Nontuberculous Mycobacterial Infection Research Articles

Risk of Potential Invasive Non-Tuberculous Mycobacterial Infection in Major Cardiothoracic Surgeries.

Nontuberculous Mycobacteria (NTM) commonly colonise municipal water supplies and cause healthcare-associated outbreaks. Although the infections are rare, they are associated with high mortality. Aerosolization of NTM from colonised Heater cooler devices causes invasive infections in cardiac surgery patients. These units are widely used in open-chest heart surgery as an essential part of extracorporeal circulation but have been suggested as being a risk for infection. Water disinfection as well as effective engineering-related mitigation strategies should be designed to decrease the burden of NTM in the hospital water supply. Key Words: Nontuberculous Mycobacteria, Heater cooler devices, Endocarditis, Water, Cardiothoracic surgeries.

Nontuberculous Mycobacterial Infections in Pediatric Solid Organ Transplant and Hematopoietic Cell Transplant Recipients.

The diagnosis of nontuberculous mycobacterial infections is challenging in pediatric solid organ transplant and hematopoietic cell transplant recipients due to the absence of specific clinical manifestations, limitations of sampling, prolonged times for culture and identification, and difficulty discerning colonization from clinical disease. Treatment is dependent on the nontuberculous mycobacterial species, disease type, and pattern of drug resistance. Treatment of nontuberculous mycobacterial infections involves prolonged durations of therapy using multiple medications, which are limited by toxicities and drug-drug interactions.

Susceptibility to mycobacterial infection in VEXAS syndrome.

VEXAS is a recently described acquired auto-inflammatory and hematologic syndrome caused by somatic mutations in UBA1. To date, VEXAS is not a recognized cause of acquired immunodeficiency. Two of our 10 VEXAS patients developed a disseminated Mycobacterium avium infection. To shed light on this observation, we retrospectively studied all patients with disseminated non-tuberculous mycobacterial infections (NTMi) seen at our institution over 13 years. Inclusion criteria were a positive blood/bone marrow culture, or 2 positive cultures from distinct sites, or one positive culture with 2 involved sites. patient 1 presented with fever, rash, orbital cellulitis and lung infiltrates. Patient 2 presented with fever and purpura. In both cases, Mycobacterium avium was identified on bone marrow culture. Twenty cases of disseminated NTMi were reviewed. Among 11 HIV-negative patients, three had chronic immune-mediated disease; three had untreated myeloid neoplasm; two had VEXAS; one had undergone kidney transplantation; one had GATA-2 deficiency; and one had no identified aetiology. None had lymphoid neoplasia or had undergone bone marrow transplantation. HIV-negative cases had higher CD4 counts than HIV-positive patients (median CD4: 515/mm3 vs 38/mm3, p< 0.001). Monocytopenia was present in seven cases. At 2 years, six patients had died, including both VEXAS patients. VEXAS patients have an intrinsic susceptibility to disseminated NTMi, which may result from monocytic dysfunction. NTMi can mimic VEXAS flare. Clinicians should maintain a high suspicion for opportunistic infections before escalating immunosuppressive therapy. Further studies are needed to confirm and better decipher the herein reported observations.

Development of 2nd generation aminomethyl spectinomycins that overcome native efflux in Mycobacterium abscessus.

Mycobacterium abscessus (Mab), a nontuberculous mycobacterial (NTM) species, is an emerging pathogen with high intrinsic drug resistance. Current standard-of-care therapy results in poor outcomes, demonstrating the urgent need to develop effective antimycobacterial regimens. Through synthetic modification of spectinomycin (SPC), we have identified a distinct structural subclass of N-ethylene linked aminomethyl SPCs (eAmSPCs) that are up to 64-fold more potent against Mab over the parent SPC. Mechanism of action and crystallography studies demonstrate that the eAmSPCs display a mode of ribosomal inhibition consistent with SPC. However, they exert their increased antimicrobial activity through enhanced accumulation, largely by circumventing efflux mechanisms. The N-ethylene linkage within this series plays a critical role in avoiding TetV-mediated efflux, as lead eAmSPC 2593 displays a mere fourfold susceptibility improvement against Mab ΔtetV, in contrast to the 64-fold increase for SPC. Even a minor shortening of the linkage by a single carbon, akin to 1st generation AmSPC 1950, results in a substantial increase in MICs and a 16-fold rise in susceptibility against Mab ΔtetV. These shifts suggest that longer linkages might modify the kinetics of drug expulsion by TetV, ultimately shifting the equilibrium towards heightened intracellular concentrations and enhanced antimicrobial efficacy. Furthermore, lead eAmSPCs were also shown to synergize with various classes of anti-Mab antibiotics and retain activity against clinical isolates and other mycobacterial strains. Encouraging pharmacokinetic profiles coupled with robust efficacy in Mab murine infection models suggest that eAmSPCs hold the potential to be developed into treatments for Mab and other NTM infections.

Spontaneous Perinephric Abscess with Atypical Mycobacteria: An Entity to Ponder

Abstract Although chronic pulmonary disease due to atypical mycobacteria also known as non-tuberculous mycobacterial (NTM) infections are recognised with increasing frequency, very few cases of primary urinary involvement with this organism have been reported. It is important to distinguish between simple colonisation by these organisms and actual infection caused by them. Differentiation between NTM infection and urinary tuberculosis is also important in determining the therapeutic regimen. We present the report of a case of perinephric abscess produced by NTM in a healthy male individual.

Automated Machine Learning with Radiomics for Predicting Chronicity of Pulmonary Nodules in Patients with Nontuberculous Mycobacterial Lung Infection

Automated Machine Learning with Radiomics for Predicting Chronicity of Pulmonary Nodules in Patients with Nontuberculous Mycobacterial Lung Infection

Investigating cutaneous tuberculosis and nontuberculous mycobacterial infections a Department of Dermatology, Beijing, China: a comprehensive clinicopathological analysis.

Cutaneous tuberculosis (CTB) and nontuberculous mycobacteria (NTM) infections present considerable diagnostic and therapeutic challenges. This study aims to provide a comprehensive clinicopathological analysis of CTB and NTM infections. We conducted a retrospective analysis of 103 patients diagnosed with cutaneous tuberculosis (CTB) and nontuberculous mycobacteria (NTM) infections at a Beijing dermatology department from January 2000 to January 2024. Demographic, clinical, histological, and laboratory finding data were collected. Diagnostic methods and histopathological examination were recorded. Treatment regimens and outcomes were reviewed. Descriptive statistics were used to summarize demographic and clinical data, and continuous variables expressed as means and standard deviations (SD), and categorical variables as frequencies and percentages. Statistical analyses were conducted using SPSS version 25.0. The cohort included 103 patients (40.8% males and 59.2% females), with a mean age of 51.86 years. Common clinical manifestations included nodules (97.1%), erythema (74.8%), and plaques (68.9%). Histological examination revealed hyperkeratosis (68.9%), parakeratosis (23.3%), and extensive neutrophil infiltration (95.1%) were observed. Acid fast bacteria (AFB) stains and nucleic acid tests exhibited respective positivity rates of 39.6% and 52.3%, respectively. Most patients were treated with a combination of three drugs; 77.1% of patients showed improvement, with the cure rate for CTB being 20.0%. This study highlights the diverse clinical and histological presentations of CTB and NTM infections, emphasizing the need for comprehensive diagnostic approaches. The variability in treatment regimens reflects the complex management of these infections. The implementation of advanced molecular techniques and standardized treatment protocols is imperative for enhancing diagnostic precision and therapeutic outcomes.

Increased Inflammatory Responses in Patients With Active Disseminated Non-Tuberculous Mycobacterial Infection and High Anti-Interferon-Gamma Autoantibodies

Increased Inflammatory Responses in Patients With Active Disseminated Non-Tuberculous Mycobacterial Infection and High Anti-Interferon-Gamma Autoantibodies

Epidemiological and clinical characteristics of nontuberculous mycobacterial infections: A retrospective female cohort study in an Italian population

ObjectivesThis study aims to assess the characteristics and treatment outcomes of patients diagnosed with non-tuberculous mycobacteria (NTM) diseases at the Infectious Diseases Unit of ARNAS Garibaldi Hospital in Catania, Italy, focusing on demographics, clinical features, and treatment effectiveness. MethodsWe conducted a retrospective observational study of 10 patients diagnosed with NTM diseases between 2019 and 2021. Data was collected from electronic medical records, including demographic information, comorbidities, treatment modalities, and outcomes. The study utilized descriptive statistics to analyze continuous and categorical variables. Treatment regimens were based on individual patient needs, incorporating a combination of antibiotics. ResultsThe median age of the patients was 55.44 years, all female, predominantly suffering from pulmonary NTM diseases. Mycobacterium intracellulare was the most common pathogen. Common comorbidities included COPD, bronchiectasis, GERD, and hypovitaminosis D. Patients showed symptoms like fever, cough, and asthenia. The treatment regimens were diverse, with macrolides, rifampicin, and ethambutol forming the core. Adverse effects were noted in 40 % of patients, including gastrointestinal and neurological disorders. All patients achieved microbiological cure, with 60 % showing clinical improvement and 36 % radiological improvement. ConclusionThe study highlights the complexity of diagnosing and treating NTM diseases, emphasizing the need for personalized treatment plans and vigilant monitoring of adverse effects. Despite achieving microbiological cure, challenges remain in achieving complete clinical and radiological resolution. Further research is needed to enhance the understanding and management of NTM diseases, particularly in diverse populations.

Nontuberculous Mycobacterial Infections and Management for the Inpatient Dermatologist

Nontuberculous Mycobacterial Infections and Management for the Inpatient Dermatologist

Management Challenges of Extrapulmonary Nontuberculous Mycobacterial Infection: A Single-Center Case Series and Literature Review.

Extrapulmonary nontuberculous mycobacterial (NTM) disease remains largely enigmatic, yet these mycobacteria are increasingly acknowledged as important opportunistic pathogens in humans. Traditionally, NTM infections have been identified across various anatomical locations, with the respiratory system being the most affected and best understood. Historically, extrapulmonary NTM infection was predominantly associated with HIV/AIDS, with Mycobacterium avium lymphadenopathy being the most commonly reported. Today, however, because of the expanding utilization of immunosuppressive therapies and the demographic shift towards an aging population, an increasing number of NTM infections are expected and seen. Hence, a heightened index of suspicion is essential, necessitating a multifaceted approach to identification and drug sensitivity testing to improve treatment outcomes. In extrapulmonary NTM management, expert consultation is strongly recommended to determine the most efficacious treatment regimen, as individualized, patient-tailored therapies are often required. Furthermore, the economic burden of NTM disease is considerable, accompanied by high rates of hospitalization. To optimize the management of these intricate infections, there is an urgent need for comprehensive data on incidence, prevalence, and outcomes. This case-based series delves into the intricate nature of extrapulmonary NTM infections, focusing on both rapid and slow-growing NTM species, and explores therapeutic options, resistance mechanisms, and host-related immunological factors.

A case of cervical lymphadenitis due to a difficult-to-diagnose nontuberculous mycobacterial infection

A case of cervical lymphadenitis due to a difficult-to-diagnose nontuberculous mycobacterial infection

The Mycobacterium tuberculosis MmpL3 inhibitor MSU-43085 is active in a mouse model of infection.

MmpL3 is a protein that is required for the survival of bacteria that cause tuberculosis (TB) and nontuberculous mycobacterial (NTM) infections. This report describes the discovery and characterization of a new small molecule, MSU-43085, that targets MmpL3 and is a potent inhibitor of Mycobacterium tuberculosis (Mtb) and M. abscessus survival. MSU-43085 is shown to be orally bioavailable and efficacious in an acute model of Mtb infection. However, the analog is inactive against Mtb in chronically infected mice. Pharmacokinetic and metabolite identification studies identified in vivo metabolism of MSU-43085, leading to a short half-life in treated mice. These proof-of-concept studies will guide further development of the MSU-43085 series for the treatment of TB or NTM infections.

HIV and skin infections

HIV infection alters the skin microbiome and predisposes to a wide range of cutaneous infections, from atypical presentations of common skin infections to severe disseminated infections involving the skin that are AIDS-defining illnesses. Bacterial infection of the skin, most commonly caused by Staphylococcus aureus, occurs frequently and can result in bacteremia. Nontuberculous mycobacterial infections that are usually localized to the skin may disseminate, and guidance on the treatment of these infections is limited. Herpes simplex can be severe, and less common presentations such as herpetic sycosis and herpes vegetans have been reported. Severe herpes zoster, including disseminated infection, requires intravenous antiviral treatment. Viral warts can be particularly difficult to treat, and in atypical or treatment-resistant cases a biopsy should be considered. Superficial candidosis occurs very commonly in people living with HIV, and antifungal resistance is an increasing problem in non-albicans Candida species. Systemic infections carry a poor prognosis. In tropical settings the endemic mycoses including histoplasmosis are a problem for people living with HIV, and opportunistic infections can affect those with advanced HIV in all parts of the world. Most cutaneous infections can develop or worsen as a result of immune reconstitution in the weeks to months after starting antiretroviral therapy. Direct microscopic examination of clinical material can facilitate rapid diagnosis and treatment initiation, although culture is important to provide microbiological confirmation and guide treatment.

Clinical characteristics and prognostic factors of non-tuberculous mycobacterial disease in patients with rheumatoid arthritis.

This study aimed to identify the clinical characteristics of patients with concurrent rheumatoid arthritis (RA) and suspected non-tuberculous mycobacterial (NTM) infections as well as determine their prognostic factors. We retrospectively reviewed the medical records of 91 patients with RA whose computed tomography (CT) findings suggested NTM infection. Subsequently, we compared the clinical characteristics between patients with and without clinical or radiological exacerbation of NTM-pulmonary disease (PD) and investigated the risk factors for the exacerbation and associated mortality. The mean age of patients with RA and suspected NTM-PD was 65.0 ± 10.2 years. The nodular/bronchiectatic (NB) form of NTM-PD was the predominant radiographic feature (78.0%). During follow-up, 36 patients (41.9%) experienced a radiological or clinical exacerbation of NTM-PD, whereas 12 patients (13.2%) died. Combined interstitial lung disease (ILD), microbiologically confirmed NTM-PD, and NB with the fibrocavitary (FC) form on chest CT were identified as risk factors for the clinical or radiological exacerbation of NTM-PD. Hydroxychloroquine use was identified as a good prognostic factor. Conversely, history of tuberculosis, ILD, smoking, microbiologically confirmed NTM-PD, and NB with the FC form on chest CT were identified as poor prognostic factors for mortality in suspected NTM-PD. ILD and NB with the FC form on chest CT were associated with NTM-PD exacerbation and mortality. Hydroxychloroquine use may lower the risk of NTM-PD exacerbation. Therefore, radiographic features and presence of ILD should be considered when predicting the prognosis of patients with RA and suspected NTM-PD.

984. Detection of Mycobacterial Species from Specimens Submitted for Metagenomic Analysis

Abstract Background A national U.S. epidemic of non-tuberculous mycobacterial (NTM) infections is occurring at rates unseen over earlier decades, resulting in substantial numbers of pathogenic sequelae. Culture of mycobacteria is laborious, often requiring weeks for cultivation and speciation. Next generation sequencing (NGS) to detect NTM from clinical specimens has advantages over culture methods. From January 2018 to June 2022 we queried a large national NGS database to detect NTM rates and species. Methods DNA was isolated from 431,716 patient specimens collected from a variety of body sites: sputum, urine, sinus, wound or an unspecified swabs. Employing an Illumina’s 16S and ITS targeted-gene, deep sequencing approach, bacterial and/or fungal species resident in the specimen were determined. The identity and relative abundance of mycobacterial DNA recovered for each specimen were reported by species as the primary outcomes. Results Of the 431,716 specimens analyzed in this 4.5 year retrospective study, 0.001% (468) contained mycobacterial DNA. Forty different species of mycobacteria were detected with the most common frequency including: M abscessus, 40%; M mucogenicum, 13%; M. tuberculosis, 8.5% and M immunogenum 4.6%. M. avian and M. intracellulare were each detected in only 4% of the positive NTM specimens. 15% were other NTM species and 15% were not speciated NTM. Between 2018-2022 of the 468 NTM, the annual number of M. abscessus was 38, 53, 41 and 41, respectively. The concentration or relative abundance of mycobacterial DNA within each specimen varied from 4 to 100% of the total bacterial DNA recovered. Conclusion Over 4.5 years , NGS performed at a national molecular diagnostic laboratory detected 40 NTM species with a predominant fraction as M. abscessus (40%), supporting the clinical concern for an epidemic increase in M. abscessus infections during the last half decade. These data support the view that NGS metagenomics can uncover NTM epidemiological trends and implicate NTM infections. Disclosures Joseph F. John, Jr., MD, FACP, FIDSA, MicroGenDx: Advisor/Consultant Michael G. Schmidt, PhD, MicroGenDx: Advisor/Consultant Courtney L. Jarvis, PhD, MicroGenDX: Employee Niccole Diaz, BS, MicroGenDX: Advisor/Consultant Rick Martin, BS, MicroGenDX: Ownership Interest

Accuracy of QuantiFERON in active tuberculosis suspects with comorbidities and nontuberculous mycobacterial infection in Northern California.

The QuantiFERON-TB Gold (QFT) is routinely utilized in North American health systems to detect a cellular immune response to Mycobacterium tuberculosis antigens in symptomatic and asymptomatic patients. The sensitivity of QFT in tuberculosis (TB) patients with comorbidities is not well established and the specificity of QFT in patients with nontuberculous mycobacteria (NTM) infections is incompletely understood. Between 2012 and 2023, all patients with culture-positive TB and patients with NTM infection per the expert diagnostic guidelines or biopsy-proven NTM infection who had a concurrent QFT test were included in this study. The sensitivity and specificity of QFT were measured in TB and NTM patients, respectively. In 109 patients with active TB, the overall sensitivity of QFT was 78.0% (85/109; 95% CI: 70.1, 85.7). The sensitivity was 86.0% (49/57; 95% CI: 76.6, 94.8) and 69.2% (36/52; 95% CI: 56.7, 81.8) in immunocompetent and immunocompromised patients, respectively. The overall specificity of QFT in 88 patients with NTM infection was 76.1% (67/88; 95% CI: 67.2, 85.0). After the exclusion of 17 NTM patients with risk factors for latent TB infection, the specificity was 94.4% (67/71; 95% CI: 89.1, 99.7). Two patients had NTM species known to cross-react with QFT. In two NTM patients infected with species (Mycobacterium intracellulare subsp. intracellulare and Mycobacterium intracellulare subsp. chimaera) not known to cross-react, whole genome sequencing did not detect ESAT-6 or CFP-10. In Northern California, the QFT assay demonstrated moderately low to moderately high sensitivity in TB patients and very high specificity in NTM patients, thus ruling out concerns for cross-reactivity with NTM.

OPTIMA: An Open-Label, Noncomparative Pilot Trial of Inhaled Molgramostim in Pulmonary Nontuberculous Mycobacterial Infection.

Rationale: Inhaled granulocyte-macrophage colony-stimulating factor (GM-CSF) has been proposed as a potential immunomodulatory treatment for nontuberculous mycobacterial (NTM) infection.Objectives: This open-label, noncomparative pilot trial investigated the efficacy and safety of inhaled GM-CSF (molgramostim nebulizer solution) in patients with predominantly treatment-refractory pulmonary NTM infection (Mycobacterium avium complex [MAC] and M. abscessus [MABS]), either in combination with ongoing guideline-based therapy (GBT) or as monotherapy in patients who had stopped GBT because of lack of efficacy or intolerability.Methods: Thirty-two adult patients with refractory NTM infection (MAC, n = 24; MABS, n = 8) were recruited into two cohorts: those with (n = 16) and without (n = 16) ongoing GBT. Nebulized molgramostim 300 μg/d was administered over 48 weeks. Sputum cultures and smears and clinical assessments (6-min-walk distance, symptom scores, Quality of Life-Bronchiectasis Questionnaire score, and body weight) were collected every 4 weeks during treatment and 12 weeks after the end of treatment. The primary endpoint was sputum culture conversion, defined as three consecutive monthly negative cultures during the treatment period.Results: Eight patients (25%) achieved culture conversion on treatment (seven [29.2%] patients with MAC infection, one [12.5%] patient with MABS infection); in four patients, this was durable after the end of treatment. Of the 24 patients with MAC infection, an additional 4 patients had a partial response, converting from smear positive at baseline to smear negative at the end of treatment, and time to positivity in liquid culture media increased. Two of these patients sustained negative cultures from the end of treatment. Other clinical endpoints were unchanged. Serious adverse events were mainly pulmonary exacerbations or worsening NTM infection. Three deaths, not treatment related, were reported.Conclusions: In this population of patients with severe NTM disease, molgramostim was safe and well tolerated. Sputum culture conversion rates for patients with MAC infection (29.2%) were greater than reported for similar refractory MAC cohorts managed with GBT alone. Less benefit was seen for MABS infection. No serious safety concerns were identified. Further evaluation in a larger cohort is warranted.Clinical trial registered with www.clinicaltrials.gov (NCT03421743).

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.

Efficacy of Bortezomib for Treating Anti-Interferon-Gamma Autoantibody-Associated Adult-Onset Immunodeficiency Syndrome.

Currently, there is no effective treatment for adult-onset immunodeficiency (AOID) syndrome with anti-interferon-gamma autoantibodies (anti-IFN-γ-auto-Abs). This study aimed to investigate the effectiveness of bortezomib (BTZ) for decreasing anti-IFN-γ-auto-Abs. A pre- and post-intervention study was conducted from February 2017 through June 2019 at Siriraj Hospital (Bangkok, Thailand). Five patients were invited to receive once-weekly BTZ (1.3 mg/m2 body surface area) subcutaneously for 8 weeks followed by oral cyclophosphamide (1 mg/kg/d) for 4 months. The primary outcomes were the difference in antibody level at 8 and 48 weeks compared with baseline and the incidence of serious adverse events (AEs). The secondary outcome was the occurrence of opportunistic infections (OIs) during the 72 weeks after starting BTZ. The median patient age was 46 years (range, 34-53). All patients had 3-5 OIs prior to enrollment. All patients were receiving antimycobacterial agents for treatment of nontuberculous mycobacterial infection at enrollment. There was no significant difference in the mean optical density of auto-Abs at 8 weeks (3.73 ± 0.72) or 48 weeks (3.74 ± 0.53) compared with baseline (3.84 ± 0.49; P = .336 and P = .555, respectively). However, after serum dilution, the antibody titer nonsignificantly decreased 8-16 weeks after BTZ initiation (P = .345). Ten OIs were observed 24-72 weeks after BTZ initiation. Treatment with BTZ followed by cyclophosphamide yielded no significant decrease in antibody titer levels, and 10 OIs were observed during 24-72 weeks of BTZ treatment. No serious AEs were observed. Combining rituximab with BTZ is likely necessary to prevent generation of new autoantibody-producing plasma cells. Clinical Trials Registration. NCT03103555.