Search Results (61)

Recent studies indicate that fucoidan may play a crucial role in the metabolism and biological function of the intestinal flora. This study investigates the therapeutic potential of kelp fucoidan on the gut microbiota and immune homeostasis of cyclophosphamide-induced immunosuppressed mice. An immunosuppressive mouse model was established using cyclophosphamide, followed by administration of various kelp fucoidan doses (low-dose fucoidan: 50 mg/(kg·bw)/d, medium-dose fucoidan: 100 mg/(kg·bw)/d, and high-dose fucoidan: 150 mg/(kg·bw)/d) to the experimental groups. Changes in the gut microbiota structure were analyzed using 16S rRNA high-throughput sequencing, alongside simultaneous measurement of serum immune indicators and levels of short-chain fatty acids (SCFAs). Results indicate that kelp fucoidan significantly improved the thymus and spleen indices in immunosuppressed mice (p < 0.05) and elevated serum levels of IgM, IgG and IL-4. Post-kelp fucoidan intervention, there was significant alteration in microbiota ecosystem restructuring, such as proliferation in probiotics, including Lactobacillus and Bifidobacterium, while opportunistic pathogens, such as Enterococcus and Escherichia coli, decreased. Furthermore, the levels of acetic, propionic, and butyric acids in the colonic contents of the kelp fucoidan group significantly improved (p < 0.01). This research demonstrates that kelp fucoidan enhances immune function in immunosuppressed mice by modulating gut microbiota balance and promoting short-chain fatty acid production. Full article

Honey is a natural product produced by bees from the nectar of plants and has been widely used as a sweetener for centuries. In addition to its traditional use, it is also employed for other purposes due to its biological and nutraceutical properties. Although honey production is mostly associated with bees of the genus Apis, species from other genera, such as Melipona, also produce it, albeit on a smaller scale. The honey produced by these two genera shows significant differences in its composition. Moreover, distinct geographical localizations, which, consequently, have different flora, guide the chemical compositions of these samples. Regarding the Amazon region, the amount of knowledge about the honey samples from Melipona species is still scarce. In this context, the present study aimed to characterize the volatile compositions of honey from Melipona interrupta and Melipona seminigra, as well as from the floral sources available, in addition to evaluating their nutritional aspects, antioxidant activity, and antibacterial activity. The analysis of chemical composition was performed using gas chromatography coupled to mass spectrometry (GC-MS). Antioxidant activity was determined by DPPH and ABTS assays, while antimicrobial activity was tested against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus epidermidis, Enterococcus faecalis, Salmonella enterica, Serratia marcescens, Bacillus subtilis, Candida albicans, Candida tropicalis, and Candida parapsilosis. The results allowed the identification of volatiles present in the honey and floral sources. The samples displayed moderate antioxidant activity and slightly antibacterial activity (MIC) of 75 μg/mL against two bacterial strains tested, demonstrating potential antimicrobial activity. Full article

Piglet diarrhea caused by weaning stress will increase the mortality rate and seriously affect swine industry production efficiency. Probiotic supplementation has been reported to effectively alleviate weaning diarrhea by inhibiting the colonization of pathogenic microorganisms; however, the underlying mechanisms remain unclear. In this study, we isolated a strain of Bacillus velezensis and conducted a series of in vivo and in vitro experiments to explore its effects on weaned piglets. The piglets were fed for a 28-day period, and the results showed that dietary supplementation of B. velezensis 411 significantly alleviated weaning diarrhea (p = 0.019) and improved the average daily gain (ADG) of piglets throughout the experimental period (p = 0.004). The intestinal antioxidant capacity of piglets was also significantly enhanced. Whole-genome sequencing revealed that B. velezensis 411 contains a protein-encoding circular chromosome, which is involved in biological processes such as sporulation and antibiotic secretion. Supplementation with B. velezensis 411 significantly increased the abundance of Akkermansia in intestine samples and significantly decreased the abundance of pathogenic bacteria, including Escherichia coli and Staphylococcus aureus, in piglets (p < 0.05). The transcriptomic results suggest that B. velezensis 411 supplementation may alter the composition of intestinal microorganisms through regulating the expression of MPEG1. Collectively, dietary B. velezensis can relieve diarrhea in piglets and improve their production performance by influencing the antioxidant capacity of the intestines and the balance of the intestinal flora. This study provides valuable insights into the potential application of Bacillus velezensis in mitigating weaning-associated issues in piglets. Full article

Background: Chronic rhinosinusitis (CRS) affects 5.5–28% of the population and is primarily an inflammatory disease, with microbiota potentially playing a key role. Understanding microbial pathogens and resistance patterns is crucial for effective management. This study aimed to evaluate the incidence of Gram-negative rods in CRS in adults as a part of a prospective microbiological study. Methods: Over one year, paranasal sinus mucosa samples from CRS patients and nasal concha samples from controls were analyzed. Cultivable bacterial flora was assessed using culture-based methods. Biofilm formation was evaluated via a microtiter-plate assay, and antibiotic susceptibility was tested using the disk diffusion method. Results: Tissue samples from 74 CRS patients and 47 controls yielded 198 bacterial strains. Gram-positive cocci dominated, while Gram-negative rods accounted for 17.6%, with Escherichia coli, Klebsiella oxytoca, and Citrobacter spp. being most common. All Gram-negative rods formed biofilms in vitro. They were susceptible to cefotaxime, aztreonam, ciprofloxacin, and meropenem but showed varying sensitivity to ampicillin (20–67%), tigecycline (40–57%), and amoxicillin/clavulanic acid (73–83%). Conclusions: The result of this study underlines that treatment of CRS should be based on the result of drug susceptibility testing of the isolated microorganism. Full article

Background/Objectives: In the context of increasing bacterial resistance and the need for effective ophthalmic antiseptics, this study evaluates the antimicrobial efficacy of Corneial MED^®, a novel ophthalmic solution containing polyhexamethylene biguanide (PHMB) and cross-linked hyaluronic acid. The study investigates the in vitro fungicidal and bactericidal properties of this solution against clinically relevant fungal and bacterial strains and its impact on conjunctival flora in vivo. Methods: The in vitro assessment included time-kill assays to determine the fungicidal or fungistatic activity against Candida albicans, Aspergillus flavus, and Aspergillus fumigatus. The bactericidal activity was evaluated against Staphylococcus aureus (methicillin-sensitive and -resistant), Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. In vivo, 43 patients undergoing cataract surgery were treated with the solution for three days preoperatively. Results: Corneial MED^® demonstrated a fungistatic effect against C. albicans and A. fumigatus, while it exhibited limited activity against A. flavus. The tested solution effectively reduced bacterial load within minutes, outperforming competitor ophthalmic solutions in activity against P. aeruginosa and E. coli. Conjunctival swabs indicated a significant reduction in bacterial load post-treatment, confirming the solution’s efficacy in reducing potential ocular pathogens. Conclusions: These findings highlight the potential of PHMB-based antiseptic solutions as a viable alternative to traditional disinfectants, particularly for preoperative prophylaxis and infection control. Further clinical trials are needed to confirm long-term safety and efficacy. The combination with cross-linked hyaluronic acid not only enhances tolerability but also extends antimicrobial action, making it a promising candidate for ophthalmic disinfection. Full article

The drinking water cycle consists of the stages of untreated water, potable water, and sewage. Escherichia coli is considered an indicator of the fecal contamination of water since it is a common bacterium of the intestinal flora of humans and warm-blooded animals and is a carrier of many antibiotic resistance genes. The aim of this investigation was to assess the level of drug resistance of coliforms and E. coli isolates in samples of drinking water submitted from various sites of Central South Greece during the period 2018–2022. The highest resistance rates among both E. coli and coliform isolates were observed against ampicillin. The analysis of drug resistance conducted with reference to antibiotic groups indicated that most AMR and/or MDR isolates of E. coli or coliforms exhibited resistance against group A (ampicillin and amoxicillin/clavulanic acid). The most frequent phylogroup of the E. coli isolates was B1 followed by groups A and B2. The genus assignment for the coliform isolates other than E. coli was Enterobacter, Citrobacter, Klebsiella, and Serratia. In conclusion, various bacteria can be transferred from one stage of the drinking water cycle to the next, either through the normal operation of the cycle or due to system failures, with the consequence that even drinking water contains various bacteria, pathogenic or non-pathogenic. Full article

Background/Objectives: The gut microbiota is involved in modulating gastrointestinal function and consequently contributes to the manifestation of functional gastrointestinal disorders (FGIDs). The aim of the study was to analyze the composition of the gut microbiota in infants with functional gastrointestinal disorders (infantile colic, functional constipation, gastroesophageal reflux, functional diarrhea) according to age, environmental factors, and clinical manifestations. Methods: The study involved the clinical and laboratory examination of 134 infants divided into two groups: group I (n = 82) with FGIDs according to Rome IV criteria, divided into four subgroups (infantile colic, functional constipation, gastroesophageal reflux, and functional diarrhea), and group II (n = 52) without FGIDs. To assess the composition of intestinal microbiota, a bacteriological analysis of fecal samples was performed. Results: Infants with functional gastrointestinal disorders presented an imbalance of intestinal microflora, which was characterized by a significant decrease in the main representatives of acidifying flora represented by Lactobacillus, Bifidobacterium, and Enterococcus and high abundance of proteolytic microorganisms from the Enterobacteriaceae family such as Klebsiella species and Escherichia coli. In infants born by cesarean section or artificially fed, the incidence of functional gastrointestinal disorders and intestinal dysbiosis was significantly higher. Conclusions: The imbalance of acidifying and proteolytic microbial composition in the gut could be the key to the occurrence of functional gastrointestinal disorders in the first year of life. Full article

Escherichia coli (E. coli) is a common pathogen that causes diarrhea in newborns and animals. Antibiotics are typically used to treat bacterial diarrhea, a global intestinal health issue. Probiotics have gained interest as a potential substitute for antibiotics in the management of E. coli-induced diarrhea and present novel therapeutic options. In this study, the probiotic properties of Lactobacillus agilis SNF7 (L. agilis SNF7) isolated from feces were investigated, and whole genome sequencing was performed to evaluate the properties of the strain. Furthermore, we investigated the protective effects of L. agilis SNF7 in a mouse model of E. coli K99 infection. L. agilis SNF7 exhibits a high survival rate in artificial gastroenteric fluid and bile salt environments, along with an antagonistic effect against E. coli O₁₁₁:K₅₈ (B₄), Staphylococcus aureus (S. aureus), and E. coli K99. Multiple genes with probiotic properties, including bacteriostasis, anti-inflammation, antioxidant, CAZyme, and the utilization of carbohydrate compounds, were identified in genome. L. agilis SNF7 prevented the gut barrier from being damaged by E. coli K99, reducing the clinical manifestations of the infection. Furthermore, L. agilis SNF7 reduced the expression of inflammatory cytokines (IL-6, IL-1β, and TNF-α) by inhibiting the phosphorylation of proteins linked to the NF-κB and MAPK signaling pathways. L. agilis SNF7 improved the intestinal microbial barrier, controlled the balance of the intestinal microecology, and reduced the entry of harmful microbes into the intestine. By controlling gut flora and reducing the inflammatory response, L. agilis SNF7 may be able to prevent and treat E. coli K99 infections. The application of L. agilis SNF7 in the creation of probiotic formulations to stop intestinal illnesses brought on by E. coli infections is clarified by this work. Full article

Background: The evaluation of canine vaginal bacteria during proestrus and estrus and the chosen parameters will help to prevent the misuse of antibiotics in veterinary medicine. Methods: This study carried out a retrospective analysis to obtain microbiological examination results for vaginal swabs from 696 healthy dogs, all of whom were patients from one clinic. Age, body weight, fur length (long or short hair), the time of sampling of vaginal swabs, the duration of proestrus/estrus, progesterone (P4) concentration (the first and last samples), and bacteriological findings were evaluated. Results: Only 3.7% (26/696) of the samples were negative for bacteria. The impact of fur length was low. However, the calculation of the odds ratios revealed that the chance for a high-grade growth of Escherichia (E.) coli and Mycoplasma (M.) canis increases with body weight class. The earlier the sampling was performed, the lower the number of high-grade cultures (p < 0.01). The duration between the first and last measurement of progesterone (P4) was positively related to the cultural detection of Pasteurellaceae, Streptococcus spp., and Enterococcus spp. (p < 0.05) and negatively to the cultivation of Mycoplasma spp. (p < 0.01). Conclusions: Our findings reflect some likely factors contributing to the variability of the physiological vaginal flora in dogs, which may help interpret cultured bacteriological findings. Full article

This study investigates the impact of the solid-state fermentation products of Lactobacillus plantarum, Candida utilis, and Bacillus coagulans (LCBs) on the growth characteristics, immune function, intestinal morphology, cecum microbial community, and prevention of avian colibacillosis in broilers. One hundred and twenty Hyland Brown broilers (aged one day) were divided randomly into three groups (four replicates of ten broilers per group). (1) The CON group was fed a basal diet. (2) The MOD group was fed a basal diet. On day 40, APEC strain SX02 (1.1 × 10⁵ CFU/g) was administered to the breasts of chickens in this group. (3) The LCBs group was fed a basal diet supplemented with fermentation products (98.5% basal diet + 0.5% Lactobacillus plantarum and Candida utilis solid-state fermentation products + 1.0% Bacillus coagulans solid-state fermentation products). On day 40, the LCBs group received the same treatment as the MOD group. The experiment lasted 43 days. This study found that the average daily gain (ADG) of the LCBs group was significantly higher than that of the MOD group (p < 0.05), indicating that LCBs can significantly increase the ADG of broilers and improve the feed conversion ratio. Furthermore, compared to the MOD group, the heart bacterial load was significantly reduced in the LCBs group (p < 0.05), and the lesions less severe in the heart, liver, and jejunum were observed (p < 0.05). Additionally, the detection of intestinal flora showed a significant increase in the abundance of beneficial bacteria in the cecum of the LCBs group, while the number of Escherichia coli and Shigella decreased significantly. In conclusion, the solid fermentation of Lactobacillus plantarum, Candida utilis, and Bacillus coagulans can improve the growth performance of broilers while also protecting against avian pathogenic Escherichia coli infection. This demonstrates the potential usefulness of these LCBs in feed production. Full article

Atopic dermatitis (AD) is a persistent and recurrent inflammatory skin condition with a genetic basis. However, the fundamental reasons and mechanisms behind this phenomenon remain incompletely understood. While tea extracts are known to reduce histamine-induced skin allergies and inflammation, the specific mechanisms by which various types of Chinese tea provide their protective effects are still not fully elucidated. In this study, a model of skin itching induced by histamine is used to explore the functions and mechanisms of three types of tea extract (Keemun black tea (HC), Hangzhou green tea (LC), and Fujian white tea (BC)) in alleviating histamine-induced dermatitis. The components of three tea extracts are identified by UPLC-Q-TOF-MS, and we found that their main components are alkaloids, fatty acyls, flavonoids, organic acids, and phenols. The inhibitory effects of three types of tea extract on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in skin injury are investigated by MIC and flow cytometry. The three types of tea extract have an inhibitory effect on the growth of bacterial flora, with HC showing the best inhibitory activity. The effect of the three types of tea extract on histamine-induced dermatitis is also evaluated. Furthermore, itchy skin experiments, HE staining, toluidine blue staining, and immunohistochemical staining of mouse skin tissues were performed to determine the variations of scratching, epidermal thickness, mast cell number, IL-1β, and NGF content after the administration of the tea extracts. The three types of tea extracts all alleviate and inhibit skin itching, epidermal hyperplasia, and allergic dermatitis. BC effectively alleviates epidermal hyperplasia caused by skin allergies, and LC significantly downregulates NGF. HC reduces histamine-induced mast cell infiltration and downregulates IL-1β to alleviate skin itching. Consequently, tea emerges a potent natural product that can inhibit the growth of skin wound bacterial flora and exhibit skin repair effects on histamine-induced allergic dermatitis. Full article

This study aimed to evaluate the effects of Clostridium butyricum (C. butyricum) on the prevention of the diarrhea rates and growth performances of weaned piglets induced by Escherichia coli K88 (E. coli K88). Twenty-four weaned piglets (6.92 ± 0.11 kg) were randomly assigned to one of three treatment groups for a period of 21 days. Each group consisted of eight pigs, with each pig being housed in an individual pen. Group I received the control diet along with normal saline, Group II received the control diet along with E. coli K88, and Group III received the control diet supplemented with 5 × 10⁸ CFU/kg of C. butyricum and E. coli K88. We examined alterations in rectal microbiota and metabolites, analyzed the incidence of diarrhea, and investigated the interactions between microbiota and metabolites through the application of Illumina MiSeq sequencing and liquid chromatography–mass spectrometry. The results showed that, from days 14 to 21, the diarrhea incidence in Group III decreased significantly by 83.29% compared to Group II (p < 0.05). Over the entire experimental duration, the average daily feed intake of Group III decreased significantly by 11.13% compared to Group I (p < 0.05), while the diarrhea incidence in Group III decreased by 71.46% compared to Group II (p < 0.05). The predominant microbial flora in the rectum consisted of Firmicutes (57.32%), Bacteroidetes (41.03%), and Proteobacteria (0.66%). Administering E. coli K88 orally can elevate the relative abundance of Megasphaera (p < 0.05). Conversely, the supplementation of C. butyricum in the diet reduced the relative abundance of Megasphaera (p < 0.05), while increasing the relative abundance of unclassified_f_Lachnospiraceae (p < 0.05). Rectal metabolomics analysis revealed that supplementing C. butyricum in the feed significantly altered the amino acids and fatty acids of the piglets infected with E. coli K88 (p < 0.05). The correlation analysis showed that the occurrence of diarrhea was inversely related to adipic acid (p < 0.05) and positively associated with (5-hydroxyindol-3-YL) acetic acid and L-aspartic acid (p < 0.05). Prevotella_1 exhibited a negative correlation with octadecanoic acid (p < 0.05). Prevotellaceae_UCG-005 showed a negative correlation with (5-hydroxyindol-3-YL) acetic acid (p < 0.05). The findings from this research study aid in probiotic development and the enhancement of healthy growth in weaned piglets. Full article

This experiment was conducted to study the protective effects of dietary Chinese gallotannins (CGT) supplementation against Escherichia coli lipopolysaccharide (LPS)-induced intestinal injury in broilers. Four hundred and fifty healthy Arbor Acres broilers (one-day-old) were randomly divided into three groups: (1) basal diet (CON group), (2) basal diet with LPS challenge (LPS group), and (3) basal diet supplemented with 300 mg/kg CGT as well as LPS challenge (LPS+CGT group). The experiment lasted for 21 days. Intraperitoneal LPS injections were administered to broilers in the LPS group and the LPS+CGT group on days 17, 19, and 21 of the trial, whereas the CON group received an intraperitoneal injection of 0.9% physiological saline. Blood and intestinal mucosa samples were collected 3 h after the LPS challenge. The results showed that LPS administration induced intestinal inflammation and apoptosis and damaged small intestinal morphology and structure in broilers. However, dietary supplementation with CGT alleviated the deleterious effects on intestinal morphology and barrier integrity caused by the LPS challenge, while also reducing intestinal apoptosis and inflammation, enhancing intestinal antioxidant capacity, and increasing cecal microbial alpha diversity in the LPS-challenged broilers. Therefore, our findings demonstrated that a 300 mg/kg CGT addition could improve intestinal morphology and gut barrier structure, as well as maintaining bacterial homeostasis, in broilers exposed to LPS. This might partially be attributed to the reduced cell apoptosis, decreased inflammatory response, and enhanced antioxidant capacity in the small intestinal mucosa. Full article

(1) Background: Recently, academic studies are demonstrating that the cholesterol-lowering effects of pectin oligosaccharides (POSs) are correlated to intestinal flora. However, the mechanisms of POS on cholesterol metabolisms are limited, and the observations of intestinal flora are lacking integrative analyses. (2) Aim and methods: To reveal the regulatory mechanisms of POS on cholesterol metabolism via an integrative analysis of the gut microbiota, the changes in gut microbiota structure and metabolite composition after POS addition were investigated using Illumina MiSeq sequencing and non-targeted metabolomics through in vitro gut microbiota fermentation. (3) Results: The composition of fecal gut flora was adjusted positively by POS. POS increased the abundances of the cholesterol-related bacterial groups Bacteroidetes, Bifidobacterium and Lactobacillus, while it decreased conditional pathogenic Escherichia coli and Enterococcus, showing good prebiotic activities. POS changed the composition of gut microbiota fermentation metabolites (P24), causing significant changes in 221 species of fermentation metabolites in a non-targeted metabolomics analysis and promoting the production of short-chain fatty acids. The abundances of four types of cholesterol metabolism-related metabolites (adenosine monophosphate, cyclic adenosine monophosphate, guanosine and butyrate) were significantly higher in the P24 group than those in the control group without POS addition. (4) Conclusion: The abovementioned results may explain the hypocholesterolemic effects of POS and promotion effects on cholesterol efflux of P24. These findings indicated that the potential regulatory mechanisms of citrus POS on cholesterol metabolism are modulated by cholesterol-related gut microbiota and specific metabolites. Full article

The emergence and spread of antimicrobial resistance have been significant global health challenges, exacerbated by the COVID-19 pandemic. As healthcare systems faced unprecedented pressures, the management of non-COVID conditions, including urinary tract infections (UTIs), also encountered obstacles due to changes in microbial flora and antibiotic usage patterns. This cross-sectional study aimed to characterize the antimicrobial resistance trends among bacterial uropathogens isolated from patients in the Western region of Romania, between January 2020 and December 2022. The objectives were to map the resistance patterns and observe the pandemic’s influence on antimicrobial resistance, particularly among enterobacterial Gram-negative species, to guide treatment and infection control strategies. From a total of 2472 urine samples collected during the study period, 378 positive samples were analyzed. This study found that Escherichia coli was the most commonly isolated uropathogen, making up 46.3% of the cases (n = 175), with Klebsiella pneumoniae at 20.6% (n = 78). There was a high resistance of Klebsiella pneumoniae to several antibiotics, while carbapenemase production increased to 52.5% and extended-spectrum beta-lactamase (ESBL) present in 24.3% of the strains. Escherichia coli showed high resistance rates to amoxicillin–clavulanic acid (from 45.4% in 2020 to 53.8% in 2022) and trimethoprim/sulfamethoxazole (from 27.5% in 2020 to 47.2% in 2022). The increasing trend of antimicrobial resistance noted during the pandemic, especially in Gram-negative enterobacterial species, highlights the urgent need for robust infection control measures and rational antibiotic use. This study underscores the critical importance of continuous surveillance to adapt antibiotic therapies effectively and prevent the further spread of resistance, thereby ensuring effective management of UTIs in the evolving healthcare landscape influenced by the pandemic. Full article