Microbial Invasion Research Articles

Weak effect of temperature fluctuations on the invasion of Raphidiopsis raciborskii (Cyanobacteria) in experimental plankton microcosms.

Biological invasions are a major threat for many aquatic ecosystems. In contrast to higher plants and animals, microbial invasions are less obvious and more difficult to detect. One of the most prominent microbial invaders is the cyanobacterium Raphidiopsis raciborskii. To better understand the environmental conditions favoring its invasion success, we studied invasion under three different temperature regimes (one constant and two variable) in experimental plankton communities by invader addition experiments. To account for intraspecific variation, we tested four different strains of R. raciborskii and the mixture of them. Invasion success of R. raciborskii was higher under constant temperature conditions than under fluctuations suggesting that the resident species responded faster to the environmental changes than the invaders. We observed a clear strain-specific effect, demonstrating that strain identity is an important determinant of invasion success. The interaction of temperature fluctuations and strain identity indicates that, among the tested strains, the response to the temperature regimes varied. The mixture of all four strains did not perform better than the best single strain showing no sign of a positive genetic diversity effect. In our experiment, environmental fluctuations did not widen a window of opportunity for the invasion of R. raciborskii.

Deciphering the Interlinked CXCR4-Mediated Feedback Loop Among Signaling Pathways in Diabetic Wound Healing

Abstract: Diabetic chronic wounds and amputations are very serious complications of diabetes mellitus (DM) that result from an integration factor, including oxygen deprivation, elevated reactive oxygen species (ROS), reduced angiogenesis, and microbial invasion. These causative factors lead to tenacious wounds in an inflammatory state, which eventually results in tissue aging and necrosis. Wound healing in DM potentially targets C-X-C chemokine receptor type 4 (CXCR4) regulates several signalling pathways. The CXCR4 signalling pathway integrated with phospholipase C (PLC)/protein kinase-C (PKC) Ca2+ pathways, stromal cell-derived factor-1 (SDF-1), and mitogen- activated protein kinases (MAPKs) pathway for enhancing cell chemotaxis, proliferation, and survival. The dysregulated CXCR4 pathway is connected with poor wound healing in DM patients. Therapeutic strategies targeting CXCR4-based molecules such as UCUF-728, UCUF-965, and AMD3100 have been shown to enhance diabetic wound healing by altering miRNA expression, promoting angiogenesis, and accelerating wound closure. This study indicates that CXCR4 participation in various signalling pathways makes it essential for Understanding the healing of diabetic wounds. Using specific compounds to target CXCR4 offers a potentially effective treatment strategy to improve wound healing in diabetes. Our understanding of CXCR4 signalling and its regulation processes will enable us to develop more potent wound care solutions for diabetic chronic wounds. This report concludes that CXCR4's potential therapeutic targeting shows improvements in diabetic wound repair. This review will demonstrate that CXCR4 plays a major role in wound healing through its various signalling pathways. Targeting CXCR4 with certain agonist molecules shows a therapeutic approach to potentially increasing wound healing in diabetes. By enhancing our understanding of the CXCR4 signalling mechanism in future studies, we can develop more potential treatments for chronic diabetic wounds.

Short-sighted evolution of virulence for invasive gut microbes: From hypothesis to tests

Why microbes harm their hosts is a fundamental question in evolutionary biology with broad relevance to our understanding of infectious diseases. Several hypotheses have been proposed to explain this "evolution of virulence." In this perspective, we reexamine one of these hypotheses in the specific context of the human gut microbiome, namely short-sighted evolution. According to the short-sighted evolution hypothesis, virulence is a product of niche expansion within a colonized host, whereby variants of commensal microbes establish populations in tissues and sites where the infection causes morbidity or mortality. This evolution is short-sighted in that the evolved variants that infect those tissues and sites are not transmitted to other hosts. The specific hypothesis that we propose is that some bacteria responsible for invasive infections and disease are the products of the short-sighted evolution of commensal bacteria residing in the gut microbiota. We present observations in support of this hypothesis and discuss the challenges inherent in assessing its general application to infections and diseases associated with specific members of the gut microbiota. We then describe how this hypothesis can be tested using genomic data and animal model experiments and outline how such studies will serve to provide fundamental information about both the evolution and genetic basis of virulence, and the bacteria of intensively studied yet poorly understood habitats including the gut microbiomes of humans and other mammals.

Structural Equation Modelling as a Proof-of-Concept Tool for Mediation Mechanisms Between Topical Antibiotic Prophylaxis and Six Types of Blood Stream Infection Among ICU Patients.

Whether exposing the microbiome to antibiotics decreases or increases the risk of blood stream infection with Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter, and Candida among ICU patients, and how this altered risk might be mediated, are critical research questions. Addressing these questions through the direct study of specific constituents within the microbiome would be difficult. An alternative tool for addressing these research questions is structural equation modelling (SEM). SEM enables competing theoretical causation networks to be tested 'en bloc' by confrontation with data derived from the literature. These causation models have three conceptual steps: exposure to specific antimicrobials are the key drivers, clinically relevant infection end points are the measurable observables, and the activity of key microbiome constituents on microbial invasion serve as mediators. These mediators, whether serving to promote, to impede, or neither, are typically unobservable and appear as latent variables in each model. SEM methods enable comparisons through confronting the three competing models, each versus clinically derived data with the various exposures, such as topical or parenteral antibiotic prophylaxis, factorized in each model. Candida colonization, represented as a latent variable, and concurrency are consistent promoters of all types of blood stream infection, and emerge as harmful mediators.

Neutrophil Extracellular Traps in Oral Diseases.

To summarize the current knowledge of the neutrophil extracellular traps (NETs) and its critical role in various oral diseases. We reviewed the recent research on NETs through PubMed and Web of Science. An analysis of recent research results was summarized from three aspects: NETs induction and formation, functions of NETs, and NETs in oral diseases. The relationship between neutrophils and NETs is critical to the body's defense against microbial invasion. NETs can effectively combat pathogens with an anti-inflammatory effect and meanwhile it can contribute to inflammation. Moreover, it can synergize with other immune cells to respond to stimuli, such as pathogens, host-derived mediators, and drugs. It was revealed that NETs play different roles to influence various oral diseases like periodontitis, endodontic infection, oral mucosal diseases, maxillofacial tumors, and many other oral diseases. The balance between the protective and potentially harmful effects of NETs is a key factor in determining the outcome of infections and inflammatory responses. The role of NETs in oral diseases needs to be further studied to enable better understanding of its role in the different oral diseases.

Root cap cell corpse clearance limits microbial colonization in Arabidopsis thaliana.

Programmed cell death occurring during plant development (dPCD) is a fundamental process integral for plant growth and reproduction. Here, we investigate the connection between developmentally controlled PCD and fungal accommodation in Arabidopsis thaliana roots, focusing on the root cap-specific transcription factor ANAC033/SOMBRERO (SMB) and the senescence-associated nuclease BFN1. Mutations of both dPCD regulators increase colonization by the beneficial fungus Serendipita indica, primarily in the differentiation zone. smb-3 mutants additionally exhibit hypercolonization around the meristematic zone and a delay of S. indica-induced root-growth promotion. This demonstrates that root cap dPCD and rapid post-mortem clearance of cellular corpses represent a physical defense mechanism restricting microbial invasion of the root. Additionally, reporter lines and transcriptional analysis revealed that BFN1 expression is downregulated during S. indica colonization in mature root epidermal cells, suggesting a transcriptional control mechanism that facilitates the accommodation of beneficial microbes in the roots.

Root cap cell corpse clearance limits microbial colonization in Arabidopsis thaliana

Programmed cell death occurring during plant development (dPCD) is a fundamental process integral for plant growth and reproduction. Here, we investigate the connection between developmentally controlled PCD and fungal accommodation in Arabidopsis thaliana roots, focusing on the root cap-specific transcription factor ANAC033/SOMBRERO (SMB) and the senescence-associated nuclease BFN1. Mutations of both dPCD regulators increase colonization by the beneficial fungus Serendipita indica, primarily in the differentiation zone. smb-3 mutants additionally exhibit hypercolonization around the meristematic zone and a delay of S. indica-induced root-growth promotion. This demonstrates that root cap dPCD and rapid post-mortem clearance of cellular corpses represent a physical defense mechanism restricting microbial invasion of the root. Additionally, reporter lines and transcriptional analysis revealed that BFN1 expression is downregulated during S. indica colonization in mature root epidermal cells, suggesting a transcriptional control mechanism that facilitates the accommodation of beneficial microbes in the roots.

PHLDA1 protects intestinal barrier function via restricting intestinal epithelial cells apoptosis in inflammatory bowel disease

The current approach to treating inflammatory bowel disease (IBD) primarily focuses on managing inflammation rather than maintaining the integrity of the intestinal barrier. In our study, we sought to investigate the potential role of PHLDA1 in preserving intestinal barrier function as a promising strategy for treating IBD. We observed a significant decrease in PHLDA1 expression in intestinal epithelial cells (IECs) of both IBD patients and mice with chemically induced colitis. This deficiency of PHLDA1 led to increased apoptosis of IECs, resulting in a compromised epithelial barrier and the invasion of commensal bacteria into the mucosa. Consequently, this microbial invasion substantially exacerbated colonic inflammation in mice with the specific knockout of PHLDA1 in IECs (Phlda1IEC−KO) compared to their control littermates. Mechanistically, we found evidence of PHLDA1 interacting with MCL1 to protect against K48-linked polyubiquitylation at the K40 lysine residue, thus preventing ubiquitin-proteasome degradation through the MCL1 ubiquitin ligase E3 (Mule). We further confirmed that the PHLDA1-MCL1-Mule signaling pathway plays a critical role in the development of IBD. Notably, our study demonstrated that enhancing MCL1 levels or reducing Mule expression using adeno-associated virus (AAV) attenuated experimental colitis in Phlda1IEC−KO mice. Collectively, our findings emphasize the significance of PHLDA1 in the pathogenesis of IBD and propose that targeting the PHLDA1-MCL1-Mule signaling pathway could be a viable approach for combating IBD.

The immune landscape in apical periodontitis: From mechanism to therapy.

Apical periodontitis (AP) is featured by a persistent inflammatory response and alveolar bone resorption initiated by microorganisms, posing risks to both dental and systemic health. Nonsurgical endodontic treatment is the recommended treatment plan for AP with a high success rate, but in some cases, periapical lesions may persist despite standard endodontic treatment. Better comprehension of the AP inflammatory microenvironment can help develop adjunct therapies to improve the outcome of endodontic treatment. This review presents an overview of the immune landscape in AP, elucidating how microbial invasion triggers host immune activation and shapes the inflammatory microenvironment, ultimately impacting bone homeostasis. The destructive effect of excessive immune activation on periapical tissues is emphasized. This review aimed to systematically discuss the immunological basis of AP, the inflammatory bone resorption and the immune cell network in AP, thereby providing insights into potential immunotherapeutic strategies such as targeted therapy, antioxidant therapy, adoptive cell therapy and cytokine therapy to mitigate AP-associated tissue destruction.

Understanding dental pulp inflammation: from signaling to structure.

The pulp is a unique tissue within each tooth that is susceptible to painful inflammation, known as pulpitis, triggered by microbial invasion from carious lesions or trauma that affect many individuals. The host response involves complex immunological processes for pathogen defense and dentin apposition at the site of infection. The interplay of signaling between the immune and non-immune cells via cytokines, chemokines, neuropeptides, proteases, and reactive nitrogen and oxygen species leads to tissue reactions and structural changes in the pulp that escalate beyond a certain threshold to irreversible tissue damage. If left untreated, the inflammation, which is initially localized, can progress to pulpal necrosis, requiring root canal treatment and adversely affecting the prognosis of the tooth. To preserve pulp vitality and dental health, a deeper understanding of the molecular and cellular mechanisms of pulpitis is imperative. In particular, elucidating the links between signaling pathways, clinical symptoms, and spatiotemporal spread is essential to develop novel therapeutic strategies and push the boundaries of vital pulp therapy.

Microbial interactions impact stress tolerance in a model oral community.

Microbial interactions are critical modulators of the emergence of microbial communities and their functions. However, how these interactions impact the fitness of microbes in established communities upon exposure to environmental stresses is poorly understood. Here, we utilized a two-species community consisting of Aggregatibacter actinomycetemcomitans and Streptococcus gordonii to examine the impact of synergistic and antagonistic interactions on microbial resilience to environmental fluctuations and susceptibility to microbial invasion. We focused on the S. gordonii-produced extracellular molecules, L-lactate and H2O2, which have been shown to mediate interactions between these two microbes. We discovered that seemingly beneficial functions, such as A. actinomycetemcomitans cross-feeding on S. gordonii-produced L-Lactate, can paradoxically exacerbate vulnerabilities, such as susceptibility to antibiotics. Moreover, our data highlight the context-dependent nature of microbial interactions, emphasizing that a seemingly potent antimicrobial, such as H2O2, can have both synergistic and antagonistic effects on a microbial community dependent on the environment.

Structural basis for the access and binding of resolvin D1 (RvD1) to formyl peptide receptor 2 (FPR2/ALX), a class A GPCR.

Inflammation is essential to the body's defense against tissue injury and microbial invasion. However, uncontrolled inflammation is highly detrimental and can result in chronic inflammatory diseases such as asthma, cancer, obesity, and diabetes. An increasing body of evidence suggests that specialized pro-resolving lipid mediators (SPMs), such as resolvins, are actively involved in critical cellular events that drive the resolution of inflammation and a return to homeostasis. An imbalance caused by insufficient SPMs can result in the unsuccessful resolution of inflammation. The D-series resolvins (metabolites of docosahexaenoic acid), such as resolvin D1 (RvD1) and resolvin D2 (RvD2), carry out their pro-resolving functions by directly binding to class A G protein-coupled receptors FPR2/ALXR and GPR32, and GPR18, respectively. We recently demonstrated that RvD1 and RvD2 preferentially partition and accumulate at the polar headgroup regions of the membrane. However, the mechanistic detail of how RvD1 gains access to the FPR2 binding site from a surrounding membrane environment remains unknown. In this study, we used classical MD and well-tempered metadynamics simulations to examine the structural basis for the access and binding of RvD1 to its target receptor from aqueous and membrane environments. The results offer valuable insights into the access path, potential binding pose, and key residue interactions essential for the access and binding of RvD1 to FPR2/ALXR and may help in identifying small molecule therapeutics as a possible treatment for inflammatory disorders.

Preparation of injectable self-healing hydrogels using carboxymethyl chitosan and oxidized dextran with incorporating quercetin-loaded PF127 micelles for wound healing

Rapid achievement of the irregularly shaped post-wound closure is closely related to the effectiveness of clinical hydrogel-based wound dressings to inhibit microbial invasion and promote wound healing. Herein, an injectable and self-healing hydrogel with rapid gelation was engineered based on carboxymethyl chitosan (CMCS) and oxidized dextran (Odex). The hydrophobic drug, quercetin, with antioxidant and antibacterial effects, was loaded in the PF127 micelles with an encapsulation efficiency of 59.06 %, and then quercetin-loaded PF127 micelles were ingeniously incorporated into the hydrogels. The prepared composite hydrogels not only showed a stable and sustained release behavior of quercetin, but also possessed excellent antioxidant activities and antibacterial properties against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Moreover, the composite hydrogels with microstructure (150–250 μm) also exhibited self-healing and injectable properties. In addition, the survival rates of NIH 3T3 cells when cultured with hydrogel extract were all over 80 %, illustrating the excellent biocompatibility of hydrogels. Therefore, our prepared multifunctional composite hydrogels showed a broad prospect as wound dressings for treating acute skin injuries.

Antibacterial and Healing Potential of Zn-Al LDHs/Cellulose Acetate Nanocomposite in Burns and Wounds: A Study on Earthworms as a Human Skin Model

AbstractProtection against microbial invasion has gained much attention to accelerate wound healing. Layered double hydroxides (LDHs) have antimicrobial properties due to their partial release of metallic ions. In this study, Zn-Al LDHs was chemically prepared and then supported on cellulose acetate (CA) in the form of nanocomposite. This novel Zn-Al LDHs/CA nanocomposite was in vitro characterized, and its antibacterial efficacy was determined using the agar well diffusion method. Moreover, healing capabilities of the nanocomposite were evaluated via topical application on wounds and burns induced in earthworms as a model of human skin like. The average crystallite sizes of Zn-Al LDHs and 50% Zn-Al/CA nanocomposite were 18.4 nm and 14.8 nm, respectively. TEM micrographs revealed that pure CA, pure Zn-Al LDHs, and 50% Zn-Al LDHs/CA nanocomposites had an average particle size of 27.7 ± 13.5, 296.2 ± 123, and 223.2 ± 83.4 nm, respectively. Pure Zn-Al LDHs showed antibacterial activity against different bacterial strains (Inhibition zone: 15 ± 2 to 20 ± 4 mm). However, when 50% Zn-Al LDHs was supported on CA, the inhibition zone was significantly higher (20 ± 3 to 26 ± 2 mm). Visual inspection, scanning electron microscopy and histological studies of earthworm skin revealed better morphology and shorter healing duration with Zn-Al LDHs/CA nanosystem (66 h for wounds and 144 h for burns) when compared with untreated control (> 400 h). In conclusion, these findings reveal that Zn-Al LDHs/CA nanocomposite is a promising promoter for wound and burn healing due to its biocompatibility and antibacterial activity.

Machine learning reveals the rules governing the efficacy of mesenchymal stromal cells in septic preclinical models

BackgroundMesenchymal Stromal Cells (MSCs) are the preferred candidates for therapeutics as they possess multi-directional differentiation potential, exhibit potent immunomodulatory activity, are anti-inflammatory, and can function like antimicrobials. These capabilities have therefore encouraged scientists to undertake numerous preclinical as well as a few clinical trials to access the translational potential of MSCs in disease therapeutics. In spite of these efforts, the efficacy of MSCs has not been consistent—as is reflected in the large variation in the values of outcome measures like survival rates. Survival rate is a resultant of complex cascading interactions that not only depends upon upstream experimental factors like dosage, time of infusion, type of transplant, etc.; but is also dictated, post-infusion, by intrinsic host specific attributes like inflammatory microniche including proinflammatory cytokines and alarmins released by the damaged host cells. These complex interdependencies make a researcher’s task of designing MSC transfusion experiments challenging.MethodsIn order to identify the rules and associated attributes that influence the final outcome (survival rates) of MSC transfusion experiments, we decided to apply machine learning techniques on manually curated data collected from available literature. As sepsis is a multi-faceted condition that involves highly dysregulated immune response, inflammatory environment and microbial invasion, sepsis can be an efficient model to verify the therapeutic effects of MSCs. We therefore decided to implement rule-based classification models on data obtained from studies involving interventions of MSCs in sepsis preclinical models.ResultsThe rules from the generated graph models indicated that survival rates, post-MSC-infusion, are influenced by factors like source, dosage, time of infusion, pre-Interleukin-6 (IL-6)/ Tumour Necrosis Factor- alpha (TNF-α levels, etc.ConclusionThis approach provides important information for optimization of MSCs based treatment strategies that may help the researchers design their experiments.

A Review of the Literature: Amniotic Fluid "Sludge"-Clinical Significance and Perinatal Outcomes.

Introduction: This paper seeks to report and emphasize the most important aspects from the scientific literature about the diagnostic accuracy of the amniotic fluid "sludge" (AFS), its characterization, its treatment, and its association with premature birth. AFS is defined as a floating freely hyperechogenic material within the amniotic cavity in the proximity of the internal os. Materials and Methods: We conducted a search on Pubmed and Google Scholar for relevant articles on the subject of amniotic fluid "sludge" published until January 2024. Searches were focused on articles about diagnosis, treatment, maternal and neonatal outcomes, risk of preterm birth, and case reports. The full-text reading stage resulted in the inclusion of 51 studies. Results: AFS is independently associated with chorioamnionitis, preterm delivery, short cervix, increased risk of neonatal morbidity, and cervical insufficiency. This hyperechogenic free-floating material is linked with preterm birth before 32 weeks of gestation, especially when it is associated with short cervical length. Discussion: Present studies identify some controversial benefits of antibiotics in reducing the incidence of preterm birth in women with AFS. Nevertheless, in this review, we can conclude that the presence of AFS in pregnancy is a marker for the microbial invasion of the amniotic cavity, as it is associated with preterm birth. Further studies on a larger group of patients are necessary to clarify and exactly define the terms of managing these cases.

Host long noncoding RNAs in bacterial infections.

Bacterial infections remain a significant global health concern, necessitating a comprehensive understanding of the intricate host-pathogen interactions that play a critical role in the outcome of infectious diseases. Recent investigations have revealed that noncoding RNAs (ncRNAs) are key regulators of these complex interactions. Among them, long noncoding RNAs (lncRNAs) have gained significant attention because of their diverse regulatory roles in gene expression, cellular processes and the production of cytokines and chemokines in response to bacterial infections. The host utilizes lncRNAs as a defense mechanism to limit microbial pathogen invasion and replication. On the other hand, some host lncRNAs contribute to the establishment and maintenance of bacterial pathogen reservoirs within the host by promoting bacterial pathogen survival, replication, and dissemination. However, our understanding of host lncRNAs in the context of bacterial infections remains limited. This review focuses on the impact of host lncRNAs in shaping host-pathogen interactions, shedding light on their multifaceted functions in both host defense and bacterial survival, and paving the way for future research aimed at harnessing their regulatory potential for clinical applications.

Flourishing in Darkness: Protist Communities of Water Sites in Shulgan-Tash Cave (Southern Urals, Russia)

Karst caves, formed by the erosion of soluble carbonate rocks, provide unique ecosystems characterized by stable temperatures and high humidity. These conditions support diverse microbial communities, including wall microbial fouling, aquatic biofilms, and planktonic communities. This study discloses the taxonomic diversity of protists in aquatic biotopes of Shulgan-Tash Cave, a culturally significant site and popular tourist destination, by 18S rRNA gene metabarcoding. Our findings reveal the rich protist communities in the cave’s aquatic biotopes, with the highest diversity observed in Blue Lake at the cave entrance. In contrast, Distant Lake in the depth of the cave was inhabited by specific communities of plankton, mats, and pool fingers, which exhibited lower richness and evenness, and were adapted to extreme conditions (cold, darkness, and limited nutrients). High-rank taxa including Opisthokonta, Stramenopiles, and Rhizaria dominated all biotopes, aligning with observations from other subterranean environments. Specific communities of biotopes inside the cave featured distinct dominant taxa: amoeboid stramenopile (Synchromophyceae) and flagellates (Choanoflagellatea and Sandona) in mats; flagellates (Choanoflagellatea, Bicoecaceae, Ancyromonadida) and amoeboid protists (Filasterea) in pool fingers; flagellates (Ochromonadales, Glissomonadida, Synchromophyceae), fungi-like protists (Peronosporomycetes), and fungi (Ustilaginomycotina) in plankton. The specificity of the communities was supported by LEfSe analysis, which revealed enriched or differentially abundant protist taxa in each type of biotope. The predominance of Choanoflagellatea in the communities of cave mats and pool fingers, as well as the predominance of Synchromophyceae in the cave mats, appears to be a unique feature of Shulgan-Tash Cave. The cold-tolerant yeast Malassezia recorded in other caves was present in both plankton and biofilm communities, suggesting its resilience to low temperatures. However, no potentially harmful fungi were detected, positioning this research as a baseline for future monitoring. Our results emphasize the need for ongoing surveillance and conservation efforts to protect the fragile ecosystems of Shulgan-Tash Cave from human-induced disturbances and microbial invasions.

Characterization of ultrasonic-assisted antifungal film loaded with fermented walnut meal on Rosa roxburghii Tratt during near-freezing temperature storage.

Fermented walnut meal (FW) has antifungal activity against Penicillium victoriae, a fungus responsible for Rosa roxbughii Tratt spoilage. This study characterized and applied ultrasonic-assisted antifungal film loaded with FW to preserve R. roxbughii Tratt during near-freezing temperature (NFT). Results showed that O2 and CO2 transmission rates decreased by 80.02% and 29.05%, respectively, and antimicrobial properties were improved with ultrasound at 560W for 5min and 1% FW. Fourier transform infrared spectroscopy and X-ray diffraction results revealed ultrasound improved hydrogen bonds and inductive effect via ─NH, ─OH, and C═O bonds. The addition of FW led to the formation of CMCS-GL-FW polymer via C═O bond. Thermogravimetric analysis and transmission electron microscope results demonstrated thermal degradation process was decomposed by ultrasound, and the internal structure of P. victoriae was accelerated by the addition of FW. Compared to the U-CMCS/GL group, the vitamin C content, peroxidase, and catalase activities of U-CMCS/GL/FW were enhanced by 4.24%, 8.52%, and 14.3% during NFT (-0.8 to -0.4°C), respectively. Particularly, the fungal count of the U-CMCS/GL/FW group did not exceed 105 CFU g-1 at the end of storage, and the relative abundance of P. victoriae decreased to 0.007%. Our findings provide an effective route for agricultural waste as natural antifungal compounds in the active packaging industry. PRACTICAL APPLICATION: In this study, the barrier and antimicrobial properties of film were successfully improved by ultrasonic treatment and loaded fermented walnut meal. The ultrasonic-assisted antifungal film loaded with fermented walnut meal effectively delayed the degradation of nutrients and reduced microbial invasion of Rosa roxburghii Tratt. These results provide a theoretical basis for the application of agricultural waste in the food packaging industry.

Intratumoral Microbiome in Head and Neck Paragangliomas.

Head and neck paragangliomas (HNPGLs) are rare neoplasms arising from paraganglia of the parasympathetic nervous system. HNPGLs are characterized by high vascularity and are located in proximity to major vessels and nerves, which may be potential sources of microbial invasion in these tumors. There have been no studies in the literature on the microbiota in HNPGLs. Investigation of the microbiome associated with paragangliomas is important for understanding tumor pathogenesis. In this study, we investigated the microbiome composition in two sets of HNPGLs. First, 29 fresh frozen (FF) tissues were subjected to 16S rRNA gene sequencing; concurrently, a panel of candidate laboratory-derived contaminants was investigated. Second, we analyzed microbial reads from whole transcriptome sequencing data obtained for 82 formalin-fixed paraffin-embedded (FFPE) HNPGLs. The bacterial diversity in FF tumors was found to be significantly lower than that observed in FFPE HNPGLs. Based on 16S rRNA gene sequencing, only seven bacterial families were identified as potential tumor inhabitants: Bryobacteraceae, Enterococcaceae, Neisseriaceae, Legionellaceae, Vibrionaceae, Obscuribacteraceae, and Mycobacteriaceae. However, RNA-Seq demonstrated higher sensitivity for identifying microbiome composition and revealed abundant bacterial families that partially correlated with those previously described in pheochromocytomas and extra-adrenal paragangliomas. No viruses were found in HNPGLs. In summary, our findings indicated the presence of a microbiome in HNPGLs, comprising a number of bacterial families that overlap with those observed in pheochromocytomas/paragangliomas and glioblastomas.