Nontuberculous mycobacteria infections and anti-tumor necrosis factor-alpha therapy

Growing from common ground: nontuberculous mycobacteria and bronchiectasis

Bronchiectasis and nontuberculous mycobacteria (NTM) are intricately intertwined, with NTM capable of being both a cause and consequence of bronchiectatic disease. This narrative review focuses on the common ground of bronchiectasis and NTM pulmonary disease (NTM-PD) in terms of diagnostic approach, underlying risk factors and treatment strategies. NTM-PD diagnosis relies on a combination of clinical, radiological and microbiological criteria. Although their epidemiology is complicated by detection and reporting biases, the prevalence and pathogenicity of NTM species vary geographically, with Mycobacterium avium complex and Mycobacterium abscessus subspecies most frequently isolated in bronchiectasis-associated NTM-PD. Diagnosis of nodular bronchiectatic NTM-PD should prompt investigation of host factors, including disorders of mucociliary clearance, connective tissue diseases and immunodeficiencies, either genetic or acquired. Treatment of NTM-PD in bronchiectasis involves a multidisciplinary approach and considers the (sub)species involved, disease severity and comorbidities. Current guideline-based antimicrobial treatment of NTM-PD is considered long, cumbersome and unsatisfying in terms of outcomes. Novel treatment regimens and strategies are being explored, including rifampicin-free regimens and inclusion of clofazimine and inhaled antibiotics. Host-directed therapies, such as immunomodulators and cytokine-based therapies, might enhance antimycobacterial immune responses. Optimising supportive care, as well as pathogen- and host-directed strategies, is crucial, highlighting the need for personalised approaches tailored to individual patient needs. Further research is warranted to elucidate the complex interplay between host and mycobacterial factors, informing more effective management strategies.

Community-acquired pneumonia: a US perspective on the guideline gap

Community-acquired pneumonia continues to be one of the most common causes of morbidity and mortality due to infectious disease. The aetiologies, clinical presentations, diagnostic modalities and therapeutic options are changing and outpacing the creation of management guidelines. This educational article summarizes a roundtable activity sponsored by an unrestricted educational grant by Paratek that included US experts discussing these changes and identifying gaps in the current guidelines.

Risk factor of non-tuberculous Mycobacterium infection in patients with rheumatoid arthritis and other autoimmune diseases receiving biologic agents: A multicenter retrospective study

BACKGROUND

Evidence regarding the association of the usage of biologic agents (Etanercept, Tocilizumab, adalimumab and so on), such as anti-tumor necrosis factor α, with the incidence and risk factors of non-tuberculous Mycobacteria (NTM) infection is limited. Therefore, this study aimed to investigate the incidence and risk factors of NTM and their associations with biologic agents' usage, and also investigated the potential of Mycobacterium avium complex (MAC) antibodies as a predictor of NTM infection development.

METHODS

This retrospective study included 672 patients with autoimmune diseases from four hospitals in Nagasaki, Japan, from January 1, 2011, to June 30, 2019, who fulfilled the inclusion criteria.

RESULTS

Of the 672 patients, 9 (1.3%) developed complicated NTM infection, including two with disseminated infection, after the introduction of biologic agents. Of the nine patients, two died due to NTM infection but none tested positive for MAC antibodies prior to initiation of biologic agents. The mortality rate was higher in patients complicated with NTM than without NTM (22.2% vs 2.6%, P = 0.024). The corticosteroids dosage at the time of initiating the biologic agents was significantly higher in the NTM group than in the non-NTM group (median, 17 mg vs 3 mg, P = 0.0038).

CONCLUSION

In the patients undergoing therapy with biologic agents, although NTM complication was rare, it could be fatal. In particular, for patients on a relatively high dose corticosteroids, careful observation is essential for identifying NTM complication, even if the MAC antibody test is negative.

Disseminated mycobacterium genavense infection with central nervous system involvement in an HIV patient: a case report and literature review

BACKGROUND

Immunodeficient patients, particularly HIV patients, are at risk of opportunistic infections. Nontuberculous mycobacteria can cause severe complications in immunodeficient patients.

CASE PRESENTATION

We describe a 57-year-old HIV patient, primarily presented with coughs and constitutional symptoms, with a unique Mycobacterium genavense abdominal, pulmonary, and central nervous system infection, accompanied by intracranial masses.

CONCLUSION

The diagnosis of NTM, including M. genavense, must always be considered by clinicians in immunodeficient patients, especially those with HIV, who have a compromised immune system.

Successful rescue TNF-α blocking for Mycobacterium genavense - Related immune reconstitution inflammatory syndrome: A case report

Immune reconstitution inflammatory syndrome (IRIS) has been reported in immunocompromised patients with disseminated Mycobacterium genavense. Management relies on high-dose corticosteroids. We describe two cases of late-onset corticosteroid-refractory IRIS related to disseminated infection in a HIV-positive patient and a renal transplant patient who had a favorable outcome with a monoclonal TNF-α blocker.

Clinical course of nontuberculous mycobacterial pulmonary disease in patients with rheumatoid arthritis

OBJECTIVES

The impact of rheumatoid arthritis (RA) on nontuberculous mycobacterial pulmonary disease (NTM-PD) has not been well established. In this study, we investigated the clinical course of NTM-PD in patients with RA and the impact of RA on the prognosis of NTM-PD.

METHODS

We analyzed patients who developed NTM-PD after being diagnosed with RA from January 2004 to August 2023 at a tertiary referral hospital in South Korea. The patient's baseline characteristics, clinical course, and prognosis were evaluated. An optimal matching analysis was performed to measure the impact of RA on the risk of mortality.

RESULTS

During the study period, 18 patients with RA [median age, 68 years; interquartile range (IQR) 59-73; female, 88.9%] developed NTM-PD. The median interval between RA diagnosis and subsequent NTM-PD development was 14.8 years (IQR, 8.6-19.5). At a median of 30 months (IQR, 27-105) after NTM-PD diagnosis, 10 of 18 (55.6%) patients received anti-mycobacterial treatment for NTM-PD and 5 (50.0%) patients achieved microbiological cure. When matched to patients with NTM-PD but without RA, patients with both RA and NTM-PD had a higher risk of mortality (adjusted hazard ratio, 8.14; 95% confidence interval, 2.43-27.2).

CONCLUSION

NTM-PD occurring after RA is associated with a higher risk of mortality than NTM-PD in the absence of RA.

Association of Tumor Necrosis Factor Inhibitors with the Risk of Nontuberculous Mycobacterial Infection in Patients with Rheumatoid Arthritis: A Nationwide Cohort Study

Tumor necrosis factor inhibitors (TNFi) are proposed as a risk factor for nontuberculous mycobacteria (NTM) infection. Limited research investigates NTM infection risk in rheumatoid arthritis (RA) patients treated with TNFi compared to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), considering other concurrent or prior non-TNFi antirheumatic drugs. We aimed to evaluate the NTM infection risk associated with TNFi using a real-world database. Patients with RA treated with TNFi or csDMARDs between 2005 and 2016 were identified utilizing the Korean National Health Insurance Service database. To minimize potential bias, we aligned the initiation year of csDMARDs for both TNFi and csDMARD users and tracked them from their respective treatment start dates. The association of TNFi with NTM infection risk was estimated in a one-to-one matched cohort using a multivariable conditional Cox regression analysis. In the matched cohort (n = 4556), the incidence rates of NTM infection were 2.47 and 3.66 per 1000 person-year in TNFi and csDMARD users. Compared to csDMARDs, TNFi did not increase the risk of NTM infection (adjusted hazard ratio (aHR) 0.517 (95% confidence interval, 0.205-1.301)). The TNFi use in RA patients was not associated with an increased risk of NTM infection compared to csDMARDs. Nevertheless, monitoring during TNFi treatment is crucial.

Epidemiology, clinical presentation, and predictors of outcome in nontuberculous mycobacterial central nervous system infection: a systematic review

BACKGROUND

CNS manifestations represent an emerging facet of NTM infection with significant mortality. Due to protean presentation and low index of suspicion, many cases are often treated erroneously as tubercular meningitis or fungal infections.

OBJECTIVES

Literature on NTM CNS disease is scarce, with most available data on pulmonary disease. This systematic review aimed to evaluate the epidemiology, clinical presentation, diagnostic modalities, and predictors of outcome in CNS NTM infection.

METHODS

The literature search was performed in major electronic databases (PubMed, Google Scholar, and Scopus) using keywords "CNS," "Central nervous system," "brain abscess," "meningitis," "spinal," "Nontuberculous mycobacteria," "NTM". All cases of CNS NTM infection reported between January 1980 and December 2022 were included.

RESULTS

A total of 77 studies (112 cases) were included in the final analysis. The mean age of all patients was 38 years, with most patients male (62.5%). Mycobacterium avium complex (MAC) was the most common aetiology, followed by M. fortuitum and M. abscessus (34.8%, 21.4% and 15.2%, respectively). The disseminated disease was found in 33% of cases. HIV (33.9%) and neurosurgical hardware (22.3%) were the common risk factors. Intracranial abscess (36.6%) and leptomeningeal enhancement (28%) were the most prevalent findings in neuroimaging. The overall case fatality rate was 37.5%. On multivariate analysis, male gender (adjusted OR 2.4, 95% CI 1.2-7.9) and HIV (adjusted OR 3.7, 95% CI 1.8-6.1) were the independent predictors of mortality). M. fortuitum infection was significantly associated with increased survival (adjusted OR 0.18, 95% CI (0.08-0.45), p value 0.012).

CONCLUSIONS

Current evidence shows the emerging role of rapid-grower NTM in CNS disease. Male gender and HIV positivity were associated with significant mortality, while M fortuitum carries favourable outcomes.

Clinical characteristics of rheumatoid arthritis patients complicated with pulmonary nontuberculous mycobacterial disease: A cross-sectional case series study

OBJECTIVES

Pulmonary nontuberculous mycobacterial disease (pNTM) is a common pulmonary complication of rheumatoid arthritis (RA), but their association has rarely been researched. We aimed to reveal the clinical characteristics of RA with pNTM.

METHODS

Among all the RA patients who visited Tenri hospital from April 2017 to March 2018, we enrolled those fulfilling the 2007 ATS/IDSA diagnostic criteria of pNTM, and sex- and age- matched control group at a ratio of 1:5. Demographic characteristics were compared between the two groups.

RESULTS

Among 865 RA patients, 35 (4.0%) patients were complicated with pNTM. RA patients with pNTM had significantly lower BMI and higher rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) positivity. Bronchiectasis was the most frequent lesion, followed by clusters of small nodules, patchy consolidation and cavity. Multivariable logistic regression analysis revealed bronchiectasis as a strong independent associated factor of pNTM. Treatment for pNTM was needed in 14 of the 35 (40%) RA patients with pNTM and sputum negative conversion was accomplished in 11 of the 14 cases (78.6%).

CONCLUSIONS

RA patients with lower BMI, RF/ACPA positivity, and bronchiectasis were associated with pNTM. Treatment for pNTM may attain sputum negative conversion and radiological improvement in patients with RA.

Disseminated mycobacterial infections after tumor necrosis factor inhibitor use, revealing inborn errors of immunity

Tumor necrosis factor-a inhibitors can be associated with increased risk of infections, particularly reactivation of latent tuberculosis or nontuberculous mycobacterium (NTM). However, because disseminated NTM is rare, inborn errors of immunity should be considered. We present three patients with disseminated NTM after tumor necrosis factor-a inhibitor use who were found to have inborn errors of immunity.

Reduced macrophage killing of M. avium drives infection risk in post-menopausal patients

Non-tuberculous mycobacterial (NTM) infections, and Mycobacterium avium Complex (MAC) in particular, affect women at nearly twice the rate of men, and post-menopausal patients are at higher risk than pre-menopausal patients. The reasons for the disproportionate number of cases in women and post-menopausal patients remain unclear. One possibility is that menopause-associated immunological changes contribute to higher MAC prevalence post-menopause compared to pre-menopause. Menopause-associated immune disruption includes increased cytokine and chemokine production, and reduced cytotoxicity and phagocytosis in macrophages. Here we use an agent-based model of bacterial and host immune interactions in the airway to translate the combined impact of menopause-associated cellular immune disruptions to tissue scale outcomes. Our simulations indicate that menopause-associated immune disruptions can result in increased macrophage recruitment. However, this increase in macrophage number is unable to overcome functional deficits in macrophage phagocytosis and killing, since the post-menopausal simulations also show increased bacterial loads. Post-menopausal conditions are also associated with a lower number of cleared infections, and more simulations that have predominantly extracellular bacteria. Taken together, our work quantifies the potential impact of menopause-associated disruptions of innate immune functions on early MAC infection progression. Our findings will support the development of new therapies targeted to this high-risk group of patients.

Disseminated Mycobacterium chelonae infection complicating rheumatoid arthritis: A case report and review of the literature

INTRODUCTION

Rheumatoid arthritis (RA) may predispose patients to opportunistic infections-either from innate immune dysregulation, or as a result of immunosuppressant use to treat the RA. Particularly concerning opportunistic infections are those caused by non-tuberculous mycobacterial (NTM) organisms, the incidence of which has been increasing in epidemiological studies. Despite this, guidelines on the management of patients with RA who develop NTM infections are scarce, particularly with respect to immunosuppressant regimen modulation and duration of antibiotic therapy.

CASE REPORT

Herein, we present a case of disseminated Mycobacterium chelonae infection, manifesting as arthralgia and cutaneous nodules.

DISCUSSION

In addition, a review of the literature was conducted to Preferred Reporting Items for Systemic Reviews and Meta-Analyses guidelines to identify similar cases in the literature-revealing that all RA-associated M. Chelonae infections occurred in immunosuppressed patients (the majority with corticosteroids or tumor necrosis factor inhibitors), and considerable heterogeneity in management approaches. Further research regarding risk factors, preventative approaches and best management of such NTM infections in vulnerable patients with RA is required in order to establish consensus guidelines and consistency.

Diagnostic and Therapeutic Challenges in Disseminated Mycobacterium colombiense Infection Caused by Interferon-γ Neutralizing Autoantibodies

Adult-onset immunodeficiency due to interferon-γ-neutralizing autoantibodies (nIFNγ-autoAbs) can remain underdiagnosed. We present a case of severe Mycobacterium colombiense infection with nIFNγ-autoAbs. To ensure early diagnosis, clinicians should have a high index of suspicion in patients of Asian descent with opportunistic infections and perform QuantiFERON-TB assay for disease screening.

Immunogenicity and protection against Mycobacterium avium with a heterologous RNA prime and protein boost vaccine regimen

Prophylactic efficacy of two different delivery platforms for vaccination against Mycobacterium avium (M. avium) were tested in this study; a subunit and an RNA-based vaccine. The vaccine antigen, ID91, includes four mycobacterial antigens: Rv3619, Rv2389, Rv3478, and Rv1886. We have shown that ID91+GLA-SE is effective against a clinical NTM isolate, M. avium 2-151 smt. Here, we extend these results and show that a heterologous prime/boost strategy with a repRNA-ID91 (replicon RNA) followed by protein ID91+GLA-SE boost is superior to the subunit protein vaccine given as a homologous prime/boost regimen. The repRNA-ID91/ID91+GLA-SE heterologous regimen elicited a higher polyfunctional CD4+ TH1 immune response when compared to the homologous protein prime/boost regimen. More significantly, among all the vaccine regimens tested only repRNA-ID91/ID91+GLA-SE induced IFN-γ and TNF-secreting CD8+ T cells. Furthermore, the repRNA-ID91/ID91+GLA-SE vaccine strategy elicited high systemic proinflammatory cytokine responses and induced strong ID91 and an Ag85B-specific humoral antibody response a pre- and post-challenge with M. avium 2-151 smt. Finally, while all prophylactic prime/boost vaccine regimens elicited a degree of protection in beige mice, the heterologous repRNA-ID91/ID91+GLA-SE vaccine regimen provided greater pulmonary protection than the homologous protein prime/boost regimen. These data indicate that a prophylactic heterologous repRNA-ID91/ID91+GLA-SE vaccine regimen augments immunogenicity and confers protection against M. avium.

Modulating macrophage function to reinforce host innate resistance against Mycobacterium avium complex infection

Mycobacterium avium complex (MAC) is the main causative agent of infectious diseases in humans among nontuberculous mycobacteria (NTM) that are ubiquitous organisms found in environmental media such as soil as well as in domestic and natural waters. MAC is a primary causative agent of NTM-lung disease that threaten immunocompromised or structural lung disease patients. The incidence and the prevalence of M. tuberculosis infection have been reduced, while MAC infections and mortality rates have increased, making it a cause of global health concern. The emergence of drug resistance and the side effects of long-term drug use have led to a poor outcome of treatment regimens against MAC infections. Therefore, the development of host-directed therapy (HDT) has recently gained interest, aiming to accelerate mycobacterial clearance and reversing lung damage by employing the immune system using a novel adjuvant strategy to improve the clinical outcome of MAC infection. Therefore, in this review, we discuss the innate immune responses that contribute to MAC infection focusing on macrophages, chief innate immune cells, and host susceptibility factors in patients. We also discuss potential HDTs that can act on the signaling pathway of macrophages, thereby contributing to antimycobacterial activity as a part of the innate immune response during MAC infection. Furthermore, this review provides new insights into MAC infection control that modulates and enhances macrophage function, promoting host antimicrobial activity in response to potential HDTs and thus presenting a deeper understanding of the interactions between macrophages and MACs during infection.

Dominant negative TRAF3 variant with recurrent Mycobacterium abscessus infection and bronchiectasis

Host factors leading to pulmonary NTM (PNTM) disease is poorly understood compared to disseminated NTM disease which is linked to IL12-IFNγ signaling pathway. We elucidated TNF receptor–associated factor 3 (TRAF3) R338W variant in patient with recurrent PNTM infection: demonstrating TRAF3-and TNF-α deficient phenotype, via ex-vivo immune and cloning-transfection cellular studies.

Non-tuberculous mycobacteria pulmonary disease: A review of trends, risk factors, diagnosis and management

Non-tuberculous mycobacteria (NTM) reports have been on the rise globally, with increasing incidence and prevalence accompanied by poor outcomes. The rise has been attributed to an ageing population with increasing comorbid illnesses, and improved laboratory techniques in diagnosing the disease. However, despite the increase, some parts of the world still lack data, especially sub-Saharan African countries. The lack of data in our setting is difficult to explain, as we have a significant burden of NTM risk factors (i.e. HIV, tuberculosis and bronchiectasis). This review therefore serves as a reminder and a challenge to start searching, and reporting on our experiences. The review will highlight the rising incidence, important risk factors, diagnosis and management of NTM pulmonary disease.

Pathophysiological Concepts and Management of Pulmonary Manifestation of Pediatric Inflammatory Bowel Disease

Pulmonary manifestation (PM) of inflammatory bowel disease (IBD) in children is a rare condition. The exact pathogenesis is still unclear, but several explanatory concepts were postulated and several case reports in children were published. We performed a systematic Medline search between April 1976 and April 2022. Different pathophysiological concepts were identified, including the shared embryological origin, "miss-homing" of intestinal based neutrophils and T lymphocytes, inflammatory triggering via certain molecules (tripeptide proline-glycine-proline, interleukin 25), genetic factors and alterations in the microbiome. Most pediatric IBD patients with PM are asymptomatic, but can show alterations in pulmonary function tests and breathing tests. In children, the pulmonary parenchyma is more affected than the airways, leading histologically mainly to organizing pneumonia. Medication-associated lung injury has to be considered in pulmonary symptomatic pediatric IBD patients treated with certain agents (i.e., mesalamine, sulfasalazine or infliximab). Furthermore, the risk of pulmonary embolism is generally increased in pediatric IBD patients. The initial treatment of PM is based on corticosteroids, either inhaled for the larger airways or systemic for smaller airways and parenchymal disease. In summary, this review article summarizes the current knowledge about PM in pediatric IBD patients, focusing on pathophysiological and clinical aspects.

Prevalence of Culture-Confirmed Tuberculosis Among Patients with Nontuberculous Mycobacterial Disease

Background

Currently, the prevalence of nontuberculous mycobacteria (NTM) strains isolated from mycobacterial cultures has been well characterized. However, the data on the prevalence of tuberculosis (TB) in patients with NTM disease remain unclear.

Methods

Between January 2012 and August 2020, consecutive patients with positive mycobacterial cultures were included for analysis. The identification of Mycobacteria spp. was performed using the DNA array method or sequencing of 16S rDNA. NTM disease is diagnosed when the same infectious agent is identified in at least two sputum or is identified in sterile samples.

Results

A total of 997 strains were isolated from 828 inpatients. Of them, 261 inpatients (31.5%) were diagnosed as NTM disease. The mean age of the 261 patients was 55.7 ±15.5 years old and 64.0% (n = 167) of them were male. The prevalence of culture-confirmed TB patients among patients with NTM disease was estimated as 8.0% (21/261).

Conclusion

TB is common in NTM disease and caution should be taken when initiating the treatment of NTM disease.

Management of Mycobacterium avium complex and Mycobacterium abscessus pulmonary disease: therapeutic advances and emerging treatments

Nontuberculous mycobacterial pulmonary disease (NTM-PD) remains a challenging condition to diagnose and treat effectively. Treatment of NTM-PD is prolonged, frequently associated with adverse effects and has variable success. In this review, we consider the factors influencing clinicians when treating NTM-PD and discuss outcomes from key studies on the pharmacological management of Mycobacterium avium complex pulmonary disease and M. abscessus pulmonary disease. We highlight issues relating to treatment-related toxicity and provide an overview of repurposed and emerging therapies for NTM-PD.

TNF inhibitors increase the risk of nontuberculous mycobacteria in patients with seropositive rheumatoid arthritis in a mycobacterium tuberculosis endemic area

The aim of this study is to examine the impact of tumor necrosis factor inhibitors (TNFI) on nontuberculous mycobacterium (NTM) infection in rheumatoid arthritis (RA) patients in a mycobacterium tuberculosis (MTB) endemic area. We selected 1089 TNFI-treated RA patients and 4356 untreated RA patients using propensity-matching analysis according to age, gender, and Charlson comorbidity index using the Korean National Health Insurance Service database from July 2009 to December 2010. Both groups were followed-up until the end of 2016 to measure the incidence of mycobacterial diseases. The incidence rate of NTM in TNFI-treated RA group was similar to those of MTB (328.1 and 340.9 per 100,000 person-years, respectively). The adjusted hazard ratio (aHR) of NTM for TNFI-treated RA compared to untreated RA was 1.751(95% CI 1.105-2.774). The risk of TNFI-associated NTM in RA was 2.108-fold higher among women than men. The age-stratified effects of TNFI on NTM development were significantly high in RA patients aged 50-65 years (aHR 2.018). RA patients without comorbidities had a higher incidence of NTM following TNFI treatment (aHR 1.742). This real-world, observational study highlights the need to increase awareness of NTM in TNFI-treated RA patients in an MTB endemic area.

Clinical Characteristics and Antimicrobial Susceptibility of Mycobacterium intracellulare and Mycobacterium abscessus Pulmonary Diseases: A Retrospective Study

The incidence of nontuberculous mycobacteria (NTM) diseases is increasing every year. The present study was performed to investigate the clinical characteristics, CT findings, and drug susceptibility test (DST) results of patients diagnosed with M. intracellulare or M. abscessus nontuberculous mycobacterial pulmonary disease (NTMPD). This retrospective study included patients diagnosed with NTMPD due to M. intracellulare or M. abscessus for the first time at Anhui Chest Hospital between 01/2019 and 12/2021. The patients were grouped as M. intracellulare-NTMPD group or M. abscessus-NTMPD group. Clinical features, imaging data and DST data, were collected. Patients with M. intracellulare infection had a higher rate of acid-fast smears (66.1% vs. 45.2%, P=0.032) and a higher rate of cavitation based on pulmonary imaging (49.6% vs. 19.4%, P=0.002) than patients with M. abscessus infection, but both groups had negative TB-RNA and GeneXpert results, with no other characteristics significant differences. The results of DST showed that M. intracellulare had high susceptibility rate to moxifloxacin (95.9%), amikacin (90.1%), clarithromycin (91.7%), and rifabutin (90.1%). M. abscessus had the highest susceptibility rate to amikacin (71.0%) and clarithromycin (71.0%). The clinical features of M. intracellulare pneumopathy and M. abscessus pneumopathy are highly similar. It may be easily misdiagnosed, and therefore, early strain identification is necessary. M. intracellulare has a high susceptibility rate to moxifloxacin, amikacin, clarithromycin, and rifabutin, while M. abscessus has the highest susceptibility rate to amikacin and clarithromycin. This study provides an important clinical basis for improving the management of NTMPD.

Disseminated cutaneous Mycobacterium haemophilum infection in a patient on infliximab for rheumatoid arthritis

Mycobacterium haemophilum is a rarely encountered pathogen that is difficult to identify given its unique growth requirements. It is most often seen in adult patients who are immunosuppressed due to advanced HIV or haematological malignancy. Our case highlights a typical presentation of an atypical pathogen in a patient with rheumatoid arthritis receiving anti-tumour necrosis factor therapy. This case represents an important patient population in whom this previously rare infection is increasingly common.

Clinical Aspects of Pulmonary Nontuberculous Mycobacteriosis

Nontuberculous mycobacterial (NTM) infections are an emerging problem. Common organisms include Mycobacterium avium, M. intracellulare, and M. kansasii, along with the M. avium intracellulare complex (MAC), which includes both M. avium and M. intracellulare. Typically, NTM infections affect the lungs and subsequently demonstrate a chronic course. Therefore, persistent respiratory symptoms generally indicate of the presence of pulmonary NTM diseases, and chest radiography, along with a sputum examination, are essential for its diagnosis. Because NTM are ubiquitous environmental organisms, a positive culture from a minimum of two separate expectorated sputum samples are required to make a diagnosis. The repertoire of effective drugs for treatment is considerably limited, indicating the need for long-term management with multiple drugs. Establishing a treatment regimen with high therapeutic efficacy and safety is an important issue for the future.

Atypical Mycobacterial Tenosynovitis in the Setting of Adalimumab Use

Tumor necrosis factor-alpha (TNF-α) inhibitors indicated in the management of psoriasis, rheumatoid arthritis, ulcerative colitis, Crohn's disease, and other autoimmune diseases have been associated with the development of mycobacterial and other opportunistic infections. The majority of mycobacterial infections diagnosed in patients taking TNF-α inhibitors are secondary to Mycobacterium tuberculosis. Atypical mycobacteria have also been identified in this patient population, most commonly manifested by pulmonary or disseminated infections. Extra-pulmonary manifestations such as bone and joint infections are rare. We describe a case of atypical mycobacterial tenosynovitis in the setting of adalimumab use in a patient with psoriasis. This is a rarely reported complication that one should be aware of when prescribing these medications.

Case Report: Kampo Medicine for Non-tuberculous Mycobacterium Pulmonary Disease

Background: While the number of pulmonary tuberculosis cases has decreased, increase in non-tuberculous mycobacterium pulmonary disease (NTM-PD) is a global problem. Guideline-based therapy for NTM-PD sometimes causes complications that prevent treatment completion, and there are many cases of relapse even if the treatment can be completed. In addition to antibacterial treatment, care of host risk factors, such as aging, lean physique and immunosuppressive state, is also very important for the management of NTM-PD. In Japan, Kampo medicine, a traditional Japanese herbal formulation, used alone or in combination with standard multidrug therapy for NTM-PD, has been found to be effective for such cases.

Case Presentation: A 77-year-old lean woman had been diagnosed with Mycobacterium intracellulare pulmonary infection 6 years earlier, and had received the standard multidrug treatment 5 years later at a former hospital due to worsening of her symptoms of cough, breathlessness and hemoptysis. However, the treatment was discontinued within a year due to the development of adverse events. She refused the guideline-based antibacterial treatment, and asked for Kampo medicine instead. Bukuryoshigyakuto was subsequently prescribed, which led to cough and sputum, especially hemosputum, being well controlled. With 3 years of Kampo medicine treatment, she gained weight and her hemosputum disappeared. High-resolution computed tomography images showed improvement in her lung condition, and her sputum smear culture was negative for acid-fast bacillus.

Conclusion: Various kinds of Kampo medicines have been used empirically for NTM-PD in Japan. A literature review from 1992 to 2020 showed that hozais, in particular, seem to be key drugs for the treatment of host NTM-PD risk factors. Kampo medicines can contribute to comprehensive treatment for NTM-PD management that does not rely solely on antibacterial drugs.

Varying clinical presentations of nontuberculous mycobacterial disease : Similar to but different from tuberculosis

The incidence rate of pulmonary nontuberculous mycobacterial disease (PNTMD) in Japan is the highest among major industrialized nations. Although the typical clinical course and radiological manifestations of PNTMD are different from those of pulmonary tuberculosis (TB), confusion about these mycobacterial diseases leads to a diagnostic pitfall. Diagnostic challenges include the coexistence of Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM), false positives for NTM in MTB nucleic acid amplification tests, microbial substitution, and abnormal radiological manifestations caused by NTM. Features of extrapulmonary NTM diseases, such as pleurisy, vertebral osteomyelitis, and disseminated disease, are different from the corresponding tuberculous diseases. Moreover, the immunological background of the patient (status of human immunodeficiency virus infection with or without antiviral therapy, continuation or discontinuation of immunosuppressive therapy, use of immune checkpoint inhibitor, pregnancy and delivery, etc.) influences the pathophysiology of mycobacterial diseases. This review describes the varying clinical presentations of NTM disease with emphasis on the differences from TB. J. Med. Invest. 68 : 220-227, August, 2021.

Pharmacotherapy for nontuberculous mycobacterial pulmonary disease

DISCLAIMER

In an effort to expedite the publication of articles , AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

To provide an updated review of the diagnosis and pharmacotherapy of nontuberculous mycobacteria pulmonary disease (NTM-PD) and summarize guideline recommendations for an interdisciplinary treatment approach.

SUMMARY

A systemic approach was taken in which all articles in English in MEDLINE and PubMed were reviewed. DAILYMED was used to assess drug package inserts. Analysis of NTM treatment guidelines is summarized in the article with a focus on medications, dosing, interactions, and medication monitoring.

CONCLUSION

It is critical to manage patients with NTM with a multidisciplinary team approach. Treatment is prolonged and expensive, and the potential for drug toxicity, adverse effects, and drug interactions requires monitoring. Clinical pharmacists play a role in the management of NTM.

The Tumor Necrosis Factor Alpha and Interleukin 6 Auto-paracrine Signaling Loop Controls Mycobacterium avium Infection via Induction of IRF1/IRG1 in Human Primary Macrophages

Macrophages sense and respond to pathogens by induction of antimicrobial and inflammatory programs to alert other immune cells and eliminate the infectious threat. We have previously identified the transcription factor IRF1 to be consistently activated in macrophages during Mycobacterium avium infection, but its precise role during infection is not clear. Here, we show that tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) autocrine/paracrine signaling contributes to controlling the intracellular growth of M. avium in human primary macrophages through activation of IRF1 nuclear translocation and expression of IRG1, a mitochondrial enzyme that produces the antimicrobial metabolite itaconate. Small interfering RNA (siRNA)-mediated knockdown of IRF1 or IRG1 increased the mycobacterial load, whereas exogenously provided itaconate was bacteriostatic at high concentrations. While the overall level of endogenous itaconate was low in M. avium-infected macrophages, the repositioning of mitochondria to M. avium phagosomes suggests a mechanism by which itaconate can be delivered directly to M. avium phagosomes in sufficient quantities to inhibit growth. Using mRNA hybridization, we further show that uninfected bystander cells actively contribute to the resolution of infection by producing IL-6 and TNF-α, which, via paracrine signaling, activate IRF1/IRG1 and strengthen the antimicrobial activity of infected macrophages. This mechanism contributes to the understanding of why patients on anti-inflammatory treatment, e.g., with tocilizumab or infliximab, can be more susceptible to mycobacterial disease.

Mycobacterium avium Subsp. hominissuis Interactions with Macrophage Killing Mechanisms

Non-tuberculosis mycobacteria (NTM) are ubiquitously found throughout the environment. NTM can cause respiratory infections in individuals with underlying lung conditions when inhaled, or systemic infections when ingested by patients with impaired immune systems. Current therapies can be ineffective at treating NTM respiratory infections, even after a long course or with multidrug treatment regimens. NTM, such as Mycobacterium avium subspecies hominissuis (M. avium), is an opportunistic pathogen that shares environments with ubiquitous free-living amoeba and other environmental hosts, possibly their evolutionary hosts. It is highly likely that interactions between M. avium and free-living amoeba have provided selective pressure on the bacteria to acquire survival mechanisms, which are also used against predation by macrophages. In macrophages, M. avium resides inside phagosomes and has been shown to exit it to infect other cells. M. avium's adaptation to the hostile intra-phagosomal environment is due to many virulence mechanisms. M. avium is able to switch the phenotype of the macrophage to be anti-inflammatory (M2). Here, we have focused on and discussed the bacterial defense mechanisms associated with the intra-phagosome phase of infection. M. avium possesses a plethora of antioxidant enzymes, including the superoxide dismutases, catalase and alkyl hydroperoxide reductase. When these defenses fail or are overtaken by robust oxidative burst, many other enzymes exist to repair damage incurred on M. avium proteins, including thioredoxin/thioredoxin reductase. Finally, M. avium has several oxidant sensors that induce transcription of antioxidant enzymes, oxidation repair enzymes and biofilm- promoting genes. These expressions induce physiological changes that allow M. avium to survive in the face of leukocyte-generated oxidative stress. We will discuss the strategies used by M. avium to infect human macrophages that evolved during its evolution from free-living amoeba. The more insight we gain about M. avium's mode of pathogenicity, the more targets we can have to direct new anti-virulence therapies toward.

Recurrent Carpal Tunnel Syndrome Associated with Mycobacterium szulgai Infection: A Case Report

CASE

We present the case of an otherwise healthy 77-year-old male retired firefighter and recreational pheasant hunter who presented with recurrent symptoms of carpal tunnel syndrome and tenosynovitis because of Mycobacterium szulgai. He was initially treated unsuccessfully for a presumed seronegative rheumatologic flare, followed by surgical diagnosis and treatment including revision carpal tunnel release with tenosynovectomy, and a secondary debridement and wound closure. His symptoms resolved after several months of multidrug antibiotic therapy with only mild residual median nerve deficit.

CONCLUSION

Nontuberculous Mycobacterium infections of the upper extremity are extremely rare and challenging to diagnose/treat. This report highlights diagnostic and surgical challenges in this rarely reported infection.

Comparison of In Vitro Susceptibility of Delafloxacin with Ciprofloxacin, Moxifloxacin, and Other Comparator Antimicrobials against Isolates of Nontuberculous Mycobacteria

Nontuberculous mycobacterial (NTM) infections are increasing globally. Mycobacterium avium complex (MAC) and M. abscessus complex are the most commonly reported NTM. Oral treatment options are limited, especially for the M. abscessus complex. We tested delafloxacin, a new oral fluoroquinolone, against 131 isolates of NTM. Delafloxacin microdilution MICs were performed as recommended by the Clinical and Laboratory Standards Institute using cation adjusted Mueller-Hinton broth. The rapidly growing mycobacteria tested included M. abscessus subsp. abscessus (n = 16) and subsp. massiliense (n = 5), M. chelonae (n = 11), M. immunogenum (n = 5), M. fortuitum group (n = 13), M. porcinum (n = 7), M. senegalense (n = 7), M. mucogenicum group (n = 5), and M. goodii (n = 1). For the slowly growing NTM (SGM), M. avium (n = 16), M. intracellulare (n = 13), M. chimaera (n = 9), M. arupense (n = 5), M. simiae (n = 5), M. lentiflavum (n = 4), M. kansasii (n = 6), and M. marinum (n = 3) were tested. Delafloxacin was most active in vitro against the M. fortuitum and M. mucogenicum groups and M. kansasii, with MIC₅₀ values of 0.12 to 0.5 μg/ml (MIC range, 0.001 to 4 μg/ml) compared to ≤0.06 to >4 μg/ml for ciprofloxacin and ≤0.06 to >8 μg/ml for moxifloxacin. For other SGM (including MAC), and the M. abscessus/M. chelonae, the delafloxacin MIC range was 8 to >16 μg/ml compared to ciprofloxacin and moxifloxacin of 0.5 to >4 μg/ml and ≤0.06 to 8 μg/ml, respectively. To our knowledge, this is the first MIC study with delafloxacin to use Clinical and Laboratory Standards Institute (CLSI) recommended methods. This study illustrates the potential utility of delafloxacin in treatment of infections due to some NTM.

Nontuberculous mycobacterial pulmonary disease: an integrated approach beyond antibiotics

Nontuberculous mycobacterial (NTM) pulmonary disease (PD) is an emerging condition with heterogeneous manifestations from both the microbiological and the clinical point of view. Diagnostic and therapeutic guidelines are available but there are still unmet patients' and physicians' needs, including therapy-related adverse events, symptom control, management of comorbidities, risk of re-exposure to the pathogen and unfavourable outcomes.

In the present review, we provide currently available evidence for an integrated approach to NTM-PD beyond antibiotic therapy. This includes 1) avoiding exposure to environments where mycobacteria are present and careful evaluation of lifestyle and habits; 2) implementing a personalised pulmonary rehabilitation plan and airway clearance techniques to improve symptoms, exercise capacity, health-related quality of life (QoL) and functional capacity in daily living activities; 3) a nutritional evaluation and intervention to improve health-related QoL and to control gastrointestinal side-effects during antimicrobial therapy, particularly in those with low body mass index and history of weight loss; and 4) managing comorbidities that affect disease outcomes, including structural lung diseases, immune status evaluation and psychological support when appropriate.

An integrated approach, including risk factor prevention, management of comorbidities, nutritional evaluation and intervention and pulmonary rehabilitation, should be considered in the optimal management of nontuberculous mycobacterial pulmonary diseasehttps://bit.ly/2YEqvQg

Infections associated with the new 'nibs and mabs' and cellular therapies

PURPOSE OF REVIEW

In recent years, we have witnessed a remarkable surge in the clinical development of effective biological and cellular therapies for the treatment of neoplastic and autoimmune disorders. The present review summarizes our understanding of the pathogen-specific infection risk associated with the use of such therapies.

RECENT FINDINGS

A variety of biologics, in the form of either monoclonal antibodies (Mabs) or small molecule kinase inhibitors (Nibs), are continuously introduced in the clinic for the management of autoimmune and malignant diseases. In addition, cellular therapies such as the infusion of chimeric antigen receptor (CAR) T-cells are becoming increasingly available for patients with treatment-refractory lymphoid malignancies. Some of these biological and cellular interventions exert direct or indirect adverse effects on the induction of protective immune responses against various pathogens, resulting in heightened infection susceptibility.

SUMMARY

The introduction of biological and cellular therapies for the treatment of malignant and autoimmune diseases has been associated with increased infection susceptiblity, which varies greatly depending on the specific immunomodulatory therapy, the infecting pathogen and the recipient patient population. A high index of clinical suspicion and efforts aiming at early diagnosis, targeted vaccination or prophylaxis, and prompt initiation of antimicrobial treatment should help improve infection outcomes.

Subunit vaccine protects against a clinical isolate of Mycobacterium avium in wild type and immunocompromised mouse models

The nontuberculous mycobacteria (NTM) Mycobacterium avium is a clinically significant pathogen that can cause a wide range of maladies, including tuberculosis-like pulmonary disease. An immunocompromised host status, either genetically or acutely acquired, presents a large risk for progressive NTM infections. Due to this quietly emerging health threat, we evaluated the ability of a recombinant fusion protein ID91 combined with GLA-SE [glucopyranosyl lipid adjuvant, a toll like receptor 4 agonist formulated in an oil-in-water stable nano-emulsion] to confer protection in both C57BL/6 (wild type) and Beige (immunocompromised) mouse models. We optimized an aerosol challenge model using a clinical NTM isolate: M. avium 2-151 smt, observed bacterial growth kinetics, colony morphology, drug sensitivity and histopathology, characterized the influx of pulmonary immune cells, and confirmed the immunogenicity of ID91 in both mouse models. To determine prophylactic vaccine efficacy against this M. avium isolate, mice were immunized with either ID91 + GLA-SE or bacillus Calmette-Guérin (BCG). Immunocompromised Beige mice displayed a delayed influx of innate and adaptive immune cells resulting in a sustained and increased bacterial burden in the lungs and spleen compared to C57BL/6 mice. Importantly, both ID91 + GLA-SE and BCG vaccines significantly reduced pulmonary bacterial burden in both mouse strains. This work is a proof-of-concept study of subunit vaccine-induced protection against NTM.

The New Frontier of Host-Directed Therapies for Mycobacterium avium Complex

Mycobacterium avium complex (MAC) is an increasingly important cause of morbidity and mortality, and is responsible for pulmonary infection in patients with underlying lung disease and disseminated disease in patients with AIDS. MAC has evolved various virulence strategies to subvert immune responses and persist in the infected host. Current treatment for MAC is challenging, requiring a combination of multiple antibiotics given over a long time period (for at least 12 months after negative sputum culture conversion). Moreover, even after eradication of infection, many patients are left with residual lung dysfunction. In order to address similar challenges facing the management of patients with tuberculosis, recent attention has focused on the development of novel adjunctive, host-directed therapies (HDTs), with the goal of accelerating the clearance of mycobacteria by immune defenses and reducing or reversing mycobacterial-induced lung damage. In this review, we will summarize the evidence supporting specific adjunctive, HDTs for MAC, with a focus on the repurposing of existing immune-modulatory agents targeting a variety of different cellular pathways. We also highlight areas meriting further investigation.

The Use of Infliximab (Remicade®) for the Treatment of Rheumatic Diseases at a Tertiary Center in Lebanon: A 17-Year Retrospective Chart Review

Objectives:

Infliximab (Remicade®) was the first tumour necrosis factor-α (TNF) inhibitor to receive its initial marketing approval from the US Food and Drug Administration (FDA) for the treatment of Crohn’s disease. Following that, infliximab became approved for several immune-mediated inflammatory diseases. No evidence exists in the Middle East and North Africa region on the experience with infliximab use over an extended period in terms of efficacy and safety.

Methods:

The Rheumatology division at the American University of Beirut Medical Centre (AUBMC), one of the largest tertiary centres in the Middle East and North Africa region, has been using infliximab infusions for the treatment of certain rheumatic diseases for around two decades. By reviewing retrospectively medical charts at AUBMC, we investigate indications, safety and efficacy, rate of withdrawals, rate of switching to another biologic, and financial coverage of the drug to present data for practitioners and patients in the region considering infliximab for treatment of immune-mediated inflammatory diseases.

Results:

A total of 198 patients were identified in the past 17 years to have taken infliximab. The largest proportion of treated patients had RA. Fourteen percent of the total cohort experienced serious adverse events, with 96.4% of those events being mild hypersensitivity reactions. Five patients withdrew the medication because of infectious complications, 4 of which were cases of tuberculosis reactivation. Despite that, around half of the patients were switched to another biologic agent such anti-TNF-α, anti-CD20, and anti-IL-6 due to partial response, and less than half were receiving add-on disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate, 70% of patients who used infliximab only or were switched achieved complete remission at their last hospital information. Around 98% of infliximab users were financially covered.

Conclusion:

According to our experience, infliximab has made remission and prevention of long-term disability realistic goals of therapy in the Middle East region.

Mycobacterium malmoense: an unusual pathogen causing endocarditis, a case report and literature review

Non-tuberculous mycobacterias (NTM) are important pathogens responsible for a broad spectrum of diseases in humans. Although exposure is widespread since they are distributed in the environment, the development of the disease is rare. It will depend on the specific species, their virulence (only 50 have been found to cause disease), and the host’s immune response. M Mycobacterium Malmoense is a NTM first reported in 1977 at Malmö, Sweden, based on four cases of lung infections. After these, other infections have been reported mainly involving the respiratory tract. Extrapulmonary infections are limited to cervical adenitis, and rarely to tenosynovitis and disseminated disease. We are hence reporting, to our knowledge, the first case of M. malmoense as the cause of bacterial endocarditis in the world.

Macrophage Signaling Pathways in Pulmonary Nontuberculous Mycobacteria Infections

The incidence and prevalence of nontuberculous mycobacteria (NTM) lung disease is rising worldwide and accounts for most clinical cases of NTM disease. NTM infections occur in both immunocompetent and immunocompromised hosts. Macrophages are the primary host cells that initiate an immune response to NTM. Defining the molecular events that govern the control of infection within macrophages is fundamental to understanding the pathogenesis of NTM disease. Here, we review key macrophage host signaling pathways that contribute to the host immune response to pulmonary NTM infections. In this review, we focus primarily on NTM that are known to cause lung disease, including Mycobacterium avium intracellulare, M. abscessus, and M. kansasii.

Mechanisms of Antibiotic Tolerance in Mycobacterium avium Complex: Lessons From Related Mycobacteria

Mycobacterium avium complex (MAC) species are the most commonly isolated nontuberculous mycobacteria to cause pulmonary infections worldwide. The lengthy and complicated therapy required to cure lung disease due to MAC is at least in part due to the phenomenon of antibiotic tolerance. In this review, we will define antibiotic tolerance and contrast it with persistence and antibiotic resistance. We will discuss physiologically relevant stress conditions that induce altered metabolism and antibiotic tolerance in mycobacteria. Next, we will review general molecular mechanisms underlying bacterial antibiotic tolerance, particularly those described for MAC and related mycobacteria, including Mycobacterium tuberculosis, with a focus on genes containing significant sequence homology in MAC. An improved understanding of antibiotic tolerance mechanisms can lay the foundation for novel approaches to target antibiotic-tolerant mycobacteria, with the goal of shortening the duration of curative treatment and improving survival in patients with MAC.

Mycobacterium avium complex infection in a patient with systemic sclerosis- associated interstitial lung disease: A case report

We describe a case of a 65-year-old male with recently diagnosed diffuse cutaneous systemic sclerosis associated with usual interstitial pneumonia and pulmonary hypertension. Patient presented to the emergency department complaining of low-grade fever, increased sputum production, progressive dyspnea and weight loss. High-resolution computed tomography scan showed multifocal bronchiectasis with multiple small nodules. Bronchoalveolar lavage culture was positive for Mycobacterium intracellulare. Antimicrobial treatment was started which improved respiratory symptoms. One month after the initiation of antibiotics, cyclophosphamide therapy was started with adequate tolerance.

A rare case of tuberculosis-induced hypercalcemia

Laboratory investigations of hypercalcemia involve testing of various biochemical parameters such as parathyroid hormone (PTH), 25-(OH) Vitamin D (25-(OH) VitD), 1,25-(OH)₂ Vitamin D3 (calcitriol) and PTH related peptide (PTHrp). We herein present an atypical case of severe hypercalcemia in a patient with rheumatoid arthritis who has been treated for years by various biological disease-modifying antirheumatic drugs (DMARDs) and suddenly presented with general state alteration, oedema and ulceration of her right ankle. We illustrate how tuberculosis (TB) can cause high calcitriol concentration and subsequently lead to potentially severe hypercalcemia. Moreover, we highlight the importance of TB testing and follow-up in patients treated with biological DMARDs.

Host immune response against environmental nontuberculous mycobacteria and the risk populations of nontuberculous mycobacterial lung disease

Nontuberculous mycobacterial lung disease (NTM-LD) prevalence has been increasing over the recent decades. Numerous host factors are associated with NTM-LD development, including susceptible phenotypes such as ciliary defect and lung structural change, pulmonary clearance defect with poor clearance of secretions, and immune suppression. Specifically, regarding the susceptible host phenotypes without clear pathogenesis, a slender body, pectus excavatum, and postmenopausal female status are common. Also, decreased host immunity to NTM, especially T helper 1 cell responses is frequently observed. Even so, the underlying mechanisms remain unclear and relevant large-scale studies are lacking. Infections due to host genetics associated defects are mostly untreatable but rare in Asia, particularly Taiwan. Nevertheless, some risks for NTM-LD are controllable over disease progression. We suggest that clinicians first manage host factors and deal with the controllable characteristics of NTM-LD, followed by optimizing anti-NTM treatment. Further researches focusing on NTM-LD pathogenesis, especially the host-NTM interaction may advance understanding the nature of the disease and develop efficient therapeutic regimens.

Pulmonary non-tuberculous mycobacterial infections: current state and future management

Currently, there is a trend of increasing incidence in pulmonary non-tuberculous mycobacterial infections (PNTM) together with a decrease in tuberculosis (TB) incidence, particularly in developed countries. The prevalence of PNTM in underdeveloped and developing countries remains unclear as there is still a lack of detection methods that could clearly diagnose PNTM applicable in these low-resource settings. Since non-tuberculous mycobacteria (NTM) are environmental pathogens, the vicinity favouring host-pathogen interactions is known as important predisposing factor for PNTM. The ongoing changes in world population, as well as socio-political and economic factors, are linked to the rise in the incidence of PNTM. Development is an important factor for the improvement of population well-being, but it has also been linked, in general, to detrimental environmental consequences, including the rise of emergent (usually neglected) infectious diseases, such as PNTM. The rise of neglected PNTM infections requires the expansion of the current efforts on the development of diagnostics, therapies and vaccines for mycobacterial diseases, which at present, are mainly focused on TB. This review discuss the current situation of PNTM and its predisposing factors, as well as the efforts and challenges for their control.