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International Journal of Systematic and... Sep 2019One novel actinobacterial isolate, designated strain NEAU-G17, was isolated from muddy soil collected from a riverbank in Chad and characterised using polyphasic...
One novel actinobacterial isolate, designated strain NEAU-G17, was isolated from muddy soil collected from a riverbank in Chad and characterised using polyphasic approach. Morphological and chemotaxonomic characteristics of this strain coincided with those of the genus . The 16S rRNA gene sequence analysis showed that strain NEAU-G17 was most closely related to JCM 10648 (98.7 %) and NEAU-Gz5 (98.6 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-G17 formed a cluster with JCM 10648, NEAU-Gz5 and CS5-AC15 (96.4 %). However, the combination of DNA-DNA hybridisation values and some phenotypic characteristics allowed the isolate to be differentiated from their most closely related species. The major menaquinones were identified as MK-9(H), MK-9(H) and MK-9(H). Their polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified phospholipid and an unidentified lipid. The major fatty acids were identified as C, -C and C ω9c. Therefore, it is proposed that strain NEAU-G17 should be classified as representative of a novel species of the genus , for which the name sp. nov. is proposed. The type strains is NEAU-G17 (=CGMCC 4.7411=DSM 105122).
Topics: Actinobacteria; Bacterial Typing Techniques; Base Composition; Chad; DNA, Bacterial; Fatty Acids; Nucleic Acid Hybridization; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Soil Microbiology; Vitamin K 2
PubMed: 31287395
DOI: 10.1099/ijsem.0.003579 -
Journal of Virology Jan 2020To counteract the serious health threat posed by known and novel viral pathogens, drugs that target a variety of viruses through a common mechanism have attracted recent...
To counteract the serious health threat posed by known and novel viral pathogens, drugs that target a variety of viruses through a common mechanism have attracted recent attention due to their potential in treating (re)emerging infections, for which direct-acting antivirals are not available. We found that labyrinthopeptins A1 and A2, the prototype congeners of carbacyclic lanthipeptides, inhibit the proliferation of diverse enveloped viruses, including dengue virus, Zika virus, West Nile virus, hepatitis C virus, chikungunya virus, Kaposi's sarcoma-associated herpesvirus, cytomegalovirus, and herpes simplex virus, in the low micromolar to nanomolar range. Mechanistic studies on viral particles revealed that labyrinthopeptins induce a virolytic effect through binding to the viral membrane lipid phosphatidylethanolamine (PE). These effects are enhanced by a combined equimolar application of both labyrinthopeptins, and a clear synergism was observed across a concentration range corresponding to 10% to 90% inhibitory concentrations of the compounds. Time-resolved experiments with large unilamellar vesicles (LUVs) reveal that membrane lipid raft compositions (phosphatidylcholine [PC]/PE/cholesterol/sphingomyelin at 17:10:33:40) are particularly sensitive to labyrinthopeptins in comparison to PC/PE (90:10) LUVs, even though the overall PE amount remains constant. Labyrinthopeptins exhibited low cytotoxicity and had favorable pharmacokinetic properties in mice (half-life [] = 10.0 h), which designates them promising antiviral compounds acting by an unusual viral lipid targeting mechanism. For many viral infections, current treatment options are insufficient. Because the development of each antiviral drug is time-consuming and expensive, the prospect of finding broad-spectrum antivirals that can fight multiple, diverse viruses-well-known viruses as well as (re)emerging species-has gained attention, especially for the treatment of viral coinfections. While most known broad-spectrum agents address processes in the host cell, we found that targeting lipids of the free virus outside the host cell with the natural products labyrinthopeptin A1 and A2 is a viable strategy to inhibit the proliferation of a broad range of viruses from different families, including chikungunya virus, dengue virus, Zika virus, Kaposi's sarcoma-associated herpesvirus, and cytomegalovirus. Labyrinthopeptins bind to viral phosphatidylethanolamine and induce virolysis without exerting cytotoxicity on host cells. This represents a novel and unusual mechanism to tackle medically relevant viral infections.
Topics: Aedes; Animals; Bacteriocins; Cell Line; Membrane Microdomains; Phosphatidylethanolamines; Virus Diseases; Viruses
PubMed: 31666384
DOI: 10.1128/JVI.01471-19 -
International Journal of Molecular... Dec 2023Madurastatins are a group of pentapeptides containing an oxazoline moiety, and, in a few cases, an imidazolidinone ring as an additional structural feature. In our...
Madurastatins are a group of pentapeptides containing an oxazoline moiety, and, in a few cases, an imidazolidinone ring as an additional structural feature. In our search for new potential antiparasitic metabolites from natural sources, we studied the acetone extracts from a culture of sp. CA-135719. The LC/HRMS analysis of this extract identified the presence of the known madurastatins C1 (), D1 (), and D2 () together with additional members of the family that were identified as the new madurastatins H2 () and 33--D1 () after isolation and spectroscopic analysis. The planar structures of the new compounds were established by HRMS, ESI-qTOF-MS/MS, and 1D and 2D NMR data, and their absolute configuration was proposed using Marfey's and bioinformatic analyses of the biosynthetic gene cluster (BGC). A revision of the absolute configuration of madurastatins D1 and D2 is proposed. Additionally, madurastatins containing imidazolidinone rings are proved to be artifacts originating during acetone extraction of the bacterial cultures.
Topics: Solvents; Acetone; Biological Products; Tandem Mass Spectrometry; Antiparasitic Agents
PubMed: 38203471
DOI: 10.3390/ijms25010301 -
Systematic and Applied Microbiology Sep 2021Rpf protein, a kind of resuscitation promoting factor, was first found in the culture supernatant of Micrococcus luteus. It can resuscitate the growth of M. luteus in...
Rpf protein, a kind of resuscitation promoting factor, was first found in the culture supernatant of Micrococcus luteus. It can resuscitate the growth of M. luteus in "viable but non-culture, VBNC" state and promote the growth of Gram-positive bacteria with high G + C content. This paper investigates the resuscitating activity of M. luteus ACCC 41016 Rpf protein, which was heterologously expressed in E. coli, to cells of M. luteus ACCC 41016 and Rhodococcus marinonascens HBUM200062 in VBNC state, and examines the effect on the cultivation of actinobacteria in soil. The results showed that the recombinant Rpf protein had resuscitation effect on M. luteus ACCC 41016 and R. marinonascens HBUM200062 in VBNC state. 83 strains of actinobacteria, which were distributed in 9 families and 12 genera, were isolated from the experimental group with recombinant Rpf protein in the culture medium. A total of 41 strains of bacteria, which were distributed in 8 families and 9 genera, were isolated from the control group without Rpf protein. The experimental group showed richer species diversity than the control group. Two rare actinobacteria, namely HBUM206391 and HBUM206404, were obtained in the experimental group supplemented with Rpf protein. Both may be potential new species of Actinomadura and Actinokineospora, indicating that the recombinant expression of M. luteus ACCC 41016 Rpf protein can effectively promote the isolation and culture of actinobacteria in soil.
Topics: Actinobacteria; Bacterial Proteins; Cytokines; Escherichia coli; Micrococcus luteus; Rhodococcus; Soil Microbiology
PubMed: 34343788
DOI: 10.1016/j.syapm.2021.126234 -
Transactions of the Royal Society of... Apr 2021Actinomycetoma is a chronic granulomatous infection that follows traumatic implantation. Thoracic actinomycetoma (TA) is rare and may lead to severe complications.
BACKGROUND
Actinomycetoma is a chronic granulomatous infection that follows traumatic implantation. Thoracic actinomycetoma (TA) is rare and may lead to severe complications.
METHODS
A retrospective study of cases of TA diagnosed from 1985 to 2019 was carried out. Each case underwent direct examination, culture and biopsy.
RESULTS
Sixty-four cases (12.8%) were included, with a male predominance (84.3%); the main occupation was peasant farmer (71.8%) and the main site was the back (76.5%). Vertebral involvement was observed in 21.8% and pulmonary involvement in 7.8%. Nocardia brasiliensis was the main aetiological agent (53 cases, 74.5%).
CONCLUSIONS
TA is a poorly studied disease that can cause neurological and lung complications.
Topics: Biopsy; Female; Humans; Male; Mycetoma; Nocardia; Retrospective Studies
PubMed: 33690859
DOI: 10.1093/trstmh/trab037 -
Environmental Science and Pollution... Dec 2021Vermicompost was used as an additive in swine manure composting to investigate the expression of bacterial functional genes on nutrients biotransformation. Three...
Vermicompost was used as an additive in swine manure composting to investigate the expression of bacterial functional genes on nutrients biotransformation. Three treatments with vermicompost compositions of 10%, 20%, and 30% in swine manure were set up. Raw manure was used as the control. The thermophilic period increased to 12 days, the NH -N/NO -N ratio decreased to 0.85, and the germination index (GI) increased to 166% after vermicompost addition. Furthermore, higher relative abundances of Firmicutes were observed in the substrate during the initial stages of experiment. The abundance of the dominant phylum Proteobacteria and its related pathogenic genera Acinetobacter and Stenotrophomonas decreased in the thermophilic stage while the potentially beneficial genera Actinomadura and Chryseolinea increased. The expression of primary functional genes associated with the metabolism of carbohydrates, amino acids, xenobiotics, and fatty acids was enhanced during the thermophilic phase. Besides, most dominant genera showed strengthened correlations with NO-N and GI, which were the strongest environmental factors for bacterial communities. Network analysis revealed a new metabolic pathway associated with dominant genera Pseudomonas, Acinetobacter, Stenotrophomonas, and Oceanobacter, whose abundance increased with vermicompost addition. Collectively, the results of this study indicate that vermicompost can promote composting efficiency by increasing the potentially beneficial bacteria, decreasing pathogenic bacteria, and enhancing the metabolic capacity of bacterial communities.
Topics: Animals; Bacteria; Composting; Genes, Bacterial; Manure; Soil; Swine
PubMed: 34322803
DOI: 10.1007/s11356-021-14498-x -
Transactions of the Royal Society of... Apr 2021Mycetoma is a localized, chronic, granulomatous disease that can be caused by fungi (eumycetoma) or bacteria (actinomycetoma). Of the 70 different causative agents...
Mycetoma is a localized, chronic, granulomatous disease that can be caused by fungi (eumycetoma) or bacteria (actinomycetoma). Of the 70 different causative agents implicated in mycetoma worldwide, Actinomadura madurae is the only one that causes multiple cases on all continents. Recently, new Actinomadura species were described as causative agents of human mycetoma. One of these new causative agents was Actinomadura mexicana, which was identified in Latin America. Here we demonstrate that this causative agent is not confined to Latin America and that it is also a causative agent of actinomycetoma in Sudan. The disease was managed by antibiotic treatment alone and resulted in complete cure after 6 months of treatment, which is quick when compared with actinomycetoma cases caused by other Actinomadura species.
Topics: Actinomadura; Anti-Bacterial Agents; Humans; Mycetoma; Sudan
PubMed: 33382899
DOI: 10.1093/trstmh/traa145 -
MSphere Mar 2021, one of the largest bacterial phyla, are ubiquitous in many of Earth's ecosystems and often act as defensive symbionts with animal hosts. Members of the phylum have...
, one of the largest bacterial phyla, are ubiquitous in many of Earth's ecosystems and often act as defensive symbionts with animal hosts. Members of the phylum have repeatedly been isolated from basidiomycete-cultivating fungus-farming termites that maintain a monoculture fungus crop on macerated dead plant substrate. The proclivity for antimicrobial and enzyme production of make them likely contributors to plant decomposition and defense in the symbiosis. To test this, we analyzed the prophylactic (biosynthetic gene cluster [BGC]) and metabolic (carbohydrate-active enzyme [CAZy]) potential in 16 (10 existing and six new genomes) termite-associated and compared these to the soil-dwelling close relatives. Using antiSMASH, we identified 435 BGCs, of which 329 (65 unique) were similar to known compound gene clusters, while 106 were putatively novel, suggesting ample prospects for novel compound discovery. BGCs were identified among all major compound categories, including 26 encoding the production of known antimicrobial compounds, which ranged in activity (antibacterial being most prevalent) and modes of action that might suggest broad defensive potential. Peptide pattern recognition analysis revealed 823 (43 unique) CAZymes coding for enzymes that target key plant and fungal cell wall components (predominantly chitin, cellulose, and hemicellulose), confirming a substantial degradative potential of these bacteria. Comparison of termite-associated and soil-dwelling bacteria indicated no significant difference in either BGC or CAZy potential, suggesting that the farming termite hosts may have coopted these soil-dwelling bacteria due to their metabolic potential but that they have not been subject to genome change associated with symbiosis. have repeatedly been isolated in fungus-farming termites, and our genome analyses provide insights into the potential roles they may serve in defense and for plant biomass breakdown. These insights, combined with their relatively higher abundances in fungus combs than in termite gut, suggest that they are more likely to play roles in fungus combs than in termite guts. Up to 25% of the BGCs we identify have no similarity to known clusters, indicating a large potential for novel chemistry to be discovered. Similarities in metabolic potential of soil-dwelling and termite-associated bacteria suggest that they have environmental origins, but their consistent presence with the termite system suggests their importance for the symbiosis.
Topics: Actinobacteria; Animals; Fungi; Genome, Bacterial; Genomics; Isoptera; Multigene Family; Phylogeny; Symbiosis
PubMed: 33658277
DOI: 10.1128/mSphere.01233-20 -
Environmental Microbiology Dec 2023The herbicide glyphosate has several potential entry points into composting sites and its impact on composting processes has not yet been evaluated. To assess its impact...
The herbicide glyphosate has several potential entry points into composting sites and its impact on composting processes has not yet been evaluated. To assess its impact on bacterial diversity and abundance as well as on community composition and dynamics, we conducted a mesocosm experiment at the Montreal Botanical Garden. Glyphosate had no effect on physicochemical property evolution during composting, while it was completely dissipated by the end of the experiment. Sampling at Days 0, 2, 28 and 112 of the process followed by 16S rRNA amplicon sequencing also found no effect of glyphosate on species richness and community composition. Differential abundance analyses revealed an increase of a few taxa in the presence of glyphosate, namely TRA3-20 (order Polyangiales), Pedosphaeraceae and BIrii41 (order Burkholderiales) after 28 days. In addition, five amplicon sequence variants (ASVs) had lower relative abundance in the glyphosate treatment compared to the control on Day 2, namely Comamonadaceae, Pseudomonas sp., Streptomyces sp., Thermoclostridium sp. and Actinomadura keratinilytica, while two ASVs were less abundant on Day 112, namely Pedomicrobium sp. and Pseudorhodoplanes sp. Most differences in abundance were measured between the different sampling points within each treatment. These results present glyphosate as a poor determinant of species recruitment during composting.
Topics: Glyphosate; Composting; RNA, Ribosomal, 16S; Herbicides; Streptomyces
PubMed: 36975075
DOI: 10.1111/1462-2920.16374 -
Antiviral Research May 2020Acute lower respiratory tract infections (ALRI) caused by respiratory syncytial virus (RSV) are associated with a severe disease burden among infants and elderly...
Acute lower respiratory tract infections (ALRI) caused by respiratory syncytial virus (RSV) are associated with a severe disease burden among infants and elderly patients. Treatment options are limited. While numerous drug candidates with different viral targets are under development, the utility of RSV entry inhibitors is challenged by a low resistance barrier and by single mutations causing cross-resistance against a wide spectrum of fusion inhibitor chemotypes. We developed a cell-based screening assay for discovery of compounds inhibiting infection with primary RSV isolates. Using this system, we identified labyrinthopeptin A1 and A2 (Laby A1/A2), lantibiotics isolated from Actinomadura namibiensis, as effective RSV cell entry inhibitors with ICs of 0.39 μM and 4.97 μM, respectively, and with favourable therapeutic index (>200 and > 20, respectively). Both molecules were active against multiple RSV strains including primary isolates and their antiviral activity against RSV was confirmed in primary human airway cells ex vivo and a murine model in vivo. Laby A1/A2 were antiviral in prophylactic and therapeutic treatment regimens and displayed synergistic activity when applied in combination with each other. Mechanistic studies showed that Laby A1/A2 exert virolytic activity likely by binding to phosphatidylethanolamine moieties within the viral membrane and by disrupting virus particle membrane integrity. Probably due to its specific mode of action, Laby A1/A2 antiviral activity was not affected by common resistance mutations to known RSV entry inhibitors. Taken together, Laby A1/A2 represent promising candidates for development as RSV inhibitors. Moreover, the cell-based screening system with primary RSV isolates described here should be useful to identify further antiviral agents.
Topics: Animals; Antiviral Agents; Bacteriocins; Cell Line; Cells, Cultured; Female; Humans; Lung; Mice; Mice, Inbred BALB C; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Virus Internalization
PubMed: 32197980
DOI: 10.1016/j.antiviral.2020.104774