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Meat Science Dec 2014Nontuberculous mycobacteria (NTM) are ubiquitous, potentially pathogenic organisms that have been isolated from a variety of environmental sources. NTM have been... (Review)
Review
Nontuberculous mycobacteria (NTM) are ubiquitous, potentially pathogenic organisms that have been isolated from a variety of environmental sources. NTM have been isolated from various kinds of food and many studies support the hypothesis that food, especially raw or partially cooked products, plays a role as a source of NTM for humans. Animals with disseminated infection have been diagnosed with NTM not only in the gastro-intestinal tract and intestinal lymph nodes, but also in tissues like muscle and parenchymatous organs. Infected animals may harbor NTM in their tissues even without clinical symptoms and especially minced meat with the possible addition of lymph nodes are considered as potential source of NTM. The purpose of this paper was to review articles concerning the detection of mycobacteria in the muscle tissue and lymph nodes of domestic animals, farmed and free-living game and to summarize methods and techniques for their detection.
Topics: Animals; Animals, Domestic; Animals, Wild; Lymph Nodes; Meat Products; Muscle, Skeletal; Mycobacterium avium; Nontuberculous Mycobacteria
PubMed: 25170820
DOI: 10.1016/j.meatsci.2014.08.001 -
Protein Science : a Publication of the... Mar 2020A protein superfamily with a "Domain of Unknown Function,", DUF3349 (PF11829), is present predominately in Mycobacterium and Rhodococcus bacterial species suggesting...
A protein superfamily with a "Domain of Unknown Function,", DUF3349 (PF11829), is present predominately in Mycobacterium and Rhodococcus bacterial species suggesting that these proteins may have a biological function unique to these bacteria. We previously reported the inaugural structure of a DUF3349 superfamily member, Mycobacterium tuberculosis Rv0543c. Here, we report the structures determined for three additional DUF3349 proteins: Mycobacterium smegmatis MSMEG_1063 and MSMEG_1066 and Mycobacterium abscessus MAB_3403c. Like Rv0543c, the NMR solution structure of MSMEG_1063 revealed a monomeric five α-helix bundle with a similar overall topology. Conversely, the crystal structure of MSMEG_1066 revealed a five α-helix protein with a strikingly different topology and a tetrameric quaternary structure that was confirmed by size exclusion chromatography. The NMR solution structure of a fourth member of the DUF3349 superfamily, MAB_3403c, with 18 residues missing at the N-terminus, revealed a monomeric α-helical protein with a folding topology similar to the three C-terminal helices in the protomer of the MSMEG_1066 tetramer. These structures, together with a GREMLIN-based bioinformatics analysis of the DUF3349 primary amino acid sequences, suggest two subfamilies within the DUF3349 family. The division of the DUF3349 into two distinct subfamilies would have been lost if structure solution had stopped with the first structure in the DUF3349 family, highlighting the insights generated by solving multiple structures within a protein superfamily. Future studies will determine if the structural diversity at the tertiary and quaternary levels in the DUF3349 protein superfamily have functional roles in Mycobacteria and Rhodococcus species with potential implications for structure-based drug discovery.
Topics: Bacterial Proteins; Models, Molecular; Mycobacterium; Nuclear Magnetic Resonance, Biomolecular; Protein Conformation
PubMed: 31658388
DOI: 10.1002/pro.3758 -
Scientific Reports May 2023There exists decades-old evidence that some mycobacteria, including Mycobacterium avium and Mycobacterium smegmatis, produce hydrazidase, an enzyme that can hydrolyze...
There exists decades-old evidence that some mycobacteria, including Mycobacterium avium and Mycobacterium smegmatis, produce hydrazidase, an enzyme that can hydrolyze the first-line antitubercular agent isoniazid. Despite its importance as a potential resistance factor, no studies have attempted to reveal its identity. In this study, we aimed to isolate and identify M. smegmatis hydrazidase, characterize it, and evaluate its impact on isoniazid resistance. We determined the optimal condition under which M. smegmatis produced the highest amount of hydrazidase, purified the enzyme by column chromatography, and identified it by peptide mass fingerprinting. It was revealed to be PzaA, an enzyme known as pyrazinamidase/nicotinamidase whose physiological role remains unknown. The kinetic constants suggested that this amidase with broad substrate specificity prefers amides to hydrazides as a substrate. Notably, of the five tested compounds, including amides, only isoniazid served as an efficient inducer of pzaA transcription, as revealed by quantitative reverse transcription PCR. Moreover, high expression of PzaA was confirmed to be beneficial for the survival and growth of M. smegmatis in the presence of isoniazid. Thus, our findings suggest a possible role for PzaA, and other hydrazidases yet to be identified, as an intrinsic isoniazid resistance factor of mycobacteria.
Topics: Isoniazid; Mycobacterium; Antitubercular Agents; Mycobacterium smegmatis; Amides; Mycobacterium tuberculosis
PubMed: 37210419
DOI: 10.1038/s41598-023-35213-5 -
Biochimie Oct 2017Phenolic glycolipids (PGL) are polyketide synthase products that are uniquely produced by a subset of pathogenic mycobacteria and are displayed at the bacterial cell... (Review)
Review
Phenolic glycolipids (PGL) are polyketide synthase products that are uniquely produced by a subset of pathogenic mycobacteria and are displayed at the bacterial cell surface, in a strategic position to interfere with host immune cells. Their expression has been associated with enhanced mycobacterial virulence in vivo, and suppression of the inflammatory responses of host phagocytes in vitro. In this review, we will present our current understanding of the mode of operation of PGL, along with functional evidence that demonstrates the evolutionary advantage conferred by PGL production for host cell invasion, intracellular persistence and evasion of host immune and bactericidal responses.
Topics: Animals; Glycolipids; Humans; Immunosuppressive Agents; Mycobacterium
PubMed: 28322927
DOI: 10.1016/j.biochi.2017.03.012 -
Infection Jun 2023
Topics: Humans; Abscess; Mycobacterium; Muscles; Nontuberculous Mycobacteria
PubMed: 36472781
DOI: 10.1007/s15010-022-01961-1 -
Chemical Record (New York, N.Y.) Nov 2021The highly lipophilic outer barrier of mycobacteria, such as M. tuberculosis and M. leprae, is key to their virulence and intrinsic antibiotic resistance. Various... (Review)
Review
The highly lipophilic outer barrier of mycobacteria, such as M. tuberculosis and M. leprae, is key to their virulence and intrinsic antibiotic resistance. Various components of this mycomembrane interact with the host immune system but many of these interactions remain ill-understood. This review covers several chemical syntheses of one of these components, mycobacterial phenolic glycolipids (PGLs), and outlines the interaction of these PGLs with the human immune system, as established using these well-defined pure compounds.
Topics: Glycolipids; Humans; Mycobacterium leprae; Mycobacterium tuberculosis
PubMed: 34581501
DOI: 10.1002/tcr.202100200 -
International Journal of Molecular... Jul 2021The mycobacterial cell wall is composed of large amounts of lipids with varying moieties. Some mycobacteria species hijack host cells and promote lipid droplet... (Review)
Review
The mycobacterial cell wall is composed of large amounts of lipids with varying moieties. Some mycobacteria species hijack host cells and promote lipid droplet accumulation to build the cellular environment essential for their intracellular survival. Thus, lipids are thought to be important for mycobacteria survival as well as for the invasion, parasitization, and proliferation within host cells. However, their physiological roles have not been fully elucidated. Recent studies have revealed that mycobacteria modulate the peroxisome proliferator-activated receptor (PPAR) signaling and utilize host-derived triacylglycerol (TAG) and cholesterol as both nutrient sources and evasion from the host immune system. In this review, we discuss recent findings that describe the activation of PPARs by mycobacterial infections and their role in determining the fate of bacilli by inducing lipid metabolism, anti-inflammatory function, and autophagy.
Topics: Animals; Autophagy; Cholesterol; Humans; Lipid Metabolism; Mycobacterium; Mycobacterium Infections; Peroxisome Proliferator-Activated Receptors; Signal Transduction
PubMed: 34299217
DOI: 10.3390/ijms22147597 -
Antonie Van Leeuwenhoek Jul 2018The taxonomic positions of two fast growing mycobacteria (CECT 8778 and CECT 8779) were established using a polyphasic approach. The strains were shown to have...
The taxonomic positions of two fast growing mycobacteria (CECT 8778 and CECT 8779) were established using a polyphasic approach. The strains were shown to have chemotaxonomic, cultural and morphological properties consistent with their classification in the genus Mycobacterium. Multi-locus sequence analyses (MLSA) show that strain CECT 8778 forms a well-supported clade together with the type strains of Mycobacterium aurum, Mycobacterium austroafricanum and Mycobacterium vanbaalenii while strain CECT 8779 presents as a distinct branch that is well separated from its near phylogenetic neighbours; it is also apparent from the MLSA genetic distances that these strains are most closely related to the type strains of Mycobacterium mageritense and M. vanbaalenii, respectively. Digital DNA:DNA hybridization and average nucleotide identity values between each of the strains and its close phylogenetic neighbour are below the 70 and 96% threshold values for definition of prokaryotic species; these results are underpinned by corresponding phenotypic data. Based upon the consensus of the phenotypic and phylogenetic analyses, it can be concluded that the two strains represent novel species within the genus Mycobacterium for which the following names are proposed: Mycobacterium neglectum sp. nov., with the type strain CECT 8778 (BN 3150 = DSM 44756) and Mycobacterium palauense sp. nov., with the type strain CECT 8779 (= DSM 44914).
Topics: DNA, Bacterial; Multilocus Sequence Typing; Mycobacterium; Nucleic Acid Hybridization; Phylogeny; RNA, Ribosomal, 16S
PubMed: 29404824
DOI: 10.1007/s10482-018-1029-5 -
Sub-cellular Biochemistry 2022The mycobacteria genus is responsible for numerous infectious diseases that have afflicted the human race since antiquity-tuberculosis and leprosy in particular. An...
The mycobacteria genus is responsible for numerous infectious diseases that have afflicted the human race since antiquity-tuberculosis and leprosy in particular. An important contributor to their evolutionary success is their unique cell envelope, which constitutes a quasi-impermeable barrier, protecting the microorganism from external threats, antibiotics included. The arabinofuranosyltransferases are a family of enzymes, unique to the Actinobacteria family that mycobacteria genus belongs to, that are critical to building of this cell envelope. In this chapter, we will analyze available structures of members of the mycobacterial arabinofuranosyltransferase, clarify their function, as well as explore the common themes present amongst this family of enzymes, as revealed by recent research.
Topics: Anti-Bacterial Agents; Cell Membrane; Cell Wall; Humans; Mycobacterium; Mycobacterium tuberculosis
PubMed: 36151383
DOI: 10.1007/978-3-031-00793-4_12 -
International Journal of... Jun 2015Pulmonary infections with nontuberculous mycobacteria (NTM) are recognized as a problem in immunodeficient individuals and are increasingly common in older people with... (Review)
Review
Pulmonary infections with nontuberculous mycobacteria (NTM) are recognized as a problem in immunodeficient individuals and are increasingly common in older people with no known immune defects. NTM are found in soil and water, but factors influencing transmission from the environment to humans are mostly unknown. Studies of the epidemiology of NTM disease have matched some clinical isolates of NTM with isolates from the patient's local environment. Definitive matching requires strain level differentiation based on molecular analyses, including partial sequencing, PCR-restriction fragment length polymorphism (RFLP) analysis, random amplified polymorphic DNA (RAPD) PCR, repetitive element (rep-) PCR and pulsed field gel electrophoresis (PFGE) of large restriction fragments. These approaches have identified hospital and residential showers and faucets, hot-tubs and garden soil as sources of transmissible pathogenic NTM. However, gaps exist in the literature, with many clinical isolates remaining unidentified within environments that have been tested, and few studies investigating NTM transmission in developing countries. To understand the environmental reservoirs and transmission routes of pathogenic NTM, different environments, countries and climates must be investigated.
Topics: Environmental Microbiology; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 26972876
DOI: 10.1016/j.ijmyco.2015.03.002