-
Frontiers in Immunology 2023Metabolic reprogramming potentiates host protection against antibiotic-sensitive or -resistant bacteria. However, it remains unclear whether a single reprogramming...
INTRODUCTION
Metabolic reprogramming potentiates host protection against antibiotic-sensitive or -resistant bacteria. However, it remains unclear whether a single reprogramming metabolite is effective enough to combat both antibiotic-sensitive and -resistant bacteria. This knowledge is key for implementing an antibiotic-free approach.
METHODS
The reprogramming metabolome approach was adopted to characterize the metabolic state of zebrafish infected with tetracycline-sensitive and -resistant and to identify overlapping depressed metabolite in dying zebrafish as a reprogramming metabolite.
RESULTS
Aspartate was identify overlapping depressed metabolite in dying zebrafish as a reprogramming metabolite. Exogenous aspartate protects zebrafish against infection caused by tetracycline-sensitive and -resistant . Mechanistically, exogenous aspartate promotes nitric oxide (NO) biosynthesis. NO is a well-documented factor of promoting innate immunity against bacteria, but whether it can play a role in eliminating both tetracycline-sensitive and -resistant is unknown. Thus, in this study, aspartate was replaced with sodium nitroprusside to provide NO, which led to similar aspartate-induced protection against tetracycline-sensitive and -resistant .
DISCUSSION
These findings support the conclusion that aspartate plays an important protective role through NO against both types of . Importantly, we found that tetracycline-sensitive and -resistant are sensitive to NO. Therefore, aspartate is an effective reprogramming metabolite that allows implementation of an antibiotic-free approach against bacterial pathogens.
Topics: Animals; Zebrafish; Enterobacteriaceae Infections; Edwardsiella tarda; Nitric Oxide; Aspartic Acid; Anti-Bacterial Agents; Fish Diseases; Bacteria; Tetracyclines
PubMed: 37885884
DOI: 10.3389/fimmu.2023.1277281 -
Veterinary Research Sep 2021Edwardsiella tarda is a facultative intracellular pathogen in humans and animals. The Gram-negative bacterium is widely considered a potentially important bacterial...
Edwardsiella tarda is a facultative intracellular pathogen in humans and animals. The Gram-negative bacterium is widely considered a potentially important bacterial pathogen. Adaptation to acid stress is important for the transmission of intestinal microbes, so the acid-resistance (AR) system is essential. However, the AR systems of E. tarda are totally unknown. In this study, a lysine-dependent acid resistance (LDAR) system in E. tarda, CadBA, was characterized and identified. CadB is a membrane protein and shares high homology with the lysine/cadaverine antiporter. CadA contains a PLP-binding core domain and a pyridoxal phosphate-binding motif. It shares high homology with lysine decarboxylase. cadB and cadA are co-transcribed under one operon. To study the function of the cadBA operon, isogenic cadA, cadB and cadBA deletion mutant strains TX01ΔcadA, TX01ΔcadB and TX01ΔcadBA were constructed. When cultured under normal conditions, the wild type strain and three mutants exhibited the same growth performance. However, when cultured under acid conditions, the growth of three mutants, especially TX01ΔcadA, were obviously retarded, compared to the wild strain TX01, which indicates the important involvement of the cadBA operon in acid resistance. The deletion of cadB or cadA, especially cadBA, significantly attenuated bacterial activity of lysine decarboxylase, suggesting the vital participation of cadBA operon in lysine metabolism, which is closely related to acid resistance. The mutations of cadBA operon enhanced bacterial biofilm formation, especially under acid conditions. The deletions of the cadBA operon reduced bacterial adhesion and invasion to Hela cells. Consistently, the deficiency of cadBA operon abated bacterial survival and replication in macrophages, and decreased bacterial dissemination in fish tissues. Our results also show that the expression of cadBA operon and regulator cadC were up-regulated upon acid stress, and CadC rigorously regulated the expression of cadBA operon, especially under acid conditions. These findings demonstrate that the AR CadBA system was a requisite for the resistance of E. tarda against acid stress, and played a critical role in bacterial infection of host cells and in host tissues. This is the first study about the acid resistance system of E. tarda and provides new insights into the acid-resistance mechanism and pathogenesis of E. tarda.
Topics: Acids; Biofilms; Edwardsiella tarda; Virulence Factors
PubMed: 34521475
DOI: 10.1186/s13567-021-00987-x -
Microbes and Infection 2022Biofilms contribute to the resistance of Edwardsiella tarda to antibiotics and host immunity. AroC in the shikimate pathway produces chorismate to synthesize crucial...
Biofilms contribute to the resistance of Edwardsiella tarda to antibiotics and host immunity. AroC in the shikimate pathway produces chorismate to synthesize crucial intermediates such as indole. In this study, the differences between biofilms produced by aroC mutants (△aroC), wild-type (WT) strains, and △aroC complementary strains (C△aroC) were detected both in vitro with 96-well plates, tubes, or coverslips and in vivo using a mouse model of subcutaneous implants. When examining potential mechanisms, we found that the diameters of the movement rings in soft agar plates and the flagellar sizes and numbers determined by silver staining were all lower for △aroC than for WT and C△aroC. Moreover, qRT-PCR showed that the transcription levels of flagellar synthesis genes, fliA and fliC, were reduced in △aroC. AroC, FliC, or FliA may accompany the motility of △aroC strains. In addition, compared with the WT and C△aroC, the amounts of indole in △aroC were significantly decreased. Notably, the formation of biofilms by these strains could be promoted by exogenous indole. Therefore, the aroC gene could affect the biofilm formation of E. tarda concerning its impact on flagella and indole.
Topics: Bacterial Proteins; Biofilms; Edwardsiella tarda; Indoles; Phosphorus-Oxygen Lyases
PubMed: 35272020
DOI: 10.1016/j.micinf.2022.104955 -
Frontiers in Immunology 2021Long non-coding RNAs (lncRNAs) play widespread roles in fundamental biological processes, including immune responses. The olive flounder (), an important economical...
Long non-coding RNAs (lncRNAs) play widespread roles in fundamental biological processes, including immune responses. The olive flounder (), an important economical flatfish widely cultured in Japan, Korea, and China, is threatened by infectious pathogens, including bacteria, viruses, and parasites. However, the role of lncRNAs in the immune responses of this species against pathogen infections is not well-understood. Therefore, in this study, we aimed to identify lncRNAs in the intestine of olive flounder and evaluate their differential expression profiles during infection, which is an important zoonotic and intestinal pathogen. A total of 4,445 putative lncRNAs were identified, including 3,975 novel lncRNAs and 470 annotated lncRNAs. These lncRNAs had shorter lengths and fewer exons compared with mRNAs. In total, 115 differentially expressed lncRNAs (DE-lncRNAs) were identified during infection. To validate the expression pattern of lncRNAs, six DE-lncRNAs were randomly selected for quantitative real-time PCR. The co-located and co-expressed mRNAs of DE-lncRNAs were predicted, which were used to conduct the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The target genes of DE-lncRNAs enriched numerous immune-related processes and exhibited a strong correlation with immune-related signaling pathways. To better understand the extensive regulatory functions of lncRNAs, the lncRNA-miRNA-mRNA regulatory networks were constructed, and two potential competing endogenous RNA (ceRNA) networks, LNC_001979-novel_171-Potusc2 and LNC_001979-novel_171-Podad1, were preliminarily identified from the intestine of olive flounders for the first time. In conclusion, this study provides an invaluable annotation and expression profile of lncRNAs in the intestine of olive flounder infected with ; this forms a basis for further studies on the regulatory function of lncRNAs in the intestinal mucosal immune responses of olive flounder.
Topics: Animals; Edwardsiella tarda; Enterobacteriaceae Infections; Fish Diseases; Flounder; Gene Expression Profiling; Gene Regulatory Networks; Host-Pathogen Interactions; Intestines; MicroRNAs; RNA, Long Noncoding; RNA, Messenger; Transcriptome
PubMed: 33868240
DOI: 10.3389/fimmu.2021.623764 -
International Journal of Molecular... Mar 2023The genus presents five different pathogenic species: , , , and . These species cause infections mainly in fish, but they can also infect reptiles, birds or humans....
The genus presents five different pathogenic species: , , , and . These species cause infections mainly in fish, but they can also infect reptiles, birds or humans. Lipopolysaccharide (endotoxin) plays an important role in the pathogenesis of these bacteria. For the first time, the chemical structure and genomics of the lipopolysaccharide (LPS) core oligosaccharides of , , and were studied. The complete gene assignments for all core biosynthesis gene functions were acquired. The structure of core oligosaccharides was investigated by ¹H and C nuclear magnetic resonance (NMR) spectroscopy. The structures of and core oligosaccharides show the presence of →3,4)-L--α-D--Hep, two terminal β-D-Glc, →2,3,7)-L--α-D--Hep, →7)-L--α-D--Hep, terminal α-D-GlcN, two →4)-α-D-GalA, → 3)-α-D-GlcNAc, terminal β-D-Gal and →5-substituted Kdo. core oligosaccharide shows only one terminal β-D-Glc, and instead of terminal β-D-Gal a terminal α-D-GlcNAc. core oligosaccharide shows only one terminal β-D-Glc, one →4)-α-D-GalA and do not have terminal α-D-GlcN (see complementary figure).
Topics: Animals; Humans; Carbohydrate Sequence; Lipopolysaccharides; Oligosaccharides; Magnetic Resonance Spectroscopy; Methylation
PubMed: 36902212
DOI: 10.3390/ijms24054768 -
Oxford Medical Case Reports Jan 2024is typically isolated from aquatic environments. It rarely causes infections in humans. infections in humans result from the consumption of infected or contaminated...
is typically isolated from aquatic environments. It rarely causes infections in humans. infections in humans result from the consumption of infected or contaminated food. Here, we present a case of recurrent cholangitis and bacteraemia associated with . An 82-year-old man with no history of seafood inoculation was admitted to our hospital because of difficulty in moving his body. The patient was diagnosed with cholangitis, and the blood culture revealed the presence of . The patient underwent bile duct stenting and received antibiotic therapy for 14 days. Forty-four days after discharge, cholangitis recurred, and blood culture again showed the presence of . The patient underwent bile duct stenting and antibiotic therapy for 11 days. No cholangitis or bacteraemia associated with was observed in the following 3 years. Our case strongly suggests that colonization with results in recurrent cholangitis and bacteraemia.
PubMed: 38292162
DOI: 10.1093/omcr/omad148 -
Wiadomosci Lekarskie (Warsaw, Poland :... 2021Edwardsiellosis is a zoonotic infectious disease that caused by Edwardsiella tarda and characterized by gastroenteritis in humans. Contaminated water can also be a...
Edwardsiellosis is a zoonotic infectious disease that caused by Edwardsiella tarda and characterized by gastroenteritis in humans. Contaminated water can also be a source of infection. Primary nutritional toxicity clinical signs may mask aquatic zoonosis caused by Edwardsiella tarda. Infectious border control should ensure that the import into Ukraine of such preservatives of food products, highly probably infected by this agent is not allowed.
Topics: Edwardsiella tarda; Enterobacteriaceae Infections; Gastroenteritis; Humans; Ukraine
PubMed: 33851609
DOI: No ID Found -
Infection and Immunity Apr 2015Edwardsiella tarda is a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and gastro- and extraintestinal infections in humans. The type III...
Edwardsiella tarda is a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and gastro- and extraintestinal infections in humans. The type III secretion system (T3SS) of E. tarda has been identified as a key virulence factor that contributes to pathogenesis in fish. However, little is known about the associated effectors translocated by this T3SS. In this study, by comparing the profile of secreted proteins of the wild-type PPD130/91 and its T3SS ATPase ΔesaN mutant, we identified a new effector by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. This effector consists of 1,359 amino acids, sharing high sequence similarity with Orf29/30 of E. tarda strain EIB202, and is renamed EseJ. The secretion and translocation of EseJ depend on the T3SS. A ΔeseJ mutant strain adheres to epithelioma papillosum of carp (EPC) cells 3 to 5 times more extensively than the wild-type strain does. EseJ inhibits bacterial adhesion to EPC cells from within bacterial cells. Importantly, the ΔeseJ mutant strain does not replicate efficiently in EPC cells and fails to replicate in J774A.1 macrophages. In infected J774A.1 macrophages, the ΔeseJ mutant elicits higher production of reactive oxygen species than wild-type E. tarda. The replication defect is consistent with the attenuation of the ΔeseJ mutant in the blue gourami fish model: the 50% lethal dose (LD50) of the ΔeseJ mutant is 2.34 times greater than that of the wild type, and the ΔeseJ mutant is less competitive than the wild type in mixed infection. Thus, EseJ represents a novel effector that contributes to virulence by reducing bacterial adhesion to EPC cells and facilitating intracellular bacterial replication.
Topics: Adenosine Triphosphatases; Animals; Bacterial Adhesion; Bacterial Proteins; Bacterial Secretion Systems; Cells, Cultured; Edwardsiella tarda; Enterobacteriaceae Infections; Fish Diseases; Fishes; Macrophages; Mice; Molecular Sequence Data; Proteomics; Reactive Oxygen Species; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Virulence Factors
PubMed: 25667268
DOI: 10.1128/IAI.02566-14 -
Bacteriophage 2014Bacteriophages have been proposed as an alternative to antibiotic usage and several studies on their application in aquaculture have been reported. This review... (Review)
Review
Bacteriophages have been proposed as an alternative to antibiotic usage and several studies on their application in aquaculture have been reported. This review highlights progress to date on phage therapies for the following fish and shellfish diseases and associated pathogens: hemorrhagic septicemia (Aeromonas hydrophila) in loaches, furunculosis (Aeromonas salmonicida) in trout and salmon, edwardsiellosis (Edwardsiella tarda) in eel, columnaris disease (Flavobacterium columnare) in catfish, rainbow trout fry syndrome or cold water disease (Flavobacterium psychrophilum) in trout and salmon, lactococcosis (Lactococcus spp.) in yellowtail, ulcerative skin lesions (Pseudomonas aeruginosa) in freshwater catfish, bacterial hemorrhagic ascites disease (Pseudomonas plecoglossicida) in ayu fish, streptococcosis (Streptococcus iniae) in flounder, and luminescent vibriosis (Vibrio harveyi) in shrimp. Information is reviewed on phage specificity, host resistance, routes of administration, and dosing of fish and shellfish. Limitations in phage research are described and recommended guidelines are provided for conducting future phage studies involving fish and shellfish.
PubMed: 26713223
DOI: 10.4161/21597081.2014.975540 -
Biology Oct 2021The black rockfish, , is a typical viviparous teleost, which belongs to the family Scorpaenidae. Due to its high economic and ecological values, has been widely...
The black rockfish, , is a typical viviparous teleost, which belongs to the family Scorpaenidae. Due to its high economic and ecological values, has been widely cultured in East Asian countries. With the enlargement of cultivation scale, bacterial and viral diseases have become the main threats to the farming industry of , which have resulted in significant economic losses. In this study, Illumina shotgun sequencing, single-molecule real-time (SMRT) sequencing, 10× genomics and high-throughput chromosome conformation capture (Hi-C) technologies were collectively applied to assemble the genome of . Then, we identified the antimicrobial peptide genes (AMPs) in the genome. In total, 214 AMPs were identified in the genome, which can be divided into 33 classes according to the annotation and cataloging of the Antimicrobial Peptides Database (APD3). Among these AMPs, thrombin-derived C-terminal peptide (TCP) was the dominant type, followed by RegIIIgamma and chemokine. The amino acid sequences of the TCP, cgUbiquitin, RegIIIalpha, RegIIIgamma, chemokine shared 32.55%, 42.63%, 29.87%, 28.09%, and 32.15% similarities among the same type in Meanwhile, the expression patterns of these AMPs in nine healthy tissues and at different infection time points in intestine were investigated. The results showed that the numbers and types of AMPs that responded to infection gradually increased as the infection progressed. In addition, we analyzed the phylogenetic relationships of hepcidins in teleost. The identification of AMPs based on the whole genome could provide a comprehensive database of potential AMPs, and benefit for the understanding of the molecular mechanisms of immune responses to infection in . This would further offer insights into an accurate and effective design and development of AMP for aquaculture therapy in the future.
PubMed: 34681113
DOI: 10.3390/biology10101015