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Microbiology Spectrum Apr 2022Pathogenic intracellular mycobacteria, such as Mycobacterium tuberculosis and Mycobacterium avium, which cause lung diseases, can grow in macrophages. Extracellular...
Pathogenic intracellular mycobacteria, such as Mycobacterium tuberculosis and Mycobacterium avium, which cause lung diseases, can grow in macrophages. Extracellular mycobacteria have been reported in the lungs, blood, and sputum of patients, indicating the involvement of these pathogens in disease progression. Erythrocytes are involved in the symptoms associated with pulmonary mycobacterial diseases, such as bloody sputum and hemoptysis; however, little attention has been paid to the role of erythrocytes in mycobacterial diseases. Herein, we found that Mycobacterium avium subsp. (MAH) and Mycobacterium intracellulare colocalized with erythrocytes at the sites of lung infection, inside capillaries and necrotic areas of granulomas, using histopathological examinations. Electron microscopy showed that MAH adhered and entered human erythrocytes when they were cocultured . MAH adhered to erythrocytes through complement receptor 1 and cell-surface sialo-glycoproteins. Importantly, MAH grew vigorously without causing any pronounced damage to erythrocytes. This erythrocyte-mediated enhancement of MAH growth occurred extracellularly depending on its direct attachment to erythrocytes. In contrast, MAH failed to multiply inside erythrocytes. Similarly, erythrocytes augmented the growth of other pathogenic mycobacteria, such as M. intracellulare and M. tuberculosis. THP-1 cell-derived human macrophages preferentially phagocytosed erythrocytes that were attached to mycobacteria (compared to bacteria alone), suggesting that erythrocyte-attached mycobacteria are an efficient infectious source for macrophages. Our findings provide new insights into the pathogenesis of mycobacterial diseases and offer an alternative and useful strategy for treating mycobacterial disease. Pathogenic mycobacteria, such as Mycobacterium tuberculosis, Mycobacterium avium subsp. (MAH), and Mycobacterium intracellulare, cause pulmonary infections as intracellular parasites of lung macrophages and epithelial cells. Here, using histopathological examinations we found that MAH and M. intracellulare colocalized with erythrocytes in lung infection sites. Subsequent studies demonstrated that direct interaction with erythrocytes enhances the extracellular proliferation of mycobacteria based on the following results: 1. MAH adhered and invaded human erythrocytes upon coculture ; 2. MAH adhered to erythrocytes through complement receptor 1 and cell-surface sialo-glycoproteins; 3. MAH rapidly proliferated when directly attached to erythrocytes but not within them; 4. other mycobacteria, such as M. intracellulare and M. tuberculosis, also proliferated in the same way as MAH. The finding that pathogenic mycobacteria grow extracellularly in an erythrocyte-dependent manner is of considerable clinical importance for understanding disease progression and latent infection.
Topics: Disease Progression; Erythrocytes; Glycoproteins; Humans; Mycobacterium; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Mycobacterium tuberculosis; Receptors, Complement; Tuberculosis
PubMed: 35293805
DOI: 10.1128/spectrum.02454-21 -
Annals of Agricultural and... Mar 2022The complex (MAC) is a group of acid-resistant bacteria within the Mycobacteriaceae. Their cell walls have a specific structure impervious to many disinfectants.... (Review)
Review
INTRODUCTION AND OBJECTIVE
The complex (MAC) is a group of acid-resistant bacteria within the Mycobacteriaceae. Their cell walls have a specific structure impervious to many disinfectants. Mycobacteria are widespread in the environment and can also be found in food. This aim of the article is to review the current state of knowledge about the sources of infection, symptoms and treatment of MAC diseases in humans and animals, and summarizes the available methods for identifying the bacteria. It pays a special attention to the zoonotic potential of MAC bacteria and possible routes of transmission between humans and animals, including possible food-borne routes.
BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE.
MAC bacterial infections occur both in immunocompetent people and those with functional predispositions and compromised immunity, particularly during HIV infection or immunosuppressive treatment. The incidence of MAC infections in humans is growing, with the most common form of infection being pulmonary disease (MTC-PD); however, there are conflicting reports on the role of paratuberculosis (MAP) in the development of Crohn's disease. MAC bacteria can also attack livestock, household pets, and wild animals. Unfortunately, treatment is lengthy and often fails due to microbiological relapse; there is also increasing evidence of MAC bacteria are developing multi-drug resistance.
CONCLUSIONS
Although new antibiotics are being created to inhibit the growth and division of , there is clearly a need for further research into the virulence factors associated with MAC bacteria. Further studies should also examine the role of MAP in the etiopathogenesis of Crohn's disease.
Topics: Animals; Crohn Disease; HIV Infections; Humans; Mycobacterium avium Complex; Mycobacterium avium subsp. paratuberculosis; Mycobacterium avium-intracellulare Infection
PubMed: 35352901
DOI: 10.26444/aaem/136398 -
Journal of Global Antimicrobial... Sep 2021The incidence of infections due to Mycobacterium avium complex (MAC) and Mycobacterium abscessus (MABS) is increasing worldwide. Current antimycobacterial agents are not... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
The incidence of infections due to Mycobacterium avium complex (MAC) and Mycobacterium abscessus (MABS) is increasing worldwide. Current antimycobacterial agents are not sufficiently effective against nontuberculous mycobacteria (NTM) and there is a need for new drugs. This study aimed to estimate the overall in vitro activity of clofazimine (CFZ) against MAC and MABS clinical isolates.
METHODS
We systematically searched four databases up to 1 March 2020 to identify relevant studies. Studies were included if they used the Clinical and Laboratory Standards Institute (CLSI) criteria for drug susceptibility testing (DST). We assessed the pooled in vitro CFZ resistance rate in MAC and MABS clinical isolates using a random- effects model. Sources of heterogeneity were evaluated using Cochran's Q and the I statistic. Potential for publication bias was explored using Begg's and Egger's tests. All analyses were conducted using Stata 14.0.
RESULTS
A total of 20 publications (11 reports for MAC and 15 for MABS) were included. The pooled rates of in vitro resistance to CFZ in clinical isolates of MAC and MABS were 9.0% [95% confidence interval (CI) 3.0-17.0%] and 16.0% (95% CI 4.0-34.0%), respectively. There was no evidence of publication bias.
CONCLUSION
This study reports the frequency of CFZ resistance in clinical isolates of MAC and MABS. According to the results, establishing accurate DST methods for detecting CFZ resistance, performing DST for all NTM isolates to provide effective treatment, and continuous monitoring of drug resistance are suggested for the prevention and control of CFZ-resistant NTM.
Topics: Clofazimine; Humans; Microbial Sensitivity Tests; Mycobacterium abscessus; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Mycobacterium tuberculosis
PubMed: 34153525
DOI: 10.1016/j.jgar.2021.06.002 -
Revue Scientifique Et Technique... Apr 2001Tuberculosis, caused by Mycobacterium tuberculosis, and leprosy, caused by M. leprae, are diseases known since antiquity. In developing countries, tuberculosis is still... (Review)
Review
Tuberculosis, caused by Mycobacterium tuberculosis, and leprosy, caused by M. leprae, are diseases known since antiquity. In developing countries, tuberculosis is still the leading cause of mortality due to an infectious disease. Taxonomically, mycobacteria belong to the genus Mycobacterium, which is the single genus within the family of Mycobacteriaceae, in the order Actinomycetales. Actinomycetales include diverse micro-organisms, but mycobacteria and allied taxa are easily distinguished on the basis of the ability to synthesise mycolic acids. Mycobacterial species are traditionally differentiated on the basis of phenotypic characteristics, and the authors provide an updated list of the biochemical tests currently employed and the culture properties that help to discriminate among various species of mycobacteria. However, as the phenotypic characteristics do not allow precise identification of all species, recent molecular taxonomical approaches for mycobacterial classification and phylogeny are also described. Mycobacteria are also a leading cause of infection in various domesticated animals and wildlife. The authors briefly describe the mycobacteria involved in animal infections, the wildlife reservoirs and strategies to control bovine tuberculosis, and the use of molecular tools for diagnostics and epidemiology of mycobacterial infections in animals. The characteristic of intracellular parasitism is discussed, in addition to the fate of pathogenic mycobacteria that have the ability to grow inside phagosomes and phagolysosomes of infected host macrophages. The mycobacterial cell envelope, which is a complex tripartite structure containing a high proportion of lipids (approximately 30% to 40% of the total weight) could play a crucial role in the adaptation of mycobacteria to intracellular growth and survival, immune modulation and drug resistance.
Topics: Animals; Cattle; Classification; DNA Fingerprinting; DNA, Bacterial; Genotype; Humans; Mycobacterium; Mycobacterium Infections; Mycolic Acids; Phenotype; Phylogeny; Polymorphism, Restriction Fragment Length; Terminology as Topic; Tuberculosis, Bovine
PubMed: 11288513
DOI: 10.20506/rst.20.1.1265 -
Proteomics. Clinical Applications Apr 2016Identification and typing of bacteria occupy a large fraction of time and work in clinical microbiology laboratories. With the certification of some MS platforms in... (Review)
Review
Identification and typing of bacteria occupy a large fraction of time and work in clinical microbiology laboratories. With the certification of some MS platforms in recent years, more applications and tests of MS-based diagnosis methods for bacteria identification and typing have been created, not only on well-accepted MALDI-TOF-MS-based fingerprint matches, but also on solving the insufficiencies of MALDI-TOF-MS-based platforms and advancing the technology to areas such as targeted MS identification and typing of bacteria, bacterial toxin identification, antibiotics susceptibility/resistance tests, and MS-based diagnostic method development on unique bacteria such as Clostridium and Mycobacteria. This review summarizes the recent development in MS platforms and applications in bacteria identification and typing of common pathogenic bacteria.
Topics: Bacterial Toxins; Bacterial Typing Techniques; Campylobacter jejuni; Clostridium; Escherichia coli; Humans; Listeria monocytogenes; Microbial Sensitivity Tests; Mycobacteriaceae; Peptide Fragments; Proteolysis; Proteomics; Salmonella; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Trypsin
PubMed: 26751976
DOI: 10.1002/prca.201500086 -
New Biotechnology Jan 2022Efficient and convenient genetic manipulation of mycobacteria, important microorganisms in human healthcare and the pharmaceutical industry, is limited. In this study,...
Efficient and convenient genetic manipulation of mycobacteria, important microorganisms in human healthcare and the pharmaceutical industry, is limited. In this study, using a model strain Mycolicibacterium neoaurum ATCC 25795, the classical bacterium for the production of valuable steroidal pharmaceuticals, a genome editing system employing CRISPR-Cas12a to achieve efficient and precise genetic manipulation has been developed. Targeted genome mutations could be easily achieved by the CRISPR-Cas12a system without exogenous donor templates, assisted by innate non-homologous end-joining (NHEJ). CRISPR-Cas12a enabled rapid one-step genomic DNA fragment deletions of 1 kb, 5 kb, 10 kb, 15 kb, 20 kb and 24 kb with efficiencies of 70 %, 30 %, 30 %, 20 %, 20 % and 10 %, respectively. Combined with the pNIL/pGOAL system, CRISPR-Cas12a successfully integrated the gene of interest into the targeted genomic site by single crossover and double crossovers with efficiencies of 100 % and 9 %, respectively, using a two-plasmid system. The robust CRISPR systems developed demonstrated strong potential for precise genome editing in M. neoaurum, including targeted deletion of DNA sequences of various lengths and integration of targeted genes into desired sites in the genome.
Topics: CRISPR-Cas Systems; DNA End-Joining Repair; Gene Editing; Mycobacteriaceae; Plasmids
PubMed: 34653700
DOI: 10.1016/j.nbt.2021.10.003 -
Emerging Infectious Diseases Mar 2022Although human infections caused by Mycobacterium mageritense are rare, there are some case reports involving sinusitis, pneumonia, and hospital-acquired infections in...
Although human infections caused by Mycobacterium mageritense are rare, there are some case reports involving sinusitis, pneumonia, and hospital-acquired infections in adults. We report a case of lymphadenitis caused by M. mageritense in a child in Spain.
Topics: Adult; Child; Family; Humans; Lymphadenitis; Mycobacteriaceae; Mycobacterium Infections; Mycobacterium Infections, Nontuberculous; Pneumonia
PubMed: 35202540
DOI: 10.3201/eid2803.211486 -
Veterinary Medicine and Science Nov 2023Mycobacterium phlei is a gram-positive acid-fast mycobacterium from the family Mycobacteriaceae. It is a valuable resource for both natural drugs and microecological... (Review)
Review
Mycobacterium phlei is a gram-positive acid-fast mycobacterium from the family Mycobacteriaceae. It is a valuable resource for both natural drugs and microecological preparations. It has been widely used in the field of human medicine; however, in the field of animal husbandry and veterinary medicine, the research and application of M. phlei is still in the preliminary exploration stage. This study aims to summarize the research progress of M. phlei in the field of veterinary medicine and provide a valuable reference for future research. Key words, such as 'M. phlei', 'veterinary field', 'immune balancer', 'genome' and other relevant words to this study, were used to search through PubMed, Web of Science, SciELO, Science Direct and Google Scholar databases. The results showed that the culture conditions of M. phlei were relatively simple, but its bacterial composition and genome sequence were relatively complex, and various components in the cell wall may have immunoregulatory effects. Therefore, the inactivated preparation made from M. phlei can have various applications in the veterinary field, such as growth regulation, immune regulation, antitumour, anti-parasite and asthma treatment. The literature review indicates that M. phlei preparation is an efficient and convenient immune system balance agent. Despite the challenges associated with the use of M. phlei preparations, it has a strong potential for application in veterinary medicine.
Topics: Humans; Animals; Mycobacterium phlei; Mycobacterium; Asthma; Cell Wall
PubMed: 37723902
DOI: 10.1002/vms3.1262 -
Virulence Oct 2017
Topics: Animals; Interferon-beta; Mice; Mycobacterium tuberculosis; Nontuberculous Mycobacteria
PubMed: 28605283
DOI: 10.1080/21505594.2017.1341035 -
Clinical & Developmental Immunology 2012Airway epithelial cells (AECs) are part of the frontline defense against infection of pathogens by providing both a physical barrier and immunological function. The role... (Review)
Review
Airway epithelial cells (AECs) are part of the frontline defense against infection of pathogens by providing both a physical barrier and immunological function. The role of AECs in the innate and adaptive immune responses, through the production of antimicrobial molecules and proinflammatory factors against a variety of pathogens, has been well established. Tuberculosis (TB), a contagious disease primarily affecting the lungs, is caused by the infection of various strains of mycobacteria. In response to mycobacteria infection, epithelial expression of Toll-like receptors and surfactant proteins plays the most prominent roles in the recognition and binding of the pathogen, as well as the initiation of the immune response. Moreover, the antimicrobial substances, proinflammatory factors secreted by AECs, composed a major part of the innate immune response and mediation of adaptive immunity against the pathogen. Thus, a better understanding of the role and mechanism of AECs in response to mycobacteria will provide insight into the relationship of epithelial cells and lung immunocytes against TB, which may facilitate our understanding of the pathogenesis and immunological mechanism of pulmonary tuberculosis disease.
Topics: Adaptive Immunity; Animals; Antimicrobial Cationic Peptides; Host-Pathogen Interactions; Humans; Immunity, Innate; Lung; Mycobacteriaceae; Respiratory Mucosa; Toll-Like Receptors; Tuberculosis, Pulmonary
PubMed: 22570668
DOI: 10.1155/2012/791392