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Frontiers in Microbiology 2023is a Gram-negative bacterium ubiquitously found in aquatic environments. It is a foodborne pathogen that causes diarrhea in humans and hemorrhagic septicemia in fish....
The mobile gene cassette carrying tetracycline resistance genes in strain Ah5S-24 isolated from catfish pond sediments shows similarity with a cassette found in other environmental and foodborne bacteria.
is a Gram-negative bacterium ubiquitously found in aquatic environments. It is a foodborne pathogen that causes diarrhea in humans and hemorrhagic septicemia in fish. In the present study, we used whole-genome sequencing (WGS) to evaluate the presence of antimicrobial resistance (AMR) and virulence genes found in Ah5S-24 isolated from catfish pond sediments in South-East, United States. We found , , , , , and resistance genes encoded in the chromosome of Ah5S-24. We also found the tetracycline and genes placed next to the ISIS transposase, integrase, and hypothetical proteins that formed as a genetic structure or transposon designated as ISIS. BLAST analysis showed that a similar mobile gene cassette (MGC) existed in chromosomes of other bacteria species such as isolated from retail fish at markets, from human stool and from a sewage bioreactor. In addition, the ISIS cassette was also found in the plasmid of isolated from shrimp. As for virulence genes, we found the tap type IV pili ( and ), polar flagellae ( and ), lateral flagellae ( and ), and fimbriae ( and ) genes responsible for motility and adherence. We also found the hemolysin genes (, and ), toxin, biofilm formation, and quorum sensing (, and ) genes. However, there were no MGCs encoding virulence genes found in AhS5-24. Thus, our findings show that MGCs could play a vital role in the spread of AMR genes between chromosomes and plasmids among bacteria in aquatic environments. Overall, our findings are suggesting that MGCs encoding AMR genes could play a vital role in the spread of resistance acquired from high usage of antimicrobials in aquaculture to animals and humans.
PubMed: 37007502
DOI: 10.3389/fmicb.2023.1112941 -
Pharmaceuticals (Basel, Switzerland) Jun 2021Mycobacteriosis affects wild fish and aquaculture worldwide, and alternatives to antibiotics are needed for an effective and environmentally sound control of infectious...
Mycobacteriosis affects wild fish and aquaculture worldwide, and alternatives to antibiotics are needed for an effective and environmentally sound control of infectious diseases. Probiotics have shown beneficial effects on fish growth, nutrient metabolism, immune responses, disease prevention and control, and gut microbiota with higher water quality. However, the identification and characterization of the molecules and mechanisms associated with probiotics is a challenge that requires investigation. To address this challenge, herein we used the zebrafish model for the study of the efficacy and mechanisms of probiotic interventions against tuberculosis. First, bacteria from fish gut microbiota were identified with high content of the surface glycotope Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) that has been shown to induce protective immune responses. The results showed that probiotics of selected bacteria with high α-Gal content, namely Aeromonas veronii and , were biosafe and effective for the control of Mycobacterium marinum. Protective mechanisms regulating immunity and metabolism activated in response to α-Gal and probiotics with high α-Gal content included modification of gut microbiota composition, B-cell maturation, anti-α-Gal antibodies-mediated control of mycobacteria, induced innate immune responses, beneficial effects on nutrient metabolism and reduced oxidative stress. These results support the potential of probiotics with high -Gal content for the control of fish mycobacteriosis and suggested the possibility of exploring the development of combined probiotic treatments alone and in combination with -Gal for the control of infectious diseases.
PubMed: 34208966
DOI: 10.3390/ph14070635 -
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 -
Ecotoxicology and Environmental Safety Aug 2021Cherax quadricarinatus is a type of large freshwater crayfish that is characterized by rapid growth and formidable adaptability. It has also been widely cultured and...
A new insight to characterize immunomodulation based on hepatopancreatic transcriptome and humoral immune factor analysis of the Cherax quadricarinatus infected with Aeromonas veronii.
Cherax quadricarinatus is a type of large freshwater crayfish that is characterized by rapid growth and formidable adaptability. It has also been widely cultured and studied as a model organism. Aeromonas veronii is the dominant pathogen in aquatic environments and the primary threat to aquaculture's economic stability. To better understand the interactions between C. quadricarinatus and A. veronii, high-throughput RNA sequencing of the C. quadricarinatus hepatopancreas was carried out on a control group, susceptible group (6 h after infection), and resistant group (48 h after infection). A total of 65,850,929 genes were obtained. Compared with the control group, 2616 genes were up-regulated and 1551 genes were down-regulated in the susceptible group; while 1488 genes were up-regulated and 1712 genes were down-regulated in the resistant group. GO and KEGG analysis showed that these differentially expressed genes (DEGs) were associated with multiple immune pathways, including Toll-like receptors (TLRs), antigen processing and presentation, NOD-like receptor signaling pathway, phagosome, lysosome, JAK-STAT signaling pathway. qRT-PCR showed that infection by A. veronii changed the expression pattern of the serine proteinase inhibitor (SPI), crustacean hyperglycemic hormone (CHH), anti-lipopolysaccharide factor (ALF), and extracellular copper/zinc superoxide dismutase (SOD1), all of which were significantly higher than in the control group up to 48 h after infection. In addition, detection of superoxide dismutase (SOD), catalase (CAT), lysozyme (LZM), and phenoloxidase (PO) activity, as well as ceruloplasmin (CP) concentration at different times after infection showed diverse trends. Furthermore, pathological sections obtained 24 h after infection show lesions on the hepatopancreas and intestinal tissues caused by A. veronii. The results of this study provide a foundation for analyzing the immune mechanism of C. quadricarinatus infected with A. veronii at the transcriptional level and a theoretical basis for screening disease-resistant individuals to ensure healthy economic development of the aquatic industry.
Topics: Aeromonas veronii; Animals; Astacoidea; Factor Analysis, Statistical; Gram-Negative Bacterial Infections; Hepatopancreas; High-Throughput Nucleotide Sequencing; Immunologic Factors; Immunomodulation; Toll-Like Receptors; Transcriptome
PubMed: 34044307
DOI: 10.1016/j.ecoenv.2021.112347 -
Pathogens (Basel, Switzerland) Aug 2023Brazil is one of the world's leading producers of Nile tilapia, . However, the industry faces a major challenge in terms of infectious diseases, as at least five new...
Brazil is one of the world's leading producers of Nile tilapia, . However, the industry faces a major challenge in terms of infectious diseases, as at least five new pathogens have been formally described in the last five years. species are Gram-negative anaerobic bacteria that are often described as fish pathogens causing Motile Aeromonas Septicemia (MAS). In late December 2022, an epidemic outbreak was reported in farmed Nile tilapia in the state of São Paulo, Brazil, characterized by clinical signs and gross pathology suggestive of MAS. The objective of this study was to isolate, identify, and characterize in vitro and in vivo the causative agent of this epidemic outbreak. The bacterial isolates were identified as based on the homology of 16S rRNA (99.9%), (98.9%), and the gene (99.1%). showed susceptibility only to florfenicol, while it was resistant to the other three antimicrobials tested, oxytetracycline, enrofloxacin, and amoxicillin. The lowest florfenicol concentration capable of inhibiting bacterial growth was ≤0.5 µg/mL. The phenotypic resistance of the isolate observed for quinolones and tetracycline was genetically confirmed by the presence of the ( plasmid) and antibiotic-resistant genes, respectively. isolate was highly pathogenic in juvenile Nile tilapia tested in vivo, showing a mortality rate ranging from 3 to 100% in the lowest (1.2 × 10) and highest (1.2 × 10) bacterial dose groups, respectively. To our knowledge, this study would constitute the first report of highly pathogenic and multidrug-resistant associated with outbreaks and high mortality rates in tilapia farmed in commercial net cages in Brazil.
PubMed: 37623980
DOI: 10.3390/pathogens12081020 -
Pathogens (Basel, Switzerland) Dec 2022Bacterial communities, microbial populations, and antibiotic resistance of potential pathogens in the water and fish (, flesh and gut) from different areas (A1, A2 and...
Bacterial communities, microbial populations, and antibiotic resistance of potential pathogens in the water and fish (, flesh and gut) from different areas (A1, A2 and A3-A1 was linked with river water, A2 with cattle activity, and A3 with waters of a spring after heavy rains) of Lake Karla (Thessaly, Central Greece) were investigated. The isolated bacteria were identified using Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and were tested for resistance in 21 antibiotics. The microbiota composition of fish flesh was also studied using 16S amplicon-based sequencing and several species of (e.g., , , etc.) exhibited the highest abundances in all studied samples, while the microbiota profile between the three studied areas was similar, according to the culture-dependent analysis. Of them, was found to be resistant in the majority of the antibiotics for the water and fish (gut and flesh), mainly of the areas A1 and A2. Regarding 16S metabarcoding, the presence of and at genus level was confirmed, but they found at very lower abundances than those reported using the culture-dependent analysis. Finally, the TVC and the rest of the studied microbiological parameters were found at acceptable levels (4 log cfu/mL or cfu/g and 2-4 log cfu/mL or cfu/g, extremely low levels of /coliforms) in both water and fish flesh. Based on our findings, the water of Lake Karla would be used for activities such as irrigation, recreation and fishing, however, the development and implementation of a quality management tool for Lake Karla, to ensure environmental hygiene and prevention of zoonosis during the whole year, is imperative.
PubMed: 36558807
DOI: 10.3390/pathogens11121473 -
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 -
International Journal of Molecular... Dec 2020is one of the main pathogens causing various diseases in humans and animals. It is currently difficult to eradicate drug-resistant due to the biofilm formation by...
is one of the main pathogens causing various diseases in humans and animals. It is currently difficult to eradicate drug-resistant due to the biofilm formation by conventional antibiotic treatments. In this study, a marine peptide-N6NH and its analogs were generated by introducing Orn or replacing with D-amino acids, Val and Pro; their enzymic stability and antibacterial/antibiofilm ability against multi-drug resistant (MDR) ACCC61732 were detected in vitro and in vivo, respectively. The results showed that DN6NH more rapidly killed ACCC61732 and had higher stability in trypsin, simulated gastric/intestinal fluid, proteinase K, and mouse serum than the parent peptide-N6NH. DN6NH and other analogs significantly improved the ability of N6NH to penetrate the outer membrane of ACCC61732. DN6NH, N6PNH and V112N6NH protected mice from catheter-associated biofilm infection with MDR ACCC61732, superior to N6NH and CIP. DN6NH had more potent efficacy at a dose of 5 μmol/kg (100% survival) in a mouse peritonitis model than other analogs (50-66.67%) and CIP (83.33%), and it inhibited the bacterial translocation, downregulated pro-inflammatory cytokines, upregulated the anti-inflammatory cytokine, and ameliorated multiple-organ injuries (including the liver, spleen, lung, and kidney). These data suggest that the analogs of N6NH may be a candidate for novel antimicrobial and antibiofilm agents against MDR infections.
Topics: Aeromonas veronii; Animals; Anti-Bacterial Agents; Biofilms; Drug Resistance, Multiple; Female; Gram-Negative Bacterial Infections; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; Multiple Organ Failure; Skin Ulcer
PubMed: 33348848
DOI: 10.3390/ijms21249637 -
Microbiological Research Sep 2021Bacillus amyloliquefaciens X030 (BaX030) has broad-spectrum antibacterial activity against the fish pathogens Aeromonas hydrophila and Aeromonas veronii. To improve its...
Bacillus amyloliquefaciens X030 (BaX030) has broad-spectrum antibacterial activity against the fish pathogens Aeromonas hydrophila and Aeromonas veronii. To improve its antibacterial effect, BaX030 was subjected to compound mutagenesis of atmospheric and room temperature plasma (ARTP) and nitrosoguanidine (NTG). The results showed that, compared with the original strain, the production of macrolactin A and oxydifficidin in mutated strain N-11 increased to 39 % and 268 %, respectively. The re-sequencing analysis suggested that there were SNPs and InDels in the gene clusters focused on the sucrose utilization pathway, glycolysis pathway and fatty acid synthesis pathway. Scanning electron microscopy revealed that strain N-11 became thin and long. The qRT-PCR results indicated that the expression of immune factors in the liver or kidney tissue of grass carp increased after feeding with N-11. H&E staining and protection experiments also showed that the mortality and surface symptoms of grass carp infected by the two pathogens were significantly reduced. The study identified a probiotic strain with potential application value in aquaculture production and provided a new strategy for the discovery of new strains with higher antibacterial biological activity.
Topics: Aeromonas hydrophila; Aeromonas veronii; Animals; Bacillus amyloliquefaciens; Carps; Fish Diseases; Microbial Interactions; Mutation; Probiotics
PubMed: 34139525
DOI: 10.1016/j.micres.2021.126801 -
Frontiers in Microbiology 2022is a Gram-negative bacterium ubiquitously found in aquatic environments. It is a foodborne pathogen associated with diarrhea in humans and skin ulceration in fish. In...
is a Gram-negative bacterium ubiquitously found in aquatic environments. It is a foodborne pathogen associated with diarrhea in humans and skin ulceration in fish. In this study, we used whole genome sequencing to profile all antimicrobial resistance (AMR) and virulence genes found in . strain SD/21-15 isolated from marine sediments in Denmark. To gain a better understanding of virulence and AMR genes found in several . strains, we included 24 whole genomes retrieved from the public databanks whose isolates originate from different host species and environmental samples from Asia, Europe, and North America. We also compared the virulence genes of strain SD/21-15 with . , . , and . reference strains. We detected pili, tap IV pili, and lateral flagella genes responsible for expression of motility and adherence proteins in all isolates. We also found , , and hemolysin genes in all isolates responsible for virulence in all isolates while the gene was not detected in all . isolates but was present in . . , and . reference strains. In addition, we detected and responsible for quorum sensing and biofilm formation as well as the ferric uptake regulator (), heme and siderophore genes responsible for iron acquisition in all . isolates. As for the secretory systems, we found all genes that form the T2SS in all isolates while only the , , , and genes that form parts of the T6SS were detected in some isolates. Presence of and β-lactamases as well as and genes in all isolates is suggestive that these genes were intrinsically encoded in the genomes of all . isolates. Finally, the presence of various transposases, integrases, recombinases, virulence, and AMR genes in the plasmids examined in this study is suggestive that . has the potential to transfer virulence and AMR genes to other bacteria. Overall, we anticipate these data will pave way for further studies on virulence mechanisms and the role of . in the spread of AMR genes.
PubMed: 36532448
DOI: 10.3389/fmicb.2022.1022639