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Virus Research Oct 2023Aeromonas is one of the most serious pathogens in freshwater aquaculture. Overuse of antibiotics for the treatment of fish diseases has led to the frequent occurrence of...
Aeromonas is one of the most serious pathogens in freshwater aquaculture. Overuse of antibiotics for the treatment of fish diseases has led to the frequent occurrence of drug-resistant strains. Phage therapy is an alternative approach to overcoming the multi-drug resistance associated with antibiotics. In this study, a novel phage phiA034 targeting the host A. veronii A034 was isolated. The phage could infect 14 strains of 4 species Aeromonas. The phage phiA034 displayed head-tail structure with an icosahedral head in the TEM image. At the optimal MOI of 1, it had a latent period of nearly 20 minutes and a burst size of 286 PFU/cell. Besides, the phage phiA034 exhibited high tolerance to a wide range of temperature (30-70 °C) and acid-base (pH 6.0-10.0). The whole genome of phage phiA034 was sequenced with a size of 61,443 bp and annotated with 82 ORFs, mainly related to structure, DNA replication, and lysis. Based on the analysis and comparison of the genomes and proteomes, phage phiA034 could be classified as a novel species of an existing genus Duplodnaviria Heunggongvirae, Uroviricota, Caudoviricetes, Casjensviridae, Sharonstreetvirus. These findings have expanded the species bank and genomes library of bacterial virus and will promote the application of phage therapy in Aeromonas disease.
Topics: Animals; Bacteriophages; Aeromonas; DNA, Viral; Genome, Viral; Anti-Bacterial Agents
PubMed: 37579848
DOI: 10.1016/j.virusres.2023.199193 -
Genes Jun 2023To further investigate the immune response of against , comparative transcriptomic analyses of the hepatopancreas were conducted on challenge and control groups at 6,...
To further investigate the immune response of against , comparative transcriptomic analyses of the hepatopancreas were conducted on challenge and control groups at 6, 12, and 24 h post-infection (hpi), independently. A total of 51,707 high-quality unigenes were collected from the RNA-seq data, and 8060 differentially expressed genes (DEGs) were discovered through paired comparisons. Among the three comparison groups, a KEGG pathway enrichment analysis showed that 173 immune-related DEGs were considerably clustered into 28 immune-related pathways, including the lysosome, the phagosome, etc. Moreover, the expression levels of the four key immune-related genes (, , , and ) were evaluated at various stages following post-infection in the hepatopancreas, hemolymph, and gills. Both and genes were highly up-regulated in all three tissues at 6 hpi with ; was up-regulated in the hepatopancreas and hemolymph but down-regulated in the gill at 6 hpi, and was up-regulated in hemolymph and gill, but down-regulated in the hepatopancreas at 6 hpi. These findings lay the groundwork for understanding the immune mechanism of after contracting .
Topics: Animals; Aeromonas veronii; Palaemonidae; Glycogen Synthase Kinase 3 beta; I-kappa B Kinase; Transcriptome; Immunity
PubMed: 37510289
DOI: 10.3390/genes14071383 -
Fish Physiology and Biochemistry Aug 2023In this study, the effects of Coriandrum sativum to control Aeromonas veronii infection in Oreochromis niloticus were determined. Coriandrum sativum extract (CE) was...
Therapeutic efficacy of coriander (Coriandrum sativum) enriched diets in Oreochromis niloticus: effect on hepatic-renal functions, the antioxidant-immune response and resistance to Aeromonas veronii.
In this study, the effects of Coriandrum sativum to control Aeromonas veronii infection in Oreochromis niloticus were determined. Coriandrum sativum extract (CE) was tested in vitro against A. veronii by the disc diffusion assay. In in vivo, 150 O. niloticus (from El-Abbassa, Sharkia, Egypt, weighing 34.95 ± 1.98 g) was distributed in five groups (with three replications) in glass aquariums (80 × 40 × 30 cm). The first group (control) was intraperitoneally injected with 0.2 ml of sterilized tryptic soya broth. Groups 2-5 were intraperitoneally challenged with 0.2 ml of A. veronii (4.3 × 10). The five groups were administered a basal diet until clinical signs appeared, and then therapeutic feeding (15 days) was followed: the first (CONT) and second (AV) groups were administered a normal basal diet. The third (AV+CP) and fourth (AV+CE) groups were administered diets supplemented with C. sativum powder and extract, respectively, each at 30 mg/kg. The fifth group (AV+OT) was administered a diet supplemented with oxytetracycline at 500 mg/kg diet. The results of the in vitro experiment revealed that CE has a zone of inhibition of 43 mm against A. veronii. The in vivo results showed that fish administered a therapeutic diet supplemented with CE showed a significant improvement in hematological, biochemical, and immunological parameters, as well as antioxidant capacity (P < 0.05) and the pathological findings of the liver and kidney tissues. The current findings supported that the administration of a CE-enriched diet (30 mg/kg) is an eco-friendly strategy for controlling A. veronii in O. niloticus.
Topics: Animals; Antioxidants; Aeromonas veronii; Coriandrum; Cichlids; Diet; Dietary Supplements; Disease Resistance; Kidney; Fish Diseases; Animal Feed; Gram-Negative Bacterial Infections
PubMed: 37438674
DOI: 10.1007/s10695-023-01220-6 -
Microorganisms May 2023Microalgae may produce a range of high-value bioactive substances, making them a promising resource for various applications. In this study, the antibacterial activity...
Microalgae may produce a range of high-value bioactive substances, making them a promising resource for various applications. In this study, the antibacterial activity of twelve microalgae species isolated from lagoons in western Greece was examined against four fish pathogenic bacteria (, , , and ). Two experimental approaches were used to evaluate the inhibitory effect of microalgae on pathogenic bacteria. The first approach used bacteria-free microalgae cultures, whereas the second approach used filter-sterilized supernatant from centrifuged microalgae cultures. The results demonstrated that all microalgae had inhibitory effects against pathogenic bacteria in the first approach, particularly 4 days after inoculation, where and sp. (red var., Pappas) exhibited the highest inhibitory activity, reducing bacterial growth by 1 to 3 log units. In the second approach, sp. (red var., Pappas) showed significant inhibition against between 4 and 25 h after inoculation. Moreover, all tested cyanobacteria exhibited inhibitory activity against between 21 and 48 h after inoculation. Statistical analysis was performed using the independent samples -test. These findings suggested that microalgae produce compounds with antibacterial activity, which could be useful in aquaculture.
PubMed: 37374898
DOI: 10.3390/microorganisms11061396 -
Biomedicines Jun 2023The increased prevalence of disease, mortality, and antibiotic resistance among aquatic microorganisms has renewed interest in non-conventional disease prevention and...
The increased prevalence of disease, mortality, and antibiotic resistance among aquatic microorganisms has renewed interest in non-conventional disease prevention and control approaches. Nanoparticles present several benefits in aquaculture and hold significant potential for controlling both human and animal infections. This study reports on the antibacterial properties of green copper oxide nanoparticles (CuO NPs) synthesized from the urine of Mithun (MU) (). In addition, an array of analytical techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-visible spectroscopy (UV), and Fourier transform infrared spectroscopy (FTIR), were employed to investigate the synthesized MU-CuO nanoparticles. and , two bacterial fish pathogens known to cause severe infectious diseases in fish, were tested for their antibacterial efficacy against MU-CuO NPs. At 100 µg/mL, MU-CuO NPs exhibit enhanced antibacterial efficacy against two bacterial pathogens commonly found in fish. Applications in aquaculture may be looked at given that MU-CuO NPs showed greater antibacterial activity.
PubMed: 37371785
DOI: 10.3390/biomedicines11061690 -
Antibiotics (Basel, Switzerland) Jun 2023is a Gram-negative bacterial species that causes disease in fish and is nowadays increasingly recurrent in enteric infections of humans. This study was performed to...
is a Gram-negative bacterial species that causes disease in fish and is nowadays increasingly recurrent in enteric infections of humans. This study was performed to characterize newly sequenced isolates by comparing them with complete genomes deposited at the NCBI (National Center for Biotechnology Information). Nine isolates from fish, environments, and humans from the São Francisco Valley (Petrolina, Pernambuco, Brazil) were sequenced and compared with complete genomes available in public databases to gain insight into taxonomic assignment and to better understand virulence and resistance profiles of this species within the One Health context. One local genome and four NCBI genomes were misidentified as . A total of 239 virulence genes were identified in the local genomes, with most encoding adhesion, motility, and secretion systems. In total, 60 genes involved with resistance to 22 classes of antibiotics were identified in the genomes, including and . The results suggest that the use of methods such as ANI is essential to avoid misclassification of the genomes. The virulence content of from local isolates is similar to those complete genomes deposited at the NCBI. Genes encoding colistin resistance are widespread in the species, requiring greater attention for surveillance systems.
PubMed: 37370358
DOI: 10.3390/antibiotics12061039 -
Microorganisms May 2023is widespread in aquatic environments and is capable of infecting various aquatic organisms. infection is lethal for Chinese soft-shelled turtles (, CSST). We isolated...
is widespread in aquatic environments and is capable of infecting various aquatic organisms. infection is lethal for Chinese soft-shelled turtles (, CSST). We isolated a gram-negative bacterium from the liver of diseased CSSTs, which was named XC-1908. This isolate was identified as based on its morphological and biochemical characteristics, and 16S rRNA gene sequence analysis. was pathogenic for CSSTs with an LD of 4.17 × 10 CFU/g. The symptoms of CSSTs artificially infected with isolate XC-1908 were consistent with those of the naturally infected CSSTs. The levels of total protein, albumin, and white globule in the serum samples of the diseased turtles were decreased, whereas those of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were elevated. Moreover, the diseased CSSTs exhibited the following histopathological changes: the liver contained numerous melanomacrophage centers, renal glomerulus were edematous, intestinal villi were shed, and in oocytes, the number of vacuoles increased and red-rounded particles were observed. Antibiotic sensitivity tests revealed that the bacterium was sensitive to ceftriaxone, doxycycline, florfenicol, cefradine, and gentamicin, and resistant to sulfanilamide, carbenicillin, benzathine, clindamycin, erythromycin, and streptomycin. This study provides control strategies to prevent outbreaks of infection in CSSTs.
PubMed: 37317278
DOI: 10.3390/microorganisms11051304 -
Frontiers in Physiology 2023The bacterium is a co-pathogenic species that can negatively impact the health of both humans and aquatic animals. In this study, we used single-cell transcriptome...
The bacterium is a co-pathogenic species that can negatively impact the health of both humans and aquatic animals. In this study, we used single-cell transcriptome analysis (scRNA-seq) to investigate the effects of infection with on head kidney cells and the regulation of gene expression in the dark sleeper (). scRNA-seq was used to assess the effects of infection with in B cells, endothelial cells, macrophages, and granulocytes, and differential enrichment analysis of gene expression in B cells and granulocytes was performed. The analyses revealed a significant increase in neutrophils and decrease in eosinophils in granulocytes infected with . Activation of neutrophils enhanced ribosome biogenesis by up-regulating the expression of and to fight against invading pathogens. Crucial pro-inflammatory mediators , and the major histocompatibility class II genes and , which are involved in virulence processes, were upregulated, suggesting that activates an immune response that presents antigens and activates immunoglobulin receptors in B cells. These cellular immune responses triggered by infection with enriched the available scRNA-seq data for teleosts, and these results are important for understanding the evolution of cellular immune defense and functional differentiation of head kidney cells.
PubMed: 37275236
DOI: 10.3389/fphys.2023.1201914 -
Frontiers in Microbiology 2023The raise of multi-drug resistant bacteria involving carbapenem, colistin, or tigecycline resistance constitutes a threat to public health, which partly results from the...
INTRODUCTION
The raise of multi-drug resistant bacteria involving carbapenem, colistin, or tigecycline resistance constitutes a threat to public health, which partly results from the transmission of corresponding mobile resistance genes, such as and for carbapenem, for colistin, and gene cluster for tigecycline. Herein, we described the emergence of an strain HD6454 co-harboring , , and gene cluster from hospital sewage.
METHODS
Whole genome sequencing (WGS) was used to determine the genome sequence of HD6454, and the detailed genomic analysis of genetic elements or regions carrying key antimicrobial resistance genes (ARGs) from HD6454 were performed. Cloning experiment was conducted to confirm the function of key ARGs in mediating antimicrobial resistance. Conjugation experiment was conducted to determine the mobility of the plasmid.
RESULTS
The results showed that this strain belonged to a novel sequence type (ST) variant ST1016, and carried 18 important ARGs. Among them, the was carried by non-self-transmissible IncP-6 plasmid, while gene cluster and were carried by integrative and mobilizable element (IME) or IME-related region in chromosome. The , , and genes were further inferred to originate from IMEs of species. Additionally, for the first time, the was confirmed to confer low-level resistance to colistin under inducible expression, while gene cluster was confirmed to confer low-level resistance to tigecycline.
DISCUSSION
This is the first report of a strain co-harboring , , and gene cluster. Although the resistance and/or mobility of these ARGs are limited in this strain, the emergence of this multiple important ARGs-carrying strain deserves further attention.
PubMed: 37266015
DOI: 10.3389/fmicb.2023.1115740 -
Marine Drugs Apr 2023Exploration of seaweeds to unravel their bioactive metabolites from the perspective of wider applications gained substantial importance. The present study was performed...
Exploration of seaweeds to unravel their bioactive metabolites from the perspective of wider applications gained substantial importance. The present study was performed to investigate the total phenolic, flavonoid, tannin content, antioxidant activity and antibacterial potential of various solvent extracts of green seaweed . The methanolic extract showed higher phenolic (11.99 ± 0.48 mg gallic acid equivalents/g), tannin (18.59 ± 0.54 mg tannic acid equivalents/g) and flavonoid (33.17 ± 0.76 mg quercetin equivalents/g) content than other extracts. Antioxidant activity was determined by using 2,2-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay with different concentrations of extracts. The methanolic extract showed higher scavenging potential in both the DPPH and ABTS activity with the inhibition value of 54.21 ± 1.39% and 76.62 ± 1.08%, respectively. Bioactive profiling was also identified by using Gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared (FT-IR) techniques. These studies revealed the presence of valuable bioactive compounds in extracts and these compounds might be responsible for antimicrobial, antioxidant, anticancer and anti-mutagenic properties. Major compounds identified in GC-MS were 3,7,11,15-Tetramethyl-2-hexadecen-1-ol, 3-hexadecene and Phthalic acid. In terms of antibacterial activity, has promising antibacterial potential against aquatic pathogens and . Further evaluation studies focusing aquatic related aspects would reveal the novel bioproperties and applications of .
Topics: Antioxidants; Gas Chromatography-Mass Spectrometry; Caulerpa; Seaweed; Spectroscopy, Fourier Transform Infrared; Plant Extracts; Anti-Bacterial Agents; Flavonoids; Phenols; Phytochemicals; Tannins
PubMed: 37233472
DOI: 10.3390/md21050278