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Frontiers in Immunology 2024The immune memory is one of the defensive strategies developed by both unicellular and multicellular organisms for ensuring their integrity and functionality. While the... (Review)
Review
The immune memory is one of the defensive strategies developed by both unicellular and multicellular organisms for ensuring their integrity and functionality. While the immune memory of the vertebrate adaptive immune system (based on somatic recombination) is antigen-specific, encompassing the generation of memory T and B cells that only recognize/react to a specific antigen epitope, the capacity of vertebrate innate cells to remember past events is a mostly non-specific mechanism of adaptation. This "innate memory" can be considered as germline-encoded because its effector tools (such as innate receptors) do not need somatic recombination for being active. Also, in several organisms the memory-related information is integrated in the genome of germline cells and can be transmitted to the progeny for several generations, but it can also be erased depending on the environmental conditions. Overall, depending on the organism, its environment and its living habits, innate immune memory appears to be a mechanism for achieving better protection and survival against repeated exposure to microbes/stressful agents present in the same environment or occurring in the same anatomical district, able to adapt to changes in the environmental cues. The anatomical and functional complexity of the organism and its lifespan drive the generation of different immune memory mechanisms, for optimal adaptation to changes in the living/environmental conditions. The concept of innate immunity being non-specific needs to be revisited, as a wealth of evidence suggests a significant degree of specificity both in the primary immune reaction and in the ensuing memory-like responses. This is clearly evident in invertebrate metazoans, in which distinct scenarios can be observed, with both non-specific (immune enhancement) or specific (immune priming) memory-like responses. In the case of mammals, there is evidence that some degree of specificity can be attained in different situations, for instance as organ-specific protection rather than microorganism-specific reaction. Thus, depending on the challenges and conditions, innate memory can be non-specific or specific, can be integrated in the germline and transmitted to the progeny or be short-lived, thereby representing an exceptionally plastic mechanism of defensive adaptation for ensuring individual and species survival.
Topics: Animals; Immunologic Memory; Immunity, Innate; Humans; Germ Cells; Adaptation, Physiological
PubMed: 38903500
DOI: 10.3389/fimmu.2024.1386578 -
Annals of Clinical Microbiology and... Jun 2024The aim of this study was to evaluate the characteristics of immunocyte associated with bloodstream infection (BSI) caused by Klebsiella pneumoniae (Kpn).
OBJECTIVES
The aim of this study was to evaluate the characteristics of immunocyte associated with bloodstream infection (BSI) caused by Klebsiella pneumoniae (Kpn).
METHODS
Patients with BSI-Kpn were included from 2015 to 2022 in our hospital. Immunocyte subpopulations of enrolled BSI-Kpn patients were tested on the same day of blood culture using multicolor flow cytometry analysis. Antibiotic susceptibility test was determined by agar dilution or broth dilution method. All included isolates were subjected to whole genome sequencing and comparative genomics analysis. Clinical and genetic data were integrated to investigate the risk factors associated with clinical outcome.
RESULTS
There were 173 patients with non-duplicate BSI-Kpn, including 81 carbapenem-resistant Kpn (CRKP), 30 extended-spectrum β-lactamases producing Kpn (ESBL-Kpn), 62 none CRKP or ESBL-Kpn (S-Kpn). Among 68 ST11-CRKP isolates, ST11-O2v1:KL64 was the most common serotypes cluster (77.9%, 53/68), followed by ST11-OL101: KL47 (13.2%, 9/68). Compared with CSKP group, subpopulations of immunocyte in patients with CRKP were significantly lower (P < 0.01). In patients with ST11-O2v1:KL64 BSI-Kpn, the level of cytotoxic T lymphocytes (CD3 + CD8 +) is the highest, while the B lymphocytes (CD3-CD19 +) was the least. In addition, the level of immunocyte in patients with Kpn co-harbored clpV-ybtQ-qacE were lower than that in patients with Kpn harbored one of clpV, ybtQ or qacE and without these three genes. Furthermore, co-existence of clpV-ybtQ-qacE was independently associated with a higher risk for 30-day mortality.
CONCLUSIONS
The results demonstrate that patients with BSI-CRKP, especially for ST11-O2v1:KL64, exhibit lower leukomonocyte counts. In addition, BSI-Kpn co-harbored clpV-ybtQ-qacE is correlated to higher 30-day mortality.
Topics: Humans; Klebsiella pneumoniae; Klebsiella Infections; Male; Female; Bacteremia; Middle Aged; Aged; beta-Lactamases; Anti-Bacterial Agents; Microbial Sensitivity Tests; Whole Genome Sequencing; Serogroup; Genomics; Adult; Aged, 80 and over; Carbapenems
PubMed: 38902832
DOI: 10.1186/s12941-024-00721-3 -
Microbial Cell Factories Jun 2024Chelerythrine is an important alkaloid used in agriculture and medicine. However, its structural complexity and low abundance in nature hampers either bulk chemical...
BACKGROUND
Chelerythrine is an important alkaloid used in agriculture and medicine. However, its structural complexity and low abundance in nature hampers either bulk chemical synthesis or extraction from plants. Here, we reconstructed and optimized the complete biosynthesis pathway for chelerythrine from (S)-reticuline in Saccharomyces cerevisiae using genetic reprogramming.
RESULTS
The first-generation strain Z4 capable of producing chelerythrine was obtained via heterologous expression of seven plant-derived enzymes (McoBBE, TfSMT, AmTDC, EcTNMT, PsMSH, EcP6H, and PsCPR) in S. cerevisiae W303-1 A. When this strain was cultured in the synthetic complete (SC) medium supplemented with 100 µM of (S)-reticuline for 10 days, it produced up to 0.34 µg/L chelerythrine. Furthermore, efficient metabolic engineering was performed by integrating multiple-copy rate-limiting genes (TfSMT, AmTDC, EcTNMT, PsMSH, EcP6H, PsCPR, INO2, and AtATR1), tailoring the heme and NADPH engineering, and engineering product trafficking by heterologous expression of MtABCG10 to enhance the metabolic flux of chelerythrine biosynthesis, leading to a nearly 900-fold increase in chelerythrine production. Combined with the cultivation process, chelerythrine was obtained at a titer of 12.61 mg per liter in a 0.5 L bioreactor, which is over 37,000-fold higher than that of the first-generation recombinant strain.
CONCLUSIONS
This is the first heterologous reconstruction of the plant-derived pathway to produce chelerythrine in a yeast cell factory. Applying a combinatorial engineering strategy has significantly improved the chelerythrine yield in yeast and is a promising approach for synthesizing functional products using a microbial cell factory. This achievement underscores the potential of metabolic engineering and synthetic biology in revolutionizing natural product biosynthesis.
Topics: Metabolic Engineering; Benzophenanthridines; Saccharomyces cerevisiae; Biosynthetic Pathways
PubMed: 38902758
DOI: 10.1186/s12934-024-02448-4 -
BMC Microbiology Jun 2024Rhizosphere bacterial community and endophytes are now known to influence plant health and response to environmental stress. Very few studies have reported the diversity...
BACKGROUND
Rhizosphere bacterial community and endophytes are now known to influence plant health and response to environmental stress. Very few studies have reported the diversity of endophytic bacterial communities of Vanilla planifolia and their potential roles in promoting plant growth or contributing to aromatic quality.
RESULTS
In this study, the composition and diversity of the Vanilla rhizosphere bacterial community were explored by analyzing rhizosphere soil and root tissue samples as well as green pods of three accessions of Vanilla planifolia grown on different types of substrates (compost and leaf litter). In addition, the endophytic bacterial diversity of roots and green pods as well as the evolution of endophytic bacteria after the curing process of vanilla green pods were analyzed based on a metabarcoding approach. The results showed that bacterial species richness and diversity were higher in the compost. The analysis of the soil bacterial composition displayed that Halomonas, Pseudoalteromonas, Enterobacter and Bradyrhizobium were the most abundant genera. Moreover, the results indicated that the soil bacterial community structure was linked to the host plant genotype. Regarding the roots endophytic bacteria composition, the genera Halomonas, Pseudoalteromonas, Bacillus and Carboxydocella genera were present in all samples, independently from the substrate nature. Several genera including Bacillus, Bradyrhizobium, Burkholderia and Halomonas were transmitted internally from the roots to the green pods. The curing process reduced the bacterial richness and bacterial diversity associated with the green pods. Halomonas, Pseudoalteromonas, Bacillus, and Carboxydocella are the dominant genera in the pods after the curing process.
CONCLUSIONS
This study provides an overview of changes of the bacterial communities dynamics especially endophytic in the roots and the green pods. It highlighted bacterial genera (Halomonas, Pseudoalteromonas, Bacillus, and Carboxydocella) potentially implicated in the formation of aroma compounds of vanilla beans.
Topics: Endophytes; Bacteria; Soil Microbiology; Plant Roots; Rhizosphere; Vanilla; Biodiversity; RNA, Ribosomal, 16S; Phylogeny; Microbiota; DNA, Bacterial
PubMed: 38902615
DOI: 10.1186/s12866-024-03362-w -
BMC Plant Biology Jun 2024Plant heterotrimeric G proteins respond to various environmental stresses, including high salinity. It is known that Gβ subunit AGB1 functions in maintaining local and...
BACKGROUND
Plant heterotrimeric G proteins respond to various environmental stresses, including high salinity. It is known that Gβ subunit AGB1 functions in maintaining local and systemic Na/K homeostasis to accommodate ionic toxicity under salt stress. However, whether AGB1 contributes to regulating gene expression for seedling's survival under high salinity remains unclear.
RESULTS
We showed that AGB1-Venus localized to nuclei when facing excessive salt, and the induction of a set of bZIP17-dependent salt stress-responsive genes was reduced in the agb1 mutant. We confirmed both genetic and physical interactions of AGB1 and bZIP17 in plant salinity response by comparing salt responses in the single and double mutants of agb1 and bzip17 and by BiFC assay, respectively. In addition, we show that AGB1 depletion decreases nuclei-localization of transgenic mRFP-bZIP17 under salt stress, as shown in s1p s2p double mutant in the Agrobacteria-mediated transient mRFP-bZIP17 expression in young seedlings.
CONCLUSIONS
Our results indicate that AGB1 functions in S1P and/or S2P-mediated proteolytic processing of bZIP17 under salt stress to regulate the induction of salinity-responsive gene expression.
Topics: Arabidopsis; Arabidopsis Proteins; GTP-Binding Protein beta Subunits; Basic-Leucine Zipper Transcription Factors; Unfolded Protein Response; Salinity; Salt Stress; Gene Expression Regulation, Plant; Seedlings
PubMed: 38902609
DOI: 10.1186/s12870-024-05296-x -
NPJ Biofilms and Microbiomes Jun 2024During the COVID-19 pandemic, facemasks played a pivotal role in preventing person-person droplet transmission of viral particles. However, prolonged facemask wearing...
During the COVID-19 pandemic, facemasks played a pivotal role in preventing person-person droplet transmission of viral particles. However, prolonged facemask wearing causes skin irritations colloquially referred to as 'maskne' (mask + acne), which manifests as acne and contact dermatitis and is mostly caused by pathogenic skin microbes. Previous studies revealed that the putative causal microbes were anaerobic bacteria, but the pathogenesis of facemask-associated skin conditions remains poorly defined. We therefore characterized the role of the facemask-associated skin microbiota in the development of maskne using culture-dependent and -independent methodologies. Metagenomic analysis revealed that the majority of the facemask microbiota were anaerobic bacteria that originated from the skin rather than saliva. Previous work demonstrated direct interaction between pathogenic bacteria and antagonistic strains in the microbiome. We expanded this analysis to include indirect interaction between pathogenic bacteria and other indigenous bacteria classified as either 'pathogen helper (PH)' or 'pathogen inhibitor (PIn)' strains. In vitro screening of bacteria isolated from facemasks identified both strains that antagonized and promoted pathogen growth. These data were validated using a mouse skin infection model, where we observed attenuation of symptoms following pathogen infection. Moreover, the inhibitor of pathogen helper (IPH) strain, which did not directly attenuate pathogen growth in vitro and in vivo, functioned to suppress symptom development and pathogen growth indirectly through PH inhibitory antibacterial products such as phenyl lactic acid. Taken together, our study is the first to define a mechanism by which indirect microbiota interactions under facemasks can control symptoms of maskne by suppressing a skin pathogen.
Topics: Animals; Mice; Masks; Microbiota; Humans; COVID-19; Skin; Acne Vulgaris; SARS-CoV-2; Female; Metagenomics; Disease Models, Animal; Bacteria; Microbial Interactions; Dermatitis, Contact
PubMed: 38902263
DOI: 10.1038/s41522-024-00512-w -
Scientific Reports Jun 2024A polyphasic approach was applied to characterize taxonomically a novel endophytic bacterial strain, designated as EP178, which was previously isolated from Passiflora...
A polyphasic approach was applied to characterize taxonomically a novel endophytic bacterial strain, designated as EP178, which was previously isolated from Passiflora incarnata leaves and characterized as plant-growth promoter. The strain EP178 forms Gram stain-negative and rod-shaped cells, and circular and yellow-pigmented colonies. Its growth occurs at 10-37 °C, at pH 6.0-8.0, and tolerates up to 7% (w/v) NaCl. The major cellular fatty acids found were summed feature 8 (C ω7c), summed feature 3 (C ω6c /C ω7c), and C, and the predominant ubiquinone was Q-9. The phylogenetic and nucleotide-similarity analysis with 16S rRNA gene sequences showed that strain EP178 belongs to Pseudomonas genus. The genomic-based G + C content was 65.5%. The average nucleotide identity and digital DNA-DNA hybridization values between strains EP178 and the closest type strain, P. oryzihabitans DSM 6835, were 92.6% and 52.2%, respectively. Various genes associated with plant-growth promoting mechanisms were annotated from genome sequences. Based on the phenotypic, genomic, phylogeny and chemotaxonomic data, strain EP178 represents a new species of the genus Pseudomonas, for which the name Pseudomonas flavocrustae sp. nov. was proposed. The type strain is EP178 (= CBMAI 2609 = ICMP 24844 = MUM 23.01).
Topics: Endophytes; Phylogeny; Pseudomonas; Passiflora; RNA, Ribosomal, 16S; Base Composition; Fatty Acids; DNA, Bacterial; Plant Leaves; Nucleic Acid Hybridization
PubMed: 38902258
DOI: 10.1038/s41598-024-64349-1 -
Microbiology (Reading, England) Jun 2024Long-term administration of certain macrolides is efficacious in patients with persistent pulmonary infection, despite how limited the clinically achievable...
Long-term administration of certain macrolides is efficacious in patients with persistent pulmonary infection, despite how limited the clinically achievable concentrations are, being far below their MICs. An increase in the sub-MIC of macrolide exposure-dependent sensitivity to nitrosative stress is a typical characteristic of . However, a few clinical isolates do not respond to sub-MIC of macrolide treatment. Therefore, we examined the effects of sub-MIC of erythromycin (EM) on the sensitivity to nitrosative stress together with an efflux pump inhibitor (EPI) phenylalanine arginyl β-naphthylamide (PAβN). The sensitivity to nitrosative stress increased, suggesting that the efflux pump was involved in inhibiting the sub-MIC of macrolide effect. Analysis using efflux pump-mutant revealed that MexAB-OprM, MexXY-OprM, and MexCD-OprJ are factors in reducing the sub-MIC of macrolide effect. Since macrolides interfere with quorum sensing (QS), we demonstrated that the QS-interfering agent furanone C-30 (C-30) producing greater sensitivity to nitric oxide (NO) stress than EM. The effect of C-30 was decreased by overproduction of MexAB-OprM. To investigate whether the increase in the QS-interfering agent exposure-dependent sensitivity to nitrosative stress is characteristic of clinical isolates, we examined the viability of treated with NO. Although treatment with EM could reduce cell viability, a high variability in EM effects was observed. Conversely, C-30 was highly effective at reducing cell viability. Treatment with both C-30 and PAβN was sufficiently effective against the remaining isolates. Therefore, the combination of a QS-interfering agent and an EPI could be effective in treating infections.
Topics: Pseudomonas aeruginosa; Quorum Sensing; Microbial Sensitivity Tests; Anti-Bacterial Agents; Nitrosative Stress; Erythromycin; Membrane Transport Proteins; Furans; Dipeptides; Macrolides; Pseudomonas Infections; Humans; Bacterial Outer Membrane Proteins; Bacterial Proteins
PubMed: 38900549
DOI: 10.1099/mic.0.001464 -
Applied Microbiology and Biotechnology Jun 2024Despite increased attention to the aquaculture environment, there is still a lack of understanding regarding the significance of water quality. To address this knowledge...
Despite increased attention to the aquaculture environment, there is still a lack of understanding regarding the significance of water quality. To address this knowledge gap, this study utilized high-throughput sequencing of 16S rRNA and 18S rRNA to examine microbial communities (bacteria and eukaryotes) in coastal water over different months through long-term observations. The goal was to explore interaction patterns in the microbial community and identify potential pathogenic bacteria and red tide organisms. The results revealed significant differences in composition, diversity, and richness of bacterial and eukaryotic operational taxonomic units (OTUs) across various months. Principal coordinate analysis (PCoA) demonstrated distinct temporal variations in bacterial and eukaryotic communities, with significant differences (P = 0.001) among four groups: F (January-April), M (May), S (June-September), and T (October-December). Moreover, a strong association was observed between microbial communities and months, with most OTUs showing a distinct temporal preference. The Kruskal-Wallis test (P < 0.05) indicated significant differences in dominant bacterial and eukaryotic taxa among months, with each group exhibiting unique dominant taxa, including potential pathogenic bacteria and red tide organisms. These findings emphasize the importance of monitoring changes in potentially harmful microorganisms in aquaculture. Network analysis highlighted positive correlations between bacteria and eukaryotes, with bacteria playing a key role in network interactions. The key bacterial genera associated with other microorganisms varied significantly (P < 0.05) across different groups. In summary, this study deepens the understanding of aquaculture water quality and offers valuable insights for maintaining healthy aquaculture practices. KEY POINTS: • Bacterial and eukaryotic communities displayed distinct temporal variations. • Different months exhibited unique potential pathogenic bacteria and red tide organisms. • Bacteria are key taxonomic taxa involved in microbial network interactions.
Topics: Bacteria; Aquaculture; RNA, Ribosomal, 16S; Eukaryota; Seawater; RNA, Ribosomal, 18S; High-Throughput Nucleotide Sequencing; Microbiota; Seasons; Biodiversity; Phylogeny
PubMed: 38900314
DOI: 10.1007/s00253-024-13176-5 -
Skin Research and Technology : Official... Jun 2024Ultraviolet (UV)-induced fluorescence technology is widely used in dermatology to identify microbial infections. Our clinical observations under an ultraviolet-induced...
BACKGROUND
Ultraviolet (UV)-induced fluorescence technology is widely used in dermatology to identify microbial infections. Our clinical observations under an ultraviolet-induced fluorescent dermatoscope (UVFD) showed red fluorescence on the scalps of androgenetic alopecia (AGA) patients. In this study, based on the hypothesis that microbes are induced to emit red fluorescence under UV light, we aimed to explore the microbial disparities between the AGA fluorescent area (AF group) and AGA non-fluorescent area (ANF group).
METHODS
Scalp swab samples were collected from 36 AGA patients, including both fluorescent and non-fluorescent areas. The bacterial communities on the scalp were analyzed by 16S rRNA gene sequencing and bioinformatics analysis, as well as through microbial culture methods.
RESULTS
Significant variations were observed in microbial evenness, abundance composition, and functional predictions between fluorescent and non-fluorescent areas. Sequencing results highlighted significant differences in Cutibacterium abundance between these areas (34.06% and 21.36%, respectively; p < 0.05). Furthermore, cultured red fluorescent colonies primarily consisted of Cutibacterium spp., Cutibacterium acnes, Staphylococcus epidermidis, and Micrococcus spp.
CONCLUSIONS
This is the first study to investigate scalp red fluorescence, highlighting microbial composition variability across different scalp regions. These findings may provide novel insights into the microbiological mechanisms of AGA.
Topics: Humans; Alopecia; Ultraviolet Rays; Male; Adult; Middle Aged; Scalp; Female; Dermoscopy; Fluorescence; Microbiota; RNA, Ribosomal, 16S; Bacteria
PubMed: 38899718
DOI: 10.1111/srt.13777