed ancient sublineages of the Beijing genotype in the Omsk region of southwestern Siberia, an intriguing area at the intersection of European Russia, Siberia, and Central Asia.MethodsThe study included 423 M. tuberculosis strains isolated in 2013–2017 and subjected to drug susceptibility testing, genotyping, and whole genome sequencing.ResultsThe Beijing genotype constituted 280 out of 423 strains. Forty Beijing strains belonged to the early ancient sublineage (wild type mutT4-48). Of these, 11 belonged to the 14717-15 MIRU-VNTR cluster and had intact RD181, 29 belonged to the 1071-32 cluster and had the RD181 deletion. Thirty-nine ancient strains were multidrug-resistant (MDR) and 20 pre-extensively drug resistant (XDR)/XDR. Comparison with global data demonstrated that these clones circulate mainly in Asian Russia with certain phylogenetic affinity to strains from Japan, Korea, and northeastern China. The genome-wide analysis revealed 29–37 single nucleotide polymorphism distances between isolates from different Russian regions within these two clusters.ConclusionsBased on phylogenetic, phylogeographic, genomic, and historical data, we hypothesize that these two clones or their direct ancestors were probably brought to Russia ～70 years ago after the Second World War with Japanese prisoners of war and, until recently, were mainly circulating in Siberia and the Far East. Their elevated prevalence in Omsk along with the extremely strong association with not only MDR but also pre-XDR/XDR also observed in other locations highlight their epidemic potential and the need for monitoring and attention from health authorities.     

Design,Synthesis, and in vitro antitubercular activity of 1,2,3‐triazolyl‐dihydroquinoline derivatives

In the quest for new active molecules against Mycobacterium tuberculosis, a series of dihydroquinoline derivatives possessing triazolo substituents were efficiently synthesized using click chemistry. The structure of 6l was evidenced by X‐ray crystallographic study. The newly synthesized compounds were evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv (ATCC27294). The compounds 6a , 6g, and 6j (MIC: 3.13 μg/ml) showed promising activity when compared to the first‐line drug such as ethambutol. In addition, the structure and antitubercular activity relationship were further supported by in silico molecular docking studies of the active compounds against 3IVX.PDB (crystal structure of pantothenate synthetase in complex with 2‐(2‐(benzofuran‐2‐ylsulfonylcarbamoyl)‐5‐methoxy‐1H‐indol‐1‐yl)acetic acid).     

某院结核分枝杆菌利福平和异烟肼耐药基因特征

目的了解某院结核分枝杆菌(MTB)利福平耐药相关基因rpo B及异烟肼耐药相关基因kat G、inh A的突变特征,为耐药结核病的预防和治疗提供科学依据。方法收集83例结核病患者痰标本,分离培养MTB,采用BD960液体法检测利福平、异烟肼耐药性,提取菌株DNA,采用聚合酶链反应扩增rpo B、kat G、inh A全基因,对扩增产物进行测序分析。结果 83株样本中,39株对利福平耐药,51株对异烟肼耐药。耐利福平菌株rpo B基因突变率为97.44%(38/39),531位点突变率60.53%(23/38),526位点突变率23.68%(9/38),32株出现多位点联合突变。耐异烟肼菌株kat G基因突变率为98.04%(50/51),共发现16种突变类型,其中以kat G 315位点突变为主,占70.00%(35/50),1株为kat G与inh A联合突变。结论该院耐多药MTB产生耐药性与rpo B和kat G基因突变相关,检测MTB耐多药相关基因突变可为早期快速诊断耐药结核病提供参考依据。     

PCR method is essential for detecting Mycobacterium tuberculosis in oral cavity samples

Tuberculosis is a re-emerging infectious disease, and infection by Mycobacterium tuberculosis has been increasing in immunocompromised hosts, including elderly persons. M. tuberculosis-infected persons may receive dental treatment. To evaluate the risk of M. tuberculosis infection in dental clinics, we examined the detection rates of M. tuberculosis in sample of mixed saliva, dental plaque, extracted teeth, caries lesions, and denture plaque by nested polymerase chain reaction (PCR). The detection rates by PCR in samples from mixed saliva, dental plaque, caries lesions and denture plaque obtained from tuberculosis patients were 98.0%, 92.0%, 89.0%, and 100%, respectively. The detection rates by the culture method were 17.3%, 2.0%, 0%, and 0%, respectively. M. tuberculosis also was detected from the nontuberculous mycobacteria-infected group. Strains of Actinomyces naeslundii, Porphyromonas gingivalis, and Fusobacterium nucleatum inhibited the growth of clinical strains of M. tuberculosis, but strains of Streptococcus mutans, Streptococcus sanguinis, and Actinobacillus actinomycetemcomitans did not. The present study concludes that the PCR method is essential for detecting M. tuberculosis in oral samples.     

中国结核分枝杆菌谱系2群体遗传学研究

目的 研究中国流行的结核分枝杆菌谱系2的遗传结构和地理分布,为制定结核病防控策略提供科学依据。方法 采用标准15位点分枝杆菌散在重复单位-数目可变串联重复序列（variable number tandem repeats,VNTR）技术对来自全国31省市抽样调查的2 900株结核分枝杆菌谱系2进行基因分型。基于上述菌株15-VNTR数据,采用贝叶斯聚类法STRUCTURE进行群体遗传结构分析;构建邻接（Neighbor-Joining,NJ）树和最小生成树（Minimum Spanning Trees,MST）进行群体遗传分化分析。运用主成分分析（principal component analysis,PCA）验证。结果 STRUCTURE分析显示谱系2可分为4个亚群;MST拓扑结构提示亚群2位于奠基者位置,较古老;其他亚群（亚群1、3、4）位于分枝位置,较现代。亚群2主要分布于西南地区和东北三省;亚群1,3,4主要分布于我国东中部地区,推测由于人口的迁徙,造成菌株间遗传距离较近,由东北地区向东中部地区传播。主成分分析显示4群菌株分化不明显。结论 结核分枝杆菌谱系2可分为4个亚群,各亚群的遗传地理分布不同,上述结果对制定我国精准结核病防控策略将产生积极影响。