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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 -
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 -
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 2015The lack of new antibiotics in the pharmaceutical pipeline guides more and more researchers to leave the classical isolation procedures and to look in special niches and... (Review)
Review
The lack of new antibiotics in the pharmaceutical pipeline guides more and more researchers to leave the classical isolation procedures and to look in special niches and ecosystems. Bioprospecting of extremophilic Actinobacteria through mining untapped strains and avoiding resiolation of known biomolecules is among the most promising strategies for this purpose. With this approach, members of acidtolerant, alkalitolerant, psychrotolerant, thermotolerant, halotolerant and xerotolerant Actinobacteria have been obtained from respective habitats. Among these, little survey exists on the diversity of Actinobacteria in arid areas, which are often adapted to relatively high temperatures, salt concentrations, and radiation. Therefore, arid and desert habitats are special ecosystems which can be recruited for the isolation of uncommon Actinobacteria with new metabolic capability. At the time of this writing, members of Streptomyces, Micromonospora, Saccharothrix, Streptosporangium, Cellulomonas, Amycolatopsis, Geodermatophilus, Lechevalieria, Nocardia, and Actinomadura are reported from arid habitats. However, metagenomic data present dominant members of the communities in desiccating condition of areas with limited water availability that are not yet isolated. Furthermore, significant diverse types of polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) genes are detected in xerophilic and xerotolerant Actinobacteria and some bioactive compounds are reported from them. Rather than pharmaceutically active metabolites, molecules with protection activity against drying such as Ectoin and Hydroxyectoin with potential application in industry and agriculture have also been identified from xerophilic Actinobacteria. In addition, numerous biologically active small molecules are expected to be discovered from arid adapted Actinobacteria in the future. In the current survey, the diversity and biotechnological potential of Actinobacteria obtained from arid ecosystems, along with the recent work trend on Iranian arid soils, are reported.
PubMed: 26858692
DOI: 10.3389/fmicb.2015.01541 -
Scientific Reports May 2022Mucin-degrading microbes are known to harbor glycosyl hydrolases (GHs) which cleave specific glycan linkages. Although several microbial species have been identified as...
Mucin-degrading microbes are known to harbor glycosyl hydrolases (GHs) which cleave specific glycan linkages. Although several microbial species have been identified as mucin degraders, there are likely many other members of the healthy gut community with the capacity to degrade mucins. The aim of the present study was to systematically examine the CAZyme mucin-degrading profiles of the human gut microbiota. Within the Verrucomicrobia phylum, all Akkermansia glycaniphila and muciniphila genomes harbored multiple gene copies of mucin-degrading GHs. The only representative of the Lentisphaerae phylum, Victivallales, harbored a GH profile that closely mirrored Akkermansia. In the Actinobacteria phylum, we found several Actinomadura, Actinomyces, Bifidobacterium, Streptacidiphilus and Streptomyces species with mucin-degrading GHs. Within the Bacteroidetes phylum, Alistipes, Alloprevotella, Bacteroides, Fermenitomonas Parabacteroides, Prevotella and Phocaeicola species had mucin degrading GHs. Firmicutes contained Abiotrophia, Blautia, Enterococcus, Paenibacillus, Ruminococcus, Streptococcus, and Viridibacillus species with mucin-degrading GHs. Interestingly, far fewer mucin-degrading GHs were observed in the Proteobacteria phylum and were found in Klebsiella, Mixta, Serratia and Enterobacter species. We confirmed the mucin-degrading capability of 23 representative gut microbes using a chemically defined media lacking glucose supplemented with porcine intestinal mucus. These data greatly expand our knowledge of microbial-mediated mucin degradation within the human gut microbiota.
Topics: Animals; Clostridiales; Gastrointestinal Microbiome; Humans; Mucins; Polysaccharides; Swine; Verrucomicrobia
PubMed: 35589783
DOI: 10.1038/s41598-022-11819-z -
Saudi Journal of Biological Sciences Jun 2022Fungi colonizing fruits in the field and post-harvest constitute a major threat to the global food sector. This study focuses on the biocontrol of (aflatoxin-producing...
Fungi colonizing fruits in the field and post-harvest constitute a major threat to the global food sector. This study focuses on the biocontrol of (aflatoxin-producing mold considered carcinogenic by IARC) and f. sp. albedinis (FOA) (phytopathogenic agent, causal of El Bayoud in the Algerian and Moroccan Sahara). These molds have a significant economic impact and pose a serious human health problem. The aim of this work is to study the antifungal activity of two rare actinomycetes strains; sp. COL22 and sp. COL08 strains against toxinogenic and . f. sp. albedinis. The strains are isolated from rhizosphere on different media: ISP2, GLM, TSA, Starch-casein-agar and WYE and with different treatments of the samples (physical, chemical treatment and enrichment). The antifungal tests against the pathogenic microorganisms were performed on ISP2, GLM and TSA medium by means of the agar cylinders method. The kinetics of antibiotic production were performed on ISP medium over 16 days. The characterization of the antimicrobial compounds by LC-ESI/MS-MS showed that the bacterial extracts contain Antibiotic SF 2738C, Tetrodecamycin and Aplysillamide B. The phenotypic and molecular studies showed that sp. COL22 is closely related to the strain type and that sp. COL08 is closely related to the strain type. The two strains are rare and showed an interesting activity against toxinogenic and f. sp. albedinis.
PubMed: 35574281
DOI: 10.1016/j.sjbs.2022.103288 -
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 -
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 -
Annales de Dermatologie Et de... Jan 2003Mycetoma is a pathological process in which eumycotic (fungal) or actinomycotic causative agents from exogenous source produce grains. It follows penetrating injury...
BACKGROUND
Mycetoma is a pathological process in which eumycotic (fungal) or actinomycotic causative agents from exogenous source produce grains. It follows penetrating injury inoculating soil organisms, occurring preferentially in rural areas usually among labourers who work barefoot. Mycetoma is a localized chronic, and deforming infectious disease of subcutaneous tissues, skin and bones. We report 130 cases of mycetoma in Senegal from 1983 to 2000.
PATIENTS AND METHODS
There were 130 patients with mycetoma. Clinical diagnosis of mycetoma was based on open tract sinuses, tumefaction or discharge of grain. Diagnosis confirmation was based on mycology and histology. An X-ray was preformed to detect bone lesions. Treatment was medical for actinomycetoma and surgical for eumycetoma.
RESULTS
We observed 76 actinomycetoma and 54 eumycetoma (Sex ratio M/F=6.6; mean age=34.7 +/- 14.8 years). The mean duration before the first medical evaluation was 4.8 +/- 5.6 years. Actinomycetoma was due to Actinomadura pelletieri, (54 cases), Actinomadura madurae (17 cases) and Streptomyces somaliensis (5 cases). Eumycetoma was due to Madurella mycetomatis (38 cases), Leptospahria senegalensis (9 cases), Pseudoallescheria boydii (6 cases) and Rhinoclediella atrovirens (1 case). Clinical inflammatory features significantly associated with actinomyces (p<0.001 OR=2.64) were predominant (85 cases). Tumoral and cystic features were found in the others forms. Lesions were located on the foot in 81 patients. Bone lesions, depending on the duration, were observed in 68 patients. Neurological damage occurred in 3 patients with dorsolumbar actinomycetoma. Sixty-six patients with actinomycetoma were cured by medical treatment.
DISCUSSION
The 130 cases of mycetoma were remarkable by the long duration of the disease before the first medical evaluation. Pain and tumor were the two main symptoms which brought the patients to the hospital and had appeared after 5 years duration and the predominance of actinomadura pelletieri actinomycetoma was responsible for 41.3 p. 100 of our cases. In Niger and Mauritania, mycetoma were actinomycetoma in respectively 71.2 p. 100 and 25 p. 100 of cases. The geographic distribution of pathogenic mycetoma agents was determined by the annual rainfall. Distinction between eumycetoma and actinomycetoma is very important for the treatment.
Topics: Adolescent; Adult; Aged; Female; Humans; Male; Middle Aged; Mycetoma; Retrospective Studies
PubMed: 12605151
DOI: No ID Found -
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