• Burkholderia seminalis
• Anti-fungus
• C4-dicarboxylates
• Cyclo (Phe-Pro)
• Dct system

• Burkholderia/metabolism
• Burkholderia/genetics
• Fusarium/metabolism
• Fusarium/genetics
• Fusarium/drug effects
• Peptides, Cyclic/biosynthesis
• Peptide Synthases/genetics
• Peptide Synthases/metabolism
• Dicarboxylic Acids/metabolism
• Bacterial Proteins/metabolism
• Bacterial Proteins/genetics

• 31872017, 32072472 National Natural Science Foundation of China
• LZ24C140004 The Zhejiang Provincial Natural Science Foundation of China
• 2019C02035 Key Research and Development Project in Zhejiang Province
• 20231203A05 Hangzhou Science and Technology Development Plan Project
• 2010DS700124-KF202205 State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products

• colitis
• proanthocyanidins
• synergistic anti-inflammatory function
• β-glucan

• Animals
• beta-Glucans/administration & dosage
• beta-Glucans/pharmacology
• Dextran Sulfate/adverse effects
• Mice
• Proanthocyanidins/administration & dosage
• Proanthocyanidins/pharmacology
• Gastrointestinal Microbiome/drug effects
• Colitis/chemically induced
• Colitis/drug therapy
• Colitis/metabolism
• Colitis/immunology
• Mice, Inbred C57BL
• Male
• Humans
• Bacteria/classification
• Bacteria/isolation & purification
• Bacteria/genetics
• Bacteria/drug effects
• Bacteria/metabolism
• Anti-Inflammatory Agents/administration & dosage
• Drug Synergism
• Disease Models, Animal
• Colon/metabolism
• Colon/drug effects
• Colon/immunology
• Colon/microbiology
• Intestinal Mucosa/metabolism
• Intestinal Mucosa/drug effects
• Oxidative Stress/drug effects

• Immunity, Innate
• Animals
• Mice
• Inflammation/immunology
• Inflammation/metabolism
• Vibrio vulnificus/immunology
• Vibrio Infections/immunology
• Mice, Inbred C57BL
• Humans
• Inflammasomes/immunology
• Inflammasomes/metabolism
• Bacterial Proteins/metabolism
• Bacterial Proteins/immunology

• Gut microbiota
• Gut-brain axis
• Gut-liver axis
• Lead
• Polystyrene microplastics

• Arrhythmia
• Cardiac bitter taste receptors
• Cardiac inflammation
• Contractile dysfunction
• Novel therapeutics

• Humans
• Taste
• Receptors, G-Protein-Coupled/metabolism
• Oxidative Stress
• Arrhythmias, Cardiac
• Heart Diseases
• Inflammation

We report on a case of Vibrio vulnificus (V. vulnificus) detected by metagenomics next-generation sequencing (mNGS) in a 53-year-old male patient with polymicrobial gas gangrene and successful treatment by surgery. This report raises awareness among dermatologists that when a patient is clinically suspected of a special type of pathogenic infection, the mNGS method should be preferred to identify the patient’s pathogen infection as soon as possible and then take effective treatment in time to save patients’ lives.

A 53-year-old male who worked in the aquatic market complained of redness and swelling of the lower limbs, blisters and ulcers with fever for 3 d. We used mNGS to test the pathogens in ulcer secretions. The results were returned in 24 h and indicated: V. vulnificus, Fusobacterium necrophorum, Staphylococcus haemolyticus, Staphylococcus aureus, Streptococcus dysgalactiae and Klebsiella aerogenes. This patient was diagnosed with V. vulnificus infection. The emergency operation was performed immediately under combined lumbar and epidural anesthesia: Left leg expansion and exploration (August 10, 2021). After surgery, we continued to use piperacillin sodium tazobactam sodium 4.5 g every 8 h and levofloxacin 0.5 g for anti-infection treatment. The patient underwent further surgery under lumbar anesthesia on August 17, 2021 and August 31, 2021: Left leg deactivation and skin grafting, negative pressure closed drainage and right thigh skin removal. After treatment, the transplanted flap survived.

We could confirm the diagnosis of Vibrio vulnificus infection within 24 h through mNGS detection and then immediately performed emergency surgery.

• Metagenomics next-generation sequencing
• Vibrio vulnificus
• Polymicrobial gas gangrene
• Surgery
• Case report

• Humans
• Candida glabrata
• Staphylococcus epidermidis
• Biofilms
• Microbial Interactions
• Antifungal Agents/pharmacology
• Antifungal Agents/metabolism
• Candida albicans

• Fungi
• Mass spectrometry
• Secondary metabolite
• Wax moth larvae

• Vibrio vulnificus
• antivirulence therapy
• environmental signal
• transcription factor
• virulence factor

• AKT
• NF-κB p65
• Vibrio harveyi
• p38 MAPK

• Animals
• Cytokines/immunology
• Macrophages, Peritoneal/immunology
• Macrophages, Peritoneal/microbiology
• Mice
• NF-kappa B/metabolism
• Phosphatidylinositol 3-Kinases/metabolism
• Proto-Oncogene Proteins c-akt/metabolism
• Signal Transduction
• Vibrio
• Vibrio Infections/immunology
• p38 Mitogen-Activated Protein Kinases/metabolism

• antimicrobial
• biodegradable
• drug delivery
• multilayered nanofibers
• poly(vinyl alcohol)

2,5-diketopiperazines (DKPs) are cyclic dipeptides ubiquitously found in nature. In particular, cyclo(Phe-Pro), cyclo(Leu-Pro), and cyclo(Val-Pro) are frequently detected in many microbial cultures. Each of these DKPs has four possible stereoisomers due to the presence of two chirality centers. However, absolute configurations of natural DKPs are often ambiguous due to the lack of a simple, sensitive, and reproducible method for stereochemical assignment. This is an important problem because stereochemistry is a key determinant of biological activity. Here, we report a synthetic DKP library containing all stereoisomers of cyclo(Phe-Pro), cyclo(Leu-Pro), and cyclo(Val-Pro). The library was subjected to spectroscopic characterization using mass spectrometry, NMR, and electronic circular dichroism (ECD). It turned out that ECD can clearly differentiate DKP stereoisomers. Thus, our ECD dataset can serve as a reference for unambiguous stereochemical assignment of cyclo(Phe-Pro), cyclo(Leu-Pro), and cyclo(Val-Pro) samples from natural sources. The DKP library was also subjected to a biological screening using assays for E. coli growth and biofilm formation, which revealed distinct biological effects of cyclo(D-Phe-L-Pro).

• biofilms
• diketopiperazines
• electronic circular dichroism
• epimerization
• mixed microbial culture
• stereochemistry

• Circular Dichroism
• Diketopiperazines/chemistry
• Dipeptides/chemical synthesis
• Dipeptides/chemistry
• Dipeptides/pharmacology
• Escherichia coli/drug effects
• Peptides, Cyclic/chemical synthesis
• Peptides, Cyclic/chemistry
• Peptides, Cyclic/pharmacology
• Stereoisomerism
• Structure-Activity Relationship

• P30 CA008748 NCI NIH HHS
• T34GM007823 NIGMS NIH HHS

• Bacteroides vulgatus
• Cyclo-Phe-Pro
• Gut microbiota
• Membrane disruption
• ObgE
• Vibrio vulnificus

• Animals
• Bacteroides
• Cell Membrane
• Gastrointestinal Microbiome
• Mice
• Vibrio vulnificus

• National Research Foundation of Korea

Candida albicans and Klebsiella pneumoniae frequently co-exist within the human host as a complex biofilm community. These pathogens are of interest because their association is also related to significantly increased morbidity and mortality in hospitalized patients. With the aim of highlighting metabolic shifts occurring in the dual-species biofilm, an untargeted GC-MS-based metabolomics approach was applied to single and mixed biofilms of C. albicans and K. pneumoniae. Metabolomic results showed that among the extracellular metabolites identified, approximately 40 compounds had significantly changed relative abundance, mainly involving central carbon, amino acid, vitamin, and secondary metabolisms, such as serine, leucine, arabitol, phosphate, vitamin B6, cyclo-(Phe-Pro), trehalose, and nicotinic acid. The results were related to the strict interactions between the two species and the different microbial composition in the early and mature biofilms.

• Candida albicans
• GC-MS
• Klebsiella pneumoniae
• interspecies interactions
• metabolomics
• polymicrobial biofilms

• Algorithms
• Biofilms
• Candida albicans/metabolism
• Culture Media
• Gas Chromatography-Mass Spectrometry
• Glucose/metabolism
• Klebsiella pneumoniae/metabolism
• Least-Squares Analysis
• Metabolomics/methods
• Principal Component Analysis

The complexity of animal microbiomes presents challenges to defining signaling molecules within the microbial consortium and between the microbes and the host. By focusing on the binary symbiosis between Vibrio fischeri and Euprymna scolopes, we have combined genetic analysis with direct imaging to define and study small molecules in the intact symbiosis.

The lifelong relationship between the Hawaiian bobtail squid Euprymna scolopes and its microbial symbiont Vibrio fischeri represents a simplified model system for studying microbiome establishment and maintenance. The bacteria colonize a dedicated symbiotic light organ in the squid, from which bacterial luminescence camouflages the host in a process termed counterillumination. The squid host hatches without its symbionts, which must be acquired from the ocean amidst a diversity of nonbeneficial bacteria, such that precise molecular communication is required for initiation of the specific relationship. Therefore it is likely there are specialized metabolites used in the light organ microenvironment to modulate these processes. To identify small molecules that may influence the establishment of this symbiosis, we used imaging mass spectrometry to analyze metabolite production in V. fischeri with altered biofilm production, which correlates directly to colonization capability in its host. “Biofilm-up” and “biofilm-down” mutants were compared to a wild-type strain, and ions that were more abundantly produced by the biofilm-up mutant were detected. Using a combination of structural elucidation and synthetic chemistry, one such signal was determined to be a diketopiperazine, cyclo(d-histidyl-l-proline). This diketopiperazine modulated luminescence in V. fischeri and, using imaging mass spectrometry, was directly detected in the light organ of the colonized host. This work highlights the continued need for untargeted discovery efforts in host-microbe interactions and showcases the benefits of the squid-Vibrio system for identification and characterization of small molecules that modulate microbiome behaviors.

• mass spectrometry
• specialized metabolites
• symbiosis

• GC-MS
• bacteria
• footprinting
• fungi
• metabolomics
• polymicrobial

Oomycete and fungal pathogens, mainly Phytophthora and Fusarium species, are notorious causal agents of huge economic losses and environmental damages. For instance, Phytophthora ramorum, Phytophthora cryptogea, Phytophthora plurivora and Fusarium solani cause significant losses in nurseries and in forest ecosystems. Chemical treatments, while harmful to the environment and human health, have been proved to have little or no impact on these species. Recently, biocontrol bacterial species were used to cope with these pathogens and have shown promising prospects towards sustainable and eco-friendly agricultural practices. Olive trees prone to Phytophthora and Fusarium disease outbreaks are suitable for habitat-adapted symbiotic strategies, to recover oomycetes and fungal pathogen biocontrol agents. Using this strategy, we showed that olive trees-associated microbiome represents a valuable source for microorganisms, promoting plant growth and healthy benefits in addition to being biocontrol agents against oomycete and fungal diseases. Isolation, characterization and screening of root microbiome of olive trees against numerous Phytophthora and other fungal pathogens have led to the identification of the Bacillus velezensis OEE1, with plant growth promotion (PGP) abilities and strong activity against major oomycete and fungal pathogens. Phylogenomic analysis of the strain OEE1 showed that B. velezensis suffers taxonomic imprecision that blurs species delimitation, impacting their biofertilizers’ practical use. Genome mining of several B. velezensis strains available in the GenBank have highlighted a wide array of plant growth promoting rhizobacteria (PGPR) features, metals and antibiotics resistance and the degradation ability of phytotoxic aromatic compounds. Strain OEE1 harbours a large repertoire of secreted and volatile secondary metabolites. Rarefaction analysis of secondary metabolites richness in the B. velezenis genomes, unambiguously documented new secondary metabolites from ongoing genome sequencing efforts that warrants more efforts in order to assess the huge diversity in the species. Comparative genomics indicated that B. velezensis harbours a core genome endowed with PGP features and accessory genome encoding diverse secondary metabolites. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of OEE1 Volatile Organic Compounds (VOCs) and Liquid Chromatography High Resolution Mass Spectrometry (LC-HRMS) analysis of secondary metabolites identified numerous molecules with PGP abilities that are known to interfere with pathogen development. Moreover, B. velezensis OEE1 proved effective in protecting olive trees against F. solani in greenhouse experiments and are able to inhabit olive tree roots. Our strategy provides an effective means for isolation of biocontrol agents against recalcitrant pathogens. Their genomic analysis provides necessary clues towards their efficient implementation as biofertilizers.

• Bacillus velezensis
• Fusarium solani
• abiotic stress
• antimicrobial activity
• endophytes
• plant growth promoting bacteria
• secondary metabolites

• Amino Acids/metabolism
• Animals
• Dipeptides/metabolism
• Humans
• Indoles/metabolism
• Peptides, Cyclic/metabolism
• Pyrazoles/metabolism
• Quorum Sensing/physiology
• Vibrio/pathogenicity
• Vibrio/physiology
• Virulence/physiology
• Virulence Factors/metabolism

• HU
• LeuO
• RpoS
• Vibrio vulnificus
• cyclo-(l-Phe-l-Pro)
• hydroperoxidase
• oxidative stress
• quorum sensing
• vHUαβ

• clinical study
• cyclo(d-Phe-l-Pro)
• nitric oxide
• roasted barley extract
• vasodilatation

• Adult
• Animals
• Blood Flow Velocity/drug effects
• Diketopiperazines/analysis
• Diketopiperazines/pharmacology
• Double-Blind Method
• Female
• Food Handling/methods
• Hordeum/chemistry
• Hot Temperature
• Humans
• Japan
• Laser-Doppler Flowmetry
• Male
• Placebos
• Plant Extracts/pharmacology
• Rats
• Rats, Wistar
• Skin/blood supply
• Skin Temperature/drug effects
• Specific Pathogen-Free Organisms
• Tail/blood supply
• Vasodilation/drug effects

Th17 cells mediate inflammation and autoimmunity. Although it was known that cytokine IL-2 inhibits Th17 cell differentiation, how it does so was elusive. Using IL-17–specific PTEN-deficient mice, Kim et al. show that phosphatase PTEN inhibits IL-2 production and thus promotes Th17 cell differentiation.

T helper 17 (Th17) cells are a CD4⁺ T cell subset that produces IL-17A to mediate inflammation and autoimmunity. IL-2 inhibits Th17 cell differentiation. However, the mechanism by which IL-2 is suppressed during Th17 cell differentiation remains unclear. Here, we show that phosphatase and tensin homologue (PTEN) is a key factor that regulates Th17 cell differentiation by suppressing IL-2 production. Th17-specific Pten deletion (Pten^fl/flIl17a^cre) impairs Th17 cell differentiation in vitro and ameliorated symptoms of experimental autoimmune encephalomyelitis (EAE), a model of Th17-mediated autoimmune disease. Mechanistically, Pten deficiency up-regulates IL-2 and phosphorylation of STAT5, but reduces STAT3 phosphorylation, thereby inhibiting Th17 cell differentiation. PTEN inhibitors block Th17 cell differentiation in vitro and in the EAE model. Thus, PTEN plays a key role in Th17 cell differentiation by blocking IL-2 expression.

Vibrio vulnificus (V. vulnificus), a Gram-negative marine bacterium, can cause life-threatening primary septicemia, especially in patients with liver diseases. How V. vulnificus affects the liver and how it acts on macrophages are not well understood. In this report, we demonstrated that V. vulnificus infection causes a strong inflammatory response, marked expansion of liver-resident macrophages, and liver damage in mice. We demonstrated further that V. vulnificus activates mTOR in macrophages and inhibition of mTOR differentially regulates V. vulnificus induced inflammatory responses, suggesting the possibility of targeting mTOR as a strategy to modulate V. vulnificus induced inflammatory responses.

• Animals
• Enzyme Activation
• Inflammation/microbiology
• Kupffer Cells/cytology
• Liver/immunology
• Macrophages/metabolism
• Macrophages/microbiology
• Mice
• Mice, Inbred C57BL
• NF-kappa B/metabolism
• Neutrophils/cytology
• TOR Serine-Threonine Kinases/metabolism
• Vibrio Infections/complications
• Vibrio vulnificus/physiology

• R01 AI101206 NIAID NIH HHS
• National Institute of Allergy and Infectious Diseases
• National Natural Science Foundation of China
• Natural Science Foundation of Zhejiang Province
• Zhejiang Provincial Medical Science Foundation
• Open Fund of Zhejiang Provincial Top Key Discipline of Clinical Medicine-Laboratory Medicine

Phagocytosis of pathogens, apoptotic cells and debris is a key feature of macrophage function in host defense and tissue homeostasis. Quantification of macrophage phagocytosis in vitro has traditionally been technically challenging. Here we report the optimization and validation of the IncuCyte ZOOM® real time imaging platform for macrophage phagocytosis based on pHrodo® pathogen bioparticles, which only fluoresce when localized in the acidic environment of the phagolysosome. Image analysis and fluorescence quantification were performed with the automated IncuCyte™ Basic Software. Titration of the bioparticle number showed that the system is more sensitive than a spectrofluorometer, as it can detect phagocytosis when using 20× less E. coli bioparticles. We exemplified the power of this real time imaging platform by studying phagocytosis of murine alveolar, bone marrow and peritoneal macrophages. We further demonstrate the ability of this platform to study modulation of the phagocytic process, as pharmacological inhibitors of phagocytosis suppressed bioparticle uptake in a concentration-dependent manner, whereas opsonins augmented phagocytosis. We also investigated the effects of macrophage polarization on E. coli phagocytosis. Bone marrow-derived macrophage (BMDM) priming with M2 stimuli, such as IL-4 and IL-10 resulted in higher engulfment of bioparticles in comparison with M1 polarization. Moreover, we demonstrated that tolerization of BMDMs with lipopolysaccharide (LPS) results in impaired E. coli bioparticle phagocytosis. This novel real time assay will enable researchers to quantify macrophage phagocytosis with a higher degree of accuracy and sensitivity and will allow investigation of limited populations of primary phagocytes in vitro.

• Bafilomycin A1 (PubChem CID: 6375210)
• Cytochalasin D (PubChem CID: 5458428)
• Inflammation
• LPS
• Macrophage
• Nocodazole (PubChem CID: 4122)
• Phagocytosis

Cyclo(phenylalanine‐proline) is produced by various organisms such as animals, plants, bacteria and fungi. It has diverse biological functions including anti‐fungal activity, anti‐bacterial activity and molecular signalling. However, a few studies have demonstrated the effect of cyclo(phenylalanine‐proline) on the mammalian cellular processes, such as cell growth and apoptosis. In this study, we investigated whether cyclo(phenylalanine‐proline) affects cellular responses associated with DNA damage in mammalian cells. We found that treatment of 1 mM cyclo(phenylalanine‐proline) induces phosphorylation of H2AX (S139) through ATM‐CHK2 activation as well as DNA double strand breaks. Gene expression analysis revealed that a subset of genes related to regulation of reactive oxygen species (ROS) scavenging and production is suppressed by the cyclo(phenylalanine‐proline) treatment. We also found that cyclo(phenylalanine‐proline) treatment induces perturbation of the mitochondrial membrane, resulting in increased ROS, especially superoxide, production. Collectively, our study suggests that cyclo(phenylalanine‐proline) treatment induces DNA damage via elevation of ROS in mammalian cells. Our findings may help explain the mechanism underlying the bacterial infection‐induced activation of DNA damage response in host mammalian cells.

• DNA damage
• comet assay
• cyclo dipeptide
• cyclo(phenylalanine-proline)
• reactive oxygen species