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Acta Tropica Jan 2022Mycetoma is a chronic granulomatous inflammatory disease that is caused either by bacteria or fungi. Bacterial mycetoma (actinomycetoma) can be caused by various... (Review)
Review
Mycetoma is a chronic granulomatous inflammatory disease that is caused either by bacteria or fungi. Bacterial mycetoma (actinomycetoma) can be caused by various causative agents of the genera Nocardia, Streptomyces and Actinomadura. On the other hand, fungal mycetoma (eumycetoma) is most commonly caused by causative agents belonging to the genera Madurella, Scedosporium and Falciformispora. Early and accurate diagnosis of the causative organisms can guide proper patient management and treatment. To allow rapid and accurate species identification, different molecular techniques were developed over the past decades. These techniques can be protein based (MALDI-TOF MS) as well as DNA based (Sequencing, PCR and isothermal amplification methods). In this review, we provide an overview of the different molecular techniques currently in use and identify knowledge gaps, which need to be addressed before we can implement molecular diagnostics for mycetoma in different clinical settings.
Topics: Fungi; Humans; Madurella; Mycetoma; Polymerase Chain Reaction; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 34687643
DOI: 10.1016/j.actatropica.2021.106205 -
International Journal of Systematic and... Oct 2020The taxonomic positions of two novel aerobic, Gram-positive actinobacteria, designated strains RB29 and RB68, were determined using a polyphasic approach. Based on 16S...
The taxonomic positions of two novel aerobic, Gram-positive actinobacteria, designated strains RB29 and RB68, were determined using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the closest phylogenetic neighbours of RB29 were identified as DSM 102126 (99.2 % similarity) and DSM 43919 (98.7 %), and for strain RB68 was DSM 44148 (98.3 %). Digital DNA-DNA hybridization (dDDH) between RB29 and its closest phylogenetic neighbours, DSM 102126 and DSM 43919, resulted in similarity values of 53.2 % (50.6-55.9 %) and 26.4 % (24.1-28.9 %), respectively. Additionally, the average nucleotide identity (ANI) was 93.2 % (94.0 %) for DSM 102126 and 82.3 % (78.9 %) for DSM 43919. dDDH analysis between strain RB68 and DSM 44148 gave a similarity value of 24.5 % (22.2-27.0 %). Both strains, RB29 and RB68, revealed morphological characteristics and chemotaxonomic features typical for the genus , such as the presence of -diaminopimelic acid in the cell wall, galactose and glucose as major sugar components within whole-cell hydrolysates and the absence of mycolic acids. The major phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. Predominant menaquinones were MK-9(H) and MK-9(H) for RB29 and MK-9(H) and MK-9(H) for RB68. The main fatty acids were identified as 10-methyloctadecanoic acid (10-methyl C), 14-methylpentadecanoic acid (iso-C), hexadecanoic acid (C) and -9-octadecanoic acid (C ω9). Here, we propose two novel species of the genus : sp. nov. with the type strain RB29 (=CCUG 72668=NRRL B-65537) and sp. nov. with the type strain RB68 (=CCUG 72669=NRRL B-65538).
Topics: Actinobacteria; Animals; Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Diaminopimelic Acid; Fatty Acids; Gastrointestinal Microbiome; Isoptera; Nucleic Acid Hybridization; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; South Africa; Vitamin K 2
PubMed: 32845828
DOI: 10.1099/ijsem.0.004403 -
RSC Advances Jul 2019Actinomycetes are outstanding and fascinating sources of potent bioactive compounds, particularly antibiotics. In recent years, rare actinomycetes have had an... (Review)
Review
Actinomycetes are outstanding and fascinating sources of potent bioactive compounds, particularly antibiotics. In recent years, rare actinomycetes have had an increasingly important position in the discovery of antibacterial compounds, especially , and . Focusing on the period from 2008 to 2018, we herein summarize the structures and bioactivities of secondary metabolites from rare actinomycetes, involving 21 genera.
PubMed: 35518871
DOI: 10.1039/c9ra03579f -
Frontiers in Pharmacology 2022Colorectal cancer (CRC) is a common, and deadly disease. Despite the improved knowledge on CRC heterogeneity and advances in the medical sciences, there is still an... (Review)
Review
Colorectal cancer (CRC) is a common, and deadly disease. Despite the improved knowledge on CRC heterogeneity and advances in the medical sciences, there is still an urgent need to cope with the challenges and side effects of common treatments for the disease. Natural products (NPs) have always been of interest for the development of new medicines. Actinobacteria are known to be prolific producers of a wide range of bioactive NPs, and scientific evidence highlights their important protective role against CRC. This review is a holistic picture on actinobacter-derived cytotoxic compounds against CRC that provides a good perspective for drug development and design in near future. This review also describes the chemical structure of 232 NPs presenting anti-CRC activity with the being majority of quinones, lactones, alkaloids, peptides, and glycosides. The study reveals that most of these NPs are derived from marine actinobacteria followed by terrestrial and endophytic actinobacteria, respectively. They are predominantly produced by , , and , respectively, in which as the predominant contributor generating over 76% of compounds exclusively. Besides it provides a valuable snapshot of the chemical structure-activity relationship of compounds, highlighting the presence or absence of some specific atoms and chemical units in the structure of compounds can greatly influence their biological activities. To the best of our knowledge, this is the first comprehensive review on natural actinobacterial compounds affecting different types of CRC. Our study reveals that the high diversity of actinobacterial strains and their NPs derivatives, described here provides a new perspective and direction for the production of new anti-CRC drugs and paves the way to innovation for drugs discovery in the future. The knowledge obtain from this review can help us to understand the pivotal application of actinobacteria in future drugs development.
PubMed: 35899111
DOI: 10.3389/fphar.2022.929161 -
Frontiers in Microbiology 2021, an important Chinese medicinal herb, can be mainly cultivated in two planting patterns, cropland planting (DT) and understory planting (LX). We speculate that the...
, an important Chinese medicinal herb, can be mainly cultivated in two planting patterns, cropland planting (DT) and understory planting (LX). We speculate that the rhizosphere microbiome may vary in DT and LX and may play an important role in promoting the growth and health of . In the present study, culture-independent Illumina HiSeq was employed to investigate the rhizosphere bacteria and fungi under DT and LX planting patterns. Predominant phyla include , , , , and in the two planting patterns. DT has higher alpha diversity index than LX. The predominant LX-core genera include , , and the predominant DT-core genera include , , and . Total relative abundance of the disease-suppression phylum (, , and ) and the potential plant growth-promoting rhizobacteria (PGPR) were both significantly higher in LX than in DT. We also identified over-presented microbial functional traits mediating plant-microbe and microbe-microbe interactions, nutrition acquisition, and plant growth promotion in rhizosphere. Our findings provide a valuable reference for studying beneficial microbes and pathogens of planted in DT and LX.
PubMed: 34177857
DOI: 10.3389/fmicb.2021.673512 -
Natural Product Reports Mar 2024Covering: up to the end of 2022In recent years rare Actinobacteria have become increasingly recognised as a rich source of novel bioactive metabolites. are... (Review)
Review
Covering: up to the end of 2022In recent years rare Actinobacteria have become increasingly recognised as a rich source of novel bioactive metabolites. are Gram-positive bacteria that occupy a wide range of ecological niches. This review highlights about 230 secondary metabolites produced by spp., reported until the end of 2022, including their bioactivities and selected biosynthetic pathways. Notably, the bioactive compounds produced by spp. demonstrate a wide range of activities, including antimicrobial, antitumor and anticoccidial effects, highlighting their potential in various fields.
Topics: Actinomadura; Actinobacteria; Anti-Infective Agents; Bacteria; Biology
PubMed: 38099919
DOI: 10.1039/d3np00047h -
Bacterial Microbiome Differences between the Roots of Diseased and Healthy Chinese Hickory () Trees.Journal of Microbiology and... Oct 2023is an important economic nut tree that is endemic to eastern China. As such, outbreaks of root rot disease in result in reduced yields and serious economic losses....
is an important economic nut tree that is endemic to eastern China. As such, outbreaks of root rot disease in result in reduced yields and serious economic losses. Moreover, while soil bacterial communities play a crucial role in plant health and are associated with plant disease outbreaks, their diversity and composition in are not clearly understood. In this study, Proteobacteria, Acidobacteria, and Actinobacteria were found to be the most dominant bacterial communities (accounting for approximately 80.32% of the total) in the root tissue, rhizosphere soil, and bulk soil of healthy specimens. Further analysis revealed the abundance of genera belonging to Proteobacteria, namely, , , , , and , was higher in the root tissues of healthy specimens than in those of diseased and dead trees. In addition, the abundance of four genera belonging to Actinobacteria, namely, , , , and , was significantly higher in the root tissues of healthy specimens than in those of diseased and dead trees. Altogether, these results suggest that disruption in the balance of these bacterial communities may be associated with the development of root rot in , and further, our study provides theoretical guidance for the isolation and control of pathogens and diseases related to this important tree species.
Topics: Actinobacteria; Bacteria; Carya; Gammaproteobacteria; Microbiota; Plant Roots; Proteobacteria; Rhizosphere; Soil; Soil Microbiology; Trees
PubMed: 37528558
DOI: 10.4014/jmb.2304.04054 -
Pharmaceuticals (Basel, Switzerland) Jun 2023Terpenes and their derivatives (terpenoids and meroterpenoids, in particular) constitute the largest class of natural compounds, which have valuable biological... (Review)
Review
Terpenes and their derivatives (terpenoids and meroterpenoids, in particular) constitute the largest class of natural compounds, which have valuable biological activities and are promising therapeutic agents. The present review assesses the biosynthetic capabilities of actinomycetes to produce various terpene derivatives; reports the main methodological approaches to searching for new terpenes and their derivatives; identifies the most active terpene producers among actinomycetes; and describes the chemical diversity and biological properties of the obtained compounds. Among terpene derivatives isolated from actinomycetes, compounds with pronounced antifungal, antiviral, antitumor, anti-inflammatory, and other effects were determined. Actinomycete-produced terpenoids and meroterpenoids with high antimicrobial activity are of interest as a source of novel antibiotics effective against drug-resistant pathogenic bacteria. Most of the discovered terpene derivatives are produced by the genus ; however, recent publications have reported terpene biosynthesis by members of the genera , , , , , , , , etc. It should be noted that the use of genetically modified actinomycetes is an effective tool for studying and regulating terpenes, as well as increasing productivity of terpene biosynthesis in comparison with native producers. The review includes research articles on terpene biosynthesis by between 2000 and 2022, and a patent analysis in this area shows current trends and actual research directions in this field.
PubMed: 37375819
DOI: 10.3390/ph16060872 -
Molecules (Basel, Switzerland) Nov 2022Large scale cultivation and chemical investigation of an extract obtained from sp. resulted in the identification of six previously undescribed spirotetronates...
Large scale cultivation and chemical investigation of an extract obtained from sp. resulted in the identification of six previously undescribed spirotetronates (pyrrolosporin B and decatromicins C-G; -), along with six known congeners, namely decatromicins A-B (-), BE-45722B-D (-), and pyrrolosporin A (). The chemical structures of compounds - were characterized via comparison with previously reported data and analysis of 1D/2D NMR and MS data. The structures of all new compounds were highly related to the spirotetronate type compounds, decatromicin and pyrrolosporin, with variations in the substituents on the pyrrole and aglycone moieties. All compounds were evaluated for antibacterial activity against the Gram-negative bacteria, and Gram-positive bacteria, and were investigated for their cytotoxicity against the human cancer cell line A549. Of these, decatromicin B (), BE-45722B (), and pyrrolosporin B () exhibited potent antibacterial activities against both Gram-positive (MIC between 1-3 μM) and Gram-negative bacteria (MIC values ranging from 12-36 μM) with weak or no cytotoxic activity against A549 cells.
Topics: Humans; Polyketides; Actinomadura; Anti-Bacterial Agents; Gram-Negative Bacteria; Gram-Positive Bacteria; Microbial Sensitivity Tests
PubMed: 36500287
DOI: 10.3390/molecules27238196 -
New Microbes and New Infections Nov 2021Two hundred and eighty-six isolates from human clinical samples were identified between 1996 and 2019 as belonging to 8 families, 19 genera and 88 species of . The most...
Two hundred and eighty-six isolates from human clinical samples were identified between 1996 and 2019 as belonging to 8 families, 19 genera and 88 species of . The most identified genera were (182 strains from 45 species), (29 strains, 5 species), (21 strains, 6 species) and (18 strains, 5 species). The rest of the identified genera (15) contained 27 species with 36 isolates. Of the species studied, only 13/88 had been documented previously as isolates from clinical samples, and in some cases, as true pathogens. In this sense, a literature review of the species found in infections or in clinical samples without clear involvement in pathology has been carried out. Finally, the susceptibility to 8 antimicrobial agents has been studied. showed high resistance (80.8%) against cefotaxime and cotrimoxazole (55.5%), and no isolate resistance to amikacin and linezolid have been found. Lower percentages of resistance have been found in other genera, except in (100% against cotrimoxazole and 44.4% against erythromycin). The greatest resistance in these genera was to cotrimoxazole (29.8) and erythromycin (27,9%), and no resistance to linezolid has been found in these genera. In , no resistant isolates have been found against any antibiotic studied. Only 3/104 isolates were resistant to amikacin in , , and One isolate of was resistant to imipenem.
PubMed: 34917388
DOI: 10.1016/j.nmni.2021.100946