Search Results (2,617)

Biofilm formation represents a key survival strategy employed by Vibrio cholerae to adapt to the complex intestinal environment of the host. While most previous studies on V. cholerae biofilms have focused on genetic regulation and monospecies cultures, its ability to form dual-species biofilms with other intestinal pathogens is still poorly understood. In this study, using samples from both cholera patients and healthy individuals, Fusobacterium nucleatum was identified as a bacterium capable of co-aggregating with V. cholerae. Untargeted metabolomic analysis revealed that F. nucleatum-derived metabolites, specifically 6-hypoxanthine, enhance biofilm formation in V. cholerae. Further validation confirmed that these F. nucleatum-derived metabolites upregulate the biofilm-associated regulatory gene vpsT. In an adult mouse model, co-infection with F. nucleatum and V. cholerae significantly enhanced the intestinal adaptability of V. cholerae compared to infection with V. cholerae alone. Together, these findings elucidate the mechanism enabling the co-infection of F. nucleatum and V. cholerae in the host intestine, thereby shedding new light on how other pathogenic bacteria can assist in V. cholerae infection. Full article

Background: Behçet-like syndrome (BLS) refers to the presence of Behçet’s disease (BD) features occurring in association with distinct clinical–pathological conditions such as inborn errors of immunity, myeloproliferative disorders, infections, or drug exposure. BLS may differ clinically from BD and is increasingly recognized as a separate entity. Distinguishing BLS from primary BD is essential for appropriate management, and studying BLS may provide insights into BD pathogenesis. Objectives: To summarize clinical features, treatments, and genetic abnormalities reported in BLS, we reviewed all published cases up to January 2024. Methods: A systematic search of PubMed, Scopus, and Embase was performed using the terms “Behçet-like syndrome”, “Behçet-like disease”, and “Pseudo-Behçet disease”. We included English-language reports of patients > 12 years old with a defined underlying etiology and Behçet-like manifestations, defined by ≥2 ICBD criteria and/or gastrointestinal involvement, mucosal ulcers, thrombosis, or non-recurrent disease. Epidemiological, clinical, laboratory, histological, and treatment data were extracted and analyzed descriptively. Results: Of 679 publications, 53 met inclusion criteria, comprising 100 patients with BLS. The median age was 44 years (IQR 22–52), with a female predominance (1:2). Fifty-three percent were from non-European countries. A genetic disorder was identified in 70% of cases, while HLA-B51 was present in 10%. Frequent manifestations included skin lesions (68%), fever (56%), intestinal involvement (43%), and joint symptoms (43%). Treatments included glucocorticoids (65%), conventional DMARDs (32%), and biologics (22%), mainly anti-TNF agents. Antiviral/antibiotic therapy was used in 9% and chemotherapy in 15%. Two patients with trisomy-8 MDS underwent allogeneic stem cell transplantation. Conclusions: Diverse conditions—including monogenic diseases, immune defects, myeloproliferative disorders, infections, and drug-related reactions—can produce Behçet-like features. Our findings highlight differences in clinical expression and treatment response across BLS etiologies. Recognizing BLS is essential for appropriate management and may contribute to a deeper understanding of BD pathogenesis and future targeted therapies. Full article

Gastric cancer (GC) is the fifth most common cancer worldwide, with the highest incidence in East Asia. Although H. pylori is a well-known risk factor, carcinogenesis can occur independently of H. pylori infection, and approximately 43% of adults carry H. pylori as part of their native microbiota. This study aimed to identify potential oral and gastric microbial markers across different histological stages of GC in both H. pylori-positive and -negative patients. Buccal swabs and gastric mucosa samples were collected from patients with intestinal metaplasia, low-grade dysplasia, high-grade dysplasia, early GC, or advanced GC. Total DNA was extracted, and 16S rRNA gene amplicon sequencing was performed. Microbiome diversity generally remained stable across histological stages, with no directional shifts in community structure. Differential abundance analysis revealed higher relative abundances of Anaerostipes, Phocaeicola, and Collinsella in the gastric antrum of cancerous samples. Anaerostipes and Phocaeicola are typically enriched in the intestinal microbiota but are rarely observed in the stomach, suggesting their potential ecological and pathological relevance in gastric carcinogenesis. In H. pylori-negative patients, however, a different stage-associated abundance pattern was observed, in which Faecalibacterium, a genus predominantly associated with the intestinal environment, was less abundant in advanced gastric cancer samples than in earlier histological stages within the gastric body. These findings suggest that microbial changes during gastric cancer progression may follow different trajectories depending on H. pylori infection status. In oral samples, Haemophilus and Prevotella were more abundant in intestinal metaplasia than in low-grade dysplasia, and network analysis indicated links between Neisseria and Filifactor at oral and gastric sites. However, as the study population was limited to a single country and ethnicity, the applicability of these microbial markers should be carefully considered. Full article

Astroviruses are non-enveloped, positive-sense single-stranded RNA viruses known to infect various mammals and birds, including humans, often causing gastrointestinal disorders. In recent years, astroviruses have also been linked to neurological and respiratory diseases across several species, including ruminants, mink, deer, and other mammals. Notably, astrovirus infections in goats have been documented in countries such as Switzerland and China, where novel genotypes have been identified in fecal samples. However, their role in the context of disease remains unclear, and reports focusing solely on goat astrovirus in the United States have not been published. A necropsy case of a Boer goat kid with a history of diarrhea was submitted for investigation following death in January 2025. Fresh tissues were received and used for histopathology and enteric pathogen testing, including parasitic, bacterial, and viral workups. Metagenomic-based next-generation sequencing (mNGS) was also applied for this case. Histological examination revealed severe necrotizing enterocolitis. The small intestine exhibited epithelial ulcerations, villus atrophy, hyperplastic and dilated crypts with necrotic debris, few intraenterocytic coccidian parasites, and increased inflammatory cells in the lamina propria. The large intestine showed similar findings with pleomorphic crypt enterocytes. Standard enteric pathogen tests were negative except for aerobic culture that identified Escherichia.coli and Enterococcus hirae. mNGS and bioinformatic analysis identified a novel astrovirus in the intestinal content that showed the highest nucleotide identity (86%) to the sheep strain Mamastrovirus 13 sheep/HA3 from China based on BLAST analysis. Phylogenetic analysis indicated that the newly identified caprine astrovirus IL90175 clustered with astrovirus strains from small ruminants in Asia and Europe. This research reports the discovery, histopathologic features, and genetic characteristics of a gastrointestinal disease-causing astrovirus in a goat kid, which had not been previously described in the United States. Full article

Adherent-invasive E. coli (AIEC) is closely related to inflammatory bowel disease (IBD). However, its pathogenic mechanism has not yet been fully elucidated. Using a BLASTP search, we discovered that the amino acid sequence of a putative protein (UFP37798.1) in the AIEC LF82 strain is highly homologous to some regulators in the SlyA family. We named it EruA. We displayed the secondary structures of EruA using bioinformatics, overexpressed the His₆-tagged EruA protein using SDS-PAGE, and dissected the genetic organization of the eruA chromosomal region using 5′RACE. We constructed an eruA deletion mutant (ΔeruA) and a complementary strain (CΔeruA) of the LF82 strain. The transcriptomes of wild-type (WT) and ΔeruA bacteria were compared using RNA sequencing and qRT-PCR, thereby identifying 32 differentially expressed genes (DEGs). Based on YASARA software and EMSA analysis, EruA directly binds to the consensus sequences (P_fimA and P_tnaB) in the promoter region of the fimA and tnaB genes from these DEGs. By using a super-resolution confocal microscope (SCM), counting CFUs of colonies on plates, indole quantification, and crystal violet staining of biofilms adhered to tubes or 96-well plates, we found that EruA activates the fimA to promote bacterial adhesion to intestinal epithelial cells and activates the tnaB to enhance bacterial indole production and biofilm formation. Moreover, EruA helps AIEC resist environmental stress and enhances bacterial survival within macrophages as well as loading in mouse tissues. Notably, EruA promotes AIEC colonization in the colons of mice and exacerbates intestinal inflammation caused by bacterial infection in mice with DSS-induced inflammatory colitis, manifested by weight loss, colon length shortening, and pathological changes in colon tissues. Therefore, EruA plays a key role in the pathogenicity of AIEC. Full article

The gut–heart axis represents a key determinant of cardiovascular (CV) system health. Emerging evidence indicates that intestinal dysbiosis can induce a state of chronic systemic inflammation which, together with mechanisms of endothelial dysfunction, increases the risk of CV diseases. Infective endocarditis (IE) exemplifies this concept, as microbiota alterations may promote bacterial translocation from the gut into the bloodstream, leading to colonization of cardiac valves and subsequent endocardial infection. This narrative review examines current scientific evidence on the relationship between the gut microbiota and CV diseases, with a particular focus on IE. We also summarize the mechanisms underlying impaired intestinal barrier integrity, immune activation, and the production of microbiota-derived metabolites that contribute to CV disease. Special attention is given to potential preventive and therapeutic strategies, including microbiota modulation, targeted antibiotic management, and personalized medicine approaches tailored to individual patient profiles. Full article

Invasive Candida infections in the neonatal intensive care unit (NICU) are associated with significant morbidity and mortality, particularly among extremely preterm neonates. Early treatment with antifungals is critical to improve survival rates and avoid long-term adverse outcomes. Prevention with antifungal prophylaxis in high-risk neonates has been shown to reduce the prevalence of invasive Candida infections effectively. However, the irrational and/or inappropriate use of antifungals has been documented. This narrative review aims to provide an overview of the rationales for the inappropriate use of antifungals in the NICU, the consequences that ensue, and the promising strategy of antifungal stewardship programs to optimize antifungal use. The nonspecific clinical presentation of systemic Candida infections and the lack of rapid, accurate diagnostic techniques for Candida identification and specification in most settings lead to a high rate of empirical treatment in neonates without a proven infection. Moreover, evidence on the optimal dosing of antifungal agents and the treatment duration in the neonatal population is lacking, which may result in excessive or subtherapeutic drug exposure. Antifungal misuse is associated with microbiological consequences, including the emergence of antifungal-resistant Candida strains, and clinical consequences, such as drug toxicities and alterations in the intestinal mycobiome. It is therefore imperative to optimize antifungal use in the NICU. The implementation of antifungal stewardship programs, which, through a multidisciplinary approach, aim to improve diagnosis and guide clinicians on antifungal selection, dosing, and duration for both prevention and treatment according to the local epidemiology, represents a promising strategy for antifungal optimization in the NICU. Full article

Spirometra mansoni is a zoonotic parasite that inhabits the intestines of dogs and cats. The plerocercoids (spargana) parasitize several vertebrates, including humans, resulting in a food-borne zoonosis known as sparganosis. In this study, it has been established that a LAMP assay can detect S. mansoni eggs in dog feces. A total of 97 fecal samples were collected from Changsha City, Hunan Province. The fecal DNA was extracted before designing primers for LAMP based on the S. mansoni cox1 gene. The specificity of this method was verified by PCR using LAMP outer primers or inner primers and nested PCR with S. mansoni-specific cox1 primers. DNA samples from five control dog worms were analyzed using the LAMP assay to evaluate the specificity. The detection rate of LAMP for S. mansoni eggs was 70.21% in stray dogs. PCR and nested PCR produced specific bands on agarose gel electrophoresis consistent with the expected length. When the LAMP assay was conducted using S. mansoni-infected samples, negative samples, and genomic DNA from control worms, only the S. mansoni-infected samples showed a typical ladder pattern. The samples were stained with SYBR Green I, and only the S. mansoni-infected samples had a fluorescent signal. In addition, compared with PCR and microscope, LAMP method can detect eggs in the shortest infection days, and its detection rate was higher than that of PCR. These results suggest that the established LAMP method have many advantages in detecting Spirometra mansoni. Full article

Inflammatory bowel diseases (IBD) are increasingly acknowledged not merely as confined gastrointestinal disorders but as systemic immunometabolic syndromes. Central to this paradigm is the gut microbiota including non-bacterial components such as the virome, whose functional disruption marked by reduced short-chain fatty acids (SCFAs), increasingly implicated in pathogenic processes extending beyond intestinal mucosa. This review outlines how these alternations compromise the epithelial barrier and immune regulation, increasing the risk of recurrent Clostridioides difficile infections to anemia, neuropsychiatric comorbidities, and extraintestinal manifestations. We critically evaluate emerging microbiota-targeted strategies, including fecal microbiota transplantation (FMT), live biotherapeutic products (LBPs), and precision postbiotics, positioning them as potential adjuncts to conventional immunosuppression. Finally, we discuss the current barriers to clinical translation, such as safety and heterogeneity, and propose a future framework for personalized, functionally integrated IBD care aimed at restoring long-term microbiota homeostasis. Full article

The preventive effect of leucine (Leu) against colonic damage in piglets infected with porcine epidemic diarrhea virus (PEDV) was examined in this study. Three groups (n = 6) were randomly assigned to eighteen 7-day-old Du-roc × Landrace × Large piglets (body weight [BW] = 2.58 ± 0.05 kg): Control, PEDV-infected (PEDV), and Leu-supplemented + PEDV-infected (Leu + PEDV). Following a three-day period of acclimatization, the Leu + PEDV group was given Leu (400 mg/kg BW) orally every day. On day eight, the PEDV and Leu + PEDV groups were challenged with PEDV, while the Control group was given Dulbecco’s Modified Eagle’s Medium. Colonic tissues were collected on day 11. PEDV infection induced severe colonic damage by an increase in crypt, disrupting intestinal homeostasis, including impaired barrier integrity (matrix metalloproteinase-7 and matrix metalloproteinase-13 upregulation), mucus disorganization (mucin 5AC elevation), oxidative stress (reduced catalase activity and increased malondialdehyde levels), inflammation, electrolyte imbalance and enhanced viral replication. Leu supplementation reversed these injuries by alleviating oxidative stress, suppressing inflammation, inhibiting viral replication and stabilizing ion homeostasis. This study provides a scientific basis for Leu as a nutritional intervention to alleviate PEDV-induced colonic damage in piglets. Full article

Human microbiota, a complex consortium of microorganisms co-evolved with the host, profoundly influences tissue development, immune regulation, and disease progression. Growing evidence shows that microbial metabolites and signaling molecules modulate key stem cell pathways—such as Hedgehog, Wnt/β-catenin, and Notch—thereby reprogramming stem cell fate toward tumor-suppressive or tumor-promoting outcomes. Specific taxa within oral, intestinal, and urogenital niches have been linked to cancer initiation, therapy resistance, and recurrence. In parallel, clinical studies reveal that microbiota composition affects infection dynamics: bacterial isolates from symptomatic urinary tract infections inhibit commensal growth more strongly than the reverse, with Gram-positive and Gram-negative strains displaying distinct interaction profiles. Collectively, these findings highlight microbiota’s dual role in regulating cellular plasticity and pathogenicity. Elucidating host–microbe and microbe–microbe mechanisms may guide microbiota-targeted interventions to improve cancer and infectious disease management. Full article

Background/Objectives: Antimicrobial peptides (AMPs), evolutionarily conserved components of innate immunity characterized by their broad-spectrum efficacy and minimal resistance development, are increasingly recognized as promising therapeutic candidates. This review aims to integrate current knowledge concerning natural and synthetic antimicrobial peptides and their therapeutic effectiveness in addressing gastrointestinal infections. Methods: A literature review was performed, evaluating recent peer-reviewed studies on AMPs. The research concentrated on their molecular mechanisms of action, antimicrobial spectrum, and their interactions with standard antibiotics. More in detail, the peptide classes examined herein included defensins, cathelicidins, histatins, and various natural peptides such as lactoferricin, protamines, RegIII, and hepcidin, along with synthetic analogs like WR12, D-IK8, MSI-78, and IMX942. Results: Natural AMPs demonstrated significant antimicrobial and immunomodulatory effects against Escherichia coli, Klebsiella pneumoniae, Salmonella spp., and Shigella spp. Beyond direct antimicrobial activity, antimicrobial peptides act as integrated anti-infective agents not only by modulating host–microbiota interactions, but also preserving epithelial barrier integrity, and limiting inflammation, thereby offering a multifaceted strategy to control gastrointestinal infections. On the other hand, synthetic peptides showed improved stability, reduced cytotoxicity, and synergistic interactions with antibiotics, which suggests that they could be used either alone or in combination with other treatments. Conclusions: AMPs constitute a promising category endowed with anti-infective activity, especially for therapy of intestinal diseases, which is attributed to their distinctive anti-infective mechanisms, immune-modulating characteristics, and a relatively low propensity for resistance development compared to conventional antibiotics. However, more clinical trials and improvements to their formulation are needed to translate promising in vitro results into reliable patient outcomes. Full article

Aquaculture has been established as a sustainable alternative to traditional fisheries, which face challenges such as overexploitation and environmental degradation. However, disease outbreaks, often caused by poor farming conditions, pollution, and environmental stress, remain a major concern, leading to economic losses and increasing the risk of antibiotic resistance due to the overuse of antibiotics. Therefore, it is crucial to seek new strategies that improve fish health and well-being, preventing drug resistance and promoting sustainable practices. GHRP-6, a synthetic growth hormone-releasing peptide that mimics ghrelin, has shown potential immunostimulatory properties and feed efficiency in fish. In this study, we evaluated the effects of orally administered GHRP-6 in an oil-based formulation on juvenile tilapia (Oreochromis sp.) challenged or unchallenged with Pseudomonas aeruginosa. We assessed its influence on immune gene expression and digestive enzyme activity. The results demonstrated that GHRP-6 treatment significantly enhanced growth performance (weight and length), reduced in vivo bacterial load after infection, and modulated key genes related to innate and adaptive immunity in the gills, intestine and head kidney. In addition, our results demonstrated, for the first time, a direct link between a growth hormone secretagogue in fish and the modulation of specific enzyme activity in the gut following a bacterial challenge. These findings highlight the potential of GHRP-6 as a dietary immunomodulator and growth promoter in fish farming, offering a promising strategy to reduce antibiotic usage and promote more sustainable aquaculture practices. Full article

Background: Non-typhoidal Salmonella (NTS) is a major foodborne pathogen, with poultry products, especially eggs, being the primary source of human infections. Current serovar-specific poultry vaccines effectively reduce targeted Salmonella serovars but may inadvertently promote the emergence of untargeted serovars within poultry flocks. Therefore, novel vaccine candidates providing broad cross-serovar protection are needed to improve overall effectiveness of Salmonella control programs. Objectives: This study evaluated the immunogenicity of the novel subunit vaccine candidate InvG and assessed its ability to reduce Salmonella colonization in vaccinated laying hens and their progeny through maternally derived antibodies transferred via egg yolk. Methodology: Three experiments were performed. Experiment I evaluated the immunogenicity of purified recombinant InvG by (a) measuring anti-InvG antibodies using an enzyme-linked immunosorbent assay (ELISA) and (b) completing transcriptomic profiling of immune responses in vaccinated chickens. Vaccinated chickens were subsequently challenged with Salmonella Enteritidis to assess the efficacy of anti InvG antibodies in reducing intestinal colonization of Salmonella. Experiment II involved immunizing hens with InvG, to evaluate passive transfer of antibodies via egg yolk and the protective efficacy of maternally derived antibodies against Salmonella challenge. Passive transfer was assessed by measuring IgY antibodies in hen serum, egg yolk, and progeny serum, as well as secretory IgA (sIgA) antibodies in progeny intestinal washings using ELISA. Protective efficacy was evaluated by orally challenging one-day-old chicks with three different Salmonella serovars. Experiment III assessed the persistence of anti-InvG antibodies in the serum of vaccinated hens and their transfer into eggs following two doses of InvG. Results: InvG vaccination induced robust IgY antibody responses in hens, with efficient maternal antibody transfer to progeny via egg yolk. A statistically significant reduction in Salmonella colonization was observed in both vaccinated hens and their progeny. Conclusions: These findings demonstrate that InvG represents a promising subunit vaccine candidate for Salmonella control in poultry and warrants further investigation towards development as a broadly protective commercial poultry vaccine against Salmonella. Full article

The primary objective of this study was to investigate the mechanism through which small peptides regulate the productive performance and egg quality of laying hens during the late-laying period. A total of 200 Lohmann Pink laying hens, aged 400 days, were randomly assigned into a control treatment (CON) and a small peptide treatment (SP) for a 120-day treating period. Productive performance, egg quality, serum antioxidant capacity, intestinal morphology, microbial community, and hepatic gene expressions were measured. Results showed that SP supplementation significantly increased eggshell strength and albumen height, while reducing the rate of abnormal eggs (p < 0.05). SP notably enhanced the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and hepatic lipase (p < 0.05). Additionally, SP supplementation significantly increased microbial α-diversity (p < 0.05) and elevated the relative abundances of Ruminococcus, Lactobacillus, and Faecalibacterium (p < 0.05). Hepatic transcriptomic analysis revealed that up-regulated genes in the SP treatment were primarily enriched in steroid biosynthesis, while down-regulated genes were mainly associated with the Yersinia infection pathway. In conclusion, small peptide supplementation efficiently improved eggshell strength and albumen height while reducing the rate of abnormal eggs by modulating the interactions between gut microbiota and hepatic gene expressions. Our findings may provide an effective option for enhancing egg quality in the late-laying period. Full article