Nontuberculous Mycobacterial Pulmonary Disease: Patients, Principles, and Prospects.

Nontuberculous mycobacterial pulmonary disease (NTM-PD) is increasing in incidence globally and challenging to manage. The 2020 multisociety treatment guideline and the 2022 consensus recommendations provide comprehensive evidence-based guides to manage pulmonary diseases caused by the most common NTM. However, with >190 different NTM species that may require different multidrug regimens for treatment, the breadth and complexity of NTM-PD remain daunting for both patients and clinicians. In this narrative review, we aim to distill this broad, complex field into principles applicable to most NTM species and highlight important nuances, specifically elaborating on the presentation, diagnosis, principles of patient-centered care, principles of pathogen-directed therapy, and prospects of NTM-PD.

Target regimen profiles for tuberculosis treatment.

Simpler, shorter, safer and more effective treatments for tuberculosis that are easily accessible to all people with tuberculosis are desperately needed. In 2016, the World Health Organization (WHO) developed target regimen profiles for the treatment of tuberculosis to make drug developers aware of both the important features of treatment regimens, and patient and programmatic needs at the country level. In view of recent ground-breaking advances in tuberculosis treatment, WHO has revised and updated these regimen profiles. We used a similar process as for the 2016 profiles, including a baseline treatment landscape analysis, an initial stakeholder survey, modelling studies estimating the impact and cost-effectiveness of novel tuberculosis treatment regimens, and an extensive stakeholder consultation. We developed target regimen profiles for the treatment of rifampicin-susceptible and rifampicin-resistant tuberculosis, as well as a pan-tuberculosis regimen that would be appropriate for patients with any type of tuberculosis. We describe the revised target regimen profile characteristics, with specific minimal and optimal targets to be met, rationale and justification, and aspects relevant to all target regimen profiles (drug susceptibility testing, adherence and forgiveness, treatment strategies, post-tuberculosis lung disease, and cost and access considerations). We discuss the trade-offs of proposed characteristics for decision-making at developmental or operational levels. We expect that, following these target regimen profile revisions, tuberculosis treatment developers will produce regimens that are quality-assured, affordable and widely available, and that meet the needs of affected populations.

Des traitements de la tuberculose plus simples, plus courts, plus sûrs et plus efficaces, facilement accessibles à toutes les personnes atteintes de tuberculose, font cruellement défaut. En 2016, l'Organisation mondiale de la santé (OMS) a élaboré des profils de schéma thérapeutique cible pour le traitement de la tuberculose, afin de sensibiliser les concepteurs de médicaments aux caractéristiques importantes des schémas thérapeutiques et aux besoins des patients et des programmes au niveau national. Compte tenu des avancées récentes dans le traitement de la tuberculose, l'OMS a révisé et mis à jour ces profils de schéma thérapeutique. Nous avons appliqué un processus similaire à celui des profils de 2016, y compris une analyse de base des différentes possibilités thérapeutiques, une enquête initiale auprès des parties prenantes, des études de modélisation estimant l'impact et le rapport coût-efficacité des nouveaux schémas thérapeutiques pour la tuberculose, ainsi qu'une vaste consultation des parties prenantes. Nous avons élaboré des profils de schéma thérapeutique cible pour le traitement de la tuberculose sensible à la rifampicine ou résistant à la rifampicine, ainsi qu'un schéma multiforme qui conviendrait aux patients atteints de n'importe quel type de tuberculose. Nous décrivons les caractéristiques du profil révisé de schéma thérapeutique cible, avec les objectifs minimaux et optimaux spécifiques à atteindre, le raisonnement et les aspects pertinents pour tous les profils de schéma thérapeutique cible (tests de sensibilité aux médicaments, observance thérapeutique et manque d'observance («forgiveness¼), stratégies de traitement, maladie pulmonaire post-tuberculeuse et considérations de coût et d'accès). Nous discutons des compromis des caractéristiques proposées pour la prise de décisions au niveau du développement ou au niveau opérationnel. Nous espérons qu'à la suite de ces révisions du profil de schéma thérapeutique cible, les concepteurs de traitements antituberculeux produiront des schémas dont la qualité est assurée, qui sont abordables et largement disponibles et qui répondent aux besoins des populations touchées.

Se necesitan con urgencia tratamientos más sencillos, breves, seguros y eficaces contra la tuberculosis que sean fácilmente accesibles para todas las personas con tuberculosis. En 2016, la Organización Mundial de la Salud (OMS) elaboró perfiles objetivo de esquemas terapéuticos para el tratamiento de la tuberculosis con el fin de que los fabricantes de medicamentos conocieran tanto las características importantes de estos esquemas como las necesidades programáticas y de los pacientes en cada país. Teniendo en cuenta los recientes avances pioneros en el tratamiento de la tuberculosis, la OMS ha revisado y actualizado estos perfiles de esquemas terapéuticos. Se ha seguido un proceso similar al de los perfiles de 2016, que incluye un análisis de referencia del panorama terapéutico, una encuesta inicial a las partes interesadas, estudios de modelización para estimar el impacto y la rentabilidad de los nuevos esquemas terapéuticos para el tratamiento de la tuberculosis, y una amplia consulta a las partes interesadas. Se desarrollaron perfiles objetivo de esquemas terapéuticos para el tratamiento de la tuberculosis sensibles a la rifampicina y resistente a la rifampicina, así como un esquema farmacológico capaz de tratar todas las formas de tuberculosis que sería apropiado para pacientes con cualquier tipo de tuberculosis. Se describieron las características revisadas de los perfiles objetivo de los esquemas terapéuticos, con los objetivos mínimos y óptimos específicos que deben alcanzarse, los fundamentos y la justificación, y los aspectos relevantes para todos los perfiles objetivo de los esquemas terapéuticos (pruebas de sensibilidad a los fármacos, adherencia y olvido, estrategias de tratamiento, enfermedad pulmonar postuberculosa, y consideraciones de coste y acceso). Se discutieron las ventajas y desventajas de las características propuestas para la toma de decisiones a nivel de desarrollo u operativo. Se espera que, tras estas revisiones de los perfiles objetivo de los esquemas terapéuticos, las personas encargadas del desarrollo de tratamientos para la tuberculosis elaboren esquemas terapéuticos de calidad garantizada, asequibles y ampliamente disponibles, y que respondan a las necesidades de las poblaciones afectadas.

Genomic epidemiology of Mycobacterium abscessus at an adult cystic fibrosis programme reveals low potential for healthcare-associated transmission.

Rationale: Nontuberculous mycobacteria (NTM) has been reported to be transmitted between people with cystic fibrosis (CF) attending CF centres. A suspected Mycobacterium abscessus outbreak was investigated at the University of Texas Southwestern (UTSW) Adult CF Program using a combination of pathogen genomic sequencing and epidemiologic methods. The objectives of the present study were to apply the Healthcare-Associated Links in Transmission of NTM (HALT NTM) study to investigate the occurrence of potential healthcare-associated transmission and/or acquisition of NTM among people with CF infected with genetically similar NTM isolates. Methods: Whole-genome sequencing of respiratory M. abscessus isolates from 50 people with CF receiving care at UTSW was performed to identify genetically similar isolates. Epidemiologic investigation, comparison of respiratory and environmental isolates, and home residence watershed mapping were studied. Measurements and main results: Whole-genome sequencing analysis demonstrated seven clusters of genetically similar M. abscessus (four ssp. abscessus and three ssp. massiliense). Epidemiologic investigation revealed potential opportunities for healthcare-associated transmission within three of these clusters. Healthcare environmental sampling did not recover M. abscessus, but did recover four human disease-causing species of NTM. No subjects having clustered infections lived in the same home residence watershed. Some subjects were infected with more than one M. abscessus genotype, both within and outside of the dominant circulating clones. Conclusions: Healthcare-associated person-to-person transmission of M. abscessus appears to be rare at this centre. However, polyclonal infections of M. abscessus species and subspecies, not originating from the endemic hospital environment, suggest multiple shared modes of acquisition outside the healthcare setting.

Brensocatib in non-cystic fibrosis bronchiectasis: ASPEN protocol and baseline characteristics.

Introduction: Brensocatib is an investigational, oral, reversible inhibitor of dipeptidyl peptidase-1 shown to prolong time to first exacerbation in adults with bronchiectasis. Outlined here are the clinical trial design, and baseline characteristics and treatment patterns of adult patients enrolled in the phase 3 ASPEN trial (NCT04594369). Methods: The ASPEN trial is a global study enrolling patients with a clinical history consistent with bronchiectasis (cough, chronic sputum production and/or recurrent respiratory infections), diagnosis confirmed radiologically and ≥2 exacerbations in the prior 12 months. It was designed to evaluate the impact of two brensocatib doses (10 mg and 25 mg) on exacerbation rate over a 52-week treatment period versus placebo. Comprehensive clinical data, including demographics, disease severity, lung function, Pseudomonas aeruginosa status and quality of life, were collected at baseline. Results: 1682 adults from 35 countries were randomised from December 2020 to March 2023. Mean age was 61.3 years and 64.7% were female. ∼70% had moderate-to-severe Bronchiectasis Severity Index (BSI) scores, 29.3% had ≥3 exacerbations in the prior 12 months and 35.7% were positive for P. aeruginosa. Mean BSI scores were highest in Australia/New Zealand (8.3) and lowest in Latin America (5.9). Overall, the most common aetiology was idiopathic (58.4%). In P. aeruginosa-positive versus P. aeruginosa-negative patients, lung function was lower, with greater long-term macrolide (21.5% versus 14.0%) and inhaled corticosteroid use (63.5% versus 53.9%). There was wide regional variation in long-term antibiotic use in patients with bronchiectasis and P. aeruginosa. Discussion: ASPEN baseline characteristics and treatment profiles were representative of a global bronchiectasis population.

Mycobacterium gordonae: the canary in the coal mine?

Mycobacterium gordonae (M. gordonae) is a species of nontuberculous mycobacteria (NTM) that rarely causes infection. It has previously been labeled the most common NTM contaminant. Bronchiectasis is a disease characterized by abnormal airway dilation leading to chronic cough, sputum production and pulmonary infections. Patients with bronchiectasis are at higher risk of NTM-lung disease with more pathogenic NTM species including Mycobacterium avium complex (MAC) and Mycobacterium abscessus (M. abscessus). The relationship between bronchiectasis and less-pathogenic NTM species such as M. gordonae is less well understood. We performed a retrospective study on patients who had M. gordonae isolated from respiratory specimens at UConn Health between May 2nd, 2010 and October 18th, 2022. M. gordonae was isolated 74 times from 56 patients. It was isolated 35 (47.3%) times from 31 patients with bronchiectasis and 39 (52.7%) times from 26 patients without bronchiectasis. Data was available on all mycobacterial cultures sent from May 2nd 2018 to October 18th 2022. Mycobacterial cultures sent from patients with bronchiectasis were significantly more likely to grow M. gordonae than patients without bronchiectasis (4.3% vs. 1.6%, P=0.007). Furthermore, when considered at the patient level, there remained a significant increased rate of M. gordonae isolation among patients with bronchiectasis (7.1% vs. 2.2%, P<0.001). We then looked at past and future isolation of more pathogenic NTM species and found a non-statistically increased rate of isolation of more pathogenic NTM species including MAC and M. abscessus in patients with bronchiectasis (45.2% vs. 29%, P=0.09). Based on our results, isolation of M. gordonae should raise suspicion of chronic airway disease and defects in host immune response, such as those seen in bronchiectasis. Furthermore, isolation of M. gordonae may suggest increased risk of infection with more pathogenic NTM species such as MAC and M. abscessus.

Synergistic effects of sulopenem in combination with cefuroxime or durlobactam against Mycobacterium abscessus.

Mycobacterium abscessus (Mab) affects patients with immunosuppression or underlying structural lung diseases such as cystic fibrosis (CF). Additionally, Mab poses clinical challenges due to its resistance to multiple antibiotics. Herein, we investigated the synergistic effect of dual ß-lactams [sulopenem and cefuroxime (CXM)] or the combination of sulopenem and CXM with ß-lactamase inhibitors [BLIs-avibactam (AVI) or durlobactam (DUR)]. The sulopenem-CXM combination yielded low minimum inhibitory concentration (MIC) values for 54 clinical Mab isolates and ATCC19977 (MIC50 and MIC90 ≤0.25 µg/mL). Similar synergistic effects were observed in time-kill studies conducted at concentrations achievable in clinical settings. Sulopenem-CXM outperformed monotherapy, yielding ~1.5 Log10 CFU/mL reduction during 10 days. Addition of BLIs enhanced this antibacterial effect, resulting in an additional reduction of CFUs (~3 Log10 for sulopenem-CXM and AVI and ~4 Log10 for sulopenem-DUR). Exploration of the potential mechanisms of the synergy focused on their interactions with L,D-transpeptidases (Ldts; LdtMab1-LdtMab4), penicillin-binding-protein B (PBP B), and D,D-carboxypeptidase (DDC). Acyl complexes, identified via mass spectrometry analysis, demonstrated the binding of sulopenem with LdtMab2-LdtMab4, DDC, and PBP B and CXM with LdtMab2 and PBP B. Molecular docking and mass spectrometry data suggest the formation of a covalent adduct between sulopenem and LdtMab2 after the nucleophilic attack of the cysteine residue at the ß-lactam carbonyl carbon, leading to the cleavage of the ß-lactam ring and the establishment of a thioester bond linking the LdtMab2 with sulopenem. In conclusion, we demonstrated the biochemical basis of the synergy of sulopenem-CXM with or without BLIs. These findings potentially broaden the selection of oral therapeutic agents to combat Mab. IMPORTANCE: Treating infections from Mycobacterium abscessus (Mab), particularly those resistant to common antibiotics like macrolides, is notoriously difficult, akin to a never-ending struggle for healthcare providers. The rate of treatment failure is even higher than that seen with multidrug-resistant tuberculosis. The role of combination ß-lactams in inhibiting L,D-transpeptidation, the major peptidoglycan crosslink reaction in Mab, is an area of intense investigation, and clinicians have utilized this approach in the treatment of macrolide-resistant Mab, with reports showing clinical success. In our study, we found that cefuroxime and sulopenem, when used together, display a significant synergistic effect. If this promising result seen in lab settings, translates well into real-world clinical effectiveness, it could revolutionize current treatment methods. This combination could either replace the need for more complex intravenous medications or serve as a "step down" to an oral medication regimen. Such a shift would be much easier for patients to manage, enhancing their comfort and likelihood of sticking to the treatment plan, which could lead to better outcomes in tackling these tough infections. Our research delved into how these drugs inhibit cell wall synthesis, examined time-kill data and binding studies, and provided a scientific basis for the observed synergy in cell-based assays.

Notes from the Field: Potential Outbreak of Extrapulmonary Mycobacterium abscessus subspecies massiliense Infections from Stem Cell Treatment Clinics in Mexico - Arizona and Colorado, 2022.

Mycobacterium abscessus is an intrinsically drug-resistant, rapidly growing, nontuberculous mycobacterium; extrapulmonary infections have been reported in association with medical tourism (1). During November-December 2022, two Colorado hospitals (hospitals A and B) treated patient A, a Colorado woman aged 30-39 years, for M. abscessus meningitis. In October 2022, she had received intrathecal donor embryonic stem cell injections in Baja California, Mexico to treat multiple sclerosis and subsequently experienced headaches and fevers, consistent with meningitis. Her cerebrospinal fluid revealed neutrophilic pleocytosis and grew M. abscessus in culture at hospital A. Hospital A's physicians consulted hospital B's infectious diseases (ID) physicians to co-manage this patient (2).

Preclinical murine models for the testing of antimicrobials against Mycobacterium abscessus pulmonary infections: Current practices and recommendations.

Mycobacterium abscessus, a rapidly growing nontuberculous mycobacterium, is increasingly recognized as an important pathogen of the human lung, disproportionally affecting people with cystic fibrosis (CF) and other susceptible individuals with non-CF bronchiectasis and compromised immune functions. M. abscessus infections are extremely difficult to treat due to intrinsic resistance to many antibiotics, including most anti-tuberculous drugs. Current standard-of-care chemotherapy is long, includes multiple oral and parenteral repurposed drugs, and is associated with significant toxicity. The development of more effective oral antibiotics to treat M. abscessus infections has thus emerged as a high priority. While murine models have proven instrumental in predicting the efficacy of therapeutic treatments for M. tuberculosis infections, the preclinical evaluation of drugs against M. abscessus infections has proven more challenging due to the difficulty of establishing a progressive, sustained, pulmonary infection with this pathogen in mice. To address this issue, a series of three workshops were hosted in 2023 by the Cystic Fibrosis Foundation (CFF) and the National Institute of Allergy and Infectious Diseases (NIAID) to review the current murine models of M. abscessus infections, discuss current challenges and identify priorities toward establishing validated and globally harmonized preclinical models. This paper summarizes the key points from these workshops. The hope is that the recommendations that emerged from this exercise will facilitate the implementation of informative murine models of therapeutic efficacy testing across laboratories, improve reproducibility from lab-to-lab and accelerate preclinical-to-clinical translation.

In vitro activity of cefoxitin, imipenem, meropenem, and ceftaroline in combination with vaborbactam against Mycobacterium abscessus.

Mycobacterium abscessus (MAB) infections pose a growing public health threat. Here, we assessed the in vitro activity of the boronic acid-based ß-lactamase inhibitor, vaborbactam, with different ß-lactams against 100 clinical MAB isolates. Enhanced activity was observed with meropenem and ceftaroline with vaborbactam (1- and >4-fold MIC50/90 reduction). CRISPRi-mediated blaMAB gene knockdown showed a fourfold MIC reduction to ceftaroline but not the other ß-lactams. Our findings demonstrate vaborbactam's potential in combination therapy against MAB infections.

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.

Prospective evaluation of nontuberculous mycobacteria disease in cystic fibrosis: The design of the PREDICT study.

BACKGROUND: Nontuberculous mycobacteria (NTM) are an important cause of airway infections in people with cystic fibrosis (pwCF). Isolation of NTM from respiratory specimens of pwCF do not mandate treatment in the absence of clinical and radiologic features of NTM pulmonary disease (NTM-PD), as some pwCF clear the infection without treatment and others do not appear to progress to NTM-PD despite persistent infection. An evidence-based protocol to standardize diagnosis of NTM-PD is needed to systematically identify pwCF who may benefit from treatment. METHODS: In this multicenter observational study, eligible pwCF who are 6 years of age and older and who have had a recent positive NTM culture are systematically evaluated for NTM-PD. Participants are identified based on positive NTM culture results obtained during routine clinical care and following enrollment are evaluated for NTM-PD and CF-related comorbidities. Participants are followed in PREDICT until they meet NTM-PD diagnostic criteria and are ready to initiate NTM treatment, or until study termination. Active participants who have not met these criteria are re-consented every 5 years to enable long-term participation. RESULTS: The primary endpoint will summarize the proportion of participants who meet the NTM-PD diagnosis definition. The time from enrollment to NTM-PD diagnosis will be derived from Kaplan-Meier estimates. CONCLUSION: A prospective protocol to identify NTM-PD in pwCF will test if this standardized approach defines a cohort with signs and symptoms associated with NTM-PD, to assist with clinical decision making and to build a framework for future therapeutic trials. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02073409.

Prospective healthcare-associated links in transmission of nontuberculous mycobacteria among people with cystic fibrosis (pHALT NTM) study: Rationale and study design.

BACKGROUND: Healthcare-associated acquisition and transmission of nontuberculous mycobacteria (NTM) among people with cystic fibrosis (pwCF) has been described, and remains a concern for both patients and providers. This report describes the design of a prospective observational study utilizing the standardized epidemiologic investigation toolkit for healthcare-associated links in transmission of NTM among pwCF. METHODS: This is a parallel multi-site study of pwCF who have infections with respiratory NTM isolates and receive healthcare within a common CF Care Center. Participants have a history of one or more NTM positive airway cultures and have been identified as having NTM infections suggestive of a possible outbreak within a single Center, based on NTM isolate genomic analysis. Participants are enrolled in the study over a 3-year period. Primary endpoints are identification of shared healthcare-associated source(s) among pwCF in a Center, identification of healthcare environmental dust and water biofilm NTM isolates that are genetically highly-related to respiratory isolates, and identification of common home of residence watersheds among pwCF infected with clustered isolates. Secondary endpoints include characterization of healthcare-associated transmission and/or acquisition modes and settings as well as description of incidence and prevalence of healthcare-associated environmental NTM species/subspecies by geographical region. DISCUSSION: We hypothesize that genetically highly-related isolates of NTM among pwCF cared for at the same Center may arise from healthcare sources including patient-to-patient transmission and/or acquisition from health-care environmental dust and/or water biofilms. This study design utilizes a published, standardized, evidence-based epidemiologic toolkit to facilitate confidential, independent healthcare-associated NTM outbreak investigations within CF Care Centers. This study will facilitate real-time, rapid detection and mitigation of healthcare-associated NTM outbreaks to reduce NTM risk, inform infection prevention and control guidelines, and characterize the prevalence and origin of NTM outbreaks from healthcare-associated patient-to-patient transmission and/or environmental acquisition. This study will systematically characterize human disease causing NTM isolates from serial collection of healthcare environmental dust and water biofilms and define the most common healthcare environmental sources harboring NTM biofilms. TRIAL REGISTRATION: ClinicalTrials.gov NCT05686837.

In vitro susceptibility patterns for slowly growing non-tuberculous mycobacteria in the USA from 2018 to 2022.

BACKGROUND: Treatment of slowly growing non-tuberculous mycobacteria (SGM) is challenging. In vitro antimicrobial susceptibility testing (AST) is needed to optimize a multidrug regimen but requires weeks to result. Aggregated AST patterns, or an antibiogram, of SGM would be helpful to providers. OBJECTIVES: We aggregated and analysed human SGM isolates sent to our laboratory from across the USA between 2018 and 2022 to describe their in vitro susceptibility patterns and construct an antibiogram. METHODS: SGM isolates' species/subspecies and mutations in rrs or rrl were identified by a line probe assay. AST was done primarily by broth microdilution and interpreted using the latest CLSI guideline. Mutational and AST results for SGM with ≥15 isolates were collated and analysed with descriptive statistics. RESULTS: There were 32 different species/subspecies of SGM from 10 131 isolates between January 2018 and December 2022 from across the USA, 80% of which were from organisms in Mycobacterium avium complex (MAC). Most specimens were sputum and came from Florida (2892). MAC ranged from 94% to 100% susceptible to clarithromycin, 64% to 91% to amikacin, 2% to 31% to linezolid, and 4% to 41% to moxifloxacin. Non-MAC SGM ranged from 82% to 100% susceptible to clarithromycin, 49% to 100% to amikacin, and 76% to 100% to rifabutin, but susceptibilities to other antimicrobials varied widely. WT rrs and rrl predicted >96% of phenotypic non-resistance to amikacin and clarithromycin, respectively, whereas mutant genotypes predicted >90% of phenotypic resistance. CONCLUSIONS: Most SGM are likely to be susceptible to clarithromycin and amikacin, complementing their treatment guidance by mycobacterial experts. Molecular identification of resistant genotypes is accurate and helpful. This antibiogram for SGM will help providers.

Treatment of Mycobacterium avium Complex Pulmonary Disease: When Should I Treat and What Therapy Should I Start?

Treatment of M avium pulmonary disease requires a three-drug, macrolide-based regimen that is administered for 12 months beyond culture conversion. The regimen can be administered 3 days a week in non-cavitary, nodular bronchiectatic disease but should be given daily when cavitary disease is present. For treatment refractory disease, amikacin liposome inhalation suspension is added to the regimen. Parenteral amikacin or streptomycin should be administered in the setting of extensive radiographic involvement or macrolide resistance. Recurrence of disease is common and often due to reinfection. Novel and repurposed agents are being evaluated in clinical trials.

Long-term Safety and Tolerability of Omadacycline for the Treatment of Mycobacterium abscessus Infections.

Background: Mycobacterium abscessus is a virulent human pathogen. Treatment is complex and often poorly tolerated with suboptimal rates of eradication, highlighting the need for improved therapeutics. This study reports clinical experience with omadacycline for treatment of M abscessus infections at five large nontuberculous mycobacterial (NTM) disease clinics across the United States to better understand long-term safety and tolerability. Methods: We conducted a multicenter retrospective chart review of adults with M abscessus infections. All patients treated with omadacycline as part of a multidrug therapeutic regimen through December 2021 were included. Clinical data from time of omadacycline initiation and up to 12 months of follow-up were collected. Descriptive statistics were performed. Results: Analysis included 117 patients. Among patients with M abscessus isolate subspeciation, 58 of 71 (81.7%) were M abscessus spp abscessus. In isolates with reported drug susceptibility testing, 15 of 70 (21.4%) had confirmed susceptibility to macrolides. The most common site of infection was lungs. Median duration omadacycline treatment was 8 months (range, 0.25-33 months; interquartile range, 4-15 months). Omadacycline was discontinued in 60 patients (51.3%); 20 completed planned treatment course, 23 experienced intolerance or adverse event leading to drug cessation, and 17 stopped due to cost, death (unrelated to NTM infection or therapy), or another reason. In those with pulmonary disease, 44 of 95 (46%) had 1 or more negative cultures at time of final microbiological assessment, with 17 of 95 (18%) achieving culture conversion. Conclusions: This study reports data supporting long-term safety and tolerability of omadacycline along with signal of effectiveness in treatment of M abscessus infections.

Mycobacterium abscessus Meningitis Associated with Stem Cell Treatment During Medical Tourism.

Mycobacterium abscessus infections have been reported as adverse events related to medical tourism. We report M. abscessus meningitis in a patient who traveled from Colorado, USA, to Mexico to receive intrathecal stem cell injections as treatment for multiple sclerosis. We also review the management of this challenging central nervous system infection.

Towards development of evidence to inform recommendations for the evaluation and management of bronchiectasis.

Bronchiectasis (BE) is a chronic condition characterized by airway dilation as a consequence of a variety of pathogenic processes. It is often associated with persistent airway infection and an inflammatory response resulting in cough productive of purulent sputum, which has an adverse impact on quality of life. The prevalence of BE is increasing worldwide. Treatment guidelines exist for managing BE, but they are generally informed by a paucity of high-quality evidence. This review presents the findings of a scientific advisory board of experts held in the United States in November 2020. The main focus of the meeting was to identify unmet needs in BE and propose ways to identify research priorities for the management of BE, with a view to developing evidence-based treatment recommendations. Key issues identified include diagnosis, patient evaluation, promoting airway clearance and appropriate use of antimicrobials. Unmet needs include effective pharmacological agents to promote airway clearance and reduce inflammation, control of chronic infection, clinical endpoints to be used in the design of BE clinical trials, and more accurate classification of patients using phenotypes and endotypes to better guide treatment decisions and improve outcomes.

Patient-Reported Symptom and Health-Related Quality-of-Life Validation and Responsiveness During the First 6 Months of Treatment for Mycobacterium avium Complex Pulmonary Disease.

BACKGROUND: Nontuberculous mycobacteria (NTM), predominately Mycobacterium avium complex (MAC), cause chronic pulmonary disease. Improvements in symptoms and health-related quality of life (HRQoL) are important treatment outcomes, but no validated patient-reported outcome (PRO) measure exists. RESEARCH QUESTION: What are the validity and responsiveness of the Quality of Life-Bronchiectasis (QOL-B) questionnaire respiratory symptoms scale and key HRQoL measures during the first 6 months of MAC pulmonary disease (MAC-PD) treatment? STUDY DESIGN AND METHODS: Comparison of Two- vs Three-antibiotic Therapy for Pulmonary Mycobacterium Avium Complex Disease (MAC2v3) is an ongoing randomized, multisite pragmatic clinical trial. Patients with MAC-PD were randomized to azithromycin-based two-drug or three-drug therapy; treatment groups were combined for this analysis. PROs were measured at baseline, 3 months, and 6 months. The QOL-B respiratory symptoms, vitality, physical functioning, health perceptions, and NTM symptom domain scores (on a scale of 0-100, with 100 being best) were analyzed separately. We performed psychometric and descriptive analyses in the population enrolled as of the time of analysis and calculated the minimal important difference (MID) using distribution-based methods. Finally, we evaluated responsiveness using paired t tests and latent growth curve analysis in the subset with longitudinal surveys completed by the time of analysis. RESULTS: The baseline population included 228 patients, of whom 144 had completed longitudinal surveys. Patients predominately were female (82%) and had bronchiectasis (88%); 50% were 70 years of age or older. The respiratory symptoms domain showed good psychometric properties (no floor or ceiling effects; Cronbach's α, 0.85) and an MID of 6.4 to 6.9. Vitality and health perceptions domain scores performed similarly. Respiratory symptoms domain scores improved by 7.8 points (P < .0001) and 7.5 points (P < .0001), and the physical functioning domain score improved by 4.6 points (P < .003) and 4.2 points (P = .01) at 3 and 6 months, respectively. Latent growth curve analysis confirmed a nonlinear, statistically significant improvement in respiratory symptoms and physical functioning domain scores by 3 months. INTERPRETATION: The QOL-B respiratory symptoms and physical functioning scales exhibited good psychometric properties in patients with MAC-PD. Respiratory symptoms scores improved beyond the MID by 3 months after treatment initiation. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT03672630; URL: www. CLINICALTRIALS: gov.