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.     

Prevalencia e importancia de micobacterias no tuberculosas en pacientes adultos con fibrosis quística en un hospital de Madrid

IntroductionThe role of non-tuberculous mycobacteria (NTM) among cystic fibrosis (CF) patients, on occasion, remains unknown. The aim of our study is to evaluate the prevalence and clinical/microbiological characteristics of CF adult patients colonized by NTM, highlighting Mycobacterium abscessus (M. abscessus).MethodsA retrospective study was conducted with 92 CF adult patients: including a control group of 64 patients, not colonized by NTM, and a study group of 28 patients, colonized by NTM. We have analyzed variables such as age, F508del mutation, lung function, pancreatic involvement, auramine staining and co-colonizations between both groups.ResultsThe prevalence of NTM found was 30.4%. The most prevalent was Mycobacterium avium complex followed by M. abscessus. For M. abscessus, in the comparative study with patients colonized by other NTM, significant results were obtained for variables age.DiscussionWe have found a high prevalence of NTM among adult patients with CF, and we associated the presence of M. asbcessus with ages less than 30 years and F508del. Due to the pathogenic role of NTM, especially M. asbcessus, multicenter studies are required within the population suffering from CF.     

Decreased Cytokine Production in Patients with Nontuberculous Mycobacterial Lung Disease

Nontuberculous mycobacteria (NTM) are intracellular pathogens that elicit a specific T-cell response characterized by the production of proinflammatory cytokines, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-12. However, little information exists regarding the levels of specific cytokines in patients with NTM lung disease. Therefore, we compared cytokine production in peripheral blood mononuclear cells (PBMCs) from patients with NTM lung disease with that in PBMCs from healthy controls. Pro- and anti-inflammatory cytokine production was measured by enzyme-linked immunosorbent assay in the PBMCs of 29 patients with NTM lung disease and 15 healthy controls. Phytohemagglutinin (PHA)-induced IFN-γ production and lipopolysaccharide (LPS)-induced production of TNF-α and IL-12p40 were significantly lower in the PBMCs of patients with NTM lung disease than in those of the healthy controls. The production of these cytokines did not differ significantly between patients infected with Mycobacterium avium complex (MAC) and those infected with Mycobacterium abscessus; however, IL-10 production was lower in patients infected with M. abscessus than in those infected with MAC. Decreased IFN-γ, TNF-α, and IL-12 production may be associated with host susceptibility to the development of MAC and M. abscessus lung disease.     

Non-tuberculous Mycobacterial Pseudo-outbreak of an Intestinal Culture Specimen Caused by a Water Tap in an Endoscopy Unit

Objective Gastrointestinal lesions of non-tuberculous mycobacteria (NTM) are regarded as opportunistic infections. A large number of positive specimens of NTM were identified in an intestinal fluid culture in the endoscopy unit and it was considered to be a pseudo-outbreak. Methods We reviewed the hospital, laboratory, and colonoscopy records of 263 consecutive patients whose intestinal fluids were analyzed for a mycobacterial culture by colonoscopy at St. Marianna University Hospital, between January 2009 and December 2018. The endoscopy reprocessing procedures were reviewed and samples of water used in the endoscopy unit were cultured. Results An intestinal fluid culture of 154 (58.6%) patients tested positive for NTM (M. intracellulare; 125 cases, M. gordonae; 14 cases, M. avium; 4 cases, M. abscessus; 3 cases, and 8 other cases). In 182 cases (69.2%), an intestinal mucosal culture was performed simultaneously with a fluid culture and tested positive for NTM in 2 cases. Next, we examined the endoscopy unit for any possible environmental contamination. NTM were detected in the tap water used to prepare the antifoaming solution in the endoscopy unit. The water faucets in the endoscopy unit were considered to be the source of the contamination of NTMs. Conclusion We observed that a large number of cases tested positive due to contaminated water that had been used in an endoscopy unit, thus leading to a pseudo-outbreak of NTM.     

Clinical features of infection caused by non-tuberculous mycobacteria: 7 years’ experience

Introduction

Non-tuberculous mycobacteria (NTM) are ubiquitous organisms associated with various infections. The aim of the study was to determine the most relevant clinical characteristics of NTM during the 7-year period.

Methodology

A retrospective study of NTM infections was conducted between January 2009 and December 2016. The American Thoracic Society/Infectious Disease Society of America criteria were used to define cases of pulmonary or an extrapulmonary site.

Results

A total of 85 patients were included in the study. Pulmonary cases predominated 83/85 (98%), while extrapulmonary NTM were present in 2/95 (2%) patients. Overall, ten different NTM species were isolated. The most common organisms were slow-growing mycobacteria (SGM) presented in 70/85 (82.35%) patients. Isolated SGM strains were Mycobacterium avium complex (MAC) in 25/85 (29.41%) patients, M. xenopi in 20/85 (23.53%) patients, M. kansasii in 15/85 (17.65%) patients and M. peregrinum and M. gordonae in 5/85 (5.88%) patients each. Isolated rapid-growing mycobacteria (RGM) strains were M. abscessus in 8/85 (9.41%) patients, M. fortuitum in 4/85 (4.71%) patients and M. chelonae in 3/85 (3.53%) patients. Almost all patients (98%; 83/85) had comorbidities. Among 75 (88.24%) patients who completed follow-up, 59 (69.41%), 10 (11.76%) and 6 (7%), were cured, experienced relapse and died, respectively.

Conclusion

In the present study, pulmonary NTM infections were more frequent compared to extrapulmonary disease forms. SGM were most common isolates with MAC pulmonary disease the most frequently found. Comorbidities have an important role in NTM occurrence. Further investigation should focus on an NTM drug susceptibility testing.

     

Regional differences of nontuberculous mycobacteria species in Ulsan,Korea

Background

In Korea recently, nontuberculous mycobacteria (NTM) have been more frequently isolated in respiratory specimens, while Mycobacterium tuberculosis (MTB) isolations have decreased. The major NTM lung disease species in Korea are M. intracellulare, M. avium, and M. abscessus, whereas M. kansasii is a rare species. This retrospective study was performed to determine if there are region-specific characteristics of lung disease-causing NTM species in Ulsan, a highly industrialized city in Korea.

Methods

Between January 2010 and July 2013, the results of all acid-fast bacilli (AFB) cultures of respiratory specimens performed at Ulsan University Hospital (Ulsan, Korea) were collected. NTM were identified and regional differences of NTM species were compared.

Results

AFB cultures were performed on 33,567 respiratory specimens, obtained from 10,208 patients, during the study period. Further, 10% of the specimens (3,287/33,567) were AFB culture-positive [MTB, 2,288/3,287 (70%); NTM 999/3,287 (30%)]. The proportion of NTM isolations gradually increased between 2010 and 2013, at 25% and 38%, respectively. The most common NTM species was M. intracellulare (356/999, 36%), followed by M. kansasii (295/999, 30%), M. avium (161/999, 16%), M. abscessus (117/999, 12%) and M. fortuitum (39/999, 4%). This trend was maintained throughout the study period.

Conclusions

In Ulsan, NTM isolation from respiratory specimens is increasing, consistent with previous studies performed in Korea. The distribution of respiratory NTM species, however, differed from previous studies that were performed in other regions of Korea: M. kansasii was the second most common NTM species in Ulsan. In Ulsan, there is a regional difference in the NTM species isolated.     

Nontuberculous mycobacterial lung disease in patients without HIV infection: a retrospective analysis over 3 years

Introduction: Nontuberculous mycobacterial lung infections are relatively common in immunocompromised patients but are now increasingly being diagnosed in immunocompetent individuals. These organisms are not always pathogenic bacteria when isolated from human samples. The identification of which isolates are contaminants or colonizers is based on internationally accepted criteria. The clinical significance of the isolation of nontuberculous mycobacteria (NTM) from respiratory specimens in Italy is unknown. Objective: study was performed to evaluate the local epidemiology of NTM pulmonary infection in Naples in patients with positive respiratory specimens, and also to describe the clinical and radiological features of NTM pulmonary disease in immunocompetent patients with or without pre‐existing lung disease. Methods: Between December 2006 and September 2009, the clinical records and radiological examinations of 39 patients with 55 positive cultures for NTM species by sputum or bronchial wash or lavage were reviewed. Results: According to microbiological, clinical and radiological criteria, our study identified 16 patients with NTM lung infection as a ‘disease’ group and 23 patients in a ‘contamination’ group but without disease. M. intracellulare (n = 7, 41.2%), followed by M. kansasii (n = 5, 29.4%) were the most common NTM found in the ‘disease’ group. We detected a high number of M. gordonae isolates in respiratory samples obtained by fibrobronchoscopy. Conclusions: We evaluated the clinical significance of isolations in our reference centre in Naples. Forty‐one of all patients have ‘disease’, M. intracellulare and M. kansasii are mainly responsible. NTM species were analyzed in relation to their frequency. Assumptions were made about low pathogenic NTM isolations. Please cite this paper as: Del Giudice G, Iadevaia C, Santoro G, Moscariello E, Smeraglia R and Marzo C. Nontuberculous mycobacterial lung disease in patients without HIV infection: a retrospective analysis over 3 years. Clin Respir J 2011; 5:203–210.     

Micobacterias no tuberculosas. ¿Una amenaza emergente?

Introduction and objective

Non-tuberculous mycobacteria (NTM) isolates are becoming more common. The main objective of our study was to establish the number and diversity of NTM species in our region and their distribution according to the source sample, age and gender of the patients, and to analyse clinically significant isolates.

Risk factors for hemoptysis in Mycobacterium avium complex lung disease

BackgroundHemoptysis is a frequent and sometimes fatal complication of non-tuberculous mycobacterial (NTM) lung disease. The risk factors for hemoptysis are not well understood. In the current study, potential risk factors for hemoptysis were investigated in patients with Mycobacterium avium complex (MAC) lung disease, which is the most common NTM in Japan.MethodsMedical records from the Kinki-Chuo Chest Medical Center were reviewed. Consecutive patients with MAC lung disease diagnosed in 2014 and followed up for more than 1 year in the hospital were included in the study. Hemoptysis was confirmed between 2014 and 2016. The characteristics of patients with hemoptysis and non-hemoptysis at the time of the initial diagnosis of MAC lung disease were obtained from the medical records, and the two groups were compared. The radiological findings assessed included nodules, infiltration shadows, cavities, and bronchiectasis. Each was classified and scored individually in six lung fields, and these data were used to generate radiological scores.ResultsThe study included 82 patients with MAC lung disease, 18 with hemoptysis and 64 without. Higher total radiological severity score at the time of the initial diagnosis of MAC was associated with an increased risk of hemoptysis. Among the radiological scores, infiltration and cavities were marginally associated with the risk of hemoptysis.ConclusionsThe radiological severity score at the time of initial diagnosis of MAC lung disease was associated with hemoptysis.     

Nontuberculosis Mycobacterium Disease is a Risk Factor for Chronic Obstructive Pulmonary Disease: A Nationwide Cohort Study

Background

The aim of this study was to evaluate the association between chronic obstructive pulmonary disease (COPD) and nontuberculosis mycobacterium (NTM) disease.

Methods

We used data from the National Health Insurance Research Database of Taiwan in this study. The NTM cohort contained 3,005 patients, and each case was randomly frequency matched by age, sex, income, occupation, and index year with four people from the general population without NTM infections. Multivariate Cox proportional hazards regression was used to calculate adjusted hazard ratios (aHR) of COPD in the NTM cohort compared with the non-NTM cohort.

Results

The incidence of COPD was 3.08-fold higher (21.75 vs. 6.11 per 1,000 person-years) in the NTM cohort than in the non-NTM cohort. The aHR of COPD comparing the NTM cohort with the non-NTM cohort was 3.57 (95 % CI 2.56–4.97) for women and 2.89 (95 % CI 2.31–3.61) for men. The aHR of COPD was higher in the patients with NTM infection and a comorbidity such as bronchopneumonia, pneumonia, diabetes, asthma, and heart disease. The Mycobacterium avium-intracellulare complex group (MAC) and the non-MAC group were isolated in the NTM cohort. The MAC group had a higher aHR of COPD than the non-NTM cohort (aHR = 3.72, 95 % CI 2.94–4.72). The cumulative incidence of COPD in the NTM cohort was higher than in the non-NTM cohort (P < 0.0001, log rank test).

Conclusions

Physicians should be aware of indolent NTM disease that increases the risk of COPD.     

Pulmonary sequestration infected with nontuberculous mycobacteria: a report of two cases and literature review

We report two cases of pulmonary sequestration infected with nontuberculous mycobacteria (NTM): Mycobacterium avium and Mycobacterium abscessus. Chest computed tomography showed pneumonic consolidation in the right lower lobe, which received a systemic blood supply from the descending aorta in both patients. Video-assisted thoracoscopic surgeries were successfully performed and pathological examinations revealed multiple caseating granulomas. A review of the literature revealed only seven previous case reports of pulmonary sequestration infected with NTM, and no case with Mycobacterium abscessus has been reported.     

Isolation prevalence of pulmonary nontuberculous mycobacteria in Ontario in 2007

BACKGROUND:

The reported prevalence of pulmonary nontuberculous mycobacteria (NTM) infections is increasing.

OBJECTIVE:

To determine the ‘isolation prevalence’ of NTM in 2007 and compare it with previously published research that examined the increasing rates of isolation of NTM from clinical pulmonary specimens between 1997 and 2003.

METHODS:

Isolation prevalence was investigated retrospectively by reviewing a cohort of all positive pulmonary NTM culture results from the Tuberculosis and Mycobacteriology Laboratory, Public Health Laboratory (Toronto, Ontario) in 2007, which identifies at least 95% of NTM isolates in Ontario. Isolation prevalence was calculated as the number of persons with a pulmonary isolate in a calendar year divided by the contemporary population and expressed per 100,000 population. Changes in isolation prevalence from previous years were assessed for statistical significance using generalized linear models with a negative binomial distribution.

RESULTS:

In 2007, 4160 pulmonary isolates of NTM were collected from 2463 patients. The isolation prevalence of all species (excluding Mycobacterium gordonae) was 19 per 100,000 population in 2007 – an increase from previous observations reported for Ontario – corresponding to an average annual increase of 8.5% from 1997 to 2007 (P<0.0001). Average annual increases in isolation prevalence of Mycobacterium avium complex (8.8%, P<0.0001) and Mycobacterium xenopi (7.3%, P=0.0005) were largely responsible for the overall increase, while prevalence rates of rapidly growing mycobacteria remained relatively stable.

CONCLUSION:

The isolation prevalence of pulmonary NTM continues to increase significantly in Ontario, supporting the belief that pulmonary NTM disease is increasingly common.     

Use of MALDI-TOF MS (Bruker Daltonics) for identification of Mycobacterium species isolated directly from liquid medium

ObjectivesThe aim of this study was to describe the evaluation of the use of MALDI-TOF MS for the identification of non-tuberculous mycobacteria (NTM) and Mycobacterium tuberculosis directly from liquid MGIT cultures from January 2017 to December 2017.Material/methodsA total of 155 isolates (mainly respiratory) were analyzed by MALDI-TOF MS (Bruker Daltonics) directly from MGIT liquid medium with a previous extraction procedure.ResultsMALDI-TOF MS generated acceptable scores for 152 isolates (98.06%). Fifty isolates were identified as M. tuberculosis complex and the remaining 105 as NTM (M. abscessus subsp. abscessus, M. avium, M. celatum, M chelonae, M. chimaera, M. fortuitum, M. gordonae, M. intracellulare, M. kansasii, M. lentiflavum, M. mageritense, M. mucogenicum and M. xenopi).ConclusionsThese results indicate that MALDI-TOF MS can be useful to identify mycobacteria directly from MGIT cultures and is an accurate, rapid and cost-effective system to be used as a routine method.     

Misdiagnosis of tuberculosis and the clinical relevance of non—tuberculous mycobacteria in Zambia

ObjectiveTo determine the accuracy of TB diagnosis of TB in Zambia in the era of increasing HIV prevalence.MethodsSputum of the clinically diagnosed TB cases was additionally subjected to liquid culture and molecular identification. This study distinguished between TB cases confirmed by positive Mycobacterium tuberculosis (M. tuberculosis) cultures and mycobacterial disease caused by non-tuberculous mycobacteria (NTM).ResultsOnly 49% of the 173 presumptively diagnosed TB cases was M. tuberculosis cultured, while in 13% (22) cases, a combination of M. tuberculosis and NTM was found. In 18% of the patients only NTM were cultured. In 28%, no mycobacteria was cultivable. HIV positive status was correlated with the isolation of NTM (P <0.05).ConclusionsThe diagnosis of tuberculosis based on symptoms, sputum smear and/or chest X-ray leads to significant numbers of false-positive TB cases in Zambia, most likely due to the increased prevalence of HIV. The role of NTM in tuberculosis-like disease also seems relevant to the false diagnosis of TB in Zambia.     

Infecciones cutáneas y de partes blandas por micobacterias no tuberculosas

The frequency of isolation as well as the number of species of non-tuberculous mycobacteria (NTM) has increased in the last years. Nearly every pathogenic species of NTM may cause skin and soft tissue infections, but rapidly growing mycobacteria (Mycobacterium fortuitum, Mycobacterium chelonae and Mycobacterium abscessus), Mycobacterium marinum and Mycobacterium ulcerans are the most commonly involved. Many of these cutaneous mycobacteriosis, such as rapidly growing mycobacteria, M. marinum, Mycobacterium avium complex, Mycobacterium kansasii or Mycobacterium xenopi are world-wide distributed. In contrast, some others have a specific geographical distribution. This is the case of M. ulcerans, which causes a cutaneous diseases endemic of Central and West Africa (Buruli ulcer) and Australia (Bairnsdale ulcer), being the third mycobacterial infection after tuberculosis and leprosy. Cutaneous mycobacteriosis usually appear either after contact of traumatic or surgical wounds with water or other contaminated products, or, secondarily, as a consequence of a disseminated mycobacterial disease, especially among immunosuppressed patients. For an early diagnosis, it is necessary to maintain a high degree of suspicion in patients with chronic cutaneous diseases and a history of trauma, risk exposure and negative results of conventional microbiological studies. In general, individualized susceptibility testing is not recommended for most NTM infections, except for some species, and in case of therapeutic failure. Treatment includes a combination of different antimicrobial agents, but it must be taken into account that NTM are resistant to conventional antituberculous drugs. Severe cases or those with deep tissues involvement could also be tributary of surgical resection.     

Prognostic Comparison Between Mucinous and Nonmucinous Adenocarcinoma in Colorectal Cancer

Mucinous adenocarcinoma (MAC) is a histological subtype of colorectal cancer. The oncologic behavior of MAC differs from nonmucinous adenocarcinoma (non-MAC). Our aim in this study was to characterize patients with colorectal MAC through evaluation of a large, institutional-based cohort with long-term follow-up.A total of 6475 patients with stages I to III colorectal cancer who underwent radical surgery were enrolled from January 2000 to December 2010. Prognostic comparison between MAC (n = 274, 4.2%) and non-MAC was performed.The median follow-up period was 48.0 months. Patients with MAC were younger than those without MAC (P = 0.012) and had larger tumor size (P < 0.001), higher preoperative carcinoembryonic antigen (P < 0.001), higher pathologic T stage (P < 0.001), more right-sided colon cancer (49.3%, P < 0.001), and more frequent high-frequency microsatellite instability (10.2%, P < 0.001). Five-year disease-free survival (DFS) was 76.5% in the MAC group and 83.2% in the non-MAC group (P = 0.008), and 5-year overall survival was 81.4% versus 87.4%, respectively (P = 0.005). Mucinous histology (MAC vs non-MAC) in the entire cohort was not an independent prognostic factor of DFS but had a statistical tendency (P = 0.071). In subgroup analysis of colon cancer without rectal cancer, mucinous histology was an independent prognostic factor (P = 0.026).MAC was found at more advanced stage, located mainly at the right side and was an independent factor of survival in colon cancer. Because of the unique biological behavior of MAC, patients with MAC require special consideration during follow-up.     

Infektionen mit nichttuberkul?sen Mykobakterien bei Patienten mit Immundefekten

Infections caused by nontuberculous mycobacteria (NTM) cause a variety of clinical pictures, like nodular or cavitary lung infiltrations, lymphadenitis or lesions of the skin and soft tissue. In patients with innate or acquired immune deficiencies, an increase of disseminated but also local, atypical disease manifestations is observed. Detailed knowledge about underlying immune defects and the current immune status of patients with suspected NTM infections is indispensable to verify the detection of NTM in clinical specimens which does not necessarily account for a direct disease association. Differences in the growth kinetics of bacteria from the M. avium complex (MAC) which primarily cause lung diseases in contrast to the rapidly growing M. fortuitum and M. chelonae (RGM) involved in skin and soft tissue infections have to be considered in the diagnostics of NTM infections. Emergence of treatment strategies including biologicals in chronic inflammatory diseases resulted in an increase of local and disseminated NTM infections in the past. The duration of NTM treatment may be prolonged in patients with underlying immune deficiencies and disseminated infections. NTM prophylaxis should be discussed in HIV/AIDS patients with severe immune deficiency (CD4 ?<?50/??l) starting with antiretroviral therapy (cART) as NTM infections presenting as lymphadenitis are frequently observed in patients with immune reconstitution inflammatory syndrome (IRIS).     

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.     

Nontuberculous mycobacterial pulmonary infections

Pulmonary infections due to nontuberculous mycobacteria (NTM) are increasingly recognized worldwide. Although over 150 different species of NTM have been described, pulmonary infections are most commonly due to Mycobacterium avium complex (MAC), Mycobacterium kansasii, and Mycobacterium abscessus. The identification of these organisms in pulmonary specimens does not always equate with active infection; supportive radiographic and clinical findings are needed to establish the diagnosis. It is difficult to eradicate NTM infections. A prolonged course of therapy with a combination of drugs is required. Unfortunately, recurrent infection with new strains of mycobacteria or a relapse of infection caused by the original organism is not uncommon. Surgical resection is appropriate in selected cases of localized disease or in cases in which the infecting organism is resistant to medical therapy. Additionally, surgery may be required for infections complicated by hemoptysis or abscess formation. This review will summarize the practical aspects of the diagnosis and management of NTM thoracic infections, with emphasis on the indications for surgery and the results of surgical intervention. The management of NTM disease in patients with human immunodeficiency virus (HIV) infections is beyond the scope of this article and, unless otherwise noted, comments apply to hosts without HIV infectionKEYWORDS : Nontuberculous mycobacterium (NTM), mycobacterium avium intracellulare (MAI), bronchiectasis, mycobacterium abscessus, hot tub lung