-
Journal of Veterinary Research Jun 2023Bioactive proteins and peptides generated from fruit, vegetables, meat or fish have great potential as functional food or substitutes for antibiotics. In recent years it...
INTRODUCTION
Bioactive proteins and peptides generated from fruit, vegetables, meat or fish have great potential as functional food or substitutes for antibiotics. In recent years it has also been demonstrated that the fungus kingdom could be a source of these compounds. The study investigated the bioactivity of an extract of the lignicolous fungus and its hydrolysate.
MATERIAL AND METHODS
The fungus was collected in a mixed forest in October, extracted and hydrolysed. To inspect the protein and peptide profiles before and after hydrolysis, matrix-assisted laser desorption/ionisation-time-of-flight mass spectrometric analysis was performed. To evaluate the antioxidant properties of the preparations, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays were used. The activity of the fungus extract and hydrolysate against , , , , , , , Typhimurium, , , , , and was determined by the minimum inhibitory concentration and minimum bactericidal concentration values.
RESULTS
The extract and its hydrolysate showed almost 100% ABTS and DPPH radical scavenging with a low half maximal inhibitory concentration. The water extract and hydrolysate of exhibited antimicrobial activity against two strains, , and Typhimurium.
CONCLUSION
These results provide compelling evidence that the analysed fungus extract and its hydrolysate hold promise with their antibacterial and antioxidant properties.
PubMed: 37786431
DOI: 10.2478/jvetres-2023-0036 -
Journal of Agricultural and Food... Nov 2023Lactic acid bacteria (LAB) were screened from (red sea bass), and their antimicrobial activities were evaluated against two species isolated from the , namely, (AV)...
Lactic acid bacteria (LAB) were screened from (red sea bass), and their antimicrobial activities were evaluated against two species isolated from the , namely, (AV) and (AJ). Three LAB isolates, MU8 (EF_8), MU2 (EFL_2), and MU9 (EFL_9), were found to inhibit both AV and AJ; however, their cell-free supernatant (CFS) did not do so. Interestingly, bacteriocin-like substances (BLS) induced by cocultures of EF_8 with AV exhibited the highest antimicrobial activity against both sp. The size of BLS was less than 1.0 kDa; the purified BLS were susceptible to proteinase K digestion, indicating that they are peptides. BLS contained 13 identified peptides derived from as determined by liquid chromatography-tandem mass spectrometry. Cocultures of Gram-positive-producing and -inducing LAB strains have been used to increase bacteriocin yields. To our knowledge, this is the first report describing inducible BLS produced by cocultures of Gram-positive-producing and Gram-negative-inducing strains.
Topics: Enterococcus faecium; Bacteriocins; Aeromonas veronii; Coculture Techniques; Aeromonas; Peptides; Anti-Infective Agents; Anti-Bacterial Agents
PubMed: 37779478
DOI: 10.1021/acs.jafc.3c04019 -
Microbial Genomics Sep 2023is an opportunistic pathogen that affects both fish and mammals, including humans, leading to bacteraemia, sepsis, meningitis and even death. The increasing virulence...
is an opportunistic pathogen that affects both fish and mammals, including humans, leading to bacteraemia, sepsis, meningitis and even death. The increasing virulence and drug resistance of are of significant concern and pose a severe risk to public safety. The Type I restriction-modification (RM) system, which functions as a bacterial defence mechanism, can influence gene expression through DNA methylation. However, little research has been conducted to explore its origin, evolutionary path, and relationship to virulence and drug resistance in . In this study, we analysed the pan-genome of 233 . strains, and the results indicated that it was 'open', meaning that has acquired additional genes from other species. This suggested that had the potential to adapt and evolve rapidly, which might have contributed to its drug resistance. One Type I methyltransferase (MTase) and two complete Type I RM systems were identified, namely AveC4I, AveC4II and AveC4III in strain C4, respectively. Notably, AveC4I was exclusive to C4. Phylogenetic analysis revealed that AveC4I was derived from horizontal gene transfer from and exchanged genes with the human pathogen . Single molecule real-time sequencing was applied to identify the motif methylated by AveC4I, which was unique and not recognized by any reported MTases in the REBASE database. We also annotated the functions and pathways of the genes containing the motif, revealing that AveC4I may control drug resistance in C4. Our findings provide new insight on the mechanisms underlying drug resistance in pathogenic bacteria. By identifying the specific genes and pathways affected by AveC4I, this study may aid in the development of new therapeutic approaches to combat infections.
PubMed: 37754275
DOI: 10.1099/mgen.0.001107 -
Microbiology Spectrum Sep 2023species are emerging human enteric pathogens. This study examines the isolation of and other enteric bacterial pathogens from patients with and without inflammatory...
species are emerging human enteric pathogens. This study examines the isolation of and other enteric bacterial pathogens from patients with and without inflammatory bowel disease (IBD). This study also investigates the intestinal epithelial pathogenic mechanisms of . The isolation rates of seven enteric bacterial pathogens from 2,279 patients with IBD and 373,276 non-IBD patients were compared. An strain (AS1) isolated from intestinal biopsies of a patient with IBD was used for pathogenic mechanism investigation, and K12 was used as a bacterial control. HT-29 cells were used as a model of human intestinal epithelium. A significantly higher isolation of species was found in patients with IBD as compared to non-IBD patients ( = 0.0001, odds ratio = 2.11). upregulated 177 inflammatory genes and downregulated 52 protein-coding genes affecting chromatin assembly, multiple small nuclear RNAs, multiple nucleolar RNAs, and 55 cytoplasmic tRNAs in HT-29 cells. These downregulation effects were unique to and not observed in HT-29 cells infected with K12. induced intestinal epithelial apoptosis involving the intrinsic pathway. caused epithelial microvilli shortening and damage and epithelial production of IL-8. In conclusion, this study for the first time reports the association between IBD and enteric infection detected by bacterial cultivation. This study also reports that damages intestinal epithelial cells via multiple mechanisms, of which the downregulating cytoplasmic tRNA, small nuclear RNA, and small nucleolar RNA are novel bacterial pathogenic mechanisms. IMPORTANCE This study for the first time reports the association between inflammatory bowel disease (IBD) and enteric infection detected by bacterial pathogen cultivation, highlighting the need of clinical and public health attention. The finding that patients with IBD are more susceptible to enteric infection suggests that detection of enteric infection should be routinely performed for the diagnosis and treatment of IBD. This study also reports novel bacterial pathogenic mechanisms employed by . Through comparative transcriptomic analysis and other techniques, this study revealed the pathogenic mechanisms by which causes damage to intestinal epithelial cells. Among the various pathogenic mechanisms identified, the downregulating tRNA, small nuclear and nucleolar RNAs in human intestinal epithelial cells are novel bacterial pathogenic mechanisms.
PubMed: 37732778
DOI: 10.1128/spectrum.01088-23 -
Gastroenterology Dec 2023Pien Tze Huang (PZH) is a well-established traditional medicine with beneficial effects against inflammation and cancer. We aimed to explore the chemopreventive effect...
BACKGROUND & AIMS
Pien Tze Huang (PZH) is a well-established traditional medicine with beneficial effects against inflammation and cancer. We aimed to explore the chemopreventive effect of PZH in colorectal cancer (CRC) through modulating gut microbiota.
METHODS
CRC mouse models were established by azoxymethane plus dextran sulfate sodium treatment or in Apc mice treated with or without PZH (270 mg/kg and 540 mg/kg). Gut barrier function was determined by means of intestinal permeability assays and transmission electron microscopy. Fecal microbiota and metabolites were analyzed by means of metagenomic sequencing and liquid chromatography mass spectrometry, respectively. Germ-free mice or antibiotic-treated mice were used as models of microbiota depletion.
RESULTS
PZH inhibited colorectal tumorigenesis in azoxymethane plus dextran sulfate sodium-treated mice and in Apc mice in a dose-dependent manner. PZH treatment altered the gut microbiota profile, with an increased abundance of probiotics Pseudobutyrivibrio xylanivorans and Eubacterium limosum, while pathogenic bacteria Aeromonas veronii, Campylobacter jejuni, Collinsella aerofaciens, and Peptoniphilus harei were depleted. In addition, PZH increased beneficial metabolites taurine and hypotaurine, bile acids, and unsaturated fatty acids, and significantly restored gut barrier function. Transcriptomic profiling revealed that PZH inhibited PI3K-Akt, interleukin-17, tumor necrosis factor, and cytokine-chemokine signaling. Notably, the chemopreventive effect of PZH involved both microbiota-dependent and -independent mechanisms. Fecal microbiota transplantation from PZH-treated mice to germ-free mice partly recapitulated the chemopreventive effects of PZH. PZH components ginsenoside-F2 and ginsenoside-Re demonstrated inhibitory effects on CRC cells and primary organoids, and PZH also inhibited tumorigenesis in azoxymethane plus dextran sulfate sodium-treated germ-free mice.
CONCLUSIONS
PZH manipulated gut microbiota and metabolites toward a more favorable profile, improved gut barrier function, and suppressed oncogenic and pro-inflammatory pathways, thereby suppressing colorectal carcinogenesis.
Topics: Mice; Animals; Signal Transduction; Gastrointestinal Microbiome; Dextran Sulfate; Phosphatidylinositol 3-Kinases; Apoptosis; Medicine, Traditional; Colorectal Neoplasms; Carcinogenesis; Azoxymethane
PubMed: 37704113
DOI: 10.1053/j.gastro.2023.08.052 -
Animals : An Open Access Journal From... Aug 2023The objective of this study was to understand biological characteristics of one bacteria strain named as VPG which was isolated from multiple organs of a dead captive...
The objective of this study was to understand biological characteristics of one bacteria strain named as VPG which was isolated from multiple organs of a dead captive giant panda cub. Here, we use biochemical tests, 16S rRNA and genes for bacterial identification, the disk diffusion method for antibiotic resistance phenotype, smart chip real-time PCR for the antibiotic resistance genotype, multiplex PCR for determination of virulence genes, and the acute toxicity test in mice for testing the pathogenicity of isolates. The isolate was identified as strain based on the biochemical properties and genetic analysis. We found that the strain carried 31 antibiotic resistance genes, revealed antimicrobial resistance phenotypically to several antibiotics including penicillin, ampicillin, oxacillin, amoxicillin, imipenem, and vancomycin, and carried virulence genes including , , , , , , and . The main pathological changes in giant panda were congestion, necrotic lesions and a large number of bacteria in multiple organs. In addition, the LD in Kunming mice infected with strain VGP was 5.14 × 10 CFU/mL by intraperitoneal injection. Infection with strain VGP led to considerable histological lesions such as hemorrhage of internal organs, necrosis of lymphocytes and neurons in Kunming mice. Taken together, these results suggest that infection with strain VGP would be an important causes of death in this giant panda cub.
PubMed: 37685043
DOI: 10.3390/ani13172779 -
Scientific Reports Sep 2023Beta-glucans have immense potential to stimulate immune modulation in fish by being injected intramuscularly, supplemented with feed or immersion routes of...
Beta-glucans have immense potential to stimulate immune modulation in fish by being injected intramuscularly, supplemented with feed or immersion routes of administration. We studied how supplementing Labeo rohita's diet with reishi mushroom powder containing beta-glucan influenced immunological function. A supplemented diet containing 10% reishi mushroom powder was administered for 120 days. Afterwards, analyses were conducted on different immunological parameters such as antioxidants, respiratory burst, reactive oxygen species (ROS), alternative complement activity, and serum immunoglobulin, which resulted significant increases (p < 0.05; p < 0.01) for the reishi mushroom-fed immune primed L. rohita. Additionally, analyzing various hematological parameters such as erythrocytes and leukocytes count were assessed to elucidate the immunomodulatory effects, indicating positive effects of dietary reishi mushroom powder on overall fish health. Furthermore, the bacterial challenge-test with 1.92 × 10 CFU/ml intramuscular dose of Aeromonas veronii showed enhanced disease-defending system as total serum protein and lysozyme activity levels accelerated significantly (p < 0.01). Nevertheless, reishi mushroom powder contained with beta-glucan ameliorated the stress indicating parameters like acetylcholinesterase (AChE), serum-glutamic pyruvic transaminase (SGPT) and serum-glutamic oxaloacetic transaminase (SGOT) enzyme activities results suggested the fish's physiology was unaffected. Therefore, the results indicated that adding dietary reishi mushroom as a source of beta-glucan could significantly boost the immune responses in Rohu.
Topics: Animals; Aeromonas veronii; Powders; Reishi; Acetylcholinesterase; Diet; Cyprinidae; Agaricales
PubMed: 37670115
DOI: 10.1038/s41598-023-41557-9 -
Microorganisms Jul 2023Greater amberjack () is a new species in marine aquaculture with high mortalities at the larval stages. The microbiota of amberjack larvae was analyzed using 16S rDNA...
Greater amberjack () is a new species in marine aquaculture with high mortalities at the larval stages. The microbiota of amberjack larvae was analyzed using 16S rDNA sequencing in two groups, one added copepod nauplii () in the diet, and one without copepods (control). In addition, antagonistic bacteria were isolated from amberjack larvae and live food cultures. Proteobacteria was the most abundant phylum followed by Bacteroidota in amberjack larvae. The composition and diversity of the microbiota were influenced by age, but not by diet. Microbial community richness and diversity significantly increased over time. Rhodobacteraceae was the most dominant family followed by Vibrionaceae, which showed the highest relative abundance in larvae from the control group 31 days after hatching. and genera exhibited a significantly higher relative abundance in the copepod group. Sixty-two antagonistic bacterial strains were isolated and screened for their ability to inhibit four fish pathogens (, , , ) using a double-layer test. , sp., sp., and sp. isolated from larvae and sp. inhibited the fish pathogens. These antagonistic bacteria could be used as host-derived probiotics to improve the growth and survival of the greater amberjack larvae.
PubMed: 37630449
DOI: 10.3390/microorganisms11081889 -
Foods (Basel, Switzerland) Aug 2023This study investigated changes in the microbial compositions of crayfish tails during storage at 4 °C (for 0-12 days) as measured using high-throughput sequencing...
This study investigated changes in the microbial compositions of crayfish tails during storage at 4 °C (for 0-12 days) as measured using high-throughput sequencing (HTS). The specific spoilage organisms (SSOs) in the crayfish tails were isolated using culture-dependent cultivation methods, and they were identified by 16S rRNA and characterized for their enzymatic spoilage potentials (e.g., protease, lipase, phospholipase, and amylase). The spoilage abilities of the selected strains in the crayfish tails were assessed by inoculating them into real food. Moreover, the microbial growth and the volatile basic nitrogen (TVB-N) changes were monitored during the storage period. The results from the HTS showed that the dominant genus of shrimp tails evolved from (D0) to (D4) and, finally, to (D12) during storage. Seven bacterial species (, , and ) were screened from the spoiled shrimp tails by the culture-dependent method, among which had the strongest spoilage ability.
PubMed: 37628005
DOI: 10.3390/foods12163006 -
Pathogens (Basel, Switzerland) Aug 2023Brazil is one of the world's leading producers of Nile tilapia, . However, the industry faces a major challenge in terms of infectious diseases, as at least five new...
Brazil is one of the world's leading producers of Nile tilapia, . However, the industry faces a major challenge in terms of infectious diseases, as at least five new pathogens have been formally described in the last five years. species are Gram-negative anaerobic bacteria that are often described as fish pathogens causing Motile Aeromonas Septicemia (MAS). In late December 2022, an epidemic outbreak was reported in farmed Nile tilapia in the state of São Paulo, Brazil, characterized by clinical signs and gross pathology suggestive of MAS. The objective of this study was to isolate, identify, and characterize in vitro and in vivo the causative agent of this epidemic outbreak. The bacterial isolates were identified as based on the homology of 16S rRNA (99.9%), (98.9%), and the gene (99.1%). showed susceptibility only to florfenicol, while it was resistant to the other three antimicrobials tested, oxytetracycline, enrofloxacin, and amoxicillin. The lowest florfenicol concentration capable of inhibiting bacterial growth was ≤0.5 µg/mL. The phenotypic resistance of the isolate observed for quinolones and tetracycline was genetically confirmed by the presence of the ( plasmid) and antibiotic-resistant genes, respectively. isolate was highly pathogenic in juvenile Nile tilapia tested in vivo, showing a mortality rate ranging from 3 to 100% in the lowest (1.2 × 10) and highest (1.2 × 10) bacterial dose groups, respectively. To our knowledge, this study would constitute the first report of highly pathogenic and multidrug-resistant associated with outbreaks and high mortality rates in tilapia farmed in commercial net cages in Brazil.
PubMed: 37623980
DOI: 10.3390/pathogens12081020