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Biofilm Dec 2023The genus includes some of the deadliest pathogens of History (), but most of the species within the genus are environmental microorganisms. Because some of these...
The genus includes some of the deadliest pathogens of History (), but most of the species within the genus are environmental microorganisms. Because some of these nontuberculous mycobacteria (NTM) species can be human pathogens, the study of these mycobacterial biofilms has increased during the last decades, and the interest in this issue increased as well as the growing number of patients with diseases caused by NTM. Different molecular mechanisms have been described, being especially well known the importance of glycopeptidolipids. Moreover, the knowledge of the extracellular matrix has shown important differences with other microorganisms, especially because of the presence of lipidic molecules as a key component of this structure. The clinical importance of mycobacterial biofilms has been described for many chronic diseases, especially lung diseases and implant-related ones, both and , and even in patients. Moreover, the biofilm-producing capacity has been proven also in , while its importance is not well understood. Biofilm studies have also shown the increasing resistance of mycobacteria in sessile form, and the importance of this resistance in the management of the patients is beyond doubt, being surgery necessary in some cases to cure the patients. Diagnosis of mycobacterial diseases is still based on culture-based techniques designed for the detection of . Molecular biology-based methods are also broadly used but again designed for tuberculosis diagnosis. Antimicrobial susceptibility testing is also well developed for tuberculosis, but only some species of NTM have standardized techniques for this purpose. New tools or approaches are necessary to treat these patients, whose importance is increasing, as the number of potential hosts is also increasing throughout the world.
PubMed: 36798742
DOI: 10.1016/j.bioflm.2023.100107 -
Ugeskrift For Laeger Apr 2024This review focuses on the treatment of nontuberculous pulmonary disease caused by Mycobacterium avium complex and M. abscessus. It covers treatment indications,... (Review)
Review
This review focuses on the treatment of nontuberculous pulmonary disease caused by Mycobacterium avium complex and M. abscessus. It covers treatment indications, antibiotic choice, resistance and side effects. Treatment of nontuberculous pulmonary disease is complex, lengthy, and fraught with side effects. Increased attention on this disease is needed in order to alleviate the severe consequences of this growing disease. Cooperation between pulmonologists and infectious disease specialists is needed to ensure uniform treatment, and to account for the heterogeneity seen in patients and mycobacteria alike.
Topics: Humans; Nontuberculous Mycobacteria; Mycobacterium Infections, Nontuberculous; Lung Diseases; Pneumonia; Anti-Bacterial Agents
PubMed: 38606709
DOI: 10.61409/V06230603 -
Chest Nov 2023Nontuberculous mycobacterial pulmonary disease (NTM-PD) is widely underdiagnosed, and certain patient groups, such as those with underlying respiratory diseases, are at... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Nontuberculous mycobacterial pulmonary disease (NTM-PD) is widely underdiagnosed, and certain patient groups, such as those with underlying respiratory diseases, are at increased risk of developing the disease. Understanding patients at risk is essential to allow for prompt testing and diagnosis and appropriate management to prevent disease progression.
RESEARCH QUESTION
What are the risk factors for NTM-PD that should prompt a physician to consider NTM testing and diagnosis?
STUDY DESIGN AND METHODS
Electronic searches of PubMed and EMBASE were conducted in July 2021 for the period 2011-2021. Inclusion criteria were studies of patients with NTM-PD with associated risk factors. Data were extracted and assessed using the Newcastle-Ottawa Scale. Data analysis was conducted using the R-based "meta" package. Only studies that reported association outcomes for cases with NTM-PD compared with control participants (healthy populations or participants without NTM-PD) were considered for the meta-analysis.
RESULTS
Of the 9,530 searched publications, 99 met the criteria for the study. Of these, 24 formally reported an association between possible risk factors and the presence of NTM-PD against a control population and were included in the meta-analysis. Comorbid respiratory disease was associated with a significant increase in the OR for NTM-PD (bronchiectasis [OR, 21.43; 95% CI, 5.90-77.82], history of TB [OR, 12.69; 95% CI, 2.39-67.26], interstitial lung disease [OR, 6.39; 95% CI, 2.65-15.37], COPD [OR, 6.63; 95% CI, 4.57-9.63], and asthma [OR, 4.15; 95% CI, 2.81-6.14]). Other factors noted to be associated with an increased risk of NTM-PD were the use of inhaled corticosteroids (OR 4.46; 95% CI, 2.13-9.35), solid tumors (OR, 4.66; 95% CI, 1.04-20.94) and the presence of pneumonia (OR, 5.54; 95% CI, 2.72-11.26).
INTERPRETATION
The greatest risk for NTM-PD is conferred by comorbid respiratory diseases such as bronchiectasis. These findings could help with identification of patient populations at risk for NTM-PD to drive prompt testing and appropriate initiation of therapy.
Topics: Humans; Mycobacterium Infections, Nontuberculous; Risk Factors; Bronchiectasis; Asthma; Respiratory Tract Diseases; Nontuberculous Mycobacteria; Lung Diseases; Retrospective Studies
PubMed: 37429481
DOI: 10.1016/j.chest.2023.06.014 -
CMAJ : Canadian Medical Association... Dec 2023
Topics: Humans; Mycobacterium abscessus; Scalp; Central America; Skin Transplantation; Hair
PubMed: 38110217
DOI: 10.1503/cmaj.230794-f -
Clinical Microbiology and Infection :... Jun 2024Mycobacterium abscessus (Mab) is considered as the most pathogenic rapid-growing mycobacteria in humans, causing pulmonary and extra-pulmonary diseases, especially in... (Review)
Review
BACKGROUND
Mycobacterium abscessus (Mab) is considered as the most pathogenic rapid-growing mycobacteria in humans, causing pulmonary and extra-pulmonary diseases, especially in patients with cystic fibrosis. Mab shows intrinsic and acquired resistance to many drugs, leaving limited treatment options that lead to a generally poor prognosis. The standard therapeutic regimen last for more than 6 months and consists of a drug cocktail that ideally includes a macrolide and amikacin. Yet, toxicity and efficacy are suboptimal due also to the high toxicity. There is a need to introduce innovative and out-of-the-box approaches to improve treatments.
OBJECTIVES
In this narrative review, we summarize the recent research on the alternative strategies proposed and discuss the importance of using appropriate experimental assays to assess their activity.
SOURCES
Included articles were identified by searching PubMed and MEDLINE until June 2023. The search terms were 'Mycobacterium abscessus', 'antimicrobial', and 'alternative therapies'. Additional relevant references were obtained from articles retrieved from the primary search.
CONTENT
Therapies against Mab including host directed therapies, repurposed drugs, phage therapy, anti-virulence strategies, essential oils, and inhalation therapies.
IMPLICATIONS
Alternative treatments may represent a valid tool to cope the burden of antimicrobial resistance in Mab-caused diseases.
Topics: Mycobacterium abscessus; Humans; Mycobacterium Infections, Nontuberculous; Anti-Bacterial Agents; Complementary Therapies; Drug Repositioning; Phage Therapy
PubMed: 37820951
DOI: 10.1016/j.cmi.2023.10.001 -
Microorganisms Jul 2023Skin and soft tissue infections caused by non-tuberculous mycobacteria are occurring more frequently in recent years. However, chronic skin and soft tissue lesions... (Review)
Review
Skin and soft tissue infections caused by non-tuberculous mycobacteria are occurring more frequently in recent years. However, chronic skin and soft tissue lesions present a challenge for clinicians, as the diagnostic work-up and definitive diagnosis require knowledge and available laboratory resources. We present here the case of a 66-year-old male patient who presented with painful abscess-like nodules on his right hand and forearm, which worsened after treatment with an anti-TNF-a agent. The fluid specimen taken from the lesion was positive for mycobacteria according to the acid-fast stain. was identified, first by next-generation sequencing and finally grown on culture, after eight weeks. Acknowledging the complexity of diagnosing and managing infections by non-tuberculous mycobacteria, and especially , we provide a review of the current epidemiology, clinical characteristics, diagnosis and management of infection.
PubMed: 37512971
DOI: 10.3390/microorganisms11071799 -
Clinical Microbiology and Infection :... Oct 2023Mycobacterium abscessus complex is responsible for 2.6-13.0% of all non-tuberculous mycobacterial pulmonary infections and these are notoriously difficult to treat due...
OBJECTIVES
Mycobacterium abscessus complex is responsible for 2.6-13.0% of all non-tuberculous mycobacterial pulmonary infections and these are notoriously difficult to treat due to the complex regimens required, drug resistance and adverse effects. Hence, bacteriophages have been considered in clinical practice as an additional treatment option. Here, we evaluated antibiotic and phage susceptibility profiles of M. abscessus clinical isolates. Whole-genome sequencing (WGS) revealed the phylogenetic relationships, dominant circulating clones (DCCs), the likelihood of patient-to-patient transmission and the presence of prophages.
METHODS
Antibiotic susceptibility testing was performed using CLSI breakpoints (n = 95), and plaque assays were used for phage susceptibility testing (subset of n = 88, 35 rough and 53 smooth morphology). WGS was completed using the Illumina platform and analysed using Snippy/snp-dists and Discovery and Extraction of Phages Tool (DEPhT).
RESULTS
Amikacin and Tigecycline were the most active drugs (with 2 strains resistant to amikacin, and one strain with Tigecycline MIC of 4 μg/mL). Most strains were resistant to all other drugs tested, with Linezolid and Imipenem showing the least resistance, at 38% (36/95) and 55% (52/95), respectively. Rough colony morphotype strains were more phage-susceptible than smooth strains (77%-27/35 versus 48%-25/53 in the plaque assays, but smooth strains are not killed efficiently by those phages in liquid infection assay). We have also identified 100 resident prophages, some of which were propagated lytically. DCC1 (20%-18/90) and DCC4 (22%-20/90) were observed to be the major clones and WGS identified 6 events of possible patient-to-patient transmission.
DISCUSSION
Many strains of M. abscessus complex are intrinsically resistant to available antibiotics and bacteriophages represent an alternative therapeutic option, but only for strains with rough morphology. Further studies are needed to elucidate the role of hospital-borne M. abscessus transmission.
Topics: Humans; Mycobacterium abscessus; Amikacin; Tigecycline; Bacteriophages; Phylogeny; Mycobacterium Infections, Nontuberculous; Anti-Bacterial Agents; Drug Resistance, Multiple; Delivery of Health Care; Microbial Sensitivity Tests
PubMed: 37364635
DOI: 10.1016/j.cmi.2023.06.026