Search Results (89)

The illegal sale of mussels is a persistent problem for food safety and public health in the Campania region, where bivalve molluscs are often sold without traceability, evading regulatory controls. In this study, ten batches of mussels seized from unauthorized vendors were analyzed to evaluate their microbiological safety and trace their geographical origin. High loads of Escherichia coli, exceeding European regulatory limits (Regulation (EC) No 2073/2005), were detected in all samples. In addition, Salmonella Infantis strains resistant to trimethoprim-sulfamethoxazole and azithromycin were isolated, raising further concerns about antimicrobial resistance. Of the 93 Vibrio isolates, identified as V. alginolyticus and V. parahaemolyticus, 37.63% showed multidrug resistance. Approximately 68.57% of the isolates were resistant to tetracyclines and cephalosporins. The presence of resistance to last-resort antibiotics such as carbapenems (11.43%) is particularly alarming. Near-infrared spectroscopy, combined with chemometric models, was used to obtain traceability information, attributing a presumed origin to the seized mussel samples. Of the ten samples, seven were attributed to the Phlegraean area. These findings have provided valuable insights, reinforcing the need for continuous and rigorous surveillance and the integration of innovative tools to ensure seafood safety and support One Health approaches. Full article

Knowledge about the composition (volatile and non-volatile) and functionality of natural extracts from Mediterranean plants serves as a basis for their further application. In this study, five selected plants were used for the extraction of plant metabolites. Leaves and flowers of Critmum maritimum, Rosmarinus officinalis, Olea europea, Phylliera latifolia and Mellisa officinalis were collected, and a total of 12 extracts were prepared. Extractions were performed under microwave-assisted conditions, with two solvent types: water (W) and a hydroalcoholic (ethanolic) solution (HA). Detailed extract analysis was conducted. Phenolics were analyzed by detecting individual bioactive compounds using high-performance liquid chromatography and by calculating total phenolic and total flavonoid content through spectrophotometric analysis. Higher concentrations of total phenolics and total flavonoids were obtained in the hydroalcoholic extracts, with the significantly highest total phenolic and flavonoid values in the rosemary hydroalcoholic extract (3321.21 mg_GAE/L) and sea fennel flower extract (1794.63 mg_QE/L), respectively; and the lowest phenolics in the water extract of olive leaves (204.55 mg_GAE/L) and flavonoids in the water extracts of sea fennel leaves, rosemary, olive and mock privet (around 100 mg_QE/L). Volatile organic compounds (VOC) were detected using HS-SPME/GC–MS (Headspace Solid-Phase Microextraction coupled with Gas Chromatography-Mass Spectrometry), and antioxidant capacity was estimated using DPPH (2,2-diphenyl-1-picrylhydrazyl assay) and FRAP (Ferric Reducing Antioxidant Power) methods. HS-SPME/GC–MS analysis of samples revealed that sea fennel had more versatile profile, with the presence of 66 and 36 VOCs in W and HA sea fennel leaf extracts, 52 and 25 in W and HA sea fennel flower extracts, 57 in rosemary W and 40 in HA, 20 in olive leaf W and 9 in HA, 27 in W mock privet and 11 in HA, and 35 in lemon balm W and 10 in HA extract. The lowest values of chlorophyll a were observed in sea fennel leaves (2.52 mg/L) and rosemary (2.21 mg/L), and chlorophyll b was lowest in sea fennel leaf and flower (2.47 and 2.25 mg/L, respectively), while the highest was determined in olive (6.62 mg/L). Highest values for antioxidant activity, determined via the FRAP method, were obtained in the HA plant extracts (up to 11,216 mg_AAE/L for lemon balm), excluding the sea fennel leaf (2758 mg_AAE/L) and rosemary (2616 mg_AAE/L). Considering the application of these plants for fresh fish preservation, antimicrobial activity of water extracts was assessed against Vibrio fischeri JCM 18803, Vibrio alginolyticus 3050, Aeromonas hydrophila JCM 1027, Moraxella lacunata JCM 20914 and Yersinia ruckeri JCM 15110. No activity was observed against Y. ruckeri and P. aeruginosa, while the sea fennel leaf showed inhibition against V. fisheri (inhibition zone of 24 mm); sea fennel flower was active against M. lacunata (inhibition zone of 14.5 mm) and A. hydrophila (inhibition zone of 20 mm); and rosemary and lemon balm showed inhibition only against V. fisheri (inhibition zone from 18 to 30 mm). This study supports the preparation of natural extracts from Mediterranean plants using green technology, resulting in extracts rich in polyphenolics with strong antioxidant potential, but with no clear significant antimicrobial efficiency at the tested concentrations. Full article

Vibrio species are among the primary pathogenic bacteria affecting abalone aquaculture, posing significant threats to farming practices. Current clinical control predominantly relies on antibiotics, which can result in antibiotic residues in both abalone and the surrounding marine environments. Lactobacillus plantarum (LP) has been shown to release bioactive antagonistic substances and exhibits potent inhibitory effects against marine pathogenic bacteria. This study aimed to screen and characterize the probiotic properties of LP strains isolated from rice wine lees to develop a novel biocontrol strategy against Vibriosis in abalone. The methods employed included selective media cultivation, streak plate isolation, and single-colony purification for strain screening, followed by Gram staining, 16S rDNA sequencing, and phylogenetic tree construction using MEGA11 for identification. The resilience, antimicrobial activity, and in vivo antagonistic efficacy of the strains were evaluated through stress tolerance assays, agar diffusion tests, and animal experiments. The results demonstrated the successful isolation and purification of four LP strains (NDMJ-1 to NDMJ-4). Phylogenetic analysis revealed closer genetic relationships between NDMJ-3 and NDMJ-4, while NDMJ-1 and NDMJ-2 were found to be more distantly related. All strains exhibited γ-hemolytic activity, bile salt tolerance (0.3–3.0%), and resistance to both acid (pH 2.5) and alkali (pH 8.5), although they were temperature sensitive (inactivated above 45 °C). The strains showed susceptibility to most of the 20 tested antibiotics, with marked variations in hydrophobicity (1.91–93.15%) and auto-aggregation (13.29–60.63%). In vitro antibacterial assays revealed that cell-free supernatants of the strains significantly inhibited Vibrio parahaemolyticus, V. alginolyticus, and V. natriegens, with NDMJ-4 displaying the strongest inhibitory activity. In vivo experiments confirmed that NDMJ-4 significantly reduced mortality in abalone infected with V. parahaemolyticus. In conclusion, the LP strains isolated from rice wine lees (NDMJ-1 to NDMJ-4) possess robust stress resistance, adhesion capabilities, and broad antibiotic susceptibility. Their metabolites exhibit significant inhibition against abalone-pathogenic Vibrios, particularly NDMJ-4, which demonstrates exceptional potential as a candidate strain for developing eco-friendly biocontrol agents against Vibriosis in abalone aquaculture. Full article

Vibrio alginolyticus, a common Gram-negative opportunistic pathogen of marine animals and humans, is known for its rapid growth in organic-matter-rich environments. However, it remains unclear how it incorporates metabolic pathways in response to diverse carbon and nitrogen sources and rapidly alters gene expression. Increasing evidence suggests that post-transcriptional regulation by RNA-binding proteins and small RNAs (sRNAs) plays a crucial role in bacterial adaptation and metabolism. CsrA (carbon storage regulator A), a conserved post-transcriptional regulator in Gammaproteobacteria, is poorly characterized in Vibrio species. Using integrated transcriptomic and proteomic analyses, we found that CsrA alters the expression of 661 transcripts and 765 protein transcripts in V. alginolyticus, influencing key pathways including central carbon metabolism, amino acid metabolism and transport, quorum sensing, and bacterial secretion systems. Through directed CsrA-RNA EMSAs, we identified several direct mRNA targets of CsrA, including gltB, gcvP, aceE, and tdh, as well as secretion system components (tagH, tssL, yopD, and sctC). Notably, CsrA also directly regulates rraA, a key modulator of ribonuclease activity, suggesting a broader role in RNA metabolism. Our findings establish CsrA as a global regulator in V. alginolyticus, expanding the known targets of CsrA and providing new insights into its regulatory roles. Full article

Like other invertebrates, Litopenaeus vannamei lacks adaptive immunity and relies mainly on innate immunity for defense against foreign pathogens. In this study, three distinct Reeler domain-containing molecules were discovered in L. vannamei, designated as LvReeler1, LvReeler2, and LvReeler3. Analysis of tissue-specific expression patterns indicated that LvReeler1 showed predominant expression in the stomach, whereas LvReeler2 and LvReeler3 demonstrated peak transcriptional activity within gill tissues. The expression of these molecules was induced by Vibrio parahaemolyticus. In vivo interference with LvReelers expressions via dsRNA significantly increased the mortality rate of L. vannamei, while also leading to a marked increase in the bacterial load of V. parahaemolyticus in the gills. Additionally, recombinant proteins of LvReeler1 (rLvReeler1), LvReeler2 (rLvReeler2), and LvReeler3 (rLvReeler3) were successfully expressed in Escherichia coli. Antibacterial assays demonstrated that rLvReelers inhibited the growth of V. parahaemolyticus, Vibrio alginolyticus, and Vibrio harveyi, with rLvReeler3 exhibiting the strongest inhibitory activity. Scanning electron microscopy (SEM) observations revealed that rLvReeler3 caused bacterial aggregates to disintegrate after binding to V. parahaemolyticus and V. alginolyticus. In conclusion, LvReelers play an active role in the antimicrobial immune response of L. vannamei. Full article

Marine antifouling coatings that rely on the release of antifouling agents are the most prevalent and effective strategy for combating fouling. However, the environmental concerns arising from the widespread discharge of these agents into marine ecosystems cannot be overlooked. An innovative and promising alternative involves incorporating antimicrobial groups into polymers to create coatings endowed with intrinsic antimicrobial properties. In this study, we reported an urushiol-based benzoxazine (URB) monomer, synthesized from natural urushiol and antibacterial rosin amine. The URB monomer was subsequently polymerized through thermal curing ring-opening polymerization, resulting in the formation of a urushiol-based benzoxazine polymer (URHP) coating with inherent antimicrobial properties. The surface of the URHP coating is smooth, flat, and non-permeable. Contact angle and surface energy measurements confirm that the URHP coating is hydrophobic with low surface energy. In the absence of antimicrobial agent release, the intrinsic properties of the URHP coating can effectively kill or repel fouling organisms. Furthermore, with bare glass slides serving as the control sample, the coating demonstrates outstanding anti-adhesion capabilities against four types of bacteria (E. coli, S. aureus, V. alginolyticus, and Bacillus sp.), and three marine microalgae (N. closterium, P. tricornutum, and D. zhan-jiangensis), proving its efficacy in preventing fouling organisms from settling and adhering to the surface. Thus, the combined antibacterial and anti-adhesion properties endow the URHP coating with superior antifouling performance. This non-release antifouling coating represents a green and environmentally sustainable strategy for antifouling. Full article

The microbiome of the shrimp’s digestive tract shows differences between healthy and acute hepatopancreatic necrosis disease (AHPND)-affected shrimp. The present study aimed to evaluate the impact of probiotic consumption on the microbial community in experimentally AHPND-infected shrimp. Effective probiotics (EPs) Vibrio alginolyticus (Va32A), V. campbellii (VcHA), and Bacillus pumilus (BPY100) and non-effective probiotics (NEPs) B. pumilus (Bp43, and BpY119), were employed in bioassays with Penaeus vannamei and challenged with AHPND-causing V. parahaemolyticus (Vp_AHPND). Stomach (Sto), intestine (Int), and hepatopancreas (Hep) were analyzed by metabarcoding (16S rRNA gene) to characterize the microbiome and biomarkers. Hep-VcHA showed the highest alpha diversity (Shannon index = 5.88; 166 ASVs), whereas the lowest was for Hep-Bp43 (2.33; 7 ASVs). Proteobacteria, Actinobacteria, Bacteroidetes, and Saccharibacteria were the most abundant phyla. The relative abundance of Vibrio sp. was the highest in the Hep and Int of Bp43, BPY119 and the positive control, followed by Rhodobacteraceae in the EP group. Principle coordinate analysis (PCoA) showed a cluster grouped negative (Sto and Hep) control with almost all organs in the EP group causing 28.79% of the variation. The core microbiome of EP was mainly represented by Rhodobacteraceae, Caldilineaceae, Celeribacter indicus, Illumatobacter, Microbacterium, Ruegeria atlantica, Saccharibacteria sp., Shimia biformata, and Thalassobius mediterraneus, whose relative abundance was enriched by probiotics, which may explain their protective roles against Vp_AHPND, whereas the low survival in the NEP group was associated with a higher diversity of Vibrio spp. Our results present an ecosystem-friendly alternative based on beneficial microorganisms to prevent and control AHPND and probably other bacterial diseases in shrimp farming. Full article

Bivalve mollusks face a crisis due to infectious diseases, resulting in high mortality and economic losses. The need for continuous monitoring to prevent contamination from sewage and rainwater in aquaculture is evident. The recent mass mortality of scallops in Ilha Grande Bay (IGB), Rio de Janeiro’s largest scallop producer, due to environmental contaminants underscores the need for further research. This study aims to investigate the recent collapse of the scallop population and assess the human impact by analyzing the circulation of pathogens. Materials and Methods: Mollusks were collected from three sites in Ilha Grande Bay (IGB), a region known for its significant scallop production, and from scallop farms in Angra dos Reis, RJ. A total of 216 gill and adductor tissue samples from lion’s foot scallops were analyzed. Bacterial contamination was identified using MALDI-TOF, while antimicrobial susceptibility and carbapenem production were assessed via disk diffusion tests. Results: Mollusks were contaminated with V. alginolyticus, V. fluvialis, V. harveyi, Pseudomonas putida, and Pseudomonas monteilii. All isolates were sensitive to meropenem, but P. putida showed higher resistance to ciprofloxacin. Conclusions: The presence of these pathogenic and resistant bacteria in scallop adductor tissues is a concern for the aquaculture industry and a significant public health risk. The potential for these bacteria to enter the human food chain through consuming contaminated seafood or recreational activities such as bathing is a serious issue that needs to be addressed. Full article

Consuming raw or undercooked mussels can lead to gastroenteritis and septicemia due to Vibrio contamination. This study analyzed the prevalence, density, species diversity, and molecular traits of Vibrio spp. in 48 fresh raw wild mussels (FRMs) and 48 ready-to-eat stuffed mussels (RTE-SMs) through genome analysis, assessing health risks. The results showed Vibrio prevalence rates of 12.5% in FRMs and 4.2% in RTE-SMs, with V. alginolyticus as the most common species (46.7%). It was determined that the seasonal distribution of Vibrio spp. prevalence in the samples was higher in the summer months. The genome sizes of the Vibrio spp. ranged from approximately 3.9 to 6.1 Mb, with the GC contents varying between 41.9% and 50.4%. A total of 22 virulence factor (VF) classes and up to six antimicrobial resistance (AMR) genes were detected in different Vibrio species. The presence of nine different biosynthetic gene clusters (BGCs), 27 prophage regions, and eight CRISPR/Cas systems in 15 Vibrio strains provides information about their potential pathogenicity, survival strategies, and adaptation to different habitats. Overall, this study provides a comprehensive understanding of the genomic diversity of Vibrio spp. isolated from FRM and RTE-SM samples, shedding light on the prevalence, pathogenicity, and toxicity mechanisms of Vibrio-induced gastroenteritis. Full article

This study investigates the prevalence of Vibrio spp. in seafood from supermarkets and fish markets in Berlin, Germany. A total of 306 seafood samples, including shrimp and mussels, were bought from supermarkets between March 2023 and January 2024. Samples were analysed using the ISO standard method and multiplex PCR to identify V. parahaemolyticus, V. alginolyticus, V. cholerae and V. vulnificus. The results indicated an overall Vibrio spp. prevalence of 56%. Among the positive samples, the most prevalent species found was V. parahaemolyticus (58%), followed by V. alginolyticus (42%), V. cholerae non-O1/non-O139 (25%), and V. vulnificus (4%). Samples obtained from supermarkets exhibited a lower prevalence (50%) than those received from fish markets (91%). Virulence genes such as ctxA, tdh, or trh were not detected in the respective Vibrio species. Nevertheless, the high prevalence underscores the need and urgency of continuous seafood surveillance. Full article

Crustins are a family of antimicrobial peptides (AMPs) that play a pivotal role in the innate immune system of crustaceans. The discovery of novel AMPs from natural sources is crucial for expanding our current database of these peptides. Here, we identified and characterized a novel member of the crustin family, named PpCrus-SWD1, derived from Pollicipes pollicipes. PpCrus-SWD1 consists of 138 amino acids and contains eight cysteine residues that form a conserved ‘four-disulfide core’ structure. Our recombinant PpCrus-SWD1 (rPpCrus-SWD1) exhibited potent inhibitory activity against three Gram-positive bacteria (Staphylococcus aureus, Bacillus sp. T2, and Streptococcus agalactiae) and six Gram-negative bacteria (Aeromonas hydrophila, Escherichia coli, Vibrio anguillarum, Vibrio alginolyticus, Vibrio parahemolyticus, and Acinetobacter sp. L3), with minimum inhibitory concentrations ranging from 16 to 64 μM. Furthermore, rPpCrus-SWD1 demonstrated binding affinity towards both bacteria and pathogen-associated molecular patterns (PAMPs), and damaged bacterial barrier. Additionally, it effectively inhibited alkaline protease activity in S. aureus and V. alginolyticus strains. These findings highlight the potential utility of this newly discovered crustin as an effective alternative to antibiotics. Full article

Vibrio alginolyticus frequently breaks out in aquatic animal breeding operations involving shrimp, and it can endanger human health through food and wound infections. The antibacterial effect and mechanism of fermented pomegranate peel polyphenols (FPPPs) on V. alginolyticus were investigated. The results indicated that FPPPs had a strong inhibitory effect on the growth of V. alginolyticus, and their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were 2 and 4 mg/mL. FPPPs significantly reduced biofilm formation and biofilm metabolic activity in V. alginolyticus, down-regulated the expression levels of lafA, lafK, fliS and flaK genes involved in flagellar synthesis and inhibited swimming and swarming motility (p < 0.05). Meanwhile, under the treatment of FPPPs, the activities of catalase (CAT) and superoxide dismutase (SOD) in V. alginolyticus were significantly reduced, and the levels of reactive oxygen species (ROS) and extracellular malondialdehyde (MDA) were significantly increased (p < 0.05). FPPPs also resulted in a significant increase in alkaline phosphatase (AKP) activity, protein and nucleic acid content, as well as conductivity from V. alginolyticus cultures. Scanning electron microscopy (SEM) images further revealed that V. alginolyticus treated with FPPPs showed leakage of intracellular substances, abnormal cell morphology and damage to cell walls and cell membranes, with the severity of the damage in a clear dose-dependent manner. Therefore, FPPPs can be used as a promising food-grade antibacterial agent, notably in seafood to control V. alginolyticus. Full article

Vibrio alginolyticus is a Gram-negative pathogen of both marine animals and humans, resulting in significant losses for the aquaculture industry. Emerging evidence indicates that V. alginolyticus manipulates cell death for its pathogenicity, but the underlying molecular mechanisms remain unclear. Here, a gene designated vopS in V. alginolyticus HY9901 was identified, which was predicted to encode the T3SS effector protein. To determine whether VopS contributes to the pathogenesis of V. alginolyticus, the ΔvopS mutant strain was constructed and phenotypically characterized. The deletion of VopS not only reduced the ability to secrete extracellular proteases and virulence but also affected the expression of the T3SS genes. Furthermore, VopS was cytotoxic and induced apoptosis, as confirmed by elevated LDH and the activation of caspase-3. Metabolomic analysis revealed considerable metabolomic disruptions upon V. alginolyticus infection. The VopS effector induced host cell ferroptosis by promoting the synthesis of adrenic acid, depleting cellular glutathione, and subsequently increasing the accumulation of ferrous (Fe²⁺). Taken together, our findings provide that the VopS effector is an essential virulence factor of V. alginolyticus, which can lead to ferroptosis. Full article

The Vibrio bacteria known to cause infections to humans and wildlife have been largely overlooked in coastal environments affected by beach wrack accumulations from seaweed or seagrasses. This study presents findings on the presence and distribution of potentially pathogenic Vibrio species on coastal beaches that are used for recreation and are affected by red-algae-dominated wrack. Using species-specific primers and 16S rRNA gene amplicon sequencing, we identified V. vulnificus, V. cholerae (non-toxigenic), and V. alginolyticus, along with 14 operational taxonomic units (OTUs) belonging to the Vibrio genus in such an environment. V. vulnificus and V. cholerae were most frequently found in water at wrack accumulation sites and within the wrack itself compared to sites without wrack. Several OTUs were exclusive to wrack accumulation sites. For the abundance and presence of V. vulnificus and the presence of V. cholerae, the most important factors in the water were the proportion of V. fucoides in the wrack, chl-a, and CDOM. Specific Vibrio OTUs correlated with salinity, water temperature, cryptophyte, and blue-green algae concentrations. To better understand the role of wrack accumulations in Vibrio abundance and community composition, future research should include different degradation stages of wrack, evaluate the link with nutrient release, and investigate microbial food-web interactions within such ecosystems, focusing on potentially pathogenic Vibrio species that could be harmful both for humans and wildlife. Full article

This study investigated the effect of substances on nonspecific immune responses of head kidney leukocytes, the antimicrobial activity against Vibrio sp., as well as the time-kill of Vibrio sp. by combining the substances with lactic acid bacteria (LAB) and Pediococcus sp. The substances are B. pilosa hot water extract, B. pilosa powder extract, B. pilosa methanol extract, B. pilosa ethanol extract, B. alba hot water extract, B. alba powder extract, B. alba methanol extract, B. alba ethanol extract, and bioactive compounds, namely cytopiloyne, flavonoid, phenol, ethyl caffeate, luteolin, chlorogenic acid, butein, and linoleic acid. The results showed that some of them were nontoxic to the head kidney leukocytes, which can increase the phagocytic rate, phagocytic index, and respiratory burst. These substances were able to inhibit the growth of Vibrio sp.; they can even completely kill the pathogenic bacteria. The largest of the inhibition zone formed from the EC group at a concentration range of 5–50 µg/mL against V. parahaemolyticus, V. alginolyticus, and V. harveyi with a value of 19.7 ± 0.56, 19.3 ± 1.53, and 20.6 ± 1.53 mm. Furthermore, the time-kill studies showed that the LAB and P. acidilactici can completely kill the Vibrio sp. at 6 h incubation time, mainly in the group of combination with EC. Full article