湖南省525株非结核分枝杆菌临床分离株的菌种鉴定与流行特征

目的 对2019-2020年湖南省分离的非结核分枝杆菌(NTM)进行菌种鉴定,并分析其分布特征,为非结核分枝杆菌病的防治提供基础科学依据。方法 收集2019-2020年湖南省胸科医院疑似结核病患者分离到的分枝杆菌临床分离株,通过MPB64蛋白免疫胶体金法、PNB(对硝基苯甲酸)培养基生长试验进行结核分枝杆菌复合群和NTM鉴定,应用16S rRNA和Hsp65测序分析法对NTM菌株进行菌种鉴定。结果 共收集到6 515份分枝杆菌阳性培养物,初步鉴定为NTM共525株,占比8.06%,其中分离于男性患者285株,占比54.29%;女性患者240株,占比45.71%;人群分布以农民为主,共367株,占比69.90%;年龄分布以40岁以上中老年患者最多,共402株,占比76.57%。2019-2020年NTM菌种分布达27种,菌种分布位列前4者分别为脓肿分枝杆菌(190株,36.19%)、胞内分枝杆菌(174株,33.14%)、鸟分枝杆菌(64株,12.19%)、戈登分枝杆菌(47株,8.95%);其它50株(9.52%)包含23种NTM。脓肿分枝杆菌主要在郴州市、湘西自治州地区、衡阳市和永州市等地区流行;胞内分枝杆菌主要在郴州市、岳阳市和湘潭市流行。结论 2019-2020年湖南地区分枝杆菌中NTM检出率仍保持较高水平,以脓肿分枝杆菌、胞内分枝杆菌、鸟分枝杆菌和戈登分枝杆菌为主;感染人群以男性、中老年、农民为主。     

Clinical significance of nontuberculous mycobacteria isolated from respiratory specimens in Korea

STUDY OBJECTIVES: Precise epidemiologic data regarding nontuberculous mycobacterial (NTM) lung infection in many Asian countries have been relatively unavailable. In order to determine the clinical significance of NTM isolated from respiratory specimens, we reviewed medical records from all patients from whom NTM isolates were recovered within a 2-year period. MATERIALS AND METHODS: We identified all NTM isolates from respiratory specimens at the Samsung Medical Center (Seoul, South Korea) obtained from January 2002 to December 2003. We then reviewed the clinical and radiologic characteristics of the patients from whom NTM was isolated. Patients were classified as having either definite, probable, or unlikely NTM lung disease, as defined by the guidelines of both the American Thoracic Society and the British Thoracic Society. RESULTS: During the study period, 1,548 NTM isolates were recovered from 794 patients. Of these 794 patients, 131 patients (17%) were determined to have definite NTM lung disease, and 64 patients (8%) were designated as probable disease candidates. The most commonly involved organisms in the definite and probable NTM lung disease cases were Mycobacterium avium complex (n = 94, 48%) and Mycobacterium abscessus (n = 64, 33%). In 195 patients with NTM lung disease, 82 patients (42%) manifested the upper lobe cavitary form, 101 patients (52%) exhibited the nodular bronchiectatic form, and 12 patients (6%) exhibited the unclassifiable form. CONCLUSIONS: About one fourth of the patients in whom NTM was isolated from respiratory specimens were found to have clinically significant NTM lung infections. The spectrum of organisms responsible for the NTM lung disease in these Korean patients differed from those reported in other regions of the world. However, the estimates of clinical significance in this study may be underestimates due to the retrospective analysis. Some of the patients might have "true" NTM lung disease that could be diagnosed with continued evaluation and follow-up.     

非结核分支杆菌肺病24例临床分析

目的总结非结核分支杆菌(NTM)肺病的临床特点。方法回顾性分析我所1994年至2004年间收治的24例NTM肺病的临床特点。结果本组NTM肺病以老年患者多见,症状较轻,肺部病变范围广,耐药率高,治疗效果差,部分患者持续菌阳。结论NTM肺病治疗方案有待探讨。     

Pathogenesis of nontuberculous mycobacteria infections

M avium is a microorganism well adapted to living in the environment and in different hosts. During the past 15 years, a substantial amount of information has been accumulated about the mechanisms used by M avium to cross the host's mucosal barrier, replicate inside cells, circumvent the host's immune response, and persist inside the host. It turns out that M avium is a fascinating pathogen after all. The increasing knowledge about M avium pathogenesis may one day provide means for a more effective prophylaxis as well as for treatment of the infection.     

Identification and characterization of nontuberculous mycobacteria isolated from suspected pulmonary tuberculosis patients in eastern china from 2009 to 2019 using an identification array system

ObjectiveNontuberculous mycobacteria (NTM) species are increasingly being isolated and have become a key factor affecting public health by causing pulmonary diseases. Most NTM species do not respond to conventional tuberculosis (TB) drugs. This study aimed to identify NTM isolated from suspected pulmonary TB patients from the Zhejiang province and analyze their distribution in the region.MethodsA total of 1,113 NTM isolates from patients suspected to be suffering from acid-fast bacilli-positive tuberculosis were identified at the species level, using the CapitalBio Mycobacterium identification array and polymerase chain reaction amplification and sequencing of 16S-23S gene internal transcribed spacer (ITS), 16S rRNA, and hsp65.ResultsOf the 23,138 isolates, we identified 1,102 NTM (4.8%), mainly including Mycobacterium intracellulare (54.81%, 604/1,102), M. chelonae-M. abscessus (16.52%, 182/1,102), M. avium (13.16%, 145/1,102), M. kansasii (8.17%, 90/1,102), and M. gordonae (3.27%, 36/1,102).ConclusionThe distribution of NTM species observed in patients with suspected pulmonary tuberculosis provides guidance for the diagnosis and treatment of NTM pulmonary diseases.     

非结核分枝杆菌相关研究新进展

非结核分枝杆菌在自然界中广泛存在,部分可引起人类疾病.因非结核分枝杆菌对多种抗结核药物耐药,且诊断困难、患者预后较差,使非结核分枝杆菌感染性疾病逐渐成为医学界十分关注的研究课题.作者从非结核分枝杆菌种类及感染率、非结核分枝杆菌耐药情况及耐药机制研究、非结核分枝杆菌感染特点及治疗方案、非结核分枝杆菌检测方法及环境水非结核分枝杆菌污染研究等方面综述了非结核分枝杆菌相关的研究进展.其耐药机制及传播机制尚未阐明,需要进行深入研究.     

Laboratory diagnosis of nontuberculous mycobacteria

In conclusion, it is important to realize that there is no "stand alone" assay for the identification of NTM. Many new species may not be recognized in all assays. Newer molecular tests are more accurate for identification than phenotypic tests and have significantly improved turnaround time. Clinical significance of an isolate should be determined, however, before committing resources for the identification of a mycobacterial isolate to the species level. In addition, there are significant differences in the range and quality of services provided by different laboratories. Today, techniques and equipment are increasingly complex and costly, making it more difficult to upgrade every local laboratory to perform these assays. But because specimen delivery and communication of results can be rapidly and easily achieved, utilization of reference laboratories for rarely performed sophisticated tests is a more practical approach.     

Molecular diagnosis of nontuberculous mycobacteria

PURPOSE OF REVIEW: Diagnosis of infection due to nontuberculous mycobacteria is not easy, as it must be distinguished from colonization or contamination by other nontuberculous mycobacteria. Molecular methods offer many advantages over conventional methods of identification. The results are obtained rapidly, are reliable and reproducible, and even mixed or contaminated cultures can be examined. This review highlights the recent advances in molecular techniques for identification of nontuberculous mycobacteria. RECENT FINDINGS: Nontuberculous mycobacteria are ubiquitous towards the environment and have the potential to colonize and cause serious infection. An increasing number of species and clinical presentations are being described, and progress has been made towards the understanding of the underlying predisposing factors. Disease caused by nontuberculous mycobacteria is often associated with various forms of immunosuppression, particularly HIV infection, whereas mild forms of immune defects have been observed in some patients who, apart from their nontuberculous mycobacterial disease, seem to be healthy on initial examination. Molecular techniques have shown their usefulness for the identification of most mycobacteria. Probes are widely used in clinical laboratories for the identification of the most common mycobacterial species. Because automated DNA sequencing and the programs for analysing sequence data have become technically simpler, polymerase chain reaction-based sequencing is now used in many mycobacterial reference laboratories as a routine method for species identification. SUMMARY: Significant advances have been made with molecular tools for diagnosis of mycobacteria. The DNA microarray technique holds great promise for the future because it is easy to perform, it can be readily automated, and it allows the identification of a large number of mycobacterial species in one reaction.     

Drug resistance and its clinical relevance of nontuberculous mycobacteria in Sichuan area

正Objective To analyze the status of infection and drug resistance of nontuberculous mycobacteria(NTM)and its clinical relevance in Sichuan area.Methods Mycobacteria laboratory specimens from January 2014 to December 2015 in Public Health Clinical Center of Chengdu were retrospectively collected and analyzed.NTM identification was performed by gene chip or 16S rDNA     

非结核分支杆菌耐药基因的研究进展

非结核分支杆菌(ＮＴＭ)病的治疗是一个相当棘手的问题,因其对大多数抗结核药物均不敏感。近年来,随着ＮＴＭ感染情况日益严重,对于非结核分支杆菌耐药性问题的研究,便成为目前迫切需要解决的问题。最近,国外学者在ＮＴＭ耐药性基因研究方面作了大量的工作,现将其研究进展作一综述。一、ＮＴＭ与耐异烟肼(ＩＮＨ)ＩＮＨ是结核病治疗最重要的一线药物,它主要是通过抑制细菌分支菌酸的合成而起作用。但对于ＮＴＭ来说,ＩＮＨ并不是一个敏感药物。早年认为:耻垢和金色分支杆菌的ＩＮＨ耐药性可能与ＫａｔＧ基因编码产物———过氧化物-过氧化氢…     

非结核分枝杆菌肺病血清中细胞因子的检测及临床意义简

目的 研究血清白介素1（IL-1）、白介素2受体（IL-2R）、白介素6（IL-6）、白介素8（IL-8）、白介素10（IL-10）、肿瘤坏死因子α（TNF-α）和降钙素原（PCT）的检测在非结核分枝杆菌肺病患者的临床意义.方法 采用酶联免疫方法（ELISA）检测11例非结核分枝杆菌肺病患者和14例对照组血清中IL-1、IL-2R、IL-6、IL-8、IL-10、TNF-α和PCT的水平变化.结果 与对照组相比较,非结核分枝杆菌肺病组血清中TNF-α的含量明显升高（P〈0.05）,而IL-1 IL-2R、IL-6、IL-8、IL-10和PCT等五个细胞因子的含量无明显变化（P〉0.05）.进一步分析结果显示,非结核分枝杆菌肺病组血清中TNF-α等六个细胞因子的含量变化与有否空洞无关（P〉0.05）.结论 血清TNF-α在非结核分枝杆菌肺病患者血清中明显升高,可作为非结核分枝杆菌肺病感染诊断的辅助指标.     

Analysis of distribution characteristics of clinical isolates of nontuberculous mycobacteria in a general hospital

正Objective To investigate the current prevalence of nontuberculous mycobacteria(NTM)in Shanghai,and to study the distribution characteristics of NTM clinical isolates,which may help to improve the diagnostic level of NTM and provide guidance for effective prevention and treatment of NTM infection.Methods Culture-positive isolates of clinical mycobacteria were collected from 2008     

339株非结核分枝杆菌临床分离株菌种鉴定及耐药性分析

回顾性分析2014年3月至2019年3月天津市海河医院经罗氏培养和“DNA微阵列芯片技术”确定的339株非结核分枝杆菌(NTM),并对其药物敏感性试验(简称“药敏试验”)结果进行分析。339株NTM临床分离株中,排在前3位者分别为胞内分枝杆菌38.6%(131/339)、龟-脓肿分枝杆菌21.2%(72/339)、堪萨斯分枝杆菌18.3%(62/339)。体外药敏试验显示胞内分枝杆菌、堪萨斯分枝杆菌和龟-脓肿分枝杆菌对8种抗结核药品(异烟肼、利福平、链霉素、乙胺丁醇、对氨基水杨酸、卡那霉素、卷曲霉素、氧氟沙星)耐药率情况为:胞内分枝杆菌的耐药率分别为95.6%(108/113)、82.3%(93/113)、94.7%(107/113)、54.0%(61/113)、92.0%(69/75)、81.3%(61/75)、85.3%(64/75)、87.5%(49/56);堪萨斯分枝杆菌的耐药率分别为100.0%(54/54)、3.7%(2/54)、98.1%(53/54)、11.1%(6/54)、95.0%(38/40)、90.0%(36/40)、27.5%(11/40)、13.8%(4/29);龟-脓肿分枝杆菌的耐药率分别为96.9%(62/64)、93.8%(60/64)、95.3%(61/64)、92.2%(59/64)、88.4%(38/43)、86.0%(37/43)、88.4%(38/43)、87.1%(27/31)。临床分离NTM菌种以胞内分枝杆菌、龟-脓肿分枝杆菌、堪萨斯分枝杆菌为主,其中胞内分枝杆菌、龟-脓肿分枝杆菌对常用一线、二线抗结核药品具有较高的耐药性,堪萨斯分枝杆菌对利福平、乙胺丁醇、氧氟沙星、卷曲霉素的耐药率低。     

Overview of respiratory infection caused by nontuberculous mycobacteria

Recently, the clinical importance of nontuberculous mycobacteria (especially, Mycobacterium avium complex [MAC] respiratory infection) has been increasing. In addition, an official ATS/IDSA statement about diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases has been published in February, 2007. In this review article, essence of this official statement will be introduced. In MAC respiratory infection, (i) primarily fibrocavitary disease, (ii) nodular/bronchiectatic disease, and (iii) hypersensitivity-like disease are identified, and (i) and (ii) are clinically important. Primarily fibrocavitary disease is characterized by cavitary lesions in upper lung fields in elderly subjects, smoking patients, or patients with pneumoconiosis. Nodular/bronchiectatic disease is characterized by centrilobular nodules and diffuse bronchiectases in the right middle lobe and the left lingula in middle-aged women. In addition, disseminated MAC disease in patients with acquired immunodeficiency syndrome should be considered. Further studies concerning transmission route as well as mechanism of MAC disease should be performed.     

Epidemiology of human pulmonary infection with nontuberculous mycobacteria

A great deal of study has gone into the assessment of the epidemiology of NTM infection and disease in many different parts of the world. Review of the available studies provides insight into the frequency of this clinical problem as well as important limitations in current data. Study methods have varied greatly, undoubtedly leading to differing biases. In general, reported rates of infection and disease are likely underestimates, with the former probably less accurate than the latter, given that people without significant symptoms are not likely to have intensive investigations to detect infection. Pulmonary NTM is a problem with differing rates in various parts of the world. North American rates of infection and disease have been reported to range from approximately 1-15 per 100,000 and 0.1-2 per 100,000, respectively (see Table 1). Rates have been observed to increase with coincident decreases in TB. MAC has been reported most commonly, followed by rapid growers and M kansasii. Generally similar rates have been reported in European studies, with the exception of extremely high rates in an area of the Czech Republic where mining is the dominant industry (see Table 2). These studies have also shown marked geographic variability in prevalence. The only available population-based studies have been in South Africa and report extremely high rates of infection, three orders of magnitude greater than studies from other parts of the world (see Table 3). This undoubtedly reflects the select population with an extremely high rate of TB and resultant bronchiectasis leading to NTM infection. Rates in Japan and Australia were similar to those reported in Europe and North America and also show significant increases over time (see Table 3). Specific risk factors have been identified in several studies. CF and HIV, mentioned above, are two important high-risk groups. Other important factors include underlying chronic lung disease, work in the mining industry, warm climate, advancing age, and male sex. Aside from HIV and CF, mining with associated high rates of pneumoconiosis and previous TB may be the most important historically, reported in studies worldwide [63]. A recurring observation is the increase in rates of infection and disease. The reason for this is unclear but may be caused by any of several contributing factors. The possibility exists that the apparent increase is either spurious or less significant than studies would suggest. Changes in clinician awareness leading to increased investigations, or laboratory methods leading to isolation and identification of previously unnoticed organisms, could play a role in this trend, and studies have been published that support [67] and refute [31] this argument. We believe such factors may contribute to but do not explain the significant increases that have been observed. A true increase could be related to the host, the pathogen, or some interaction between the two. Host changes leading to increased susceptibility could play an important role, with increased numbers of patients with inadequate defenses from diseases such as HIV infection, malignancy, or simply advanced age [31]. An increase in susceptibility could also relate to the decrease in infection with two other mycobacteria. It has been speculated that infection with TB [29,38] and Bacillus Calmette-Guerin (BCG) [19,68] may provide cross-immunity protecting against NTM infection. Many investigations have observed decreasing rates of TB concomitant with the increases in NTM. In addition, studies from Sweden [68] and the Czech Republic [19] have found that children who were not vaccinated with BCG had a far higher rate of extrapulmonary NTM infection. Potential changes in the pathogens include increases in NTM virulence, and it has been argued that this should be considered as a possible contributing factor [69]. Finally, an interaction between the host and pathogen could involve a major increase in pathogen exposure or potential inoculum size. This may be occurring secondary to the increase in popularity of showering as a form of bathing [66], a habit that greatly increases respiratory exposure to water contaminants. Several limitations of our review should be noted. We reviewed English-language reports and abstracts, probably leading to fewer data from non-English speaking regions, which may explain the paucity of studies from Africa, Eastern Europe, and most Asian nations. The heterogeneity of study methods in identifying cases and the lack of a uniformly applied definition of disease makes it difficult to compare rates between studies. Finally, the lack of systematic reporting of NTM infection in most nations limits the ability to derive accurate estimates of infection and disease. Regardless, there are more than adequate data to conclude that NTM disease rates vary widely depending on population and geographic location. NTM disease is clearly a major problem in certain groups, including patients with underlying lung disease and also in individuals with impaired immunity. The rates of NTM infection and disease are increasing, so the problem will likely continue to grow and become a far more important issue than current rates suggest.     

Clinical significance of nontuberculous mycobacteria. A bacteriological survey of Swedish strains isolated between 1973 and 1981

An account is rendered of mycobacteria other than Mycobacterium tuberculosis isolated from specimens sent for culture during 9 years. The possible etiological significance of these bacteria was estimated from clinical data and the degree of bacterial growth. Pulmonary infection was the most common nontuberculous manifestation in the adults. In about 50% of the patients with slowly growing mycobacteria in their respiratory tract, these bacteria were considered to be an etiological factor. This applied to the species of the M. avium-intracellulare (MAI) complex and M. xenopi. M. Kansasii, a common cause of lung disease in many other countries, was rarely isolated. The corresponding figure for the rapidly growing mycobacteria belonging to the M. fortuitum-chelonei complex was 15%. These patients were all severely debilitated by other diseases. Lymphadenitis was the most common nontuberculous infection in children, but occurred only in children not vaccinated with BCG. Bacteria of the MAI complex was the predominating cause. Lung infection caused by nontuberculous mycobacteria did not occur in children.     

Antibacterial activities of dendritic amphiphiles against nontuberculous mycobacteria

The anti-mycobacterial activities of nine series of dicarboxyl and tricarboxyl dendritic amphiphiles with one alkyl, two alkyl, and cholestanyl tails against Mycobacterium abscessus, Mycobacterium avium, Mycobacterium chelonae, Mycobacterium marinum and Mycobacterium smegmatis have been measured. The dendritic amphiphiles overcame the limited aqueous solubility of natural long-chain fatty acids, alcohols, and amines to enable profiling the susceptibilities of the different mycobacterial species to the physicochemical properties of these amphiphiles. Several dendritic amphiphiles showed strong anti-mycobacterial activity with high critical micelle concentrations and low hemolytic activities thereby offering platforms for the development of antibiotics of higher activity against nontuberculous mycobacteria.     

Misdiagnosis of tuberculosis associated with some species of nontuberculous mycobacteria by GeneXpert MTB/RIF assay

Out of 12 nontuberculous mycobacteria (NTM) species, 5 were identified as Mycobacterium tuberculosis (MTB) by GeneXpert at a bacterial load of 10⁶. Notably, two species, including M. abscessus and M. smegmatis, were flagged as RIF-resistant MTB due to the high C(t) value of Probe E. In conclusion, our data have demonstrated that the misdiagnosis of MTB by GeneXpert assay is observed in five NTM species at a high bacterial load.