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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 -
Journal of Global Antimicrobial... Jun 2023Edwardsiella ictaluri is an important pathogen in farmed raised catfish. Recently, we showed that resistance to tetracycline and florfenicol in the E. ictaluri MS-17-156...
OBJECTIVES
Edwardsiella ictaluri is an important pathogen in farmed raised catfish. Recently, we showed that resistance to tetracycline and florfenicol in the E. ictaluri MS-17-156 strain isolated from channel catfish was facilitated by acquisition of a 135 kb plasmid (named pEIMS-171561).
METHODS
We described the genetic structure of pEIMS-171561. Plasmid copy number and stability within E. ictaluri strain MS-17-156 was determined. We also investigated the in vitro and in vivo transferability of pEIMS-171561 using catfish as a model for in vivo transfer.
RESULTS
pEIMS-171561 belonged to the IncA/C group and contained florfenicol efflux major facilitator superfamily (MFS) (floR), sulfonamides (sul2), and tetracycline efflux MFS (tetD) genes. The plasmid contained two conjugative transfer-associated regions and encoded six transposases and insertion sequences. In vitro conjugation experiments demonstrated that the IncA/C plasmid can transfer from E. ictaluri to Escherichia coli. The plasmid was stable in E. ictaluri without selection pressure for 33 days. We showed that pEIMS-171561 did not transfer from E. ictaluri MS-17-156 to endogenous microbiota in catfish. Moreover, we could not detect in vivo conjugal transfer of pEIMS-171561 from E. ictaluri to E. coli. Results from real-time PCR revealed upregulation of the floR gene in the intestines of catfish receiving florfenicol-medicated feed, compared with that in catfish receiving unmedicated feed.
CONCLUSION
This study demonstrated that pEIMS-171561 did not disseminate from E. ictaluri to gut microbiota under selective pressure. This result suggests a limited role of the fish microbiota as a reservoir for this plasmid and for the spread of resistance.
Topics: Animals; Edwardsiella ictaluri; Escherichia coli; Enterobacteriaceae Infections; Plasmids; Anti-Bacterial Agents; Tetracycline; Catfishes; Drug Resistance, Microbial
PubMed: 36944411
DOI: 10.1016/j.jgar.2023.03.005 -
Microorganisms Jul 2022The type III secretion system (T3SS) effector EseN is encoded on the chromosome and is homologous to a family of T3SS effector proteins with phosphothreonine lyase...
The type III secretion system (T3SS) effector EseN is encoded on the chromosome and is homologous to a family of T3SS effector proteins with phosphothreonine lyase activity. Previously we demonstrated that invasion activates extracellular signal-regulated kinases 1 and 2 (ERK1/2) early in the infection, which are subsequently inactivated by EseN. Comparative transcriptomic analysis showed a total of 753 significant differentially expressed genes in head-kidney-derived macrophages (HKDM) infected with an EseN mutant (∆EseN) compared to HKDM infected with wild-type (WT) strains. This data strongly indicates classical activation of macrophages (the M1 phenotype) in response to infection and a significant role for EseN in the manipulation of this process. Our data also indicates that EseN is involved in the modulation of pathways involved in the immune response to infection and expression of several transcription factors, including NF-κβ (c- and ), , and . Regulation of transcription factors leads to regulation of proinflammatory interleukins (IL-8, IL-12a, IL-15, IL-6) and cyclooxygenase-2 (COX-2) expression. Inhibition of COX-2 mRNA by WT leads to decreased production of prostaglandin E2 (PGE2), which is the product of COX-2 activity. Collectively, our results indicate that EseN is an important player in the modulation of host immune responses to infection.
PubMed: 35889053
DOI: 10.3390/microorganisms10071334 -
Frontiers in Veterinary Science 2021is a Gram-negative facultative intracellular pathogen causing enteric septicemia of catfish (ESC), a devastating disease resulting in significant economic losses in the...
is a Gram-negative facultative intracellular pathogen causing enteric septicemia of catfish (ESC), a devastating disease resulting in significant economic losses in the U.S. catfish industry. Bacterial secretion systems are involved in many bacteria's virulence, and Type VI Secretion System (T6SS) is a critical apparatus utilized by several pathogenic Gram-negative bacteria. strain 93-146 genome has a complete T6SS operon with 16 genes, but the roles of these genes are still not explored. In this research, we aimed to understand the roles of two hemolysin co-regulated family proteins, Hcp1 (EvpC) and Hcp2. To achieve this goal, single and double mutants (ΔΔ, and ΔΔ) were generated and characterized. Catfish peritoneal macrophages were able to kill Δ better than ΔΔΔ, and wild-type (WT). The attachment of Δ and ΔΔ to ovary cells significantly decreased compared to WT whereas the cell invasion rates of these mutants were the same as that of WT. Mutants exposed to normal catfish serum showed serum resistance. The fish challenges demonstrated that Δ and ΔΔ were attenuated completely and provided excellent protection against WT infection in catfish fingerlings. Interestingly, Δ caused higher mortality than that of WT in catfish fingerlings, and severe clinical signs were observed. Although fry were more susceptible to vaccination with Δ and ΔΔ, their attenuation and protection were significantly higher compared to WT and sham groups, respectively. Taken together, our data indicated that () is involved in virulence in catfish while is involved in adhesion to epithelial cells and survival inside catfish macrophages.
PubMed: 34150898
DOI: 10.3389/fvets.2021.681609 -
PloS One 2018Edwardsiella ictaluri is a Gram-negative facultative anaerobic rod and the causative agent of enteric septicemia of channel catfish (ESC), which is one of the most...
Edwardsiella ictaluri is a Gram-negative facultative anaerobic rod and the causative agent of enteric septicemia of channel catfish (ESC), which is one of the most prevalent diseases of catfish, causing significant economic losses in the catfish industry. E. ictaluri is resistant to complement system and macrophage killing, which results in rapid systemic septicemia. However, mechanisms of E. ictaluri stress responses under conditions of host environment are not studied well. Therefore, in this work, we report E. ictaluri stress responses during hydrogen peroxide, low pH, and catfish serum stresses as well as during catfish invasion. E. ictaluri stress responses were characterized by identifying expression of 13 universal stress protein (USP) genes (usp01-usp13) and seven USP-interacting protein genes (groEL, groES, dnaK, grpE, and clpB, grpE, relA). Data indicated that three usp genes (usp05, usp07, and usp13) were highly expressed in all stress conditions. Similarly, E. ictaluri heat shock proteins groEL, groES, dnaK, grpE, and clpB were highly expressed in oxidative stress. Also, E. ictaluri grpE and relA were highly expressed in catfish spleen and head kidney. These findings contribute to our understanding of stress response mechanisms in E. ictaluri stress response, and stress-related proteins that are essential for E. ictaluri could be potential targets for live attenuated vaccine development against ESC.
Topics: Animals; Disease Progression; Edwardsiella ictaluri; Enterobacteriaceae Infections; Fish Diseases; Fish Proteins; Heat-Shock Proteins; Ictaluridae; Stress, Physiological; Virulence
PubMed: 29554143
DOI: 10.1371/journal.pone.0194669 -
BMC Microbiology Mar 2019Edwardsiella ictaluri is a Gram-negative facultative intracellular anaerobe and the etiologic agent of enteric septicemia of channel catfish (ESC). To the catfish...
BACKGROUND
Edwardsiella ictaluri is a Gram-negative facultative intracellular anaerobe and the etiologic agent of enteric septicemia of channel catfish (ESC). To the catfish industry, ESC is a devastating disease due to production losses and treatment costs. Identification of virulence mechanisms of E. ictaluri is critical to developing novel therapeutic approaches for the disease. Here, we report construction of a transposon insertion library and identification of mutated genes in growth-delayed E. ictaluri colonies. We also provide safety and efficacy of transposon insertion mutants in catfish.
RESULTS
An E. ictaluri transposon insertion library with 45,000 transposants and saturating 30.92% of the TA locations present in the E. ictaluri genome was constructed. Transposon end mapping of 250 growth-delayed E. ictaluri colonies and bioinformatic analysis of sequences revealed 56 unique E. ictaluri genes interrupted by the MAR2xT7 transposon, which are involved in metabolic and cellular processes and mostly localized in the cytoplasm or cytoplasmic membrane. Of the 56 genes, 30 were associated with bacterial virulence. Safety and vaccine efficacy testing of 19 mutants showed that mutants containing transposon insertions in hypothetical protein (Eis::004), and Fe-S cluster assembly protein (IscX, Eis::039), sulfurtransferase (TusA, Eis::158), and universal stress protein A (UspA, Eis::194) were safe and provided significant protection (p < 0.05) against wild-type E. ictaluri.
CONCLUSIONS
The results indicate that random transposon mutagenesis causing growth-delayed phenotype results in identification bacterial virulence genes, and attenuated strains with transposon interrupted virulence genes could be used as vaccine to activate fish immune system.
Topics: Animals; Bacterial Vaccines; Computational Biology; DNA Transposable Elements; Edwardsiella ictaluri; Enterobacteriaceae Infections; Fish Diseases; Gene Deletion; Genome, Bacterial; Ictaluridae; Mutagenesis; Mutation; Phenotype; Vaccines, Attenuated; Virulence
PubMed: 30849940
DOI: 10.1186/s12866-019-1429-3 -
Pathogens (Basel, Switzerland) Mar 2023and are pervasive bacterial pathogens associated with significant losses in catfish aquaculture. Bacterial coinfections have the potential to increase outbreak...
and are pervasive bacterial pathogens associated with significant losses in catfish aquaculture. Bacterial coinfections have the potential to increase outbreak severity and can worsen on-farm mortality. A preliminary assessment of in vivo bacterial coinfection with (S97-773) and (ALG-00-530) was conducted using juvenile channel catfish (). Catfish were divided into five treatment groups: (1) mock control; (2) full dose (immersion; 5.4 × 10 CFU mL); (3) full dose (immersion; 3.6 × 10 CFU mL); (4) half dose (immersion; 2.7 × 10 CFU mL) followed by half dose (immersion; 1.8 × 10 CFU mL); and (5) half dose followed by half dose . In the coinfection challenges, the second inoculum was delivered 48 h after the initial exposure. At 21 days post-challenge (DPC), the single dose infection yielded a cumulative percent mortality (CPM) of 90.0 ± 4.1%, compared with 13.3 ± 5.9% in the group. Mortality patterns in coinfection challenges mimicked the single dose challenge, with CPM of 93.3 ± 5.4% for fish initially challenged with followed by , and 93.3 ± 2.7% for fish exposed to and subsequently challenged with . Despite similarities in the final CPM within the coinfection groups, the onset of peak mortality was delayed in fish exposed to first but was congruent with mortality trends in the challenge. Catfish exposed to in both the single and coinfected treatments displayed increased serum lysozyme activity at 4-DPC ( < 0.001). Three pro-inflammatory cytokines (, , ) were evaluated for gene expression, revealing an increase in expression at 7-DPC in all exposed treatments ( < 0.05). These data enhance our understanding of the dynamics of and coinfections in US farm-raised catfish.
PubMed: 36986384
DOI: 10.3390/pathogens12030462 -
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 -
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