MALDI-TOF-MS检测分枝杆菌属正确率的荟萃分析

目的对MALDI-TOF MS快速检测分枝杆菌属的正确率进行荟萃(meta)评价。方法收集1990-2015年,国外公开发表的关于MALDI-TOF MS检测分枝杆菌的文献,按meta分析的要求对文献进行检索、筛选,对纳入的文献进行质量评价,对符合条件的研究进行meta分析。结果共有11篇文献纳入,对各文献的研究进行数据提取后合并MALDI-TOF MS鉴定分枝杆菌属的正确率,结果正确率为91%。结论 MALDI-TOF MS对分枝杆菌属的鉴定有较好的准确性。     

临床分离的结核分枝杆菌的耐药性分析

目的了解海盐县分离自肺结核病人的结核分枝杆菌耐药基因突变率及耐药情况,以利抗结核治疗中抗菌药物的合理选用。方法对痰涂片阳性的新发初治和复治肺结核病人进行痰结核分枝杆菌培养,阳性菌株采用高、低两种药物浓度,四种抗结核药物耐药性测试,同时用实时PCR法对结核分枝杆菌的耐药基因rpoB和katG突变进行检测。结果131例痰培养阳性菌株总耐药率为14.5%,其中初治耐药率7.8%,复治耐药率38.2%,对四种抗结核药物的耐药率依次为异烟肼9.2%,利福平4.6%,链霉素4.6%,乙胺丁醇0.8%。耐药基因检测结果,在初治组中rpoB和katG的突变率为12.7%(13/102)和10.8%(11/102)。复治组中rpoB和katG的突变率为31.0%(9/29)和20.7%(6/29)。结论本地区分离自结核病人的结核分枝杆菌在初始治疗时已存在耐药性,而药物治疗有可能使其耐药性增加。结果表明抗结核治疗前及在治疗过程中对结核分枝杆菌进行耐药性及耐药基因检测很有意义。     

Microbial substitution of <Emphasis Type="Italic">Mycobacterium avium-intracellulare</Emphasis> to <Emphasis Type="Italic">Mycobacterium abscessus</Emphasis> during clinical course

Mycobacterium avium-intracellulare (MAI) is, among acid-fast bacilli, the most common cause of nontuberculous pulmonary diseases, and MAI infections are often treated according to the guidelines of the American Thoracic Society. However, despite the use of multiple drugs, patients sometimes do not recover with the initial round of treatment. Other kinds of nontuberculous mycobacteria are sometimes found in patients' respiratory samples, even during such treatment for MAI pulmonary disease. We experienced three patients with pulmonary disease due to Mycobacterium abscessus (MA) in whom the disease was difficult to treat because of resistance to all the antituberculous agents used. MA infection had occurred in these patients after long-term treatment with multiple drugs for previous MAI pulmonary disease. We considered that the MA infection in these patients appeared to be the result of insufficient efficacy of the drugs used for MAI and insufficiently aggressive use of antituberculous agents. It thus appeared that MA infection was the result of microbial substitution, and that, if this is the case, the guidelines for the treatment of MAI may need to be modified to eliminate microbial substitution.     

Reduced phagocytic activity of human alveolar macrophages infected with Mycobacterium avium complex

IntroductionCo-infection of nontuberculous mycobacteria (NTM) with other bacteria is associated with increased frequency of hospitalization and reduced quality of life. However, the clinical significance of co-infection with NTM and other bacteria remains unclear. Here, we investigated the distribution of alveolar macrophage populations, characterized their phagocytic function in bronchoalveolar lavage fluid (BALF), and assessed the bactericidal function of macrophages infected with NTM using cell lines.MethodsBALF samples were prospectively obtained from 30 patients with suspected NTM lung disease to evaluate phagocytic activities of macrophages using immunostaining. Bactericidal activities of Staphylococcus aureus (S. aureus) and Mycobacterium intracellulare (M. intracellulare)-infected or -non-infected macrophages were evaluated using macrophage cell lines.ResultsEleven patients with Mycobacterium avium complex (MAC) infection and 19 patients with chronic lower respiratory tract infections except for NTM infection (controls) were enrolled. The percentage of non-polarized (HLA-DR⁺, CD40^?, and CD163^?) macrophages in patients infected with MAC was significantly higher than that in controls; non-polarized macrophages demonstrated an impaired ability to phagocytose S. aureus. In vitro experiments revealed higher intracellular S. aureus colony-forming unit counts and proinflammatory cytokine levels in M. intracellulare-infected macrophages than in non-NTM-infected macrophages. Electron microscopy showed morphologically damaged macrophages and M. intracellulare and S. aureus growing in the same phagosome.ConclusionThe proportion of alveolar macrophages (HLA-DR⁺, CD40^?, and CD163^?) with impaired phagocytosis increased in MAC-infected individuals. M. intracellulare-infected macrophages reduced bactericidal activity in vitro. Dysfunction of alveolar macrophages may contribute to persistent infection by other bacteria, leading to MAC lung disease progression.     

安徽东部地区结核分枝杆菌基因分型及耐药情况的初步分析

目的 了解安徽东部地区结核分枝杆菌基因分型及耐药情况,为本地区肺结核的防治提供依据.方法 对从临床收集的80例结核菌株进行培养,分别通过可变数目串联重复序列分型技术、药敏实验对菌株进行分型、耐药情况分析.结果 单耐药菌株占25.00％,多耐药菌株占23.75％.单耐药菌株以利福平和对氨基水杨酸占多数,分别为28.75％和22.50％;多耐药菌株以对异烟肼和利福平耐药最多,占52.63％.初治病人和复治病人对吡嗪酰胺耐药差异有统计学意义(P =0.032),对其他药物的耐药差异均无统计学意义(均有P＞0.05).15个基因位点均呈现等位基因多态性,QUB11a位点多态性最高为0.85,Mtub31位点仅为0.11.80株菌株可分为33个基因型,仅有16例患者的分离株为单一基因型,其余菌株可归入14个簇.结论 本地区结核分支杆菌的耐药率较高,基因分型复杂.     

Mycobacterium bovis Infection in Humans and Cats in Same Household,Texas, USA, 2012

Mycobacterium bovis infection of cats is exceedingly rare in regions where bovine tuberculosis is not endemic. We describe the diagnosis and clinical management of pulmonary M. bovis infection in 2 indoor-housed cats and their association with at least 1 M. bovis–infected human in Texas, USA, in September 2012.     

Seasonal Patterns of Buruli Ulcer Incidence,Central Africa, 2002–2012

To determine when risk for Buruli ulcer is highest, we examined seasonal patterns in a highly disease-endemic area of Cameroon during 2002–2012. Cases peaked in March, suggesting that risk is highest during the high rainy season. During and after this season, populations should increase protective behaviors, and case detection efforts should be intensified.     

Buruli Ulcer in Traveler from Suriname,South America,to the Netherlands

We report Buruli ulcer in a man in the Netherlands. Phenotyping of samples indicate the Buruli pathogen was acquired in Suriname and activated by trauma on return to the Netherlands. Awareness of this disease by clinicians in non–Buruli ulcer–endemic areas is critical for identification.     

Characteristics of Tuberculosis Cases that Started Outbreaks in the United States, 2002–2011

A review of 26 tuberculosis outbreaks in the United States (2002–2011) showed that initial source case-patients had long infectious periods (median 10 months) and were characterized by substance abuse, incarceration, and homelessness. Improved timeliness of diagnosis and thorough contact investigations for such cases may reduce the risk for outbreaks.     

Induction and treatment of anergy in murine leprosy

Leprosy is a disease consisting of a spectrum of clinical, bacteriological, histopathological and immunological manifestations. Tuberculoid leprosy is frequently recognized as the benign polar form of the disease, while lepromatous leprosy is regarded as the malignant form. The different forms of leprosy depend on the genetic and immunological characteristics of the patient and on the characteristics of the leprosy bacillus. The malignant manifestations of lepromatous leprosy result from the mycobacterial‐specific anergy that develops in this form of the disease. Using murine leprosy as a model of anergy in this study, we first induced the development of anergy to Mycobacterium lepraemurium (MLM) in mice and then attempted to reverse it by the administration of dialysable leucocyte extracts (DLE) prepared from healthy (HLT), BCG‐inoculated and MLM‐inoculated mice. Mice inoculated with either MLM or BCG developed a robust cell‐mediated immune response (CMI) that was temporary in the MLM‐inoculated group and long‐lasting in the BCG‐inoculated group. DLE were prepared from the spleens of MLM‐ and BCG‐inoculated mice at the peak of CMI. Independent MLM intradermally‐inoculated groups were treated every other day with HLT‐DLE, BCG‐DLE or MLM‐DLE, and the effect was documented for 98 days. DLE administered at a dose of 1.0 U (1 × 10⁶ splenocytes) did not affect the evolution of leprosy, while DLE given at a dose of 0.1 U showed beneficial effects regardless of the DLE source. The dose but not the specificity of DLE was the determining factor for reversing anergy.