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Journal of Fish Diseases Mar 2023Aeromonas veronii is an important zoonotic and aquatic pathogen that causes a number of illnesses in both humans and animals. It is related to gastroenteritis, skin and...
Aeromonas veronii is an important zoonotic and aquatic pathogen that causes a number of illnesses in both humans and animals. It is related to gastroenteritis, skin and soft tissue infections and bacteremia in humans, as well as causing significant economic losses in aquaculture owing to fish sepsis. Here, we constructed the flagellar cap gene (fliD) mutant strain of A. veronii by suicide plasmid-mediated homologous recombination system and analysed its characteristics. It was found that the deletion of fliD had no effect on growth and biochemical properties and could be inherited stably. However, the motility of A. veronii ΔfliD was significantly reduced, the flagellum was defective and the biofilm formation was attenuated compared with that of A. veronii wild-type strain. In vivo experiments revealed that the colonization capacity of ΔfliD was significantly lower than that of the wild-type strain in the period of first 24 h, and the median lethal dose (LD ) was 56 times higher than that of the wild-type strain. The Cyprinus carpio infected with the wild-type strain indicated faster death speed and more severe clinical signs compared to ΔfliD strain. These results suggest that fliD is closely related to the virulence of A. veronii and plays an important role in pathogenicity, providing the foundation for pathogenic mechanism studies of A. veronii.
Topics: Humans; Animals; Aeromonas veronii; Virulence; Carps; Fish Diseases; Gram-Negative Bacterial Infections; Aeromonas
PubMed: 36515399
DOI: 10.1111/jfd.13739 -
Marine Biotechnology (New York, N.Y.) Dec 2023As an opportunistic pathogen, Aeromonas veronii can cause hemorrhagic septicemia of various aquatic animals. In our present study, a dominant strain SJ4, isolated from...
As an opportunistic pathogen, Aeromonas veronii can cause hemorrhagic septicemia of various aquatic animals. In our present study, a dominant strain SJ4, isolated from naturally infected mandarin fish (Siniperca chuatsi), was identified as A. veronii according to the morphological, physiological, and biochemical features, as well as molecular identification. Intraperitoneal injection of A. veronii SJ4 into S. chuatsi revealed clinical signs similar to the natural infection, and the median lethal dosage (LD) of the SJ4 to S. chuatsi in a week was 3.8 × 10 CFU/mL. Histopathological analysis revealed that the isolate SJ4 could cause cell enlargement, obvious hemorrhage, and inflammatory responses in S. chuatsi. Detection of virulence genes showed the isolate SJ4 carried act, fim, flgM, ompA, lip, hly, aer, and eprCAL, and the isolate SJ4 also produce caseinase, dnase, gelatinase, and hemolysin. In addition, the complete genome of A. veronii SJ4 was sequenced, and the size of the genome of A. veronii SJ4 was 4,562,694 bp, within a G + C content of 58.95%, containing 4079 coding genes. Nine hundred ten genes encoding for several virulence factors, such as type III and VI secretion systems, flagella, motility, etc., were determined based on the VFDB database. Besides, 148 antibiotic resistance-related genes in 27 categories related to tetracyclines, fluoroquinolones, aminoglycosides, macrolides, chloramphenicol, and cephalosporins were also annotated. The present results suggested that A. veronii was etiological agent causing the bacterial septicemia of S. chuatsi in this time, as well as provided a valuable base for revealing pathogenesis and resistance mechanism of A. veronii.
Topics: Animals; Aeromonas veronii; Fishes; Virulence; Virulence Factors; Anti-Bacterial Agents; Gram-Negative Bacterial Infections; Fish Diseases
PubMed: 37947961
DOI: 10.1007/s10126-023-10253-0 -
Frontiers in Microbiology 2016Digestive-tract microbiota exert tremendous influence over host health. Host-symbiont model systems are studied to investigate how symbioses are initiated and... (Review)
Review
Digestive-tract microbiota exert tremendous influence over host health. Host-symbiont model systems are studied to investigate how symbioses are initiated and maintained, as well as to identify host processes affected by resident microbiota. The medicinal leech, , is an excellent model to address such questions owing to a microbiome that is consistently dominated by two species, and , both of which are cultivable and have sequenced genomes. This review outlines current knowledge about the dynamics of the microbiome. We discuss in depth the factors required for colonization and proliferation in the leech crop and summarize the current understanding of interactions between and its annelid host. Lastly, we discuss leech usage in modern medicine and highlight how leech-therapy associated infections, often attributable to spp., are of growing clinical concern due in part to an increased prevalence of fluoroquinolone resistant strains.
PubMed: 27790190
DOI: 10.3389/fmicb.2016.01569 -
Journal of Fish Diseases Jun 2024Aeromonas veronii is an important pathogen found in various aquatic environments and products, posing a threat to public health. The Hanks-like serine/threonine protein...
Aeromonas veronii is an important pathogen found in various aquatic environments and products, posing a threat to public health. The Hanks-like serine/threonine protein kinase is closely linked to the pathogenesis of pathogenic bacteria, but the exact role of YihE in A. veronii remains still unknown. To study the specific function of the YihE kinase, we constructed a knockout mutant of the yihE gene in A. veronii. The deletion of the yihE gene resulted in changes to the metabolism of L-arginine-AMC and acetic acid, as well as enhanced resistance to ampicillin and kanamycin in A. veronii. Additionally, the ΔyihE strain demonstrated a 1.4-fold increase in biofilm formation ability and a 1.8-fold decrease in adhesion and invasion to EPCs when compared to the wild-type strain. A significant decrease in cytotoxicity was observed at 2 and 3 h post-infection with EPCs compared to the wild-type strain. Additionally, the deletion of the yihE gene was associated with a significant decrease in motility of the strain. Furthermore, the deletion of the yihE gene resulted in a 1.44-fold increase in the LD of A. veronii in zebrafish. These findings offer valuable insights into the pathogenic mechanisms of A. veronii.
PubMed: 38879868
DOI: 10.1111/jfd.13986 -
Journal of Fish Diseases Jun 2017This study evaluated antibiotic resistance and the related genes in total 47 Aeromonas veronii isolates from pet fish, eel (Anguilla japonica) and koi (Cyprinus carpio)...
This study evaluated antibiotic resistance and the related genes in total 47 Aeromonas veronii isolates from pet fish, eel (Anguilla japonica) and koi (Cyprinus carpio) in Korea. In comparison with the antibiotic susceptibilities of isolates from eel and koi, those of pet fish were more resistant to ceftiofur, aminoglycosides, tetracycline and nitrofurantoin. And isolates from pet fish showed high prevalences of class 1 integron, quinolones and tetracycline resistance determinants than those from eel and koi. Repetitive-element palindromic PCR (rep-PCR) showed larger diversities among A. veronii isolates. Collectively, pet fish may be a reservoir for multiple clones of A. veronii involved in antibiotic resistance. In this aspect, imported fish in the aquaculture trade should be steadily and continually screened for bacterial antibiotic resistance and related genes.
Topics: Aeromonas veronii; Anguilla; Animals; Anti-Bacterial Agents; Aquaculture; Carps; Drug Resistance, Bacterial; Fish Diseases; Polymerase Chain Reaction; Republic of Korea
PubMed: 27690177
DOI: 10.1111/jfd.12564 -
Archives of Virology Sep 2022Bacteria of the species Aeromonas veronii are generally ubiquitous in different aquatic environments and are capable of causing a variety of diseases in aquatic animals....
Bacteria of the species Aeromonas veronii are generally ubiquitous in different aquatic environments and are capable of causing a variety of diseases in aquatic animals. In this work, the phage isolate pAEv1812, which is lytic to A. veronii strain 1810, was characterized and sequenced. Morphological analysis revealed that pAEv1812 has a symmetrical head and a long non-contractile tail. A one-step growth curve analysis showed that the latent period and burst period of pAEv1812 were approximately 40 min and 80 min, respectively, with a burst size of 190 PFU/infected cell. The genome of phage pAEv1812 is 61,461 bp in length with a G+C content of 61.4%. Eighteen of the 75 putative proteins encoded by this phage have known functions, and there were no rRNA and tRNA genes in the genome. Phylogenetic analysis based on amino acid sequences of the major capsid protein and terminase large subunit suggested that phage pAEv1812 should be included as a member of the genus Chivirus.
Topics: Aeromonas veronii; Bacteriophages; Genome, Viral; Genomics; Phylogeny
PubMed: 35716266
DOI: 10.1007/s00705-022-05491-x -
Veterinary Microbiology Aug 2023Aeromonas veronii is a Gram-negative opportunistic bacterium found in fish, poultry and humans and has occasionally been associated with disease although not generally...
Aeromonas veronii is a Gram-negative opportunistic bacterium found in fish, poultry and humans and has occasionally been associated with disease although not generally considered a poultry pathogen. A. veronii was recently isolated from both healthy and condemned broiler carcasses at a major Danish abattoir. In this study, we did a whole genomic analysis of 24A. veronii strains from the abattoir to determine their potential sources and relatedness as well as their pathogenic potential, antimicrobial resistance determinants and associated mobile elements. No strains were multi-drug resistant, but all strains carried the beta-lactam resistance genes cphA3 and bla without being phenotypically resistant to carbapenems. One strain carried an IncA plasmid with tet(A), tet(B) and tet(E) genes. A phylogenetic tree including public A. veronii sequences showed that our isolates were not clonal but were dispersed around the phylogenetic tree, suggesting a diffuse spread of A. veronii across human, aquatic and poultry samples. Strains carried different virulence factors known to be associated with pathogenesis and severity of disease in animals and humans, e.g. type II (aerolysin, amylases, proteases, and cytotoxic enterotoxin Act) and III secretion systems where the latter has been associated with mortality in hospitalized patients. Although our genomic analysis of A. veronii shows zoonotic potential, epidemiological studies of human gastro-enteritis cases of A. veronii associated with consumption of broiler meat are needed. It remains to be proven if A. veronii is a true poultry pathogen and part of the established microflora in abattoirs and the gut-intestinal microflora of poultry.
Topics: Humans; Animals; Aeromonas veronii; Aeromonas; Chickens; Virulence; Phylogeny; Genomics; Denmark; Gram-Negative Bacterial Infections
PubMed: 37207528
DOI: 10.1016/j.vetmic.2023.109772 -
Colloids and Surfaces. B, Biointerfaces Jul 2020Flumequine was nano-immobilized by self-assembly on iron oxide nanoparticles, called surface active maghemite nanoparticles (SAMNs). The binding process was studied and...
Flumequine was nano-immobilized by self-assembly on iron oxide nanoparticles, called surface active maghemite nanoparticles (SAMNs). The binding process was studied and the resulting core-shell nanocarrier (SAMN@FLU) was structurally characterized evidencing a firmly immobilized organic canopy on which the fluorine atom of the antibiotic was exposed to the solvent. The antibiotic efficacy of the SAMN@FLU nanocarrier was tested on a fish pathogenic bacterium (Aeromonas veronii), a flumequine sensitive strain, in comparison to soluble flumequine and the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were assessed. Noteworthy, the MIC and MBC of soluble and nanoparticle bound drug were superimposable. Moreover, the interactions between SAMN@FLU nanocarrrier and microorganism were studied by transmission electron microscopy evidencing the ability of the complex to disrupt the bacterial wall. Finally, a preliminary in vivo test was provided using Daphnia magna as animal model. SAMN@FLU was able to protect the crustacean from the fatal consequences of a bacterial infection and showed no sign of toxicity. Thus, in contrast with the strength of the interaction, nano-immobilized FLU displayed a fully preserved antimicrobial activity suggesting the crucial role of fluorine in the drug mechanism of action. Besides the importance for potential applications in aquaculture, the present study contributes to the nascent field of nanoantibiotics.
Topics: Aeromonas veronii; Animals; Anti-Bacterial Agents; Daphnia; Fluoroquinolones; Magnetite Nanoparticles; Microbial Sensitivity Tests; Molecular Structure
PubMed: 32305623
DOI: 10.1016/j.colsurfb.2020.111019 -
BMC Genomics Feb 2024DNA N6-methyladenosine (6mA), as an important epigenetic modification, widely exists in bacterial genomes and participates in the regulation of toxicity, antibiotic...
BACKGROUND
DNA N6-methyladenosine (6mA), as an important epigenetic modification, widely exists in bacterial genomes and participates in the regulation of toxicity, antibiotic resistance, and antioxidant. With the continuous development of sequencing technology, more 6mA sites have been identified in bacterial genomes, but few studies have focused on the distribution characteristics of 6mA at the whole-genome level and its association with gene expression and function.
RESULTS
This study conducted an in-depth analysis of the 6mA in the genomes of two pathogenic bacteria, Aeromonas veronii and Helicobacter pylori. The results showed that the 6mA was widely distributed in both strains. In A. veronii, 6mA sites were enriched at 3' end of protein-coding genes, exhibiting a certain inhibitory effect on gene expression. Genes with low 6mA density were associated with cell motility. While in H. pylori, 6mA sites were enriched at 5' end of protein-coding genes, potentially enhancing gene expression. Genes with low 6mA density were closely related to defense mechanism.
CONCLUSIONS
This study elucidated the distribution characteristics of 6mA in A. veronii and H. pylori, highlighting the effects of 6mA on gene expression and function. These findings provide valuable insights into the epigenetic regulation and functional characteristics of A. veronii and H. pylori.
Topics: Helicobacter pylori; Epigenesis, Genetic; Aeromonas veronii; DNA; Adenosine; DNA Methylation
PubMed: 38331763
DOI: 10.1186/s12864-024-10074-y -
Frontiers in Microbiology 2022The area around Poyang Lake is the main aquaculture area in Jiangxi Province, China, and an important base for the supply of freshwater aquatic products. Aquaculture in...
The area around Poyang Lake is the main aquaculture area in Jiangxi Province, China, and an important base for the supply of freshwater aquatic products. Aquaculture in the Poyang Lake area is severely threatened by diseases caused by bacterial pathogens, and has been the main pathogen in recent years. In this paper, ERIC-PCR genotyping, virulence gene and antimicrobial resistance gene detection, and drug susceptibility tests were carried out on 46 isolates obtained from aquaculture systems in the Poyang Lake area from 2016 to 2020. The results showed that the strains in the Poyang Lake area had high genetic diversity, and 46 strains produced 36 ERIC genotypes. There were no geographical and temporal differences in the cluster analysis results and no dominant clones. All 13 virulence genes tested were detected, and all isolates had harbored 2 or more virulence genes, with a maximum of 12 virulence genes detected. Among the 22 antimicrobial resistance genes selected, 15 were detected; 97.8% of the isolates contained 2 or more antimicrobial resistance genes, with a maximum of 9 antimicrobial resistance genes. Drug susceptibility tests showed that some strains were resistant to a variety of traditionally effective drugs for such as enrofloxacin and florfenicol. This study provides a reference for exploring the impact of aquaculture in the Poyang Lake area on public health.
PubMed: 36578578
DOI: 10.3389/fmicb.2022.1042007