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Cell Host & Microbe Feb 2021The intestinal epithelium senses nutritional and microbial stimuli using epithelial sensory enteroendocrine cells (EEC). EECs communicate nutritional information to the...
The intestinal epithelium senses nutritional and microbial stimuli using epithelial sensory enteroendocrine cells (EEC). EECs communicate nutritional information to the nervous system, but whether they also relay signals from intestinal microbes remains unknown. Using in vivo real-time measurements of EEC and nervous system activity in zebrafish, we discovered that the bacteria Edwardsiella tarda activate EECs through the receptor transient receptor potential ankyrin A1 (Trpa1) and increase intestinal motility. Microbial, pharmacological, or optogenetic activation of Trpa1EECs directly stimulates vagal sensory ganglia and activates cholinergic enteric neurons by secreting the neurotransmitter 5-hydroxytryptamine (5-HT). A subset of indole derivatives of tryptophan catabolism produced by E. tarda and other gut microbes activates zebrafish EEC Trpa1 signaling. These catabolites also directly stimulate human and mouse Trpa1 and intestinal 5-HT secretion. These results establish a molecular pathway by which EECs regulate enteric and vagal neuronal pathways in response to microbial signals.
Topics: Animals; Animals, Genetically Modified; Cholinergic Neurons; Edwardsiella tarda; Enteric Nervous System; Enteroendocrine Cells; Gastrointestinal Motility; Intestinal Mucosa; Proto-Oncogene Proteins c-ret; Serotonin; Signal Transduction; TRPA1 Cation Channel; Tryptophan; Zebrafish; Zebrafish Proteins
PubMed: 33352109
DOI: 10.1016/j.chom.2020.11.011 -
Virulence Dec 2022species in aquatic environments exist either as individual planktonic cells or in communal biofilms. These organisms encounter multiple stresses, include changes in...
species in aquatic environments exist either as individual planktonic cells or in communal biofilms. These organisms encounter multiple stresses, include changes in salinity, pH, temperature, and nutrients. Pathogenic species such as , can multiply within the fish hosts. Additionally, species (), can carry antibiotic resistance genes (ARGs) on chromosomes and/or plasmids, that can be transmitted to the microbiome via horizontal gene transfer. serves as a core in the aquatic resistome. uses molecular switches (RpoS and EsrB) to control gene expression for survival in different environments. We speculate that free-living can transition to host-living and vice versa, using similar molecular switches. Understanding such transitions can help us understand how other similar aquatic bacteria switch from free-living to become pathogens. This knowledge can be used to devise ways to slow down the spread of ARGs and prevent disease outbreaks in aquaculture and clinical settings.
Topics: Animals; Bacterial Proteins; Edwardsiella; Enterobacteriaceae Infections; Fish Diseases; Virulence
PubMed: 34969351
DOI: 10.1080/21505594.2021.2006890 -
Heliyon Sep 2023This study aims to elucidate the evolution of catfish research publications over recent decades, identify emerging research clusters, examine keyword patterns, determine... (Review)
Review
This study aims to elucidate the evolution of catfish research publications over recent decades, identify emerging research clusters, examine keyword patterns, determine major contributors (including authors, organizations, and funding agencies), and analyze their collaborative networks and citation bursts on a global scale. The USA, Brazil, China, and India collectively contribute approximately 67% of the total catfish research publications, with a marked increase in prevalence since 2016. The most frequently occurring and dominant keywords are "channel catfish" and "responses," respectively. Intriguingly, our findings reveal 28 distinct article clusters, with prominent clusters including "yellow catfish," "channel catfish", "pectoral girdle," "African catfish", "Rio Sao Francisco basin," "," and "temperature mediated". Concurrently, keyword clustering generates seven main clusters: "new species", "growth performance", "heavy metal", "gonadotropin-releasing", "essential oil", and "olfactory receptor". This study further anticipates future research directions, offering fresh perspectives on the catfish literature landscape. To the best of our knowledge, this is the first article to conduct a comprehensive mapping review of catfish research publications worldwide.
PubMed: 37810135
DOI: 10.1016/j.heliyon.2023.e20081 -
Microbial Genomics Feb 2020and are important fish pathogens affecting cultured and wild fish worldwide. To investigate the genome-level differences and similarities between catfish-adapted... (Comparative Study)
Comparative Study
and are important fish pathogens affecting cultured and wild fish worldwide. To investigate the genome-level differences and similarities between catfish-adapted strains in these two species, the complete 93-146 and C07-087 genomes were evaluated by applying comparative genomics analysis. All available complete (10) and non-complete (19) genomes from five species were also included in a systematic analysis. Average nucleotide identity and core-genome phylogenetic tree analyses indicated that the five species were separated from each other. Pan-/core-genome analyses for the 29 strains from the five species showed that genus members have 9474 genes in their pan genome, while the core genome consists of 1421 genes. Orthology cluster analysis showed that and genomes have the greatest number of shared clusters. However, and also have unique features; for example, the genome encodes urease enzymes and cytochrome o ubiquinol oxidase subunits, whereas genomes encode tetrathionate reductase operons, capsular polysaccharide synthesis enzymes and vibrioferrin-related genes. Additionally, we report for what is believed to be the first time that 93-146 and three other genomes encode a type IV secretion system (T4SS), whereas none of the genomes encode this system. Additionally, the C07-087 genome encodes two different type VI secretion systems. genomes tend to encode more insertion elements, phage regions and genomic islands than . We speculate that the T4SS could contribute to the increased number of mobilome elements in compared to . Two of the genomes encode full CRISPR-Cas regions, whereas none of the genomes encode Cas proteins. Overall, comparison of the and genomes reveals unique features and provides new insights on pathogenicity that may reflect the host adaptation of the two species.
Topics: Animals; Catfishes; Edwardsiella; Edwardsiella ictaluri; Enterobacteriaceae Infections; Fish Diseases; Genome, Bacterial; Genomics; Phylogeny
PubMed: 32108566
DOI: 10.1099/mgen.0.000322 -
MSphere Oct 2023Type III secretion system (T3SS) facilitates survival and replication of . Identifying novel T3SS effectors and elucidating their functions are critical in understanding...
Type III secretion system (T3SS) facilitates survival and replication of . Identifying novel T3SS effectors and elucidating their functions are critical in understanding the pathogenesis of T3SS effector EseG and EseJ was highly secreted when T3SS gatekeeper-containing protein complex EsaB-EsaL-EsaM was disrupted by EsaB deficiency. Based on this observation, concentrated secretomes of Δ strain and ΔΔ strain were purified by loading them into SDS-PAGE gel for a short electrophoresis to remove impurities prior to the in-the gel digestion and mass spectrometry. Four reported T3SS effectors and two novel T3SS effector candidates EseQ (ETAE_2009) and Trx2 (ETAE_0559) were unraveled by quantitative comparison of the identified peptides. EseQ and Trx2 were revealed to be secreted and translocated in a T3SS-dependent manner through CyaA-based translocation assay and immunofluorescent staining, demonstrating that EseQ and Trx2 are the novel T3SS effectors of . Trx2 was found to suppress macrophage apoptosis as revealed by TUNEL staining and cleaved caspase-3 of infected J774A.1 monolayers. Moreover, Trx2 has been shown to inhibit the p65 phosphorylation and p65 translocation into the nucleus, thus blocking the NF-κB pathway. Furthermore, depletion of Trx2 slightly but significantly attenuates virulence in a fish infection model. Taken together, an efficient method was established in unraveling T3SS effectors in , and Trx2, one of the novel T3SS effectors identified in this study, was demonstrated to suppress apoptosis and block NF- κB pathway during infection. IMPORTANCE is an intracellular bacterial pathogen that causes intestinal inflammation and hemorrhagic sepsis in fish and human. Virulence depends on the type III secretion system (T3SS). Identifying the bacterial effector proteins secreted by T3SS and defining their role is key to understanding pathogenesis. EsaB depletion disrupts the T3SS gatekeeper-containing protein complex, resulting in increased secretion of T3SS effectors EseG and EseJ. EseQ and Trx2 were shown to be the novel T3SS effectors of by a secretome comparison between ∆ strain and ∆∆ strain (T3SS mutant), together with CyaA-based translocation assay. In addition, Trx2 has been shown to suppress macrophage apoptosis and block the NF-κB pathway. Together, this work expands the known repertoire of T3SS effectors and sheds light on the pathogenic mechanism of .
Topics: Animals; Humans; Type III Secretion Systems; Virulence Factors; NF-kappa B; Edwardsiella; Fishes
PubMed: 37642418
DOI: 10.1128/msphere.00346-23 -
Virulence Dec 2019is an Enterobacteriaceae that is abundant in water and causes food and waterborne infections in fish, animals, and humans. The bacterium causes Edwardsiellosis in... (Review)
Review
is an Enterobacteriaceae that is abundant in water and causes food and waterborne infections in fish, animals, and humans. The bacterium causes Edwardsiellosis in farmed fish and can lead to severe economic losses in aquaculture worldwide. is an intracellular pathogen that can also cause systemic infection. Type III and type VI secretion systems are the bacterium's most lethal weapons against host defenses. It also possesses multi-antibiotic resistant genes and is selected and enriched in the environment due to the overuse of antibiotics. Therefore, the bacterium has great potential to contribute to the evolution of the resistome. All these properties have made this bacterium a perfect model to study bacteria virulence mechanisms and the spread of antimicrobial genes in the environment. We summarize recent advance in biology and provide insights into future research in virulence mechanisms, vaccine development and novel therapeutics.
Topics: Animals; Aquaculture; Bacterial Proteins; Drug Resistance, Multiple, Bacterial; Edwardsiella; Enterobacteriaceae Infections; Fish Diseases; Fishes; Host-Pathogen Interactions; Humans; Type III Secretion Systems; Type VI Secretion Systems; Virulence; Virulence Factors
PubMed: 31122125
DOI: 10.1080/21505594.2019.1621648 -
IDCases 2022This report presents the case of a 51-year-old woman on an immunosuppressant drug and steroids, who presented with general fatigue and was admitted to the intensive care...
This report presents the case of a 51-year-old woman on an immunosuppressant drug and steroids, who presented with general fatigue and was admitted to the intensive care unit. Her serum procalcitonin, lactate, aspartate aminotransferase, and alanine aminotransferase levels and white blood cell counts were elevated. Computed tomography revealed gas formation in her liver, and her culture results revealed and infections. She underwent percutaneous transhepatic abscess drainage in addition to antimicrobial administration. She was discharged after 40 days. Cases of emphysematous liver abscess with infections are rarely reported in the literature and may present in patients with poorly controlled type 2 diabetes. The fatality rate associated with the condition is markedly high.
PubMed: 35769544
DOI: 10.1016/j.idcr.2022.e01543 -
Journal of Fish Diseases Nov 2022In the mid-2010s, Edwardsiella tarda was reaffiliated into three discrete taxa (E. anguillarum, E. piscicida, and E. tarda), obscuring previous descriptions of E....
Pathology and virulence of Edwardsiella tarda, Edwardsiella piscicida, and Edwardsiella anguillarum in channel (Ictalurus punctatus), blue (Ictalurus furcatus), and channel × blue hybrid catfish.
In the mid-2010s, Edwardsiella tarda was reaffiliated into three discrete taxa (E. anguillarum, E. piscicida, and E. tarda), obscuring previous descriptions of E. tarda-induced pathology in fish. To clarify ambiguity regarding the pathology of E. tarda, E. piscicida, and E. anguillarum infections in US farm-raised catfish, channel catfish (Ictalurus punctatus), blue catfish (I. furcatus), and channel × blue catfish hybrids were challenged with comparable doses of each bacterium. The most severe pathology and mortality occurred in fish challenged with E. piscicida, supporting previous reports of increased pathogenicity in commercially important ictalurids, while E. anguillarum and E. tarda warrant only minimal concern. Acute pathologic lesions among bacterial species were predominantly necrotizing and characteristic of gram-negative sepsis but became progressively granulomatous over time. After 100 days, survivors were exposed to the approximate median lethal doses of E. piscicida and E. ictaluri, revealing some cross-protective effects among E. piscicida, E. anguillarum, and E. ictaluri. In contrast, no fish that survived E. tarda challenge demonstrated any protection against E. piscicida or E. ictaluri. This work supports reports of increased susceptibility of channel, blue, and hybrid catfish to E. piscicida, while highlighting potential cross-protective affects among fish associated Edwardsiella spp.
Topics: Animals; Catfishes; Edwardsiella; Edwardsiella ictaluri; Edwardsiella tarda; Enterobacteriaceae Infections; Fish Diseases; Ictaluridae; Virulence
PubMed: 35880718
DOI: 10.1111/jfd.13691 -
Diseases of Aquatic Organisms Oct 2018Edwardsiella piscicida, a Gram-negative, facultative aerobic pathogen belonging to the Enterobacteriaceae family, is the etiological agent of edwardsiellosis in fish and... (Review)
Review
Edwardsiella piscicida, a Gram-negative, facultative aerobic pathogen belonging to the Enterobacteriaceae family, is the etiological agent of edwardsiellosis in fish and a significant problem in global aquaculture. E. piscicida has been reported from a broad geographical range and has been isolated from more than 20 fish host species to date, but this is likely to be an underestimation, because misidentification of E. piscicida as other species within the genus remains to be resolved. Common clinical signs associated with edwardsiellosis include, but are not limited to, exophthalmia, haemorrhages of the skin and in several internal organs, mild to moderate dermal ulcerations, abdominal distension, discoloration in the fish surface, and erratic swimming. Many antibiotics are currently effective against E. piscicida, although legal restrictions and the cost of medicated feeds have encouraged significant research investment in vaccination for the management of edwardsiellosis in commercial aquaculture. Here we summarise the current understanding of E. piscicida and highlight the difficulties with species assignment and the need for further research on epidemiology and strain variability.
Topics: Animals; Aquaculture; Edwardsiella; Enterobacteriaceae Infections; Fish Diseases; Fishes
PubMed: 30324915
DOI: 10.3354/dao03281