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The Pediatric Infectious Disease Journal Jul 2021
Review
Topics: Anti-Bacterial Agents; Child; Endocarditis, Bacterial; Female; Humans; Micrococcus luteus; Pulmonary Infarction; Tomography, X-Ray Computed
PubMed: 34097668
DOI: 10.1097/INF.0000000000003133 -
Journal of Applied Microbiology Nov 2022To reveal the antibacterial mechanism of protocatechuic acid (PCA) against Micrococcus luteus.
AIM
To reveal the antibacterial mechanism of protocatechuic acid (PCA) against Micrococcus luteus.
METHODS AND RESULTS
M. luteus was exposed to PCA, and the antibacterial mechanism was revealed by measuring membrane potential, intracellular ATP and pH levels and transcriptome analysis. PCA induced the membrane potential depolarization of M. luteus, significantly decreased the intracellular ATP and pH levels of M. luteus and disrupted the integrity of the M. luteus cell membrane. Transcriptome analysis showed that PCA induced 782 differentially expressed genes (DEGs) of M. luteus. GO enrichment analysis revealed that the majority of DEGs are involved in pathways of metabolic process, cellular process, biological regulation and transport activity. In addition, PCA inhibited the growth of M. luteus in skimmed milk and extended the shelf life of skimmed milk.
CONCLUSION
PCA had good bactericidal activity against M. luteus through the mechanism of cell membrane disruption and metabolic process disorder.
SIGNIFICANCE AND IMPACT OF THE STUDY
PCA inhibits the growth of M. luteus in skimmed milk, suggesting that PCA is promising to be used as a novel preservative in food storage.
Topics: Micrococcus luteus; Gene Expression Profiling; Anti-Bacterial Agents; Adenosine Triphosphate; Micrococcus
PubMed: 35996816
DOI: 10.1111/jam.15743 -
Archives of Microbiology Jun 2022Biodegradation is the most promising environmentally sustainable method that offers a significant opportunity with minimal negative environmental consequences while...
Biodegradation is the most promising environmentally sustainable method that offers a significant opportunity with minimal negative environmental consequences while searching for solutions to this global problem of plastic pollution that has now spread to almost everywhere in the entire world. In the present work, HDPE-degrading bacterial strain CGK112 was isolated from the fecal matter of a cow. The bacterial strain was identified as Micrococcus luteus CGK112 by 16S rRNA sequence coding analysis. Significant weight loss, i.e., 3.85% was recorded in the HDPE film treated with strain CGK112 for 90 days. The surface micromorphology was examined using FE-SEM, which revealed spectacular bacterial colonization as well as structural deformation. Furthermore, the EDX study indicated a significant decrease in the atomic percentage of carbon content, whereas FTIR analysis confirmed functional groups alternation as well as an increase in the carbonyl index which can be attributed to the metabolic activity of biofilm. Our findings provide insight into the capacity of our strain CGK112 to colonize and utilize HDPE as a single carbon source, thus promoting its degradation.
Topics: Animals; Bacteria; Biodegradation, Environmental; Biofilms; Carbon; Cattle; Female; Micrococcus luteus; Polyethylene; RNA, Ribosomal, 16S; Spectroscopy, Fourier Transform Infrared
PubMed: 35718788
DOI: 10.1007/s00203-022-03023-4 -
Carbohydrate Research Aug 2021Glycopolymers of two types were isolated from the cell wall of Micrococcus luteus C01 by stepwise extraction with cold and hot 10% aq CClCOH. The following structures of...
Glycopolymers of two types were isolated from the cell wall of Micrococcus luteus C01 by stepwise extraction with cold and hot 10% aq CClCOH. The following structures of the glycopolymers were established by compositional analysis and 1D and 2D NMR spectroscopy: where L-Glu indicates glutamic acid.
Topics: Cell Wall; Micrococcus luteus
PubMed: 34087653
DOI: 10.1016/j.carres.2021.108356 -
Experimental & Molecular Medicine Jan 2023Bacterial extracellular vesicles (EVs) have been shown to regulate various pulmonary diseases, but their functions in asthma remain uncertain. To demonstrate the...
Bacterial extracellular vesicles (EVs) have been shown to regulate various pulmonary diseases, but their functions in asthma remain uncertain. To demonstrate the clinical significance of Micrococcus luteus-derived EVs (MlEVs) in asthma, we enrolled 45 asthmatic patients (20 patients with neutrophilic asthma [NA], 25 patients with eosinophilic asthma [EA]) and 40 healthy controls (HCs). When the prevalence of IgG1 and IgG4 specific to MlEVs was evaluated in serum by ELISA, lower levels of MlEV-specific IgG4 (but not IgG1) were noted in asthmatic patients than in HCs. Among asthmatic patients, significantly lower levels of MIEV-specific IgG4 were noted in patients with NA than in those with EA. Moreover, there was a positive correlation between serum MlEV-specific IgG4 levels and FEV (%) values. In asthmatic C57BL/6 mice, MlEVs significantly attenuated neutrophilic airway inflammation by reducing the production of IL-1β and IL-17 in bronchoalveolar lavage fluid as well as the number of group 3 innate lymphoid cells (ILC3s) in lung tissues. To clarify the functional mechanism of MlEVs in NA, the effect of MlEVs on airway epithelial cells (AECs) and immune cells was investigated ex vivo. According to microarray analysis, MlEVs upregulated hsa-miR-4517 expression in AECs. Moreover, this miRNA could suppress IL-1β production by monocytes, resulting in the inhibition of ILC3 activation and neutrophil recruitment. These findings suggest that MlEVs could be a novel therapeutic agent for managing unresolved NA by regulating miRNA expression in AECs.
Topics: Mice; Animals; MicroRNAs; Micrococcus luteus; Immunity, Innate; Mice, Inbred C57BL; Lymphocytes; Asthma; Bronchoalveolar Lavage Fluid; Epithelial Cells; Extracellular Vesicles; Disease Models, Animal
PubMed: 36639716
DOI: 10.1038/s12276-022-00910-0 -
Insect Biochemistry and Molecular... Aug 2022Melanization is a key immune response mediated by serine protease (SP) cascade in insects. Multiple SP pathways exist in different species and it is unclear how...
Melanization is a key immune response mediated by serine protease (SP) cascade in insects. Multiple SP pathways exist in different species and it is unclear how conserved these cascades are. The cotton bollworm Helicoverpa armigera is a major worldwide agricultural pest. We reported a conserved melanization pathway in this species, which consists of SP41, cSP1, and cSP6. In this study, we attempted to identify an insect pathogen that elicits the cascade and test whether or not there are other SP cascades in H. armigera. After Micrococcus luteus, Enterobacter cloacae, Beauveria bassiana, or Helicoverpa armigera nucleopolyhedrovirus were injected into larvae, pathogen-induced hemolymph samples were collected for in vitro biochemical assays, which failed to detect proSP41 or procSP1 activation. In contrast, we found that procSP4, a protein proposed to participate in H. armigera melanization, was activated in M. luteus infected hemolymph. We further revealed that cSP8 was a prophenoloxidase (PPO) activating protease downstream of cSP4, and cSP4 was activated by cSP10. The pathway of cSP10-cSP4-cSP8 activated PPO in vitro. Efficiently cleaved procSPH11 and procSPH50 by cSP8 substantially enhanced phenoloxidase activity, suggesting they work together as a cofactor for cSP8 mediated PPO activation. Hemolymph from larvae challenged with M. luteus or its peptidoglycan effectively activated procSP10. Collectively, these results revealed a new PPO activation cascade specifically triggered by the bacterium. In addition, we found that the PPO activation cascades in H. armigera and Manduca sexta are conserved.
Topics: Animals; Catechol Oxidase; Enzyme Precursors; Hemolymph; Insect Proteins; Larva; Micrococcus luteus; Moths; Serine Endopeptidases; Serine Proteases
PubMed: 35504546
DOI: 10.1016/j.ibmb.2022.103775 -
Protoplasma Sep 2022The interaction of plant roots with bacteria is influenced by chemical signaling, where auxins play a critical role. Auxins exert positive or negative influences on the...
The interaction of plant roots with bacteria is influenced by chemical signaling, where auxins play a critical role. Auxins exert positive or negative influences on the plant traits responsible of root architecture configuration such as root elongation and branching and root hair formation, but how bacteria that modify the plant auxin response promote or repress growth, as well as root structure, remains unknown. Here, we isolated and identified via molecular and electronic microscopy analysis a Micrococcus luteus LS570 strain as a plant growth promoter that halts primary root elongation in Arabidopsis seedlings and strongly triggers root branching and absorptive potential. The root biomass was exacerbated following root contact with bacterial streaks, and this correlated with inducible expression of auxin-related gene markers DR5:GUS and DR5:GFP. Cellular and structural analyses of root growth zones indicated that the bacterium inhibits both cell division and elongation within primary root tips, disrupting apical dominance, and as a consequence differentiation programs at the pericycle and epidermis, respectively, triggers the formation of longer and denser lateral roots and root hairs. Using Arabidopsis mutants defective on auxin signaling elements, our study uncovers a critical role of the auxin response factors ARF7 and ARF19, and canonical auxin receptors in mediating both the primary root and lateral root response to M. luteus LS570. Our report provides very basic information into how actinobacteria interact with plants and direct evidence that the bacterial genus Micrococcus influences the cellular and physiological plant programs ultimately responsible of biomass partitioning.
Topics: Arabidopsis; Arabidopsis Proteins; Gene Expression Regulation, Plant; Indoleacetic Acids; Micrococcus luteus; Plant Roots
PubMed: 34792622
DOI: 10.1007/s00709-021-01724-z -
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 -
International Journal of Systematic and... Nov 2019, and are phenotypically and genotypically closely related, and together comprise the group. In this study, the taxonomic relationships among , and were...
, and are phenotypically and genotypically closely related, and together comprise the group. In this study, the taxonomic relationships among , and were re-evaluated by using polyphasic approaches. The similarity values of the concatenated housekeeping gene (, and ) sequences shared by the type strains of , and ranged from 98.3 to 99.4 %. The average nucleotide identity, average amino acid identity and digital DNA‒DNA hybridization values among these three taxa were greater (97.1‒98.1 %, 96.8‒98.1 % and 75.0‒83.5 %, respectively) than the thresholds for bacterial species delineation, indicating that they belong to the same species, whereas those for were clearly lower than the thresholds. In addition, phenotypic and chemotaxonomic characterization results also support the synonymy of these three taxa. Therefore, we propose that and should be reclassified as later heterotypic synonyms of .
Topics: Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Fatty Acids; Genes, Bacterial; Micrococcus; Micrococcus luteus; Nucleic Acid Hybridization; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 31454307
DOI: 10.1099/ijsem.0.003654 -
Polski Merkuriusz Lekarski : Organ... Dec 2022In order to effectively protect from dangerous infectious agents, as well as coronavirus, the scientists of I. Horbachevsky Ternopil national medical university...
UNLABELLED
In order to effectively protect from dangerous infectious agents, as well as coronavirus, the scientists of I. Horbachevsky Ternopil national medical university (Ukraine) developed a unique prototype of a mobile respiratory protection system with positive airflow - pneumatic helmet.
AIM
To evaluate the bacterial permeability of the proposed concept model of the pneumohelmet in full and partial configuration.
MATERIALS AND METHODS
With a generating device (compressor inhaler) an aerosol is created from bacterial suspension, which is directed to the inlet of the personal protective respiratory equipment. The outlet is directed at a Petri dish with meat-peptone broth. Evaluation of bacterial contamination is performed by calculating the colony-forming units by multiplying the indicator by the degree of dilution. The study is repeated with a partial configuration of the pneumatic helmet - the presence of only external, only internal filter or not using any filter components.
RESULTS
The growth of Micrococcus luteus colonies on the placed nutrient medium when using the proposed conceptual model of the pneumatic helmet in full configuration was not obtained. Removal of the inner filter did not lead to a violation of the effectiveness of antibacterial protection, as bacteria were detected only on the outer side of filter No.2. The use of a conceptual model without filters made it possible to detect colonies of Micrococcus luteus on the medium and components of the device with the calculation of colony forming units in 3- and 4-fold dilutions. During 24 hours of operation, the bacterial load on the surface of the external filter increased significantly. However, no signs of malfunction of the pneumatic helmet were detected.
CONCLUSIONS
The given results confirm the ability of the pneumatic helmet to counteract the penetration of bacteria from the environment during 6, 12, 24 hours of continuous operation. The protection was preserved even with partial configuration, which indicates the presence of a margin of reliability of this system.
Topics: Humans; Micrococcus luteus; Head Protective Devices; Reproducibility of Results; Bacteria
PubMed: 36645679
DOI: No ID Found