Prevalence of Gastroesophageal Reflux Disease in Patients With Nontuberculous Mycobacterial Lung Disease

Lower respiratory tract microbiota in patients with clinically suspected nontuberculous mycobacterial pulmonary disease according to the presence of gastroesophageal reflux

Although gastroesophageal reflux has been recognized as one of the risk factors of nontuberculous mycobacterial pulmonary disease (NTM-PD) progression, the effect of reflux on the lower respiratory tract microbiota has not been studied in detail. We investigated the composition of the lower respiratory tract microbiota in patients with clinically suspected NTM-PD, comparing them based on the presence of reflux. Forty-seven patients suspected of having NTM-PD were enrolled and assigned according to presence of reflux (n = 22) and non- reflux (n = 25). We performed a pepsin ELISA assay to identify the presence of reflux and 16S ribosomal RNA gene amplicon sequencing to evaluate the microbiota in bronchoalveolar lavage fluid. There were no significant differences in the diversity or composition of the lower respiratory microbiota between the NTM-PD and non-NTM-PD groups. Bacterial richness was observed in the non-reflux group than in the reflux group [P = 0.03] and a cluster in the reflux group was observed. The reflux group showed a predominance for Pseudomonas aeruginosa or Staphylococcus aureus among the NTM-PD group and for P. aeruginosa, Haemophilus influenzae, Klebsiella pneumoniae, or Eikenella species among the non-NTM-PD group. The non-reflux groups presented diverse patterns. A linear discriminant analysis and volcano plot demonstrated that P. aeruginosa, H. haemolyticus, Selenomonas artemidis, and Dolosigranulum pigrum were specifically associated with the NTM-PD reflux group, while P. aeruginosa was specifically associated with the non-NTM-PD reflux group. These observations confirm that the lower respiratory microbiota is consistently altered by reflux but not in NTM-PD.

Phenotypical characteristics of nontuberculous mycobacterial infection in patients with bronchiectasis

BACKGROUND

The global mortality and morbidity rates of bronchiectasis patients due to nontuberculous mycobacteria (NTM) pulmonary infection are on a concerning upward trend. The aims of this study to identify the phenotype of NTM-positive individuals with bronchiectasis.

METHODS

A retrospective single-center observational study was conducted in adult patients with bronchiectasis who underwent bronchoscopy in 2007-2020. Clinical, laboratory, pulmonary function, and radiological data were compared between patients with a positive or negative NTM culture.

RESULTS

Compared to the NTM-negative group (n=677), the NTM-positive group (n=94) was characterized (P ≤0.05 for all) by older age, greater proportion of females, and higher rates of gastroesophageal reflux disease and muco-active medication use; lower body mass index, serum albumin level, and lymphocyte and eosinophil counts; lower values of forced expiratory volume in one second, forced vital capacity, and their ratio, and lower diffusing lung capacity for carbon monoxide; higher rates of bronchiectasis in both lungs and upper lobes and higher number of involved lobes; and more exacerbations in the year prior bronchoscopy. On multivariate analysis, older age (OR 1.05, 95% CI 1.02-1.07, P=0.001), lower body mass index (OR 1.16, 95% CI 1.16-1.07, P <0.001), and increased number of involved lobes (OR 1.26, 95% CI 1.01-1.44, P=0.04) were associated with NTM infection.

CONCLUSIONS

Patients with bronchiectasis and NTM pulmonary infection are more likely to be older and female with more severe clinical, laboratory, pulmonary function, and radiological parameters than those without NTM infection. This phenotype can be used for screening patients with suspected NTM disease.

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.

Nontuberculous mycobacterial pulmonary disease added burden to COPD and bronchiectasis in Japan

Background and objective

Nontuberculous mycobacterial pulmonary disease (NTM-PD) prevalence in Japan is among the highest worldwide. COPD and bronchiectasis are common comorbidities among patients with NTM-PD, and it is challenging to treat NTM-PD in patients with these conditions. There are limited data on the incremental burden that NTM-PD adds to underlying COPD or bronchiectasis in Japan. Therefore, the objective of this study was to assess the incremental burden associated with NTM-PD in patients with pre-existing COPD and/or bronchiectasis.

Methods

This nested case-control study was based on JMDC, Inc. claims data (2015-2020). Patients with COPD and/or bronchiectasis with NTM-PD (cases) were age and sex matched 1:3 to patients with COPD and/or bronchiectasis without NTM-PD (controls), resulting in three mutually exclusive patient groups (COPD, bronchiectasis or both; with or without NTM-PD). Incremental burden of NTM-PD was assessed within each group by comparing hospitalisations during the 1-year period after NTM-PD diagnosis (index) between cases and controls with both univariate analysis and multivariate analysis adjusting for pre-index comorbidities.

Results

Univariate analyses in the three patient groups consistently demonstrated incremental hospitalisation burden in cases versus controls (e.g. COPD group: 20% of 492 cases versus 13% of 1476 controls had all-cause hospitalisations; 11% versus 5% had respiratory-related hospitalisations; and 6% versus 2% had COPD-related hospitalisations). Subsequent multivariate analysis further confirmed the findings.

Conclusions

The substantial incremental burden of hospitalisation associated with NTM-PD in patients with COPD and/or bronchiectasis highlights the urgent need for appropriate management of NTM-PD in Japan.

Treatment of the Less Common Nontuberculous Mycobacterial Pulmonary Disease

Nontuberculous mycobacterial pulmonary disease caused by the less common nontuberculous mycobacteria have distinct features depending on the species. Diagnostic evaluation follows the established criteria for all nontuberculous mycobacteria, but with certain qualifications given species-specific and regional differences in pathogenicity. Clinicians should first institute nonpharmacologic management and evaluate clinical, radiologic, and microbiologic factors in the decision regarding antimycobacterial therapy. Treatment is challenging, and evidence-based recommendations are limited for most species. Drug susceptibility testing is used to help with regimen selection; however, this approach is imperfect given the uncertain correlation between in vitro activity and clinical response for most drugs.

Lung Microbiome as a Treatable Trait in Chronic Respiratory Disorders

Once thought to be a sterile environment, it is now established that lungs are populated by various microorganisms that participate in maintaining lung function and play an important role in shaping lung immune surveillance. Although our comprehension of the molecular and metabolic interactions between microbes and lung cells is still in its infancy, any event causing a persistent qualitative or quantitative variation in the composition of lung microbiome, termed "dysbiosis", has been virtually associated with many respiratory diseases. A deep understanding of the composition and function of the "healthy" lung microbiota and how dysbiosis can cause or participate in disease progression will be pivotal in finding specific therapies aimed at preventing diseases and restoring lung function. Here, we review lung microbiome dysbiosis in different lung pathologies and the mechanisms by which these bacteria can cause or contribute to the severity of the disease. Furthermore, we describe how different respiratory disorders can be caused by the same pathogen, and that the real pathogenetic mechanism is not only dependent by the presence and amount of the main pathogen but can be shaped by the interaction it can build with other bacteria, fungi, and viruses present in the lung. Understanding the nature of this bacteria crosstalk could further our understanding of each respiratory disease leading to the development of new therapeutic strategies.

Gastroesophageal Reflux Disease Increases Susceptibility to Nontuberculous Mycobacterial Pulmonary Disease

BACKGROUND

Gastroesophageal reflux disease (GERD) is a common comorbidity of nontuberculous mycobacteria (NTM) pulmonary disease (PD). Although GERD is associated with more symptoms and severe disease in patients with NTM PD, whether GERD is associated with an increased risk of NTM PD developing is unknown.

RESEARCH QUESTION

Does GERD influence the development of NTM PD? Are there any factors associated with an increased risk of NTM PD among patients with GERD? What is the impact of NTM PD on the health-care use of patients with GERD?

STUDY DESIGN AND METHODS

Data from the Korean National Health Insurance Service National Sample Cohort between 2002 and 2015 were used. The incidence and risk of NTM PD were compared between patients with GERD (GERD cohort; n = 17,424) and patients matched for age, sex, type of insurance, and Charlson Comorbidity Index (matched cohort; n = 69,696). Using the GERD cohort, the factors associated with incident NTM PD also were evaluated.

RESULTS

During a median follow-up duration of 5.1 years, the age- and sex-adjusted incidence of NTM PD was significantly higher in the GERD cohort (34.8 per 100,000 person-years [PY]) than in the matched cohort (10.5 per 100,000 PY; P < .001), with a subdistribution hazard ratio (HR) of 3.36 (95% CI, 2.10-5.37). Regarding risk factors associated with NTM PD, age of 60 years or older (adjusted HR, 3.57; 95% CI, 1.58-8.07) and bronchiectasis (adjusted HR, 18.69; 95% CI, 6.68-52.28) were associated with an increased risk of incident NTM PD in the GERD cohort. Compared with patients with GERD who did not demonstrate NTM PD, those with NTM PD showed higher all-cause (13,321 PY vs 5,932 PY; P = .049) and respiratory disease-related (5,403 vs 801; P = .011) ED visits or hospitalizations.

INTERPRETATION

GERD is associated with an increased incidence of NTM PD. Older age and bronchiectasis are risk factors for NTM PD in patients with GERD. NTM PD in patients with GERD is associated with increased health-care use.

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.

Mycobacterium abscessus Pneumonia in Severe Alcoholism

Non-tuberculous mycobacterial infections (mycobacterium other than Mycobacterium tuberculosis and Mycobacterium leprae) are organisms that are commonly found in the environment such as water, soil, and dust. They may form difficult to eliminate biofilms and have been reported to cause significant infections in humans, especially in immunocompromised hosts. This article describes an interesting case of Mycobacterium abscessus in the lung.

Healthcare Utilization and Medical Cost of Gastrointestinal Reflux Disease in Non-tuberculous Mycobacterial Pulmonary Disease: A Population-Based Study, South Korea, 2009–2017

Gastroesophageal reflux disease (GERD) is a common non-respiratory comorbidity in patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD). However, little is known about the association between GERD and healthcare utilization and medical costs of NTM-PD. Thus, we evaluated this association using the Health Insurance Review and Assessment Service National Patient Sample. NTM-PD patients with GERD had significantly higher healthcare use and spent a higher total on medical costs (5,098 vs. 2,675 USD/person/year) than those without GERD (P <0.001 for all). Therefore, an appropriate management of GERD in NTM-PD patients can be an important factor to reduce the disease burden.

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.

Increased hospitalizations and economic burden in COPD with bronchiectasis: a nationwide representative study

With the increasing use of computed tomography, bronchiectasis has become a common finding in patients with chronic obstructive pulmonary disease (COPD). However, the clinical aspects and medical utilization of COPD with bronchiectasis (BE) remain unclear. We aimed to investigate the BE effect on prognosis and medical utilization in patients with COPD. Among 263,747 COPD patients, we excluded patients lacking chest X-ray, CT, or pulmonary function test codes and classified 2583 GOLD-C/D patients matched according to age, sex, and medical aid as having COPD-BE (447 [17.3%]) and COPD without BE (2136 [82.7%]). Patients with COPD-BE showed a higher rate of acute exacerbation requiring antibiotics than those without BE. Moreover, multivariable analysis showed that BE co-existence was a crucial factor for moderate-to-severe exacerbation (incidence rate ratio [IRR] 1.071; 95% CI 1.012-1.134; p = 0.019). Patients with COPD-BE had a significantly higher rate of exacerbations requiring antibiotics, as well as treatment cost and duration (meant as number of days using hospitalization plus outpatient appointment), than those with COPD without BE (52.64 ± 65.29 vs. 40.19 ± 50.02 days, p < 0.001; 5984.08 ± 8316.96 vs. 4453.40 ± 7291.03 USD, p < 0.001). Compared with patients with COPD without BE, patients with COPD-BE experienced more exacerbations requiring antibiotics, more hospitalizations, and a higher medical cost.

Nontuberculous Mycobacterial Pulmonary Disease: Clinical Epidemiologic Features, Risk Factors, and Diagnosis: The Nontuberculous Mycobacterial Series

Nontuberculous mycobacterial pulmonary disease (NTM-PD) continues to impose a significant clinical burden of disease on susceptible patients. The incidence of NTM-PD is rising globally, but it remains a condition that is challenging to diagnose and treat effectively. This review provides an update on the global epidemiologic features, risk factors, and diagnostic considerations associated with the management of NTM-PD.

Possible relationship between esophageal dilatation and severity of M. abscessus pulmonary disease

Objectives

Recently, incidence of Mycobacterium abscessus (Mab) pulmonary disease (Mab-PD) is increasing worldwide. We aimed to identify factors associated with severity of Mycobacterium abscessus (Mab) pulmonary disease (Mab-PD).

Methods

All patients diagnosed as Mab-PD based on the official ATS/IDSA statement between 2017 January 1 and 2021 July 31 were included (n = 13). We reviewed medical records, bacteriological and laboratory data of the patients. Severity of lung lesions and esophageal diameters in chest CT were quantitatively evaluated. Gaffky score in the sputum was used as airway mycobacterial burden. We explored the factors associated with high CT score and high Gaffky score.

Results

Maximum diameter of esophagus (MDE) in severe disease (CT score≧10) was greater than that in milder disease (CT score<10) (18.0±7.9mm, 9.3±3.1mm, respectively, p = 0.01), and MDE was well correlated with CT score (R = 0.69, p = 0.007). MDE in high mycobacterial burden group (Gaffky score ≧5) tended to be greater than that in low mycobacterial burden group (Gaffky score <5) (16.1±6.8mm, 10.1±5.5mm, respectively, p = 0.12), and MDE was well correlated with Gaffky score (R = 0.68, p = 0.009). Lung lesions were bilateral and predominant in middle or lower lobes.

Conclusions

Esophageal dilatation was correlated with severity of Mab-PD and airway mycobacterial burden. Gastroesophageal reflux might be associated with Mab disease progression.

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.

Non-tuberculous mycobacteria: a disease beyond TB and preparedness in India

BACKGROUND AND METHODS

Fifty-six Indian studies on NTM diseases were selected between 1981 and 2020 from various electronic databases (PubMed, EMBASE, Medline, BIOSIS preview, and Scopus) for systematic review.

RESULTS

NTM isolation rates increased from 0.9% between 2001 and 2010 to 1.6% between 2011 and 2020. Prevalence of NTM-pulmonary disease (NTM-PD) among presumptive-TB patients in India was 1.1% (395/34,829). M. avium complex (MAC) (19%) was most commonly isolated from pulmonary specimens followed by M. chelonae (10%), M. fortuitum (9.8%), and M. abscessus (8.8%). M. fortuitum (35.5%), M. chelonae (23.6%) and M. abscessus (15%) were frequently reported from extra-pulmonary specimens. Patients with NTM-PD were mostly treated with a macrolide-based three-drug regimen. Clarithromycin-based-drug regimen in combination with amikacin, ciprofloxacin and several other drugs (rifampicin, imipenem, ofloxacin, linezolid, azithromycin) was used for treatment of EP-NTM. Median duration of the treatment in NTM-PD was 12 months, (6-18 months) whereas it was 6 months (3.1-8.7 months) in EP-NTM. Treatment was successful in 45% (19/42) of NTM-PD patients and 75% (93/124) of EP-NTM patients.

CONCLUSION

It is concluded from this review that most Indian studies have published laboratory data on NTM isolation and speciation and lacked information on clinical, microbiological and radiological correlation and treatment outcome details. Future studies should address these issues while publishing on NTM diseases.

Nontuberculous Mycobacteria

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and 193 species of NTM have been discovered thus far. NTM species vary in virulence from benign environmental organisms to difficult-to-treat human pathogens. Pulmonary infections remain the most common manifestation of NTM disease in humans and bronchiectasis continues to be a major risk factor for NTM pulmonary disease (NTM PD). This article will provide a useful introduction and framework for clinicians involved in the management of bronchiectasis and NTM. It includes an overview of the epidemiology, pathogenesis, diagnosis, and management of NTM PD. We will address the challenges faced in the diagnosis of NTM PD and the importance of subspeciation in guiding treatment and follow-up, especially in Mycobacterium abscessus infections. The treatment of both Mycobacterium avium complex and M. abscessus, the two most common NTM species known to cause disease, will be discussed in detail. Elements of the recent ATS/ERS/ESCMID/IDSA NTM guidelines published in 2020 will also be reviewed.

Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung

The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated state. Bile acids are particularly associated with the dominance of Proteobacterial pathogens. The ability of bile acids to impact directly on both the lung microbiota and the host response offers a unifying principle underpinning the pathogenesis of CF. The modulating role of bile acids in lung microbiota dysbiosis and inflammation could offer new potential targets for designing innovative therapeutic approaches for respiratory disease.

A multidisciplinary approach to the management of nontuberculous mycobacterial lung disease: a clinical perspective

INTRODUCTION

Management of nontuberculous mycobacterial lung disease (NTM-LD) can be encumbered by difficult diagnostic criteria and complex treatment decisions. As prevalence of this debilitating, often refractory, progressive lung disease increases globally, management must evolve beyond antimicrobials to encompass holistic and customized treatments coordinated by practitioners across various specialties.

AREAS COVERED

This review aims to complement the recently updated NTM-LD treatment guidelines and expand current approaches to diagnosis, treatment, and disease management in a multidisciplinary dimension. The foundation of effective long-term management of NTM-LD is awareness of diagnostic criteria, individual patient risk factors, and the importance of managing underlying pulmonary and nonpulmonary comorbidities. The value of adopting all available pharmacological and nonpharmacological treatment modalities with a patient-centered approach to address the needs of long-term patient care cannot be minimized.

EXPERT OPINION

This section, while acknowledging the limited advances in understanding of NTM-LD and the availability of newer diagnostic and therapeutic tools over the last decade, underscores the need for a programmatic approach to this chronic, debilitating pulmonary infection. This will not only lead to more comprehensive patient care with better outcomes, but will also inspire and activate robust networks of research and public health initiatives in this field.

Reflux-Aspiration in Chronic Lung Disease

Microaspiration, or silent aspiration, is commonly suspected in patients with refractory respiratory symptoms, including unexplained chronic cough, asthma, chronic obstructive pulmonary disease, bronchiolitis, bronchiectasis, and idiopathic pulmonary fibrosis. This suspicion is driven by the high prevalence of gastroesophageal reflux in these otherwise disparate disorders. Frequently, patients receive aggressive treatment for gastroesophageal reflux disease as a means of treating their underlying respiratory conditions, even in the absence of overt symptoms of reflux. However, clinical trials have not demonstrated a clear impact on outcomes with this strategy, and in some instances there may be potential for harm. Mechanistic studies have increasingly used gastric biomarkers obtained directly from the airways to confirm the association between reflux and respiratory disease, but results are limited by methodologic flaws and correlation. The best evidence of aspiration directly causing respiratory disorders is the histopathologic detection of foreign bodies. For most of the other chronic respiratory disorders, microaspiration may be uncommon or a secondary aggravating factor, as in patients with acute exacerbations of chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis. In some cases, microaspiration is probably not a significant factor at all, such as in unexplained chronic cough. It is important to distinguish between conditions in which aspiration is primarily or directly causal and conditions in which aspiration may be indirectly aggravating, to help identify whether interventions targeting reflux and aspiration precautions should be recommended to patients. Our clinical review examines some of the evidence supporting reflux-aspiration as a mechanism for several chronic respiratory disorders and offers some management considerations when reflux-aspiration is suspected.

Nontuberculous mycobacterial lung infections in patients with eating disorders: plausible mechanistic links in a case series

Nontuberculous mycobacteria (NTM) are widely distributed in the environment and are almost always acquired into the lungs by bioaerosol inhalation or aspiration of NTM-contaminated water, biofilms, and soil. NTM are increasingly recognized as causes of lung diseases in immunocompetent hosts, a not insignificant number of whom have a life-long or nearly life-long slender body habitus as well as thoracic cage abnormalities such as scoliosis and pectus excavatum. While several hypotheses have been offered to explain the purported increase in susceptibility to NTM lung disease in such individuals, the precise explanation remains unknown. We described three patients with eating disorders associated with severe malnutrition and either purging behaviors or other risks for aspiration who were diagnosed with NTM lung infections-the largest number of such patients to date in a single report. We discuss the clinical and experimental evidence that low body weight and chronic vomiting with attendant jeopardy for aspiration, as seen in patients with eating disorders, may represent risk factors for NTM lung disease. We also speculate the possibility of occult and undiagnosed eating disorders in some of the slender NTM lung disease patients with no known risk factors for the opportunistic infection other than their low body weight.

Current therapies for gastro-oesophageal reflux in the setting of chronic lung disease: state of the art review

The inter-relationship between chronic respiratory disease and reflux disease in the airway reflux paradigm is extremely complex and remains poorly characterised. Reflux disease is reported to cause or contribute to the severity of a number of respiratory tract diseases including laryngeal disorders, sinusitis, chronic cough, asthma, COPD, idiopathic pulmonary fibrosis, cystic fibrosis, bronchiectasis and bronchiolitis obliterans post lung transplant. It is now appreciated that reflux disease is not simply caused by liquid acid reflux but rather by a variety of chemical refluxates originating from the stomach and duodenum due to a number of different mechanisms. Reflux disease can be challenging to diagnose, particularly proving its role in the causation of direct respiratory epithelial damage. Significant advances in oesophageal assessment and gastric biomarkers have emerged in recent years as our understanding increases. There are a number of treatments available for reflux disease, both medical and surgical, but there is a paucity of large randomised trials to evaluate their efficacy in the setting of chronic respiratory disease. Everyday clinical practice, however, informs us that treatment failure in reflux disease is common. This clinical review summarises associations between reflux disease in the setting of chronic respiratory diseases and examines available evidence regarding potential therapeutic strategies.

Gastro-oesophageal reflux disease is prevalent among patients with chronic respiratory disease. A number of medical and surgical treatment options are available for GORD. This review examines available evidence in the setting of chronic lung disease.https://bit.ly/34TcMJS

Epidemiology, diagnosis & treatment of non-tuberculous mycobacterial diseases

Non-tuberculous mycobacteria (NTM) are ubiquitously present in the environment, but NTM diseases occur infrequently. NTM are generally considered to be less virulent than Mycobacterium tuberculosis, however, these organisms can cause diseases in both immunocompromised and immunocompetent hosts. As compared to tuberculosis, person-to-person transmission does not occur except with M. abscessus NTM species among cystic fibrosis patients. Lung is the most commonly involved organ, and the NTM-pulmonary disease (NTM-PD) occurs frequently in patients with pre-existing lung disease. NTM may also present as localized disease involving extrapulmonary sites such as lymph nodes, skin and soft tissues and rarely bones. Disseminated NTM disease is rare and occurs in individuals with congenital or acquired immune defects such as HIV/AIDS. Rapid molecular tests are now available for confirmation of NTM diagnosis at species and subspecies level. Drug susceptibility testing (DST) is not routinely done except in non-responsive disease due to slowly growing mycobacteria ( M. avium complex, M. kansasii) or infection due to rapidly growing mycobacteria, especially M. abscessus. While the decision to treat the patients with NTM-PD is made carefully, the treatment is given for 12 months after sputum culture conversion. Additional measures include pulmonary rehabilitation and correction of malnutrition. Treatment response in NTM-PD is variable and depends on isolated NTM species and severity of the underlying PD. Surgery is reserved for patients with localized disease with good pulmonary functions. Future research should focus on the development and validation of non-culture-based rapid diagnostic tests for early diagnosis and discovery of newer drugs with greater efficacy and lesser toxicity than the available ones.

Physical Measures to Reduce Exposure to Tap Water-Associated Nontuberculous Mycobacteria

Nontuberculous mycobacteria (NTM) that cause human disease can be isolated from household tap water. Easy-to-use physical methods to reduce NTM from this potential source of exposure are needed. Filters and UV disinfection have been evaluated for their ability to reduce numbers of waterborne non-NTM organisms from drinking water, but their efficacy in reducing NTM counts are not well-established. Thus, five commercially available disinfection methods were evaluated for their potential as practical, efficient, and low-cost methods to reduce NTM from tap water. First, suspensions of tap water–adapted Mycobacterium smegmatis were passed through either a point-of-use, disposable, 7-day or 14-day Pall-Aquasafe filter. The 7-day filter prevented passage of M. smegmatis in effluent water for 13 days, and the 14-day filter prevented the passage of M. smegmatis for 25 days. Second, a granular activated carbon filter system failed to significantly reduce Mycobacterium abscessus and Mycobacterium avium numbers. Third, suspensions of tap water–adapted M. abscessus, M. avium, and M. chimaera (“MycoCocktail”) were passed through the “LifeStraw GO” hollow-fiber, two-stage membrane filtration system. LifeStraw GO prevented passage of the MycoCocktail suspension for the entire 68-day evaluation period. Finally, two different water bottle UV sterilization systems, “Mountop” and “SteriPEN,” were evaluated for their capacity to reduce NTM numbers from tap water. Specifically, MycoCocktail suspensions were dispensed into Mountop and SteriPEN water bottles and UV treated as per the manufacturer instructions once daily for 7 days, followed by a once weekly treatment for up to 56 days. After 4 days of daily UV treatment, both systems achieved a >4 log reduction in MycoCocktail CFU. After the 56-day evaluation period, suspension and biofilm-associated CFU were measured, and a >4 log reduction in CFU was maintained in both systems. Taken together, physical disinfection methods significantly reduced NTM numbers from tap water and may be easy-to-use, accessible applications to reduce environmental NTM exposures from drinking water.

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.

Revisiting John Snow to Meet the Challenge of Nontuberculous Mycobacterial Lung Disease

Nontuberculous mycobacteria (NTM) are ubiquitous components of the soil and surface water microbiome. Disparities by sex, age, and geography demonstrate that both host and environmental factors are key determinants of NTM disease in populations, which predominates in the form of chronic pulmonary disease. As the incidence of NTM pulmonary disease rises across the United States, it becomes increasingly evident that addressing this emerging human health issue requires a bold, multi-disciplinary research framework that incorporates host risk factors for NTM pulmonary disease alongside the determinants of NTM residence in the environment. Such a framework should include the assessment of environmental characteristics promoting NTM growth in soil and surface water, detailed evaluations of water distribution systems, direct sampling of water sources for NTM contamination and species diversity, and studies of host and bacterial factors involved in NTM pathogenesis. This comprehensive approach can identify intervention points to interrupt the transmission of pathogenic NTM species from the environment to the susceptible host and to reduce NTM pulmonary disease incidence.

Alpha-1-Antitrypsin Enhances Primary Human Macrophage Immunity Against Non-tuberculous Mycobacteria

Rationale: The association between non-tuberculous mycobacterial lung disease and alpha-1-antitrypsin (AAT) deficiency is likely due, in part, to underlying emphysema or bronchiectasis. But there is increasing evidence that AAT itself enhances host immunity against microbial pathogens and thus deficiency could compromise host protection.

Objectives: The goal of this project is to determine if AAT could augment macrophage activity against non-tuberculous mycobacteria.

Methods: We compared the ability of monocyte-derived macrophages cultured in autologous plasma that were obtained immediately before and soon after AAT infusion—given to individuals with AAT deficiency—to control an ex vivo Mycobacterium intracellulare infection.

Measurements and Main Results: We found that compared to pre-AAT infused monocyte-derived macrophages plus plasma, macrophages, and contemporaneous plasma obtained after a session of AAT infusion were significantly better able to control M. intracellulare infection; the reduced bacterial burden was linked with greater phagosome-lysosome fusion and increased autophagosome formation/maturation, the latter due to AAT inhibition of both M. intracellulare–induced nuclear factor-kappa B activation and A20 expression. While there was a modest increase in apoptosis in the M. intracellulare-infected post-AAT infused macrophages and plasma, inhibiting caspase-3 in THP-1 cells, monocyte-derived macrophages, and alveolar macrophages unexpectedly reduced the M. intracellulare burden, indicating that apoptosis impairs macrophage control of M. intracellulare and that the host protective effects of AAT occurred despite inducing apoptosis.

Conclusion: AAT augments macrophage control of M. intracellulare infection through enhancing phagosome-lysosome fusion and autophagy.

The Lung Microbiome and Its Role in Pneumonia

The use of next-generation sequencing and multiomic analysis reveals new insights on the identity of microbes in the lower airways blurring the lines between commensals and pathogens. Microbes are not found in isolation; rather they form complex metacommunities where microbe-host and microbe-microbe interactions play important roles on the host susceptibility to pathogens. In addition, the lower airway microbiota exert significant effects on host immune tone. Thus, this review highlights the roles that microbes in the respiratory tract play in the development of pneumonia.

Clinical and microbiological characteristics of non-tuberculous mycobacteria diseases in Singapore with a focus on pulmonary disease, 2012-2016

Background

Information on non-tuberculosis mycobacterial (NTM) diseases remains limited in Singapore and other Southeast Asian countries. This study aimed to delineate epidemiological and clinical features of pulmonary NTM disease.

Methods

A retrospective review was performed on all NTM isolates identified in Singapore General Hospital from 2012 to 2016 using the 2007 ATS/IDSA diagnostic criteria.

Results

A total of 2026 NTM isolates from 852 patients were identified. M. abscessus-chelonae group (1010, 49.9%) was the most commonly isolated and implicated in pulmonary NTM disease. Pulmonary cases (352, 76%) had the highest prevalence among patients diagnosed with NTM diseases (465/852, 54.6%) with no gender difference. Male patients were older (68.5 years, P = 0.014) with a higher incidence of chronic obstructive pulmonary disease (COPD) (23.6%, P < 0.001) and recurrent cough with phlegm production (51.6%, P = 0.035). In contrast, more female patients had bronchiectasis (50%, P < 0.001) and haemoptysis (37.6%, P = 0.042). Age and COPD were associated with multiple NTM species isolation per patient.

Conclusions

M. abscessus-chelonae group was the commonest NTM species isolated in Singapore. Pulmonary NTM infection has the highest frequency with male and female patients associated with a higher incidence of COPD and bronchiectasis respectively. Age and COPD were associated with multiple NTM species isolation per patient.

Nontuberculous Mycobacteria: Epidemiology and the Impact on Pulmonary and Cardiac Disease

This article reviews the current epidemiology of nontuberculous mycobacterial pulmonary disease and the impact on thoracic disease. The prevalence of nontuberculous pulmonary disease in the United States is much higher than that of Mycobacterium tuberculosis. Estimates support an annual increase in incidence of 8% per year. Nontuberculous mycobacteria are distinguished by 2 group designations, slowly growing mycobacteria, such as Mycobacterium avium complex, and rapidly growing mycobacteria, which includes Mycobacterium abscessus. Most pulmonary infections in humans are caused by species belonging to M avium complex. This article also reviews risk factors for disease acquisition, including host and environmental risk factors.

[The Prevalence of Nontuberculous Mycobacterial Lung Disease with orwithout Reflux Esophagitis]

Background/Aims

Gastrointestinal reflux disease (GERD) is defined as 'a condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications'. It is associated with various lung diseases, including bronchial asthma, chronic bronchitis, and bronchiectasis. GERD may also affect nontuberculous mycobacterial (NTM) lung disease. We presumed that the normal mucosal barrier of the bronchial epithelium is broken due to the aspiration of gastric juice and consequent chronic bronchial inflammation. This study investigated the prevalence of GERD in accordance with the presence or absence of NTM lung disease and analyzed the difference.

Methods

We screened patients with NTM lung disease in this hospital between January 2011 and December 2015. Among these patients, gastroscopic examinations as a health check-up were performed on 93 patients. We obtained the prevalence of Reflux esophagitis (RE) in patients with NTM and compared it with the prevalence of RE in the normal control subjects.

Results

Among 93 patients with NTM, patients without RE was 66.7% (62/93). RE-minimal change was diagnosed in 29.0% (27/93), and RE LA-A was diagnosed in 4.3% (4/93). Comparing the prevalence of RE minimal change, 29.0% (27/93) had NTM and 11.9% (3043/25536) did not have NTM. This was statistically significant.

Conclusions

We showed a greater prevalence of RE minimal change in patients with NTM than those without NTM with statistical significance.

The overlap between bronchiectasis and chronic airway diseases: state of the art and future directions

Bronchiectasis is a clinical and radiological diagnosis associated with cough, sputum production and recurrent respiratory infections. The clinical presentation inevitably overlaps with other respiratory disorders such as asthma and chronic obstructive pulmonary disease (COPD). In addition, 4-72% of patients with severe COPD are found to have radiological bronchiectasis on computed tomography, with similar frequencies (20-30%) now being reported in cohorts with severe or uncontrolled asthma. Co-diagnosis of bronchiectasis with another airway disease is associated with increased lung inflammation, frequent exacerbations, worse lung function and higher mortality. In addition, many patients with all three disorders have chronic rhinosinusitis and upper airway disease, resulting in a complex "mixed airway" phenotype.The management of asthma, bronchiectasis, COPD and upper airway diseases has traditionally been outlined in separate guidelines for each individual disorder. Recognition that the majority of patients have one or more overlapping pathologies requires that we re-evaluate how we treat airway disease. The concept of treatable traits promotes a holistic, pathophysiology-based approach to treatment rather than a syndromic approach and may be more appropriate for patients with overlapping features.Here, we review the current clinical definition, diagnosis, management and future directions for the overlap between bronchiectasis and other airway diseases.

Lung Transplant Outcomes in Systemic Sclerosis with Significant Esophageal Dysfunction. A Comprehensive Single-Center Experience

RATIONALE

Consideration of lung transplantation in patients with systemic sclerosis (SSc) remains guarded, often due to the concern for esophageal dysfunction and the associated potential for allograft injury and suboptimal post-lung transplantation outcomes.

OBJECTIVES

The purpose of this study was to systematically report our single-center experience regarding lung transplantation in the setting of SSc, with a particular focus on esophageal dysfunction.

METHODS

We retrospectively reviewed all lung transplants at our center from January 1, 2000 through August 31, 2012 (n = 562), comparing the SSc group (n = 35) to the following lung transplant diagnostic subsets: all non-SSc (n = 527), non-SSc diffuse fibrotic lung disease (n = 264), and a non-SSc matched group (n = 109). We evaluated post-lung transplant outcomes, including survival, primary graft dysfunction, acute rejection, bronchiolitis obliterans syndrome, and microbiology of respiratory isolates. In addition, we defined severe esophageal dysfunction using esophageal manometry and esophageal morphometry criteria on the basis of chest computed tomography images. For patients with SSc referred for lung transplant but subsequently denied (n = 36), we queried the reason(s) for denial with respect to the concern for esophageal dysfunction.

MEASUREMENTS AND MAIN RESULTS

The 1-, 3-, and 5-year post-lung transplant survival for SSc was 94, 77, and 70%, respectively, and similar to the other groups. The remaining post-lung transplant outcomes evaluated were also similar between SSc and the other groups. Approximately 60% of the SSc group had severe esophageal dysfunction. Pre-lung transplant chest computed tomography imaging demonstrated significantly abnormal esophageal morphometry for SSc when compared with the matched group. Importantly, esophageal dysfunction was the sole reason for lung transplant denial in a single case.

CONCLUSIONS

Relative to other lung transplant indications, our SSc group experienced comparable survival, primary graft dysfunction, acute rejection, bronchiolitis obliterans syndrome, and microbiology of respiratory isolates, despite the high prevalence of severe esophageal dysfunction. Esophageal dysfunction rarely precluded active listing for lung transplantation.

Natural history of Mycobacterium fortuitum pulmonary infection presenting with migratory infiltrates: a case report with microbiological analysis

Background

Presence of Mycobacterium fortuitum in respiratory tracts usually indicates mere colonization or transient infection, whereas true pulmonary infection occurs in patients with gastroesophageal disease. However, little is known about the diagnostic indications for true M. fortuitum pulmonary infection and the natural history of the disease.

Case presentation

A 59-year-old man was referred to our hospital for treatment against M. fortuitum pulmonary infection. Fifteen years before the referral, he underwent total gastrectomy, after which he experienced esophageal reflux symptoms. After the referral, the patient was closely monitored without antimicrobial therapy because of mild symptoms and no pathological evidence of M. fortuitum pulmonary infection. During the observation, chest imaging showed migratory infiltrates. Two years after the referral, his lung biopsy specimen revealed foamy macrophages and multinucleated giant cells, indicating lipoid pneumonia. However, he was continually monitored without any treatment because there was no evidence of nontuberculous mycobacterial infection. Four years after the referral, he developed refractory pneumonia despite receiving adequate antibiotic therapy. After confirmation of granulomatous lesions, multiple antimicrobial therapy for M. fortuitum resulted in a remarkable improvement with no exacerbation for over 5 years. Random amplified polymorphic DNA polymerase chain reaction analysis revealed identical M. fortuitum strains in seven isolates from six sputum and one intestinal fluid specimens obtained during the course of the disease.

Conclusions

We have described a patient with M. fortuitum pulmonary infection who presented with migratory infiltrates. The pathological evidence and microbiological analysis suggested that M. fortuitum pulmonary infection was associated with lipoid pneumonia and chronic exposure to gastrointestinal fluid. Therefore, physicians should carefully monitor patients with M. fortuitum detected from lower respiratory tract specimens and consider antimicrobial therapy for M. fortuitum infection when the patient does not respond to adequate antibiotic therapy against common pneumonia pathogens.

Causative species of nontuberculous mycobacterial lung disease and comparative investigation on clinical features of Mycobacterium abscessus complex disease: A retrospective analysis for two major hospitals in a subtropical region of Japan

Nontuberculous mycobacteria (NTM) lung disease is increasing globally. Although the etiological epidemiology of NTM is different across regions, Mycobacterium avium complex (MAC) is the leading cause of NTM lung disease in most countries, including mainland Japan. Okinawa is located in the southernmost region of Japan and is the only prefecture categorized as a subtropical region in Japan, it is therefore likely the etiological epidemiology of NTM lung disease is different from mainland Japan. From 2009 to 2015, the medical records of patients, with respiratory specimens positive for NTMs, visiting or admitted to two Okinawan hospitals, were retrospectively analyzed. NTM lung disease cases were defined according to the American Thoracic Society criteria and patient epidemiology and clinical information were evaluated. Results indicate four hundred sixteen patients had bacterial cultures positive for NTM. The most common NTM was M. abscessus complex (MABC) (n = 127; 30.5%), followed by M. intracellulare (n = 85; 20.4%). NTM lung disease was diagnosed in 114 patients. Of these cases, MABC was most common (n = 41; 36.0%), followed by M. intracellulare (n = 31; 27.2%). Chronic obstructive pulmonary disease (COPD) and tracheostomy patients were more likely to develop MABC than MAC lung disease. Multivariate analysis showed a probable association between COPD and MABC lung disease. Chest computed tomography (CT) evaluation revealed bronchiectasis, nodules, and consolidation were less frequently observed in MABC patients compared with MAC patients. Our data suggests Okinawa may be one of the few places where MABC is the predominant pathogen causing NTM lung disease and our results add new insight to MABC lung disease, which is not yet well understood.

Pulmonary disease by non-tuberculous mycobacteria - clinical management, unmet needs and future perspectives

INTRODUCTION

The number of patients with pulmonary disease caused by non-tuberculous mycobacteria (NTM) is increasing globally. Poor resistance against infections, for example, due to pre-existing lung diseases, immune deficiency and immune-modulating treatment, predisposes the population to developing pulmonary NTM disease. The incidence of pre-existing lung diseases such as chronic obstructive pulmonary disease and bronchiectasis has also increased. NTM disease diagnosis is often delayed due to non-specific symptoms. The therapeutic arsenal is limited and adherence to treatment guidelines is often low since the treatment regimens are complex, lengthy and side effects are common. Thus, current disease management is far from satisfactory and needs to be improved. Areas covered: This review provides an overview of the current knowledge of NTM infections and includes pathogenesis, disease patterns, epidemiology, disease management, unmet needs and future perspectives. Expert commentary: NTM disease is becoming more prevalent, in part with our increased awareness and improved diagnostic methods. However, our understanding of the disease pathogenesis is limited and treatment decisions are challenging, with difficult to employ drug regimens. Optimal management requires collaboration between healthcare providers, patients and expert centers.

Identification of nontuberculous mycobacteria isolated from hospital water by sequence analysis of the hsp65 and 16S rRNA genes

Nontuberculous mycobacteria (NTM) have emerged as an important cause of opportunistic nosocomial infections. NTM has frequently been isolated from hospital water distribution systems. The aim of this study was to survey the risk of NTM infections and determine the prevalence of NTM species in the hospital water distribution systems in Tabriz, Iran. One hundred and twenty samples of water from different sources of Tabriz hospitals were collected. The samples were filtered through 0.45-µm pore size membranes and decontaminated with 0.01% cetylpyridinium chloride. The sediment was inoculated onto Lowenstein-Jensen medium and incubated for 8 weeks. For identification to the species level, partial sequence analysis of the hsp65 and 16S rRNA genes were used. NTM were detected in 76 (63.3%) of 120 samples. Potentially pathogenic mycobacteria and saprophytic mycobacteria were isolated. Mycobacterium gordonae was the only single species that was present in all types of water. The prevalence of NTM in Tabriz hospitals' water compared with many investigations on hospital waters was high. This indicates that the immunocompromised patients and transplant recipients are at risk of contamination which necessitates considering decontamination of water sources to prevent such potential hazards.

Lung Microbiota and Its Impact on the Mucosal Immune Phenotype

The use of culture-independent techniques has allowed us to appreciate that the upper and lower respiratory tract contain a diverse community of microbes in health and disease. Research has only recently explored the effects of the microbiome on the host immune response. The exposure of the human body to the bacterial environment is an important factor for immunological development; thus, the interaction between the microbiome and its host is critical to understanding the pathogenesis of disease. In this article, we discuss the mechanisms that determine the composition of the airway microbiome and its effects on the host immune response. With the use of ecological principles, we have learned how the lower airways constitute a unique niche subjected to frequent microbial migration (e.g., through aspiration) and constant immunological pressure. The discussion will focus on the possible inflammatory pathways that are up- and downregulated when the immune system is challenged by dysbiosis. Identification of potential markers and microbial targets to address the modulation of inflammation in early disease, when changes may have the most effect, will be critical for future therapies.

Mycobacterium avium Complex Disease

Despite the ubiqitous nature of Mycobacterium avium complex (MAC) organisms in the environment, relatively few of those who are infected develop disease. Thus, some degree of susceptibility due to either underlying lung disease or immunosuppression is required. The frequency of pulmonary MAC disease is increasing in many areas, and the exact reasons are unknown. Isolation of MAC from a respiratory specimen does not necessarily mean that treatment is required, as the decision to treatment requires the synthesis of clinical, radiographic, and microbiologic information as well as a weighing of the risks and benefits for the individual patient. Successful treatment requires a multipronged approach that includes antibiotics, aggressive pulmonary hygiene, and sometimes resection of the diseased lung. A combination of azithromycin, rifampin, and ethambutol administered three times weekly is recommend for nodular bronchiectatic disease, whereas the same regimen may be used for cavitary disease but administered daily and often with inclusion of a parenteral aminoglycoside. Disseminated MAC (DMAC) is almost exclusively seen in patients with late-stage AIDS and can be treated with a macrolide in combination with ethambutol, with or without rifabutin: the most important intervention in this setting is to gain HIV control with the use of potent antiretroviral therapy. Treatment outcomes for many patients with MAC disease remain suboptimal, so new drugs and treatment regimens are greatly needed. Given the high rate of reinfection after cure, one of the greatest needs is a better understanding of where infection occurs and how this can be prevented.

Nontuberculous mycobacteria in gastrostomy fed patients with cystic fibrosis

Multi-drug resistant Mycobacterium abscessus complex (MABSC) is a form of Nontuberculous mycobacteria (NTM) of special, international concern in Cystic Fibrosis (CF). We hypothesised that gastric juice and percutaneous endoscopic gastrostomy (PEG) feeding devices might yield MABSC isolates. Gastric juice and sputa from sixteen adult PEG fed CF patients and five replaced PEG tubes were studied. Bacterial and fungal isolates were cultured. Mycobacterium were identified by rpoB, sodA and hsp65 gene sequencing and strain typed using variable number tandem repeat. Bacteria and/or fungi grew from all gastric juice, sputa and PEG samples. MABSC were detected in 7 patients. Five had MABSC in their sputum. Two had an identical MABSC strain in their sputum and gastric juice and one had the same strain isolated from their PEG tube and sputum. Two patients who were sputum sample negative had MABSC isolated in their gastric juice or PEG tube. MABSC were therefore identified for the first time from a gastric sample in a minority of patients. We conclude that gastric juice and PEG-tubes may be a potential source of MABSC isolates in CF patients, and these findings warrant further study.