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International Journal of Molecular... May 2024can be a substantial concern, as it causes various diseases in aquaculture. An effective and green method for inhibiting is urgently required. Emodin, a naturally...
can be a substantial concern, as it causes various diseases in aquaculture. An effective and green method for inhibiting is urgently required. Emodin, a naturally occurring anthraquinone compound, was exploited as a photo-antimicrobial agent against . At the minimum inhibitory concentration of emodin (256 mg/L) to inactivate in 30 min, an 11.32% survival rate was observed under 45 W white compact fluorescent light irradiation. In addition, the antibacterial activity under natural sunlight (0.78%) indicated its potential for practical application. Morphological observations demonstrated that the cell walls and membranes of were susceptible to damage by emodin when exposed to light irradiation. More importantly, the photoinactivation of was predominantly attributed to the hydroxyl radicals and superoxide radicals produced by emodin, according to the trapping experiment and electron spin resonance spectroscopy. Finally, a light-dependent reactive oxygen species punching mechanism of emodin to photoinactivate was proposed. This study highlights the potential use of emodin in sunlight-mediated applications for bacterial control, thereby providing new possibilities for the use of Chinese herbal medicine in aquatic diseases prevention.
Topics: Emodin; Aeromonas hydrophila; Sunlight; Anti-Bacterial Agents; Microbial Sensitivity Tests; Reactive Oxygen Species
PubMed: 38791482
DOI: 10.3390/ijms25105444 -
American Journal of Infection Control Mar 2024Aquatic opportunistic pathogen Aeromonas hydrophila, known to persist in low-nutrient chlorinated waters, can cause life-threatening infections. Two intensive care units...
BACKGROUND
Aquatic opportunistic pathogen Aeromonas hydrophila, known to persist in low-nutrient chlorinated waters, can cause life-threatening infections. Two intensive care units experienced a cluster of Aeromonas infections following outdoor temperature spikes coinciding with recurrent plumbing issues, with fatalities due to severe underlying comorbidities co-occurring with extensively-drug resistant (XDR) Aeromonas.
METHODS
We investigated this cluster using whole genome sequencing to assess genetic relatedness of isolates and identify antimicrobial resistance determinants. Three A. hydrophila were isolated from patients staying in or adjacent to rooms with plumbing issues during or immediately after periods of elevated outdoor temperatures. Sinks and faucets were swabbed for culture.
RESULTS
All A. hydrophila clinical isolates exhibited carbapenem resistance but were not genetically related. Diverse resistance determinants corresponding to extensively-drug resistant were found, including co-occurring KPC-3 and VIM-2, OXA-232, and chromosomal CphA-like carbapenemase genes, contributing to major treatment challenges. All 3 patients were treated with multiple antibiotic regimens to overcome various carbapenemase classes and expired due to underlying comorbidities. Environmental culture yielded no Aeromonas.
CONCLUSIONS
While the investigation revealed no singular source of contamination, it supports a possible link between plumbing issues, elevated outdoor temperatures and incidence of nosocomial Aeromonas infections. The diversity of carbapenemase genes detected in these wastewater-derived Aeromonas warrants heightened infection prevention precautions during periods of plumbing problems especially with heat waves.
Topics: Humans; Aeromonas hydrophila; Sanitary Engineering; Cross Infection; Hot Temperature; beta-Lactamases; Aeromonas; Anti-Bacterial Agents; Microbial Sensitivity Tests; Bacterial Proteins
PubMed: 37778710
DOI: 10.1016/j.ajic.2023.09.013 -
Animals : An Open Access Journal From... Oct 2023One of the main factors limiting tilapia's production is the occurrence of infections caused by and species. This work intended to evaluate a bivalent vaccine against...
One of the main factors limiting tilapia's production is the occurrence of infections caused by and species. This work intended to evaluate a bivalent vaccine against and by intraperitoneal (i.p) administration in Nile tilapia () in Brazil. The study was carried out in two phases: one in the laboratory, on a small scale, and from the results obtained, the study was expanded to a large scale in a production system in cages. The vaccine proved to be safe and effective in laboratory tests, with a vaccine efficacy (VE) of 93.66%. However, in large-scale tests with 12,000 tilapias, the VE was 59.14%, with a better food conversion ratio (1.54 kg) in the vaccinated group compared to the control group (1.27 kg). These results corroborate the efficiency of this tested vaccine; however, they indicate the need for field tests to attest to real protection.
PubMed: 37958093
DOI: 10.3390/ani13213338 -
Biology Nov 2023The transcriptional regulators of the MarR family play an important role in diverse bacterial physiologic functions, whereas their effect and intrinsic regulatory...
The transcriptional regulators of the MarR family play an important role in diverse bacterial physiologic functions, whereas their effect and intrinsic regulatory mechanism on the aquatic pathogenic bacterium are, clearly, still unknown. In this study, we firstly constructed a deletion strain of (Δ) of a MarR family transcriptional regulator in ATCC 7966 (wild type), and found that the deletion of caused significantly enhanced hemolytic activity, extracellular protease activity, and motility when compared with the wild type. The differentially abundant proteins (DAPs) were compared by using data-independent acquisition (DIA), based on a quantitative proteomics technology, between the Δ strain and wild type, and there were 178 DAPs including 80 proteins up-regulated and 98 proteins down-regulated. The bioinformatics analysis showed that the deletion of gene led to some changes in the abundance of proteins related to multiple biological processes, such as translation, peptide transport, and oxidation and reduction. These results provided a theoretical basis for better exploring the regulatory mechanism of the MarR family transcriptional regulators of on bacterial physiological functions.
PubMed: 38132299
DOI: 10.3390/biology12121473 -
Microorganisms Feb 2024Antibiotic resistance remains one of the most pressing public health issues facing the world today. At the forefront of this battle lies the ever-increasing...
Antibiotic resistance remains one of the most pressing public health issues facing the world today. At the forefront of this battle lies the ever-increasing identification of extended-spectrum beta-lactamases and carbapenemases within human pathogens, conferring resistance towards broad-spectrum and last-resort antimicrobials. This study was prompted due to the identification of a pathogenic isolate (strain MAH-4) collected from abdominal fluid, which presented a robust resistance pattern against second-, third-, and fourth-generation cephalosporins, ertapenem, ciprofloxacin, gentamicin, levofloxacin and moxifloxacin, and beta lactam/beta-lactamase inhibitor combinations. Whole genome sequencing was performed and identified a 328 kb plasmid (pMAH4) encoding 10 antibiotic resistance genes, including , , and of MAH-4. This is the first report of beta-lactamase SFO-1 within a clinical strain of . Due to the remarkable sequence identity of pMAH4 to plasmids associated with genera like and the extensive capabilities of for horizontal gene transfer, our identification of a clinical isolate encoding SFO-1 on a plasmid suggests antibiotic resistance gene mobility between and non- species.
PubMed: 38543545
DOI: 10.3390/microorganisms12030494 -
Microbial Ecology May 2024Aeromonas hydrophila is an opportunistic motile pathogen with a broad host range, infecting both terrestrial and aquatic animals. Environmental and geographical...
Aeromonas hydrophila is an opportunistic motile pathogen with a broad host range, infecting both terrestrial and aquatic animals. Environmental and geographical conditions exert selective pressure on both geno- and phenotypes of pathogens. Flagellin, directly exposed to external environments and containing important immunogenic epitopes, may display significant variability in response to external conditions. In this study, we conducted a comparative analysis of ~ 150 A. hydrophila genomes, leading to the identification of six subunits of the flagellin gene (fla-1 to fla-4, flaA, and flaB). Individual strains harbored different composition of flagellin subunits and copies. The composition of subunits showed distinct patterns depending on environmental sources. Strains from aquatic environments were mainly comprised of fla-1 to fla-4 subunits, while terrestrial strains predominated in groups harboring flaA and flaB subunits. Each flagellin showed varying levels of expression, with flaA and flaB demonstrating significantly higher expression compared to others. One of the chemotaxis pathways that control flagellin movement through a two-component system was significantly upregulated in flaA(+ 1)/flaB(+ 1) group, whereas flaA and flaB showed different transcriptomic expressions. The genes positively correlated with flaA expression were relevant to biofilm formation and bacterial chemotaxis, but flaB showed a negative correlation with the genes in ABC transporters and quorum sensing pathway. However, the expression patterns of fla-2 to fla-4 were identical. This suggests various types of flagellin subunits may have different biological functions. The composition and expression levels of flagellin subunits could provide valuable insights into the adaptation of A. hydrophila and the differences among strains in response to various external environments.
Topics: Flagellin; Aeromonas hydrophila; Transcriptome; Phylogeography; Adaptation, Physiological; Phylogeny; Biofilms
PubMed: 38695873
DOI: 10.1007/s00248-024-02373-4 -
Animals : An Open Access Journal From... Nov 2023The objective of this study was to investigate the bactericidal activity of blood plasma from cultured rainbow trout obtained from two different fish farms. Plasma from...
The objective of this study was to investigate the bactericidal activity of blood plasma from cultured rainbow trout obtained from two different fish farms. Plasma from trout naturally infected with the bacterial pathogen was found to inhibit the growth of in vitro. Incubation of in bacteriostatic trout plasma resulted in agglutination and growth retardation, without causing massive damage to the cell membrane. The proteome of the plasma with high antimicrobial activity revealed an abundance of high-density apolipoproteins, some isoforms of immunoglobulins, complement components C1q and C4, coagulation factors, lectins, periostin, and hemoglobin. Analysis of trout proteins retained on cells revealed the presence of fish immunoglobulins, lectins, and complement components on bacteria whose growth was inhibited, although the native membrane attack complex of immunised trout plasma did not assemble effectively, resulting in a weak bactericidal effect. Furthermore, this study examined the bacterial response to trout plasma and suggested that the protein synthesis pathway was the target of antimicrobial proteins from fish blood. Taken together, these findings illustrate the advantages of the affinity approach for understanding the role of plasma proteins in host defence against pathogens.
PubMed: 38003182
DOI: 10.3390/ani13223565 -
Fish and Shellfish Immunology Reports Dec 2023Interleukin-11 (IL-11) is a versatile cytokine that modulates cellular differentiation and proliferation in various cell types and tissues. In this study, IL-11 gene...
Interleukin-11 (IL-11) is a versatile cytokine that modulates cellular differentiation and proliferation in various cell types and tissues. In this study, IL-11 gene from goldfish ( L.) has been identified and characterized. Goldfish IL-11 (gfIL-11) has an open reading frame (ORF) that spans 591 base pairs (bp). The ORF encodes a precursor protein consisting of 196 amino acids (aa), which includes a 26 aa signal peptide and a conserved domain belonging to the IL-11 superfamily. Based on phylogenetic analysis, gfIL-11 was found to be closely related to other IL-11 homologues identified in various fish species. The gfIL-11 transcript exhibited varied expression levels across all the analyzed tissues, with the highest expression observed in the gill and spleen. Treatment of goldfish head kidney leukocytes (HKLs) with LPS and live , increased gfIL-11 mRNA expression level. Recombinant gfIL-11 protein (rgIL-11) induced a dose-dependent production of TNF-α and IFNγ from goldfish HKLs. Furthermore, the administration of rgIL-11 to goldfish HKLs triggered an increase in the expression of various transcription factors such as MafB, cJun, GATA2, and Egr1, which play a vital role in the differentiation of myeloid precursors into macrophages and monocytes. Our findings provide evidence that IL-11 is a crucial cytokine that promotes cell proliferation, immune response, and differentiation across various hematopoietic lineages and stages of goldfish.
PubMed: 37771817
DOI: 10.1016/j.fsirep.2023.100117 -
Foods (Basel, Switzerland) Feb 2024Bivalves can concentrate biological and chemical pollutants, causing foodborne outbreaks whose occurrence is increasing, due to climatic and anthropic factors that are...
Bivalves can concentrate biological and chemical pollutants, causing foodborne outbreaks whose occurrence is increasing, due to climatic and anthropic factors that are difficult to reverse, hence the need for improved surveillance. This study aimed to evaluate the hygienic qualities of bivalves sampled along the production and distribution chain in Sicily and collect useful data for consumer safety. Bacteriological and molecular analyses were performed on 254 samples of bivalves for the detection of enteropathogenic , spp., spp., spp., and beta-glucuronidase-positive . A total of 96 out of 254 samples, collected in the production areas, were processed for algal biotoxins and heavy metals detection. Bacterial and algal contaminations were also assessed for 21 samples of water from aquaculture implants. spp., spp., , spp., and were detected in 106/254, 79/254, 12/254, 16/254, and 95/254 molluscs, respectively. A total of 10/96 bivalves tested positive for algal biotoxins, and metals were under the legal limit. , and were detected in 5, 3, and 3 water samples, respectively. , , and spp. were detected in water samples collected with the biotoxin-containing molluscs. Traces of yessotoxins were detected in molluscs from water samples containing the corresponding producing algae. Despite the strict regulation by the European Commission over shellfish supply chain monitoring, our analyses highlighted the need for efficiency improvement.
PubMed: 38397529
DOI: 10.3390/foods13040552 -
Scientific Reports Jul 2023Species diversification from major to minor carps for their sturdiness and initial higher growth, and also a quest for antibiotic-free aqua farming in the subcontinent,...
Species diversification from major to minor carps for their sturdiness and initial higher growth, and also a quest for antibiotic-free aqua farming in the subcontinent, mandates search for and evaluation of alternatives. An experiment was performed to investigate the potential of fructooligosaccharide (FOS) and Bacillus subtilis (BS) (alone or as synbiotics) in promoting growth and immunity against infections in Labeo fimbriatus fingerlings. Six iso-nitrogenous and iso-lipidic diets containing combinations of two levels of FOS (0% and 0.5%) and three levels of BS (0, 10, 10 CFU/g feed) were fed to fish for 60 days. At the end of the feeding trial, twenty-four fish from each group were injected intra-peritoneally with pathogenic strain of Aeromonas hydrophila O:18 to test the immunoprotective efficacy of the supplements against bacterial infection. BS, but not FOS, significantly improved (P < 0.05) growth and feed utilisation attributes like percentage weight gain (PWG), specific growth rate (SGR) and feed conversion ratio (FCR). There were interactive effects of FOS and BS on PWG, SGR and FCR; however, the effects were not additive in nature. These beneficial effects of BS, alone or in combination with FOS, were corroborated by increased protease activity, microvilli density and diameter and number of goblet cells. Overall beneficial effects of FOS and BS included improved erythrocyte (RBC), hemoglobin (Hb), total protein and globulin levels. Total leucocyte (WBC) count and immunological parameters like respiratory burst activity of leucocytes (NBT reduction), lysozyme activity, albumin: globulin ratio and post-challenge survival were significantly improved by both FOS and BS, and their dietary combination yielded the highest improvement in these parameters. Synergistic effects of FOS and BS as dietary supplements indicate that a combination of 10 CFU/g BS and 0.5% FOS is optimal to improve growth, feed utilisation, immune functions, and disease resistance in L. fimbriatus fingerlings.
Topics: Animals; Aeromonas hydrophila; Animal Feed; Bacillus subtilis; Cyprinidae; Diet; Dietary Supplements; Disease Resistance; Fish Diseases; Gram-Negative Bacterial Infections; Synbiotics
PubMed: 37443328
DOI: 10.1038/s41598-023-38267-7