scholarly journals The distinct fate of smooth and rough Mycobacterium abscessus variants inside macrophages

Open Biology ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. 160185 ◽  
Author(s):  
Anne-Laure Roux ◽  
Albertus Viljoen ◽  
Aïcha Bah ◽  
Roxane Simeone ◽  
Audrey Bernut ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Cell Surface ◽  
Mycobacterium Abscessus ◽  
Mycobacterial Species ◽  
Cutaneous Infections ◽  
Mendelian Disorders ◽  
Partial Degradation ◽  
Phagosomal Membrane ◽  
Slow Growing ◽  
Immunocompetent Patients

Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium responsible for pulmonary and cutaneous infections in immunocompetent patients and in patients with Mendelian disorders, such as cystic fibrosis (CF). Mycobacterium abscessus is known to transition from a smooth (S) morphotype with cell surface-associated glycopeptidolipids (GPL) to a rough (R) morphotype lacking GPL. Herein, we show that M. abscessus S and R variants are able to grow inside macrophages and are present in morphologically distinct phagosomes. The S forms are found mostly as single bacteria within phagosomes characterized by a tightly apposed phagosomal membrane and the presence of an electron translucent zone (ETZ) surrounding the bacilli. By contrast, infection with the R form leads to phagosomes often containing more than two bacilli, surrounded by a loose phagosomal membrane and lacking the ETZ. In contrast to the R variant, the S variant is capable of restricting intraphagosomal acidification and induces less apoptosis and autophagy. Importantly, the membrane of phagosomes enclosing the S forms showed signs of alteration, such as breaks or partial degradation. Although not frequently encountered, these events suggest that the S form is capable of provoking phagosome–cytosol communication. In conclusion, M. abscessus S exhibits traits inside macrophages that are reminiscent of slow-growing mycobacterial species.

scholarly journals Construction of Mycobacterium abscessus Defined Glycopeptidolipid Mutants: Comparison of Genetic Tools

2008 ◽  
Vol 75 (5) ◽  
pp. 1331-1338 ◽  
Author(s):  
Halima Medjahed ◽  
Jean-Marc Reyrat
Keyword(s):  
Cystic Fibrosis ◽  
Mycobacterium Abscessus ◽  
Mycobacterial Species ◽  
Emerging Pathogen ◽  
Genetic Tools ◽  
Allelic Exchange ◽  
Virulence Determinant ◽  
Genomic Tools ◽  
Recent Attention

ABSTRACT Mycobacterium abscessus is a rapidly growing mycobacterial species that can be involved in pulmonary and disseminated infections in immunosuppressed or young cystic fibrosis patients. It is an emerging pathogen and has attracted recent attention due to the numerous cases of infection; furthermore, genomic tools have been developed for this species. Nevertheless, the study of this species has until now been limited to spontaneous variants. We report here a comparison of three different mutagenesis systems—the ts-sacB, the phage, and the recombineering systems—and show that there are important differences in their efficiency for the construction of allelic-exchange mutants. We show, using the mmpL4b gene of the glycopeptidolipid pathway as a target, that allelic-exchange mutants can be constructed with a reasonable efficiency (∼7%) using the recombineering system. These observations will facilitate genetic and cellular microbiology experiments involving the construction and use of well-defined mutants to study the virulence determinant of this emerging pathogen.

scholarly journals Cell Surface Remodeling of Mycobacterium abscessus under Cystic Fibrosis Airway Growth Conditions

2020 ◽  
Vol 6 (8) ◽  
pp. 2143-2154
Author(s):  
Crystal J. Wiersma ◽  
Juan Manuel Belardinelli ◽  
Charlotte Avanzi ◽  
Shiva Kumar Angala ◽  
Isobel Everall ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Cell Surface ◽  
Growth Conditions ◽  
Mycobacterium Abscessus ◽  
Cystic Fibrosis Airway ◽  
Surface Remodeling

scholarly journals Decontamination Strategies Used for AFB Culture Significantly Reduce the Viability of Mycobacterium abscessus Complex in Sputum Samples from Patients with Cystic Fibrosis

2021 ◽  
Vol 9 (8) ◽  
pp. 1597
Author(s):  
Dominic Stephenson ◽  
Audrey Perry ◽  
Andrew Nelson ◽  
Ali E. Robb ◽  
Matthew F. Thomas ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Oxalic Acid ◽  
Nontuberculous Mycobacteria ◽  
Optimal Recovery ◽  
Mycobacterium Abscessus ◽  
Colony Count ◽  
Respiratory Pathogens ◽  
Quantitative Culture ◽  
Mycobacterium Abscessus Complex ◽  
Oxalic Acids

Nontuberculous mycobacteria are important respiratory pathogens in patients with cystic fibrosis (CF). For diagnosis, international guidelines recommend culture of sputum that has been decontaminated via chemical treatment. Fifty-six sputum samples from 32 patients known to be previously colonized or infected with NTM were subdivided, and the aliquots were subjected to six different decontamination strategies, followed by quantitative culture for NTM. Thirty sputum samples contained Mycobacterium abscessus complex (MABSC) and 11 contained Mycobacterium avium complex (MAC). Decontamination strategies included treatment with N-acetyl L-cysteine with 2% sodium hydroxide (NALC-NaOH), 4% NaOH, 1% chlorhexidine, 0.5 N sulfuric acid, 5% oxalic acid, double decontamination with NALC-NaOH, followed by 5% oxalic acid, and saline (0.85%) as a control. The samples were also cultured directly with no treatment. Treatment with NALC-NaOH resulted in an average reduction in colony count of 87% for MABSC when compared with direct culture. NaOH at 4% caused a 98.3% average reduction in colony count. All treatments that included NaOH resulted in colony counts that were statistically lower than those obtained from direct culture or the saline-treated control (p < 0.05). Standard treatments using sulfuric or oxalic acids were less deleterious, but still resulted in an average reduction in colony count of at least 30%. The viability of MAC was much less affected by most decontamination treatments. In conclusion, the viability of MABSC was severely compromised by standard decontamination regimens. This supports recent evidence showing that optimal recovery of MABSC is achieved by culture on an appropriate selective agar without decontamination of sputum samples.

scholarly journals Comparing Mycobacterium massiliense and Mycobacterium abscessus lung infections in cystic fibrosis patients

2015 ◽  
Vol 14 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Anne-Laure Roux ◽  
Emilie Catherinot ◽  
Nathalie Soismier ◽  
Beate Heym ◽  
Gil Bellis ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Mycobacterium Abscessus ◽  
Mycobacterium Massiliense ◽  
Lung Infections

scholarly journals Infeksi Biofilm Bakterial

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Heriyannis . Homenta
Keyword(s):  
Cystic Fibrosis ◽  
Antibiotic Resistance ◽  
Cell Surface ◽  
Medical Devices ◽  
Extracellular Polymeric Substances ◽  
Bacterial Endocarditis ◽  
Bacterial Biofilm ◽  
Microbial Cell ◽  
Space And Time

Abstract: Biofilm is the unity of microbial cell surface surrounded by a matrix of extracellular polymeric substances (EPS). Bacteria composing the biofilm are heterogeneous in space and time. This biofilm continues to grow influenced by internal and external processes. Moreover, biofilm can be found on the surface of medical devices, as well as in bacterial endocarditis and cystic fibrosis. Biofilm that is already formed can lead to antibiotic resistance.Keywords: infections, bacterial biofilm, antibiotic resistance Abstrak: Biofilm merupakan kesatuan dari permukaan sel mikroba yang dilingkupi oleh matriks substansi polimerik ekstraseluler. Bakteri yag menyusun biofilm bersifat heterogen dalam ruang dan waktu. Biofilm terus berkembang yang dipengaruhi oleh proses internal dan eksternal. Biofilm dapat ditemukan pada permukaan alat-alat medis, endokarditis bakterial, dan kistik fibrosis. Biofilm yang telah terbentuk dapat menyebabkan resistensi antibiotik. Kata kunci: infeksi, biofilm bakterial, resistensi antibiotik

Environment in the lung of cystic fibrosis patients stimulates the expression of biofilm phenotype in Mycobacterium abscessus

2022 ◽  
Vol 71 (1) ◽  
Author(s):  
Bailey F. Keefe ◽  
Luiz E. Bermudez
Keyword(s):  
Cystic Fibrosis ◽  
Host Cell ◽  
Biofilm Formation ◽  
Type Species ◽  
Divalent Cations ◽  
Mycobacterium Abscessus ◽  
Content Type ◽  
Link Type ◽  
Populations At Risk

Introduction. Pulmonary infections caused by organisms of the Mycobacterium abscessus complex are increasingly prevalent in populations at risk, such as patients with cystic fibrosis, bronchiectasis and emphysema. Hypothesis. M. abscessus infection of the lung is not observed in immunocompetent individuals, which raises the possibility that the compromised lung environment is a suitable niche for the pathogen to thrive in due to the overproduction of mucus and high amounts of host cell lysis. Aim. Evaluate the ability of M. abscessus to form biofilm and grow utilizing in vitro conditions as seen in immunocompromised lungs of patients. Methodology. We compared biofilm formation and protein composition in the presence and absence of synthetic cystic fibrosis medium (SCFM) and evaluated the bacterial growth when exposed to human DNA. Results. M. abscessus is capable of forming biofilm in SCFM. By eliminating single components found in the medium, it became clear that magnesium works as a signal for the biofilm formation, and chelation of the divalent cations resulted in the suppression of biofilm formation. Investigation of the specific proteins expressed in the presence of SCFM and in the presence of SCFM lacking magnesium revealed many different proteins between the conditions. M. abscessus also exhibited growth in SCFM and in the presence of host cell DNA, although the mechanism of DNA utilization remains unclear. Conclusions. In vitro conditions mimicking the airways of patients with cystic fibrosis appear to facilitate M. abscessus establishment of infection, and elimination of magnesium from the environment may affect the ability of the pathogen to establish infection.

Prevention of transmission of Mycobacterium abscessus among patients with cystic fibrosis

2019 ◽  
Vol 25 (6) ◽  
pp. 646-653 ◽  
Author(s):  
Jane E. Gross ◽  
Stacey L. Martiniano ◽  
Jerry A. Nick
Keyword(s):  
Cystic Fibrosis ◽  
Mycobacterium Abscessus
Sign in / Sign up

Export Citation Format

Share Document