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Journal of the American Chemical Society Feb 2022The implementation of a reliable, rapid, inexpensive, and simple method for whole-proteome identification would greatly benefit cell biology research and clinical...
The implementation of a reliable, rapid, inexpensive, and simple method for whole-proteome identification would greatly benefit cell biology research and clinical medicine. Proteins are currently identified by cleaving them with proteases, detecting the polypeptide fragments with mass spectrometry, and mapping the latter to sequences in genomic/proteomic databases. Here, we demonstrate that the polypeptide fragments can instead be detected and classified at the single-molecule limit using a nanometer-scale pore formed by the protein aerolysin. Specifically, three different water-soluble proteins treated with the same protease, trypsin, produce different polypeptide fragments defined by the degree by which the latter reduce the nanopore's ionic current. The fragments identified with the aerolysin nanopore are consistent with the predicted fragments that trypsin could produce.
Topics: Aeromonas hydrophila; Bacterial Toxins; Cytochromes c; Hemolysin Proteins; Muramidase; Myoglobin; Nanopores; Peptide Fragments; Pore Forming Cytotoxic Proteins; Proteolysis; Proteomics; Trypsin
PubMed: 35120294
DOI: 10.1021/jacs.1c11758 -
Enfermedades Infecciosas Y... Apr 2023
Topics: Humans; Aeromonas hydrophila; Anti-Bacterial Agents; Bacteremia
PubMed: 36870822
DOI: 10.1016/j.eimce.2023.02.004 -
Journal of Fish Diseases Nov 2022Aeromonas hydrophila infections are common in aquaculture. Our previous studies found that the A. hydrophila B11 strain can survive in fish macrophages for at least...
Aeromonas hydrophila infections are common in aquaculture. Our previous studies found that the A. hydrophila B11 strain can survive in fish macrophages for at least 24 h and the two-component system EnvZ/OmpR may be involved in intracellular survival. To reveal the role and mechanism of the two-component system EnvZ/OmpR in intracellular survival of A. hydrophila, the genes of envZ/ompR were silenced by shRNAi. The results showed that the survival rates of the envZ-RNAi and ompR-RNAi strains were only 2.05% and 3.75%, respectively, which were decreased by 91% and 83.6% compared with that of the wild-type strain. The escape ability of envZ-RNAi and ompR-RNAi was also decreased by 51.4% and 19.7%, respectively. The comparative transcriptome analysis revealed that the functional genes directly related to bacterial intracellular survival mainly included the genes related to anti-stress capacity, and the genes related to Zn and Mg transport. Further research confirmed that two-component system EnvZ/OmpR can regulate the expression of the important molecular chaperones, such as groEL, htpG, dnaK, clpB and grpE. The expression of these molecular chaperones in wild-type strain was up-regulated with the increase in H O concentrations, while the expression of these molecular chaperones in silent strains did not change significantly. Cells that phagocytosed wild-type strain had higher ROS content than cells that phagocytosed silent strains. Two-component system EnvZ/OmpR could also regulate zinc transporter (znuA, znuB, znuC) and zinc efflux protein (zntA) to maintain zinc homeostasis in cells, thus affecting the ability of bacteria to survive in phagocytes. Moreover, two-component system EnvZ/OmpR could affect the growth and intracellular survival of A. hydrophila by regulating the expression of MgtA, MgtC and MgtE and participating in bacterial Mg homeostasis in fish macrophages.
Topics: Aeromonas hydrophila; Animals; Bacterial Outer Membrane Proteins; Bacterial Proteins; Fish Diseases; Reactive Oxygen Species; Zinc
PubMed: 35822274
DOI: 10.1111/jfd.13684 -
Frontiers in Immunology 2023is a kind of zoonotic pathogen, which can cause bacterial septicemia in fish and bring huge economic losses to global aquaculture. Outer membrane proteins (Omps) are...
is a kind of zoonotic pathogen, which can cause bacterial septicemia in fish and bring huge economic losses to global aquaculture. Outer membrane proteins (Omps) are conserved antigens of , which can be developed as subunit vaccines. To evaluate the protective efficacy of inactivated vaccine and recombinant outer membrane protein A (OmpA) subunit vaccine against in juvenile , the present study investigated the immunogenicity and protective effects of both vaccines, as well as the non-specific and specific immune response of . Compared with the non-vaccinated group, both inactivated and OmpA subunit vaccines improved the survival rate of upon infection. The protective effects of OmpA vaccine groups were better than that of the inactivated vaccine groups, which should be attributed to the reduced bacterial load and enhanced host immunity in the vaccinated fish. ELISA assay showed that the titer of serum immunoglobulin M (IgM) specific to up-regulated significantly in the OmpA subunit vaccine groups at 14 d post infection (dpi), which should contribute to better immune protective effects. In addition, vaccination enhanced host bactericidal abilities might also attribute to the regulation of the activities of hepatic and serum antimicrobial enzymes. Moreover, the expression of immune-related genes ( and ) increased in all groups post infection, which was more significant in the vaccinated groups. Furthermore, the number of immunopositive cells exhibiting different epitopes (CD8, IgM, IgD and IgZ) that were detected by immunohistochemical assay had increased in the vaccinated groups post infection. These results show that vaccination effectively stimulated host immune response (especially OmpA vaccine groups). In conclusion, these results indicated that both the inactivated vaccine and OmpA subunit vaccine could protect juvenile against infection, of which OmpA subunit vaccine provided more effective immune protection and can be used as an ideal candidate for the vaccine.
Topics: Animals; Aeromonas hydrophila; Vaccines, Inactivated; Bacterial Vaccines; Cypriniformes; Immunoglobulin M; Vaccines, Synthetic; Vaccines, Subunit
PubMed: 36969197
DOI: 10.3389/fimmu.2023.1133742 -
Fish & Shellfish Immunology Aug 2022Aeromonas hydrophila is an important aquatic zoonotic pathogen that causes septicemia, necrotizing fasciitis and gastroenteritis in various aquatic and non-aquatic...
Aeromonas hydrophila is an important aquatic zoonotic pathogen that causes septicemia, necrotizing fasciitis and gastroenteritis in various aquatic and non-aquatic animals. However, the pathogenesis of A. hydrophila is not fully understood. Here, we examined the pathogenicity and histopathology of A. hydrophila in the zebrafish (Danio rerio) model system. We found that the intensity of symptoms and mortality is dose-dependent. Bacterial colonization studies demonstrated that A. hydrophila never cleared out from the fish body but stayed in a state of inactivity till it enters a fresh host. Reinfection studies showed that exposure to A. hydrophila provides immunity against future infection and hence improves fish survival. Gene expression studies revealed the crosstalk between T-helper cell and macrophage responses in fish immune system in response to A. hydrophila and infection memory. Histopathological studies showed that symptoms of tissue damage and inflammation lasted for less duration with less intensity in immunized fish when compared to non-immunized fish. Together, our results suggest that the zebrafish model is a useful system in studying the interplay between A. hydrophila pathogenesis, persistence and immunity.
Topics: Aeromonas hydrophila; Animals; Fish Diseases; Gram-Negative Bacterial Infections; Virulence; Zebrafish
PubMed: 35772676
DOI: 10.1016/j.fsi.2022.06.052 -
Archives of Virology Feb 2022Aeromonas hydrophila (A. hydrophila) is an opportunistic pathogen of fish, humans, and livestock, and has a severe negative impact on aquaculture development. Phage...
Aeromonas hydrophila (A. hydrophila) is an opportunistic pathogen of fish, humans, and livestock, and has a severe negative impact on aquaculture development. Phage therapy is considered an alternative strategy for controlling bacterial infections and contamination. In this study, we isolated and characterized the genomes of two A. hydrophila-specific phages, PZL-Ah1 and PZL-Ah8, which, based on transmission electron microscopy, were identified as members of the family Podoviridae. Both of these phages had a relatively narrow host range, with lytic activity against Aeromonas spp. strains. Whole-genome sequence analysis revealed that PZL-Ah1 and PZL-Ah8 have a double-stranded DNA genome of 38,641 bp and 40,855 bp in length, with a GC content of 53.68% and 51.89%, respectively. Forty-four open reading frames (ORFs) were predicted in PZL-Ah1, and 52 were predicted in PZL-Ah8. Twenty-eight (63.6%) ORFs in PZL-Ah1 and 29 (55.8%) ORFs in PZL-Ah8 were predicted to encode functional proteins with homologs in the NCBI database, while the remaining ORFs were classified as encoding hypothetical proteins with unknown functions. A comparison with known phage genes suggested that ORF 02, ORF 29, and ORF 04 of PZL-Ah1 and ORF 2 and ORF 4 of PZL-Ah8 are involved in host cell lysis. This study expands the phage genome database and provides good candidates for phage typing applications.
Topics: Aeromonas hydrophila; Animals; Bacteriophages; DNA, Viral; Genome, Viral; Humans; Open Reading Frames; Phylogeny; Podoviridae
PubMed: 35075514
DOI: 10.1007/s00705-021-05345-y -
BMC Microbiology Jun 2020Aeromonas hydrophila is an important water-borne pathogen that leads to a great economic loss in aquaculture. Along with the abuse of antibiotics, drug-resistant strains...
BACKGROUND
Aeromonas hydrophila is an important water-borne pathogen that leads to a great economic loss in aquaculture. Along with the abuse of antibiotics, drug-resistant strains rise rapidly. In addition, the biofilms formed by this bacterium limited the antibacterial effect of antibiotics. Bacteriophages have been attracting increasing attention as a potential alternative to antibiotics against bacterial infections.
RESULTS
Five phages against pathogenic A. hydrophila, named N21, W3, G65, Y71 and Y81, were isolated. Morphological analysis by transmission electron microscopy revealed that phages N21, W3 and G65 belong to the family Myoviridae, while Y71 and Y81 belong to the Podoviridae. These phages were found to have broad host spectra, short latent periods and normal burst sizes. They were sensitive to high temperature but had a wide adaptability to the pH. In addition, the phages G65 and Y81 showed considerable bacterial killing effect and potential in preventing formation of A. hydrophila biofilm; and the phages G65, W3 and N21 were able to scavenge mature biofilm effectively. Phage treatments applied to the pathogenic A. hydrophila in mice model resulted in a significantly decreased bacterial loads in tissues.
CONCLUSIONS
Five A. hydrophila phages were isolated with broad host ranges, low latent periods, and wide pH and thermal tolerance. And the phages exhibited varying abilities in controlling A. hydrophila infection. This work presents promising data supporting the future use of phage therapy.
Topics: Aeromonas hydrophila; Animals; Bacterial Load; Bacteriophages; Biofilms; Disease Models, Animal; Gram-Negative Bacterial Infections; Hot Temperature; Hydrogen-Ion Concentration; Mice; Microscopy, Electron, Transmission; Myoviridae; Phage Therapy; Podoviridae
PubMed: 32487015
DOI: 10.1186/s12866-020-01811-w -
Brazilian Journal of Microbiology :... Sep 2020This study was aimed to understand the expression of miR-146a in zebrafish (Danio rerio) and its role in regulating immune responses during Aeromonas hydrophila and...
This study was aimed to understand the expression of miR-146a in zebrafish (Danio rerio) and its role in regulating immune responses during Aeromonas hydrophila and Edwardsiella piscicida infections. The miR-146a expression was observed from the 1-h post fertilization (hpf) stage and gradually increased up to the early larval stage of zebrafish. The ubiquitous expression of miR-146a was detected in all tested tissues, with the highest level in gills. The expression of miR-146a was significantly increased in larvae when exposed to E. piscicida infection at 24 and 48 h post exposure (hpe). Intraperitoneally (i.p.) injected A. hydrophila and E. piscicida into adult zebrafish showed significant upregulation of miR-146a in gills. Furthermore, immune-related genes, toll-like receptor, tlr-4, transducing signaling pathway molecules, traf-6 and myd88 (bacteria-infected larvae and adults), transcription factor relA and mcp-1b (bacteria-infected adults), pro-inflammatory, il-6 (A. hydrophila-exposed larvae) and mmp-9 (bacteria-exposed larvae) were significantly repressed. In contrast, il-1β, tnf-α, cxcl-18b, and ccl-34a.4 were induced in both bacteria-challenged larvae and adults. Based on the results, it is suggested that endogenous miR-146a could act as an infection inducible miRNA in zebrafish upon A. hydrophila and E. piscicida infections; also, it could potentially regulate the immune responses in zebrafish.
Topics: Aeromonas hydrophila; Animals; Edwardsiella; Fish Diseases; Gene Expression Regulation; Gram-Negative Bacterial Infections; Immunity; Life Cycle Stages; MicroRNAs; Zebrafish
PubMed: 32067211
DOI: 10.1007/s42770-020-00237-w -
Food Research International (Ottawa,... Sep 2021Aeromonas hydrophila is an emerging foodborne pathogen capable of causing human gastroenteritis, and the main reservoir is the aquatic environment. In this study, the...
Aeromonas hydrophila is an emerging foodborne pathogen capable of causing human gastroenteritis, and the main reservoir is the aquatic environment. In this study, the prevalence and virulence of A. hydrophila in seafoods and ready-to-eat (RTE) sushi distributed in various conditions (refrigerated, dried, or frozen) or seasons was investigated. Strains were isolated from seafood (refrigerated or frozen oysters, sashimi, and processed fish; n = 333) and RTE sushi (n = 88) samples collected in South Korea and then genetically analyzed for gastroenteritis-related virulence genes (aer, ast, and alt). Raw oysters showed the highest prevalence of A. hydrophila (57.1%; 47/91) among all seafoods. Among the sashimi samples, flatfish sashimi (54.8%; 34/62) and salmon sushi (51.4%; 18/35) were the most prevalent. A. hydrophila was not detected in the oysters or anchovies distributed as either frozen or dried products. Seasonal investigations of sashimi and sushi showed that the summer prevalence of A. hydrophila with putative virulence genes was significantly lower in sashimi but highest in sushi. These results indicated that sushi could have been contaminated from several sources during the manufacturing or distribution processes. Significant correlations among the prevalence of putative virulence genes were confirmed, although no combination of genes presented a Phi correlation coefficient above 0.5 (0.26-0.43). To our knowledge, this is the first study to investigate the prevalence of A. hydrophila in various types of retail seafoods and RTE sushi in the East Asia region and then relate the prevalence to the distribution conditions of the samples. This study provides background information on the level of potential risk posed by A. hydrophila in retail seafoods and RTE sushi.
Topics: Aeromonas hydrophila; Animals; Food Microbiology; Humans; Seafood; Seasons; Virulence
PubMed: 34399480
DOI: 10.1016/j.foodres.2021.110484 -
Virus Research Oct 2022In the present study, genome characteristics and codon usage patterns of 44 Aeromonas hydrophila phages were studied. Phage genomes varied from 30.8 to 262.0 kb with...
In the present study, genome characteristics and codon usage patterns of 44 Aeromonas hydrophila phages were studied. Phage genomes varied from 30.8 to 262.0 kb with mean±SD and median values of 111.3 ± 81.4 kb and 79.4 kb, respectively. Though the great variation in phage GC contents (35.1-62.2%) was observed, GC contents of all phages (except two phages) were significantly less than the GC content (62.4 ± 5.6%) of the host. The effective number of codons (ENC) values of phage genes ranged from 27.7 to 61 with a mean±SD value of 47.4 ± 6.8. Out of a total 5773 phage genes, 207 (3.6%), 3,528 (61.1%) and 2,012 (34.9%) genes had strong (ENC < 35), moderate (35 < ENC < 50) and low (ENC ≥ 50) codon usage bias, respectively. During relative synonymous codon usage (RSCU) analysis, shared usage of preferred codons was also observed between the phages and host. During codon adaptation index (CAI) analysis, 1028 (17.8%) phage genes showed significant adaptation towards the host. Among these genes, 797 (78.0%) genes encoded hypothetical proteins or proteins of unknown function; whereas 118 (12%) genes encoded the phage structural and packaging proteins. Segregation of ENC, RSCU and CAI analysis results based on genome size also indicated that codon usage bias was more prominent in phages with small genomes. Correlation, neutrality and GC3 versus ENC analyzes indicated a more dominant role of natural selection in shaping the codon usage patterns of A. hydrophila phages. The findings of the current study could be useful from evolutionary and host-pathogen interaction perspectives leading to efficient utilization of phages for therapeutic and other applications.
Topics: Aeromonas hydrophila; Bacteriophages; Base Composition; Codon; Codon Usage; Evolution, Molecular; Mutation
PubMed: 36029927
DOI: 10.1016/j.virusres.2022.198900