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International Journal of Systematic and... Sep 2023Two novel Gram-positive bacteria designated as strains STR2 and STR3 were isolated from the rhizosphere of a sample collected from Goyang-si, Republic of Korea. Strains...
Two novel Gram-positive bacteria designated as strains STR2 and STR3 were isolated from the rhizosphere of a sample collected from Goyang-si, Republic of Korea. Strains STR2 and STR3 were aerobic, rod shaped, non-sporulated, catalase negative, oxidase negative and non-motile bacteria. They grew at 15-37 °C (optimum, 25-30 °C), at pH 6.0-11.0 (optimum, pH 7.0) and in the presence of 0-2% NaCl (optimum, 0 %, w/v). The chemotaxonomic and morphological characteristics of the novel strains were consistent with those of the members of . The phylogenetic analysis of the 16S rRNA gene sequences revealed that STR2 was closely related to YIM A1136 (99.3 %) and Y4 (99.1 %), and STR3 was closely related to DSM 22017 (99.0 %), G10 (98.8 %) and HFW-21 (98.7 %). The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values of STR2 and STR3 with the most closely related strains that have publicly available whole genomes were 83.1-89.8 %, 80.9-89.6% and 26.2-39.1 %, respectively. The cell-wall peptidoglycan of strain STR2 and STR3 contained ll-diaminopimelic acid as the diagnostic amino acid. The major fatty acids in STR2 and STR3 were iso-C and C ω8, and the predominant quinone was MK-8(H). Their polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and other polar lipids. The draft genome sequences showed that the genomic DNA G+C content of STR2 and STR3 were both 72.2 mol%. Physiological and biochemical tests and 16S rRNA sequence analysis clearly revealed that STR2 and STR3 could represent novel species. Their proposed names were as follows: sp. nov. for strain STR2 (=KACC 22784=TBRC 16336) and sp. nov. for strain STR3 (= KACC 22785=TBRC 16337).
Topics: Actinobacteria; Nocardioides; Actinomyces; Pinus; Phylogeny; RNA, Ribosomal, 16S; Base Composition; Fatty Acids; Sequence Analysis, DNA; DNA, Bacterial; Bacterial Typing Techniques; Amino Acids
PubMed: 37755157
DOI: 10.1099/ijsem.0.006062 -
BMJ Case Reports Sep 2023Actinomycosis is a rare chronic infection, caused by species of the bacterium spp. This report proposes oral breast trauma as a cause of infection. An adult female in...
Actinomycosis is a rare chronic infection, caused by species of the bacterium spp. This report proposes oral breast trauma as a cause of infection. An adult female in her 30s presented with a recurrent left breast abscess to a local hospital. She had previously undergone nine operations for abscess in the past 2 years. Shortly prior to her first presentation, a sexual partner with reported dental infection bit her periareolar area. The treating team noted that her bacterial culture from the first operation was positive for spp. She was treated with long-term intravenous antibiotics and had no further recurrences of infection. Oral trauma to the periareolar area by an individual with pre-existing dental disease has led to the introduction and establishment of this pathogen in the ductal system of the breast. This infection should be considered in cases of treatment resistant recurrent breast abscess.
Topics: Female; Adult; Humans; Abscess; Breast; Mastitis; Actinomycetaceae; Empyema, Pleural; Thoracic Injuries
PubMed: 37723094
DOI: 10.1136/bcr-2022-253472 -
Clinical Pediatrics Feb 2024
Topics: Humans; Empyema; Actinomycetaceae; Actinomycosis
PubMed: 37698129
DOI: 10.1177/00099228231200090 -
Journal of Industrial Microbiology &... Feb 2023Bacteria have long been a source of natural products with diverse bioactivities that have been developed into therapeutics to treat human disease. Historically,...
UNLABELLED
Bacteria have long been a source of natural products with diverse bioactivities that have been developed into therapeutics to treat human disease. Historically, researchers have focused on a few taxa of bacteria, mainly Streptomyces and other actinomycetes. This strategy was initially highly successful and resulted in the golden era of antibiotic discovery. The golden era ended when the most common antibiotics from Streptomyces had been discovered. Rediscovery of known compounds has plagued natural product discovery ever since. Recently, there has been increasing interest in identifying other taxa that produce bioactive natural products. Several bioinformatics studies have identified promising taxa with high biosynthetic capacity. However, these studies do not address the question of whether any of the products produced by these taxa are likely to have activities that will make them useful as human therapeutics. We address this gap by applying a recently developed machine learning tool that predicts natural product activity from biosynthetic gene cluster (BGC) sequences to determine which taxa are likely to produce compounds that are not only novel but also bioactive. This machine learning tool is trained on a dataset of BGC-natural product activity pairs and relies on counts of different protein domains and resistance genes in the BGC to make its predictions. We find that rare and understudied actinomycetes are the most promising sources for novel active compounds. There are also several taxa outside of actinomycetes that are likely to produce novel active compounds. We also find that most strains of Streptomyces likely produce both characterized and uncharacterized bioactive natural products. The results of this study provide guidelines to increase the efficiency of future bioprospecting efforts.
ONE-SENTENCE SUMMARY
This paper combines several bioinformatics workflows to identify which genera of bacteria are most likely to produce novel natural products with useful bioactivities such as antibacterial, antitumor, or antifungal activity.
Topics: Humans; Multigene Family; Actinobacteria; Computational Biology; Actinomyces; Biological Products
PubMed: 37653463
DOI: 10.1093/jimb/kuad024 -
Scientific Reports Aug 2023Trueperella pecoris was described as a new species of the genus Trueperella in 2021 and might be pathogenic to various animal species. However, the lack of a suitable...
Trueperella pecoris was described as a new species of the genus Trueperella in 2021 and might be pathogenic to various animal species. However, the lack of a suitable diagnostic test system stands in the way of epidemiological surveys to clarify possible causalities. In this study, a Loop-mediated Isothermal Amplification (LAMP) assay was developed and validated that was highly specific for T. pecoris. The assay provided an analytical sensitivity of 0.5 pg/25 µL and showed 100% inclusivity and exclusivity for 11 target and 33 non-target strains, respectively. Three different DNA extraction methods were evaluated to select the most LAMP-compatible method for cell disruption in pure and complex samples. Using an on-site applicable single-buffer DNA extraction with additional heating, the cell-based detection limit was 2.3 CFU/reaction. Finally, the LAMP assay was validated by means of artificially contaminated porcine lung tissue samples in which minimal microbial loads between 6.54 and 8.37 × 10 CFU per swab sample were detectable. The LAMP assay established in this study represents a suitable diagnostic procedure for identifying T. pecoris in clinical specimens and will help to collect epidemiological data on the pathogenicity of this species.
Topics: Animals; Swine; Actinomycetaceae; Biological Assay; Cell Membrane; Heating
PubMed: 37635174
DOI: 10.1038/s41598-023-40787-1 -
The Lancet. Infectious Diseases Sep 2023
Topics: Humans; Actinomyces; Abdomen
PubMed: 37625860
DOI: 10.1016/S1473-3099(23)00182-2 -
Journal of Endodontics Nov 2023The extrusion of bacteria from infected root canals may lead to increase in symptoms, expansion of periapical lesions, and contribution to systemic diseases. The aim of...
INTRODUCTION
The extrusion of bacteria from infected root canals may lead to increase in symptoms, expansion of periapical lesions, and contribution to systemic diseases. The aim of this study is to investigate a potential proof-of-concept model to study the extent to which bacteria can escape from infected root canals under dynamic loading (simulated chewing).
METHODS
The study was completed in 2 experiments performed at 2 institutions. Biofilms of Streptococcus intermedius in the first experiment and S. intermedius and Actinomyces naeslundii were allowed to grow in root canals of single-rooted extracted teeth for 3 weeks. The roots of the teeth were suspended in a small chamber containing dental transport medium and were mounted on a lower sample holder of a chewing simulator. In the experimental group, simulated chewing cycles equivalent to 1 year of function were conducted, and then bacterial migration was quantified and compared with stationary teeth.
RESULTS
All experimental samples of the loading group revealed bacterial penetration in both experiments. Several of the unloaded samples revealed no bacterial penetration. In the first experiment, a significantly higher number of bacteria were able to escape into the periapex of the loaded group compared with the unloaded group (P = .017). In the second experiment, there was no significant difference between the 2 bacterial species used in the amount of extruded bacteria; however, there was a highly significant effect for occlusal loading (P = .0001).
CONCLUSIONS
The potential for occlusal forces to enhance bacterial extrusion from infected root canals should be further explored.
Topics: Dental Pulp Cavity; Humans; Mastication; Biofilms; Actinomyces; Streptococcus intermedius; In Vitro Techniques
PubMed: 37611655
DOI: 10.1016/j.joen.2023.08.008 -
European Journal of Dermatology : EJD Jun 2023
Topics: Animals; Humans; Male; Actinomyces; Horses; Bites and Stings
PubMed: 37594340
DOI: 10.1684/ejd.2023.4492 -
Molecules (Basel, Switzerland) Aug 2023Actinomycetes inhabit both terrestrial and marine ecosystems and are highly proficient in producing a wide range of natural products with diverse biological functions,... (Review)
Review
Actinomycetes inhabit both terrestrial and marine ecosystems and are highly proficient in producing a wide range of natural products with diverse biological functions, including antitumor, immunosuppressive, antimicrobial, and antiviral activities. In this review, we delve into the life cycle, ecology, taxonomy, and classification of actinomycetes, as well as their varied bioactive metabolites recently discovered between 2015 and 2023. Additionally, we explore promising strategies to unveil and investigate new bioactive metabolites, encompassing genome mining, activation of silent genes through signal molecules, and co-cultivation approaches. By presenting this comprehensive and up-to-date review, we hope to offer a potential solution to uncover novel bioactive compounds with essential activities.
Topics: Actinobacteria; Actinomyces; Ecosystem; Anti-Infective Agents; Biological Products
PubMed: 37570885
DOI: 10.3390/molecules28155915 -
Journal of the American Chemical Society Aug 2023The unique bioactivities of arsenic-containing secondary metabolites have been revealed recently, but studies on arsenic secondary metabolism in microorganisms have been...
The unique bioactivities of arsenic-containing secondary metabolites have been revealed recently, but studies on arsenic secondary metabolism in microorganisms have been extremely limited. Here, we focused on the organoarsenic metabolite with an unknown chemical structure, named bisenarsan, produced by well-studied model actinomycetes and elucidated its structure by combining feeding of the putative biosynthetic precursor (2-hydroxyethyl)arsonic acid to 1326 and detailed NMR analyses. Bisenarsan is the first characterized actinomycete-derived arsenic secondary metabolite and may function as a prototoxin form of an antibacterial agent or be a detoxification product of inorganic arsenic species. We also verified the previously proposed genes responsible for bisenarsan biosynthesis, especially the (2-hydroxyethyl)arsonic acid moiety. Notably, we suggest that a C-As bond in bisenarsan is formed by the intramolecular rearrangement of a pentavalent arsenic species (arsenoenolpyruvate) by the cofactor-independent phosphoglycerate mutase homologue BsnN, that is entirely distinct from the conventional biological C-As bond formation through As-alkylation of trivalent arsenic species by -adenosylmethionine-dependent enzymes. Our findings will speed up the development of arsenic natural product biosynthesis.
Topics: Arsenic; Secondary Metabolism; Actinobacteria; Actinomyces; S-Adenosylmethionine
PubMed: 37534495
DOI: 10.1021/jacs.3c04978