New antibiofilm strategies for the management of nontuberculous mycobacteria diseases.

INTRODUCTION: Nontuberculous mycobacteria (NTM) represent a group of microorganisms comprising more than 190 species. NTM infections have increased recently, and their treatment is a major challenge because to their resistance to conventional treatments. This review focuses on innovative strategies aimed at eradicating NTM biofilms, a critical factor in their resistance. Important areas addressed include biofilm formation mechanisms, current therapeutic challenges, and novel treatment approaches. The main objective is to compile and analyze information on these emerging strategies, identifying pivotal research directions and recent advancements. AREAS COVERED: A review of the scientific literature was conducted to identify emerging novel therapies for the treatment of NTM infections and to explore potential synergies with existing treatments. EXPERT OPINION: Experts highlights a limited understanding of optimal treatment regimens, often supported by insufficient scientific evidence. Current therapies are typically prolonged, involve multiple antibiotics with adverse effects, and frequently do not achieve patient cure. Certain species are even considered virtually impossible to eradicate. A thorough understanding of these new approaches is imperative for improving patients outcomes. This review provides a robust foundation for developing of more effective antibacterial strategies, which are essential because of the increasing incidence of NTM infections and the limitations of existing therapies.

Nontuberculous mycobacterial pulmonary disease (NTM PD) incidence trends in the United States, 2010-2019.

BACKGROUND: Nontuberculous mycobacteria (NTM) are ubiquitous environmental bacteria that cause chronic lung disease. Rates of NTM pulmonary disease (NTM PD) have increased over the last several decades, yet national estimates in the United States (US) have not been assessed since 2015. METHODS: We used a nationally representative population of Medicare beneficiaries aged ≥ 65 years to assess rates of NTM PD in a high-risk population from 2010 to 2019. Poisson generalized linear models were used to assess the annual percent change in incidence in the overall population and among key demographic groups such as sex, geography, and race/ethnicity. We evaluated the relative prevalence of various comorbid conditions previously found to be associated with NTM PD. RESULTS: We identified 59,724 cases of incident NTM PD from 2010 to 2019 from an annual mean population of 29,687,097 beneficiaries, with an average annual incidence of 20.1 per 100,000 population. NTM PD incidence was overall highest in the South and among women, Asian individuals, and persons aged ≥ 80 years relative to other studied demographic groups. The annual percent change in NTM PD incidence was highest in the Northeast, at 6.5%, and Midwest, at 5.9%, and among women, at 6.5%. Several comorbid conditions were highly associated with concurrent NTM diagnosis, including allergic bronchopulmonary aspergillosis, bronchiectasis, and cystic fibrosis. CONCLUSIONS: Here we provide current estimates of NTM PD incidence and prevalence and describe increasing trends in the US from 2010 to 2019. Our study suggests a need for improved healthcare planning to handle an increased future caseload, as well as improved diagnostics and therapeutics to better detect and treat NTM PD in populations aged ≥ 65 years.

Incidence of an Identifiable Organism in Children Who Underwent a Surgical Procedure for Granulomatous Cervical Lymphadenopathy.

Objectives: The incidence of cervical lymphadenopathy due to nontuberculous mycobacteria is rising in the pediatric population. Our goal with this study was to review the number of pediatric patients with granulomatous cervical adenitis and determine the incidence of identification of a specific organism as both healthcare providers and parents are interested in identifying the causative pathogen. Methods: A retrospective chart review was conducted of patients at a high-volume tertiary care children's hospital between 2017 and 2023. Children were included if they underwent a surgical procedure for lymphadenopathy. Pathology, microbiology, and other laboratory reports were reviewed to document the presence of granulomatous cervical adenitis and the incidence of identification of a specific organism. Additional data collected included patient demographics and type of procedure. Results: Of the 1538 charts reviewed, 163 patients underwent an inclusionary procedure. Mean patient age was 10.7 years (range 2.4 months-20 years), 70 (43%) were female, 25 (15%) had granulomatous cervical adenitis, and a specific organism was identified in 9 of these. Conclusion: Despite the availability of a number of ancillary tests, our data demonstrate that the identification of a specific pathogen in cases of granulomatous cervical lymphadenitis is rare. As a result, physicians should be prepared to rely primarily on the history and physical exam findings to determine a working diagnosis as well as a medical and/or surgical treatment plan.

Extrapulmonary Mycobacterium abscessus Infections, France, 2012-20201.

Mycobacterium abscessus infection is challenging to treat. Extrapulmonary M. abscessus infections (EP-MAB) are less common than pulmonary M. abscessus infections. To evaluate treatment regimens, we retrospectively analyzed consecutive microbiologically confirmed EP-MAB cases diagnosed in France during 2012-2020. We studied 45 patients with EP-MAB, including 14 bone and joint infections, 10 skin and soft tissue infections, and 8 lymph node infections. Most (62%) patients had no reported immunodeficiency. In 27 patients, EP-MAB followed healthcare-associated (44%) or environmental (16%) injuries. Of the 45 isolates, 25 were subspecies abscessus, 10 bolletii, and 9 massiliense; 1 was unidentified. Cure was achieved for 36 (80%) patients who received a median antimicrobial regimen of 6 months; 22 (55%) also underwent surgery. Four patients died, and 5 were unavailable for follow-up. EP-MAB predominantly affects immunocompetent patients after an injury; outcomes are favorable. We propose a >6-month regimen of antimicrobial therapy with consideration for surgery and regular patient reassessment.

Genome-scale analysis of Mycobacterium avium complex isolates from Portugal reveals extensive genetic diversity.

Opportunist infections caused by nontuberculous mycobacteria (NTM) have emerged as a significant public health problem. Among these, species of the Mycobacterium avium complex (MAC) are the main responsible for the increase in the number of human disease cases. In order to address the current needs in the detection and surveillance of MAC disease cases, we evaluated different species classification methodologies (BLASTn-based marker-gene approach, Kraken v2, rMLST and MLST databases) and their congruence with a core-SNP phylogenetic approach, based on whole genome sequencing (WGS) data. For this purpose, we used a collection of 142 MAC isolates from Portuguese patients diagnosed between 2014 and 2022. The marker-gene approach (based on the rpoB, hsp65 and groEL genes), showed the best results, allowing the identification of the 142 MAC isolates to the species/subspecies level (M. avium subsp. hominissuis, M. intracellulare, M. intracellulare subsp. chimaera, M. intracellulare subsp. yongonense, M. marseillence and M. colombiense). Additionally, we performed drug susceptibility testing that confirmed clarithromycin efficacy as a first-line treatment for MAC disease, as 93 % of the Portuguese isolates were susceptible. Using a core-SNP approach we also performed an in-depth phylogenetic analysis within each identified species group, and despite the high genetic diversity within the MAC species, we were able to clearly distinguish all the species/subspecies and identify genetic clusters with epidemiological potential. We highlight not only the need for the standardization of an appropriate genotyping approach for species identification and management of MAC disease, but also a more robust large-scale WGS data analysis, in a One Health perspective, in order to identify potential routes of transmission.

Epidemiology of bronchiectasis at a single center in Japan: a retrospective cohort study.

BACKGROUND: The characteristics of bronchiectasis (BE) in Asia, including Japan, remain largely unknown. We aimed to provide insights into the clinical characteristics and treatment outcomes of BE, especially regarding nontuberculous mycobacteria (NTM) infection and its poorly understood impact on prognosis. We also aimed to clarify the effect of long-term macrolide antibiotic use in patients with BE, who had no history of exacerbations. METHODS: In this single-center, retrospective study, the medical records of patients who satisfied the BE criteria between January 1, 2012, and August 31, 2023, were reviewed. Severe exacerbations and mortality during the observation period were recorded. Baseline characteristics and overall survival of patients with and without NTM infection, and factors influencing the time to the first exacerbation and death were analyzed. Additionally, the effects of long-term macrolide antibiotic use in patients without a history of severe exacerbations were estimated. RESULTS: In a cohort of 1044 patients with BE, the rate of severe exacerbation was 22.3%, with mortality rates of 3.2% over 3 years. Notably, the high prevalence of NTM infection (n = 410, 39.3%) in this cohort was distinctive. NTM infection was not associated with either the time to first severe exacerbation (p = 0.5676, adjusted hazard ratio = 1.11) or mortality (p = 0.4139, adjusted hazard ratio = 0.78). Compared with the NTM group, the non-NTM group had a higher proportion of elevated inflammatory markers, with significant differences in C-reactive protein levels (p = 0.0301) and blood neutrophil counts (p = 0.0273). Pseudomonas aeruginosa colonization was more frequent in the non-NTM group (p = 0.0003). Among patients with non-NTM infection and without a history of exacerbation in the past 2 years, 38.2% received long-term macrolide antibiotics that did not invariably prolong the time to first severe exacerbation (p = 0.4517, IPW p = 0.3555). CONCLUSIONS: This study highlights BE epidemiology in Japan, noting that the presence of NTM infection may not necessarily worsen the prognostic outcomes and advising caution in the casual use of macrolides for milder cases without a history of exacerbations. CLINICAL TRIAL REGISTRATION: UMIN Clinical Trials Registry Number: UMIN000054726 (Registered on 21 June 2024).

Diagnostic Value of Targeted Next-generation Sequencing in Pulmonary Mycobacterial Infections.

OBJECTIVE: This study aimed to explore the diagnostic value of novel technique-targeted next-generation sequencing (tNGS) of bronchoalveolar lavage fluid (BALF) in pulmonary mycobacterial infections. METHODS: This retrospective study was conducted on patients who underwent bronchoscopy and tNGS, smear microscopy, and mycobacterial culture of BALF. Patients with positive Mycobacterium tuberculosis (MTB) culture or GeneXpert results were classified into the tuberculosis case group. Those diagnosed with nontuberculous mycobacteria (NTM)-pulmonary disease (NTM-PD) composed the case group of NTM-PD patients. The control group comprised patients without tuberculosis or NTM-PD. Sensitivity, specificity, and receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance. RESULTS: For tuberculosis patients with positive mycobacterial culture results, the areas under the ROC curves (AUCs) for tNGS, GeneXpert, and smear microscopy were 0.975 (95% CI: 0.935, 1.000), 0.925 (95% CI: 0.859, 0.991), and 0.675 (95% CI: 0.563, 0.787), respectively. For tuberculosis patients with positive GeneXpert results, the AUCs of tNGS, culture, and smear microscopy were 0.970 (95% CI: 0.931, 1.000), 0.850 (95% CI: 0.770, 0.930), and 0.680 (95% CI: 0.579, 0.781), respectively. For NTM-PD, the AUCs of tNGS, culture, and smear-positive but GeneXpert-negative results were 0.987 (95% CI: 0.967, 1.000), 0.750 (95% CI: 0.622, 0.878), and 0.615 (95% CI: 0.479, 0.752), respectively. The sensitivity and specificity of tNGS in NTM-PD patients were 100% and 97.5%, respectively. CONCLUSION: tNGS demonstrated superior diagnostic efficacy in mycobacterial infection, indicating its potential for clinical application.

Sanitary Waters: Is It Worth Looking for Mycobacteria?

The freshwater environment is suitable for nontuberculous mycobacteria (NTMs) growth. Their high adaptability represents a considerable risk for sanitary water systems, which are a potential vector for NTMs transmission. This study investigated the occurrence of NTMs, such as Mycobacterium saskatchewanense, in hospital water systems to support the surveillance and control of potentially pathogenic NTMs. We analyzed 722 ultrapure dialysis fluid samples from Emilia Romagna Dialysis Services. Among these, 35 samples were found to be positive for M. saskatchewanense. The strains were characterized using whole-genome sequencing (WGS) and variability analysis was carried out along the whole M. saskatchewanense genome. This investigation revealed the exclusive presence of M. saskatchewanense in these dialysis machines, with low genetic variability among all strains (with a low number of different alleles: <15). The strong similarity among the strain groups was also confirmed in the WGS-based ML tree, with very few significant nodes, and no clusters were identified. This research highlights the necessity of implementing surveillance protocols and investigating any potential link to human infections, as well as stressing the urgency of enhancing surveillance and infection control measures.

Nontuberculous mycobacterial pulmonary disease caused by Mycobacterium seoulense.

Mycobacterium seoulense was first isolated and reported in Korea in 2007. We report a rare case of nontuberculous mycobacterial (NTM) pulmonary disease caused by M. seoulense. A woman in her mid-90s was referred to our hospital due to bloody sputum. She had medical histories of chronic heart failure and chemoradiotherapy for right small cell lung carcinoma. Chest computed tomography showed a consolidation on the mediastinal side of the right lung following radiotherapy and nodules with bronchiectasis of the right upper and middle lobes. Acid-fast culture tests of sputum were positive for M. seoulense. We are currently treating her with tranexamic acid and carbazochrome sodium sulfonate and conducting careful follow-up. M. seoulense infection may need to be recognized as one of the notable NTM pulmonary diseases presenting with respiratory symptoms and radiological findings.

Mycobacterium heraklionense: An emerging cause of hand tenosynovitis.

Misdiagnosis of Mycobacterium heraklionense tenosynovitis is common due to the challenging identification and perceived rarity of the disease. This can result in delayed therapy initiation and potentially irreversible consequences. In this report, we present an additional case of hand tenosynovitis, which highlights the diagnostic and management challenges of Mycobacterium heraklionense tenosynovitis and provides further evidence of its emergence as a cause of tenosynovitis. Additionally, we provide a comprehensive summary of published case reports that describe Mycobacterium heraklionense tenosynovitis.

Demographic and Clinical Features of Nontuberculous Mycobacteria Infection Resulting from Cosmetic Procedures: A Systematic Review.

OBJECTIVES: This systematic review aims to (1) summarize the demographic and clinical characteristics of patients with nontuberculous mycobacterial (NTM) infections following cosmetic procedures; (2) summarize the frequency of pathogenic NTM species; and (3) review and analyze the antibiotics choice as well as treatment outcomes. METHODS: We conducted a systematic search of three electronic databases (Scopus, Embase, and PubMed) from inception to March 31, 2024. We presented demographic and clinical features and the main antibiotic strategy, along with etiological information. RESULTS: 200 patients were included in the analysis, with a median onset age of 38.0 years. The median latency period before the illness was 28 days. Nodules were the most frequently reported type of lesion, occurring in 31.0% (n=62/200) of cases. Mycobacterium abscessus was the most commonly found NTM (45%). Clarithromycin was the most commonly applied (64.0%, n=128/200), followed by amikacin (31.0%, n=62/200). The median treatment duration was 6 months (0.25, 24). The overall treatment effectiveness rate was 97.4% (n=148/152). CONCLUSION: NTM infections caused by cosmetic procedures are rapidly increasing worldwide and present diagnostic and treatment challenges. Dermatologists and aesthetic practitioners should be aware of this relatively uncommon disease. Further research is needed to standardize management algorithms.

Exploring the Association of Bacterial Coinfections with Clinical Characteristics of Patients with Nontuberculous Mycobacterial Pulmonary Disease.

BACKGROUND: Clinical data for bacterial coinfection of the lower respiratory tract in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) are scarce. This study aims to assess the prevalence of bacterial coinfection and clinical features in NTM-PD patients. METHODS: This retrospective study screened 248 patients with NTM-PD who underwent bronchoscopy between July 2020 and July 2022, from whom newly diagnosed NTM-PD patients were analyzed. Bacterial culture using bronchial washing fluid was performed at the time of NTM-PD diagnosis. RESULTS: In the 180 patients (median age 65 years; 68% female), Mycobacterium avium complex (86%) was the most frequent NTM isolated. Bacterial coinfections were detected in 80 (44%) patients. Among them, the most common bacterium was Klebsiella pneumoniae (n=25/80, 31.3%), followed by Pseudomonas aeruginosa (n=20/80, 25%) and Staphylococcus aureus (n=20/80, 25%). Compared with NTM-PD patients without bacterial coinfections, patients with bacterial coinfections showed more frequent extensive lung involvement (33% vs. 1%, p<0.001). Additionally, compared with NTM-PD patients without P. aeruginosa infection, those with P. aeruginosa infection were older (74 years vs. 64 years, p=0.001), had more frequent respiratory symptoms (cough/excessive mucus production 70% vs. 38%, p=0.008; dyspnea 30% vs. 13%, p=0.047), and had extensive lung involvement (60% vs. 9%, p<0.001). CONCLUSION: Less than half of patients with newly diagnosed NTM-PD had bacterial coinfections, linked to extensive lung involvement. Specifically, P. aeruginosa coinfection was significantly associated with older age, more frequent respiratory symptoms, and extensive lung involvement.

Challenges in diagnosing bovine tuberculosis through surveillance and characterization of Mycobacterium species in slaughtered cattle in Kolkata.

BACKGROUND: Tuberculosis in cattle is caused by Mycobacterium tuberculosis complex (MTBC) species. Apart from MTBC, different Nontuberculous Mycobacteria (NTM) species have also been isolated from cattle. The presence of NTM infection in bovines makes the diagnosis of bovine tuberculosis (bTB) a cumbersome task. Therefore, a cross sectional study was conducted to isolate and characterize different Mycobacterium spp. from a slaughterhouse situated in Kolkata, a city in the eastern part of India. RESULTS: Out of 258 morbid samples, 98 isolates were found to be positive for bacterial growth, and 35% (n = 34) were positive for Mycobacterium. 94% of Mycobacterial cultural isolates were NTM (n = 32), and the rest (n = 2) were found to be MTBC. Species-level identification of the isolates by hsp65 sequencing revealed that out of 32 isolates, 24 were M. fortuitum, three were M. abscessus, two each were M. chelonae and M. parascrofulaceum, and one was M. novocastrense. A phylogenetic tree with partial hsp65 gene sequences was also constructed to determine the relatedness of the unknown isolates to the reference strains. CONCLUSION: Both NTM species and MTBCs were identified from TB-like lesions in cattle that were slaughtered at the Kolkata abattoir. This discovery may indicate that NTM contributes to the development of lesions in cattle. Also, we recommend implication of more specific diagnostic tests for bTB.

The Intriguing Pattern of Nontuberculous Mycobacteria in Bulgaria and Description of Mycobacterium bulgaricum sp. nov.

We investigated the rise of nontuberculous mycobacteria (NTM) infections in Bulgaria, focusing on species identification and distribution from 2018 to 2022. Utilizing advanced diagnostic tools, including the Hain Mycobacterium CM/AS method, Myco-biochip assay, and whole-genome sequencing, the study identifies and characterizes a diverse range of Mycobacterium species from clinical samples. While M. avium, M. gordonae, M. fortuitum, and M. chelonae were dominating, a number of rare species were also found. They include such species as M. marseillense and M. celatum. Moreover, the noticeable prevalence of M. terrae complex species missed by conventional testing was observed. We identified a rare species, highly homologous to previously described strains from Japan; based on genome-genome distance data, we propose its reannotation as a new species. Further, a novel species was identified, which is significantly distinct from its closest neighbor, M. iranicum, with ANI = 87.18%. Based on the SeqCode procedure, we propose to name this new species Mycobacterium bulgaricum sp. nov. Dynamic changes in NTM species prevalence in Bulgaria observed from 2011 to 2022 highlight the emergence of new species and variations tied to environmental and demographic factors. This underscores the importance of accurate species identification and genotyping for understanding NTM epidemiology, informing public health strategies, and enhancing diagnostic accuracy and treatment protocols.

Nontuberculous Mycobacteria Isolates in Respiratory Samples and Mycobacterial Pulmonary Disease in an Area of Northern Spain.

Introduction: The epidemiology of nontuberculous mycobacteria (NTM) is not well known. In this study, we aimed to determine the incidence of NTM isolates and nontuberculous mycobacterial pulmonary disease (NTM-PD) in five closely located hospitals in an area of northern Spain and analyse differences between them. Material and methods: Demographic, microbiological, clinical and radiological data were collected retrospectively from all patients with a NTM isolated from respiratory specimens at five hospitals between 2012 and 2019. Mycobacterium gordonae isolates were excluded. Once the data was collected, it was determined which patients met the NMT-PD criteria. Results: 594 patients were included in the study. The mean incidence rate of NTM isolates across all five hospitals in the period studied was 4.15 per 100,000 person-year, while the rate of NTM-PD was 1.2. The annual number of isolates showed an upward trend over this period, but the same did not occur in the number of cases of NTM-PD. The species most frequently isolated were Mycobacterium avium complex (MAC) and Mycobacterium xenopi and those most frequently causing disease were MAC and Mycobacterium kansassi. There were significant differences between the five centres. Conclusions: Our results are in line with similar studies in Europe in terms of NTM isolation and NTM-PD incidence and species isolated; however, we do not see the upward trend in NTM-PD rates described elsewhere. The great variability in isolation and disease rates, as well as in species isolated in geographically close areas, underlines, in our opinion, the importance of local environmental factors.

Introducción: La epidemiología de las micobacterias no tuberculosas (MNT) no se conoce bien. Nuestro objetivo fue determinar la incidencia de aislamientos de MNT y de enfermedad pulmonar por micobacterias no tuberculosas (EP-MNT) en cinco hospitales del norte de España, próximos entre sí, y analizar las diferencias entre ellos. Material y métodos: Se recopilaron retrospectivamente datos demográficos, microbiológicos, clínicos y radiológicos de todos los pacientes con una MNT aislada en muestra respiratoria entre 2012 y 2019 en los cinco hospitales. Se excluyeron los aislamientos de Mycobacterium gordonae. Una vez recogidos los datos, se determinó qué casos cumplían los criterios de EP-MNT. Resultados: Se incluyeron 594 pacientes. La tasa de incidencia media de aislamientos de NTM en los cinco hospitales fue de 4,15 por 100.000 personas-año y la tasa de EP-MNT fue de 1,2. El número anual de aislamientos mostró una tendencia creciente durante este periodo, pero no así el de EP-MNT. Las especies aisladas con mayor frecuencia fueron Mycobacterium avium complex (MAC) y Mycobacterium xenopi y las que causaron enfermedad con mayor frecuencia fueron MAC y Mycobacterium kansasii. Hubo diferencias significativas entre los cinco centros. Conclusiones: Nuestros resultados están en línea con estudios similares en Europa en términos de aislamiento de MNT, incidencia de EP-MNT y especies aisladas; sin embargo, no vemos la tendencia ascendente en las tasas de EP-MNT descrita en otros lugares. La gran variabilidad entre los cinco hospitales en las tasas de aislamiento y de enfermedad y en las especies aisladas resalta la importancia de los factores ambientales locales.

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

Objectives: This 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. Methods: We 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. Results: The 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. Conclusion: The 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.

Pulmonary Mycobacterium avium Complex With Adenocarcinoma of the Lung: A Case Report.

Nontuberculous mycobacteria are responsible for causing pulmonary as well as extrapulmonary diseases. These organisms are often multidrug resistant and management of these cases poses a therapeutic challenge. Lung cancer has been a prevalent challenge globally with a high mortality rate in affected individuals. Adenocarcinoma poses debilitating outcomes in most patients by inflicting a diagnostic and therapeutic challenge. The concomitant association of adenocarcinoma and Mycobacterium avium complex worsens the prognosis causing a challenge in managing such cases. We present a rare association between adenocarcinoma and pulmonary Mycobacterium avium complex complicating the traditional therapeutic regime. A different approach in the administration of therapy for this unique concomitant association between two debilitating diseases is outlined in the presented report.

Intra-abdominal Abscess Caused by Mycobacteroides abscessus in a Peritoneal Dialysis Patient: A Case Report.

A 57-year-old man was diagnosed with peritoneal dialysis (PD)-associated peritonitis 2 months after surgery for tunnel infection (TI) caused by Mycobacteroides abscessus (M. abscessus). The patient was treated with multiple antibiotics, and the cell count in the PD effluent decreased. However, the patient experienced abdominal pain and developed hiccups. Computed tomography revealed an encapsulated fluid collection, indicating intra-abdominal abscess (IAA) formation. Percutaneous drainage was performed to treat IAA, and the catheter was removed. This case suggests that PD-associated peritonitis caused by M. abscessus can lead to IAA formation. If symptoms persist even after a favorable course of peritonitis, IAA should be suspected.

Clinical characteristics of pulmonary Mycobacterium avium complex disease in patients with interstitial lung disease.

OBJECTIVE: Mycobacterium avium complex pulmonary disease (MAC-PD) is occasionally complicated by interstitial lung disease (ILD) in clinical practice, but clinical studies are limited. This study aims to elucidate the clinical and imaging characteristics of MAC-PD in patients with ILD. METHODS: We retrospectively analyzed imaging and clinical data from medical records of 54 consecutive ILD patients diagnosed with MAC-PD from 2011 to 2021 at our institution. We compared the imaging and clinical data of these patients with 2218 ILD patients diagnosed at our institution. RESULTS: The mean age of the patients was 74 years, with 25 males and 29 females, and a mean body mass index (BMI) of 20.0 kg/m2. Compared to all ILD patients, ILD-associated MAC-PD had older ages, lower BMI. The most common underlying ILD diagnosis was unclassifiable interstitial pneumonia. MAC-PD imaging classification was nodular-bronchiectatic (NB) type in 17 patients, fibro-cavitary (FC) type in 15 patients, and unclassifiable (UC) type in 22 patients. Many UC types were difficult to diagnose due to the absence of clear findings indicative of MAC infection. Chronic pulmonary aspergillosis complication was 24.1 %. The mean survival of ILD-associated MAC-PD was 55.6 months, shorter than that of regular MAC-PD. The UC type had a shorter survival than the NB type, similar to the FC type. CONCLUSION: MAC-PD associated with ILD frequently complicates chronic pulmonary aspergillosis and has a poor prognosis. The most common imaging type, UC type, particularly has a shorter survival. Careful management is essential for MAC-PD associated with ILD.