Clinical significance of respiratory isolates for Mycobacterium abscessus complex from pediatric patients

Successful management of Mycobacterium abscessus pneumonia in a 53-day-old immunocompetent infant

Pulmonary infection due to Mycobacterium abscessus complex (MABC) usually occurs in children with underlying risk factors including cystic fibrosis (CF), chronic lung disease, and immunocompromised status, but rarely in immunocompetent children without underlying lung disease, especially in infants. We present a case of MABC pulmonary disease (MABC-PD) in an otherwise healthy 53-day-old male infant with one week of cough and respiratory distress. Computed tomography showed multiple masses across both lungs. Isolated mycobacteria from his bronchoalveolar lavage fluid were identified as MABC. We describe our complete evaluation, including immunodeficiency evaluation incorporating whole exome sequencing and our therapeutic process given complicated susceptibility pattern of the M. abscessus isolate, and review literature for MABC-PD in immunocompetent children. The infant was successfully treated through prolonged treatment with parenteral Amikacin, Cefoxitin, Linezolid, and Clarithromycin, combined with inhaled Amikacin.

Mycobacterium abscessus pulmonary disease presenting with spontaneous pneumomediastinum and subcutaneous emphysema in childhood acute lymphoblastic leukemia: a case report and literature review

INTRODUCTION

Mycobacterium abscessus is a rapidly growing mycobacterium commonly identified in adults with underlying pulmonary diseases but is rarely observed in children. A better understanding of this pathogen in children is essential.

CASE PRESENTATION

We report the case of a 49-month-old female child without previous underlying pulmonary diseases but with acute lymphoblastic leukemia (ALL). The patient was complicated with pneumonia during chemotherapy, which was primarily characterized by spontaneous pneumomediastinum and subcutaneous emphysema on chest computed tomography (CT). M. abscessus sequences were detected by metagenomic next-generation sequencing in bronchoalveolar lavage fluid. With mechanical ventilation, closed thoracic drainage, and anti-infective therapy for 6 months, the patient's infection was controlled. The patient completed 2.5 years of treatment for ALL, and the drugs were discontinued. The patient currently remains in complete hematologic remission.

DISCUSSION

We reviewed the literature on 33 children with M. abscessus pulmonary disease. These children mostly had underlying immunodeficiency. Chest CT most often showed nodular shadows, consolidation, and bronchiectasis. Spontaneous pneumomediastinum and subcutaneous emphysema were not reported as major manifestations.

CONCLUSION

Spontaneous pneumomediastinum and subcutaneous emphysema were our patient's main characteristics on chest CT, and this study enriches the knowledge regarding possible imaging changes in M. abscessus pulmonary disease in children. This case report reflects good clinical experience in maintaining the balance between chemotherapy and anti-infective therapy in childhood ALL.

Mycobacterium abscessus Pneumonia in an Immunonormal Infant

A 2-month-old male with failure to thrive and respiratory symptoms was found to have bilateral pneumonia secondary to Mycobacterium abscessus . M. abscessus pulmonary infections have mainly been noted in immunocompromised children; prior reports presented similarly, though our patient is unique given the young age of presentation and lack of diagnosed immunodeficiency or underlying disease.

Diagnosis, management, and outcomes of pediatric tracheostomy-associated infections: A scoping review

BACKGROUND

Children with tracheostomy are frequently admitted to the hospital for tracheostomy-associated respiratory infections (TRAINs). However, there remains a paucity of evidence to direct the diagnosis, treatment, and prevention of TRAINs. An important first step to addressing this knowledge gap is to synthesize existing data regarding TRAINs to inform current practice and facilitate innovation.

DATA SOURCES

We searched PubMed, Embase, Cochrane Library, CINAHL, and Web of Science from inception to October 2020. Original research articles and published abstracts including children and young adults 0-21 years of age with tracheostomy were included. Included studies assessed the clinical definitions of and risk factors for TRAINs, microbiologic epidemiology and colonization of tracheostomies, and treatment and outcomes of TRAINs.

DATA SYNTHESIS

Out of 5755 studies identified in the search, 78 full-text studies were included in the final review. A substantial number of studies focused on the detection of specific pathogens in respiratory cultures including Pseudomonas aeruginosa. Several different definitions of TRAIN including clinical, microbiologic, and laboratory testing results were utilized; however, no uniform set of criteria were identified. The few studies focused on treatment and prevention of TRAIN emphasized the role of empiric antimicrobial therapy and the use of inhaled antibiotics.

CONCLUSIONS

Despite a growing number of research articles studying TRAINs, there is a paucity of prospective interventional trials to guide the diagnosis, treatment, and prevention of respiratory disease in this vulnerable population. Future research should include studies of interventions designed to improve short- and long-term respiratory-related outcomes of children with tracheostomy.

Successful management of Mycobacterium abscessus complex lung disease in an otherwise healthy infant

Mycobacterium abscessus complex (MABC) is an uncommon but increasingly important cause of invasive pulmonary disease, a condition associated with diagnostic and management challenges. MABC has mainly been reported in children with certain medical conditions, such as preexisting structural lung disorders and immunocompromised status. In this article, we describe a rare case of MABC pulmonary disease in an otherwise healthy infant. A 4-month-old female presented with cough and fever for 4 days. Computed tomography showed multiple masses and small nodules across both lungs. Isolated mycobacteria from her bronchoalveolar lavage fluid and gastric aspirate were identified as MABC by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and M. abscessus subsp. massiliense was ultimately identified by DNA sequence analysis. Prolonged treatment with a combination of azithromycin, cefoxitin, and moxifloxacin achieved a successful treatment outcome.

Burden of non-tuberculous mycobacterial diseases in Saudi Arabian children: The first nationwide experience

BACKGROUND

Non-tuberculous mycobacteria (NTM) causing pulmonary and extra-pulmonary diseases are increasing worldwide. A large paucity of data related to pediatric NTM diseases exists globally and particularly in Saudi Arabia.

METHODS

The first nationwide exploratory study on existence of NTM diseases among Saudi Arabian children (0-14 years old) has been carried out during 2016-2017. Suspected NTM isolates with clinical and demographical data were enrolled from regional reference laboratories. Species level identification of isolates was carried out by commercial line probe assays and gene sequencing.

RESULTS

In 12 months, 52 culture positive cases with 44(84.6%) confirmed disease incidences were identified. Demographically, Saudi nationals (86.5%) were dominated and 77.3% cases have different comorbid conditions. Lymphadenitis (40.4%) followed by 26.9% of pulmonary cases with 42.8% of confirmed clinical relevance were mainly reported. Species identification showed Mycobacterium simiae (31.8%), M. abscessus (23.1%) and nine other species including rarely encountering M. riyadhense. Ascites caused by M. monacense, pulmonary disease caused by M. riyadhense and M. monacense were rarest clinical events and reported for the first time globally in a pediatric cohort.

CONCLUSIONS

Diverse NTM diseases even in immunocompetent children are an upcoming challenge in Saudi Arabia. Lack of awareness on NTM disease must be addressed with immediate development of management plans.

Historical evolution of the diseases caused by non-pigmented rapidly growing mycobacteria in a University Hospital

OBJECTIVE

Non-pigmented rapidly growing mycobacteria (NPRGM) are a group of organisms of increasing interest due to the growing number of potential patients and the difficulties for a proper treatment in many of them. However, the evolution of these diseases in a long period of time and its evolutionary changes has been described only in a scanty number of reports.

METHODS

We performed a retrospective study between January 1st 2004 and December 31st 2017 in order to evaluate the clinical significance and types of diseases caused by NPRGM. Patients with isolates of NPRGM during this period were selected for the study, and clinical charts were reviewed using a predefined protocol.

RESULTS

During this period we identified 59 patients (76 clinical samples) with isolates of NPRGM, with 12 cases of clinical disease and one patient with doubtful significance (including 6 respiratory tract infections, 2 catheter infections, 1 skin and soft tissue infection, 1 disseminated infection, 1 conjunctivitis, 1 prosthetic joint infection and 1 mastitis). Fifty percent of M. chelonae isolates, 37.5% of M. abscessus isolates and 23.33% of M. fortuitum isolates were clinically significant. None of the isolates of other species were significant.

CONCLUSIONS

Most isolates in respiratory samples were contaminants/colonizations. M. abscessus was the main etiological agent in respiratory syndromes, whereas M. chelonae and M. fortuitum were more frequently associated with other infections, especially clinical devices and skin and soft tissue infections.

Mycobacterium abscessus Infections in Children: A Review of Current Literature

There is limited literature on Mycobacterium abscessus infections in children and limited data about its diagnosis and management. The incidence of infections due to M abscessus appears to be increasing in certain populations and can be a significant cause of morbidity and mortality.Management of these infections is challenging and relies on combination antimicrobial therapy and debridement of diseased tissue, depending on the site and extent of disease. Treatment regimens often are difficult to tolerate, and the antimicrobials used can cause significant adverse effects, particularly given the long duration of therapy needed.This review summarizes the literature and includes information from our own institution's experience on pediatric M abscessus infections including the epidemiology, transmission, clinical manifestations, and the management of these infections. Adult data have been used where there are limited pediatric data. Further studies regarding epidemiology and risk factors, clinical presentation, optimal treatment, and outcomes in children are necessary.

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

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

Mycobacterium abscessus Complex Infections in Children: A Review

PURPOSE OF REVIEW

Infections in children with Mycobacterium abscessus complex represent a particular challenge for clinicians. Increasing incidence of these infections worldwide has necessitated focused attention to improve both diagnostic as well as treatment modalities. Published medical literature was reviewed, with emphasis on material published in the past 5 years.

RECENT FINDINGS

Increasing availability of new diagnostic tools, such as matrix-assisted laser desorption ionization-time of flight mass spectrometry and custom PCRs, has provided unique insights into the subspecies within the complex and improved diagnostic certainty. Microbiological review of all recent isolates at the University of Minnesota Medical Center was also conducted, with description of the antimicrobial sensitivity patterns encountered in our center, and compared with those published from other centers in the recent literature. A discussion of conventional antimicrobial treatment regimens, alongside detailed description of the relevant antimicrobials, is derived from recent publications. Antimicrobial therapy, combined with surgical intervention in some cases, remains the mainstay of pediatric care. Ongoing questions remain regarding the transmission mechanics, immunologic vulnerabilities exploited by these organisms in the host, and the optimal antimicrobial regimens necessary to enable a reliable cure. Updated treatment guidelines based on focused clinical studies in children and accounting especially for the immunocompromised children at greatest risk are very much needed.

Endobronchial lesions caused by nontuberculous mycobacteria in apparently healthy pediatric patients

Pulmonary disease caused by nontuberculous mycobacteria in healthy children is rare, and its pathogenesis is unknown in most cases and standardized treatment is lacking. Here, we report various endobronchial manifestations in 5 patients including hitherto undescribed diffuse tracheobronchial granulomas in 2 patients. Bronchoscopic debulking was performed in all patients and tuberculostatic treatment in 4. All patients including 1 without tuberculostatic treatment showed remission.