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International Journal of Food... Jul 2023The aim of this study was to investigate seasonal variations (September, December and April) in the initial microbial communities of skin and gills' external mucosal...
Photobacterium predominate the microbial communities of muscle of European plaice (Pleuronectes platessa) caught in the Norwegian sea independent of skin and gills microbiota, fishing season, and storage conditions.
The aim of this study was to investigate seasonal variations (September, December and April) in the initial microbial communities of skin and gills' external mucosal tissues (EMT) and muscle of European plaice (Pleuronectes platessa). Moreover, a potential relationship between EMT and fresh muscle microbiota was examined. The microbial community succession in plaice muscle as a function of fishing season and storage conditions was also investigated. The selected seasons for the storage experiment were September and April. Investigated storage conditions were; fillets packaged in either vacuum or modified atmosphere (70 % CO, 20 % N, 10 % O) and chilled/refrigerated conditions (4 °C). Whole fish stored on ice (0 °C) was selected as a commercial standard. Seasonal variations were detected in the initial microbial communities of EMT and plaice muscle. The highest microbial diversity was found in EMT and muscle of April-caught plaice, followed by December and September catch indicating the important role of environmental factors in shaping the initial EMT and muscle microbial communities. The EMT microbial communities were more diverse than fresh muscle samples. The low number of shared taxa between EMT and initial muscle microbial communities indicates that only a minor part of the muscle microbiota came from the EMT. Psychrobacter and Photobacterium were the predominant genera in the EMT microbial communities in all seasons. Photobacterium dominated the initial muscle microbial communities with a gradual seasonal reduction of its abundance from September to April. Storage time and storage conditions shaped a less diverse and distinct community compared to the fresh muscle. However, no clear separation was seen between the communities at the middle and end of storage time. Regardless of EMT microbiota, fishing season and storage conditions, Photobacterium dominated the microbial communities of stored muscle samples. The Photobacterium prevalence as the primary specific spoilage organism (SSO) could be attributed to its high relative abundance in the initial microbiota of muscle and its CO-tolerance. The findings of this study indicate the important contribution of Photobacterium to the microbial spoilage of plaice. Thus, the development of innovative preservation techniques addressing the rapid growth of Photobacterium could contribute to the production of high-quality and shelf-stable convenient retail plaice products.
Topics: Animals; Carbon Dioxide; Flounder; Food Microbiology; Food Packaging; Food Preservation; Gills; Microbiota; Muscles; Photobacterium; Seasons
PubMed: 37099863
DOI: 10.1016/j.ijfoodmicro.2023.110222 -
MSystems Feb 2024Animals and their associated microbiota share long evolutionary histories. However, it is not always clear how host genotype and microbiota interact to affect phenotype....
Animals and their associated microbiota share long evolutionary histories. However, it is not always clear how host genotype and microbiota interact to affect phenotype. We applied a hologenomic approach to explore how host-microbiota interactions shape lifetime growth and parasite infection in farmed Atlantic salmon (). Multi-omics data sets were generated from the guts of 460 salmon, 82% of which were naturally infected with an intestinal cestode. A single bacterial strain, MAG01, dominated the gut metagenome of large, non-parasitized fish, consistent with previous studies showing high levels of in the gut microbiota of healthy salmon. While small and/or parasitized salmon also had high abundance of MAG01, we observed increased alpha diversity in these individuals, driven by increased frequency of low-abundance Vibrionaceae and other species that carried known virulence genes. Colonization by one of these cestode-associated strains was associated with host individual genomic variation in long non-coding RNAs. Integrating the multi-omic data sets revealed coordinated changes in the salmon gut mRNA transcriptome and metabolome that correlated with shifts in the microbiota of smaller, parasitized fish. Our results suggest that the gut microbiota of small and/or parasitized fish is in a state of dysbiosis that partly depends on the host genotype, highlighting the value of using a hologenomic approach to incorporate the microbiota into the study of host-parasite dynamics.IMPORTANCEStudying host-microbiota interactions through the perspective of the hologenome is gaining interest across all life sciences. Intestinal parasite infections are a huge burden on human and animal health; however, there are few studies investigating the role of the hologenome during parasite infections. We address this gap in the largest multi-omics fish microbiota study to date using natural cestode infection of farmed Atlantic salmon. We find a clear association between cestode infection, salmon lifetime growth, and perturbation of the salmon gut microbiota. Furthermore, we provide the first evidence that the genetic background of the host may partly determine how the gut microbiota changes during parasite-associated dysbiosis. Our study therefore highlights the value of a hologenomic approach for gaining a more in-depth understanding of parasitism.
Topics: Humans; Animals; Gastrointestinal Microbiome; Salmo salar; Aquaculture; Dysbiosis; Parasitic Diseases; Cestode Infections
PubMed: 38294254
DOI: 10.1128/msystems.01043-23 -
Microbiology Spectrum Aug 2023is a genus of naturally occurring marine predatory bacteria that attack, replicate within, and lyse vibrios and other bacteria. This study evaluated the specificity of...
is a genus of naturally occurring marine predatory bacteria that attack, replicate within, and lyse vibrios and other bacteria. This study evaluated the specificity of four strains against important sequence types (STs) of clinically relevant Vibrio parahaemolyticus, including pandemic strains ST3 and ST36. The bacteria were previously isolated from seawater from the Mid-Atlantic, Gulf of Mexico, and Hawaiian coasts of the United States. Specificity screening was performed using a double agar plaque assay technique on 23 well-characterized and genomically sequenced V. parahaemolyticus strains isolated from infected individuals from widely varying geographic locations within the United States. With few exceptions, results showed that bacteria were excellent predators of the V. parahaemolyticus strains regardless of the origins of the predator or prey. Sequence types and serotypes of V. parahaemolyticus did not influence host specificity, nor did the presence or absence of genes for the thermostable direct hemolysin (TDH) or the TDH-related hemolysin, although faint (cloudy) plaques were present when one or both hemolysins were absent in three of the strains. Plaque sizes varied depending on both the and strains evaluated, suggesting differences in replication and/or growth rates. The very broad infectivity of toward pathogenic strains of V. parahaemolyticus makes a strong candidate for use in commercial processing applications to enhance the safety of seafoods. Vibrio parahaemolyticus is a formidable obstacle to seafood safety. Strains pathogenic to humans are numerous and difficult to control, especially within molluscan shellfish. The pandemic spread of ST3 and ST36 has caused considerable concern, but many other STs are also problematic. The present study demonstrates broad predatory activity of strains obtained along U.S. coastal waters from the Mid-Atlantic, Gulf Coast, and Hawaii toward strains of pathogenic V. parahaemolyticus. This broad activity against clinically relevant V. parahaemolyticus strains suggests a role for in mediating pathogenic V. parahaemolyticus levels in seafoods and their environment as well as the potential application of these predators in the development of new disinfection technologies to reduce pathogenic vibrios in molluscan shellfish and other seafoods.
Topics: Humans; Hemolysin Proteins; Vibrio parahaemolyticus; Shellfish; Proteobacteria
PubMed: 37409976
DOI: 10.1128/spectrum.02353-23 -
Biochemistry. Biokhimiia Feb 2024Genes of putative reductases of α,β-unsaturated carboxylic acids are abundant among anaerobic and facultatively anaerobic microorganisms, yet substrate specificity has...
Genes of putative reductases of α,β-unsaturated carboxylic acids are abundant among anaerobic and facultatively anaerobic microorganisms, yet substrate specificity has been experimentally verified for few encoded proteins. Here, we co-produced in Escherichia coli a heterodimeric protein of the facultatively anaerobic marine bacterium Vibrio ruber (GenBank SJN56019 and SJN56021; annotated as NADPH azoreductase and urocanate reductase, respectively) with Vibrio cholerae flavin transferase. The isolated protein (named Crd) consists of the sjn56021-encoded subunit CrdB (NADH:flavin, FAD binding 2, and FMN bind domains) and an additional subunit CrdA (SJN56019, a single NADH:flavin domain) that interact via their NADH:flavin domains (Alphafold2 prediction). Each domain contains a flavin group (three FMNs and one FAD in total), one of the FMN groups being linked covalently by the flavin transferase. Crd readily reduces cinnamate, p-coumarate, caffeate, and ferulate under anaerobic conditions with NADH or methyl viologen as the electron donor, is moderately active against acrylate and practically inactive against urocanate and fumarate. Cinnamates induced Crd synthesis in V. ruber cells grown aerobically or anaerobically. The Crd-catalyzed reduction started by NADH demonstrated a time lag of several minutes, suggesting a redox regulation of the enzyme activity. The oxidized enzyme is inactive, which apparently prevents production of reactive oxygen species under aerobic conditions. Our findings identify Crd as a regulated NADH-dependent cinnamate reductase, apparently protecting V. ruber from (hydroxy)cinnamate poisoning.
Topics: Oxidoreductases; NAD; Cinnamates; Oxidation-Reduction; Vibrio; NADH, NADPH Oxidoreductases; NADH Dehydrogenase; Flavins; Transferases; Flavin-Adenine Dinucleotide
PubMed: 38622093
DOI: 10.1134/S0006297924020056 -
Infection, Genetics and Evolution :... Jun 2024Non-O1/non-O139 Vibrio cholerae (NOVC) are ubiquitous in aquatic ecosystems. In rare cases, they can cause intestinal and extra-intestinal infections in human. This...
Non-O1/non-O139 Vibrio cholerae (NOVC) are ubiquitous in aquatic ecosystems. In rare cases, they can cause intestinal and extra-intestinal infections in human. This ability is associated with various virulence factors. The presence of NOVC in German North Sea and Baltic Sea was observed in previous studies. However, data on virulence characteristics are still scarce. Therefore, this work aimed to investigating the virulence potential of NOVC isolated in these two regions. In total, 31 NOVC strains were collected and subjected to whole genome sequencing. In silico analysis of the pathogenic potential was performed based on the detection of genes involved in colonization and virulence. Phenotypic assays, including biofilm formation, mobility and human serum resistance assays were applied for validation. Associated toxin genes (hlyA, rtxA, chxA and stn), pathogenicity islands (Vibrio pathogenicity island 2 (VPI-II) and Vibrio seventh pathogenicity island 2 (VSP-II)) and secretion systems (Type II, III and VI secretion system) were observed. A maximum likelihood analysis from shared core genes revealed a close relationship between clinical NOVCs published in NCBI and environmental strains from this study. NOVC strains are more mobile at 37 °C than at 25 °C, and 68% of the NOVC strains could form strong biofilms at both temperatures. All tested strains were able to lyse erythrocytes from both human and sheep blood. Additionally, one strain could survive up to 60% and seven strains up to 40% human serum at 37 °C. Overall, the genetic virulence profile as well as the phenotypic virulence characteristics of the investigated NOVC from the German North Sea and Baltic Sea suggest potential human pathogenicity.
Topics: Virulence Factors; Humans; Virulence; Vibrio cholerae non-O1; Germany; Genomic Islands; Biofilms; Phylogeny; North Sea; Vibrio cholerae; Cholera; Animals; Whole Genome Sequencing
PubMed: 38518953
DOI: 10.1016/j.meegid.2024.105587 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Aug 2023Pullulanase is a starch debranching enzyme, which is difficult in secretory expression due to its large molecular weight. is a novel expression host with excellent...
Pullulanase is a starch debranching enzyme, which is difficult in secretory expression due to its large molecular weight. is a novel expression host with excellent efficiency in protein synthesis. In this study, we achieved secretory expression of the full-length pullulanase PulA and its truncated mutant PulN2 using . VnDX strain. Subsequently, we investigated the effects of signal peptide, fermentation temperature, inducer concentration, glycine concentration and fermentation time on the secretory expression. Moreover, the extracellular enzyme activities of the two pullulanases produced in . VnDX and . BL21(DE3) were compared. The highest extracellular enzyme activity of PulA and PulN2 in . VnDX were 61.6 U/mL and 64.3 U/mL, which were 110% and 62% that of those in . BL21(DE3), respectively. The results indicated that . VnDX can be used for secretory expression of the full-length PulA with large molecular weight, which may provide a reference for the secretory expression of other large molecular weight proteins in . VnDX.
Topics: Escherichia coli; Fermentation; Vibrio
PubMed: 37622370
DOI: 10.13345/j.cjb.220971 -
International Journal of Systematic and... May 2024Two Gram-stain-negative, rod-shaped bacteria, designated as strains KJ10-1 and KJ40-1, were isolated from marine brown algae. Both strains were catalase-positive,...
Two Gram-stain-negative, rod-shaped bacteria, designated as strains KJ10-1 and KJ40-1, were isolated from marine brown algae. Both strains were catalase-positive, oxidase-positive, and facultative aerobic. Strain KJ10-1 exhibited optimal growth at 25 °C, pH 7.0, and 3 % NaCl, whereas strain KJ40-1 showed optimal growth at 25 °C, pH 7.0, and 2 % NaCl. The respiratory quinones of strain KJ10-1 were ubiquinone-8, ubiquinone-7, menaquinone-7, and methylated menaquinone-7, while the respiratory quinone of strain KJ40-1 was only ubiquinone-8. As major fatty acids, strain KJ10-1 contained C, C ω8, iso-C, and summed feature 3 (C 7 and/or C 6) and strain KJ40-1 contained C and summed features 3 and 8 (C 7 and/or C 6). The major polar lipids in strain KJ10-1 were phosphatidylethanolamine, phosphatidylglycerol, and an unidentified aminolipid, whereas those in strain KJ40-1 were phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The DNA G+C contents of strains KJ10-1 and KJ40-1 were 42.1 and 40.8 mol%, respectively. Based on 16S rRNA gene sequences, strains KJ10-1 and KJ40-1 exhibited the closest relatedness to MMS16-UL250 (98.6 %) and S-1 (95.4 %), respectively. Phylogenetic analyses, based on both 16S rRNA and 92 housekeeping genes, showed that the strains formed distinct phylogenic lineages within the genera and . Digital DNA-DNA hybridization and orthologous average nucleotide identity values between strain KJ10-1 and other species, as well as between strain KJ40-1 and other species, were below the thresholds commonly accepted for prokaryotic species delineation. Based on the phenotypic, chemotaxonomic, and phylogenetic data, strains KJ10-1 and KJ40-1 represent novel species of the genera and , respectively, for which the names sp. nov. and sp. nov. are proposed, respectively. The type strains of and are KJ10-1 (=KACC 22589=JCM 35409) and KJ40-1 (=KACC 22588=JCM 35410), respectively.
Topics: RNA, Ribosomal, 16S; Base Composition; Phylogeny; Fatty Acids; DNA, Bacterial; Bacterial Typing Techniques; Sequence Analysis, DNA; Vibrio; Ubiquinone; Shewanella; Phaeophyceae; Vitamin K 2; Phospholipids; Nucleic Acid Hybridization; Seawater
PubMed: 38728177
DOI: 10.1099/ijsem.0.006378 -
Fish & Shellfish Immunology Aug 2023Vibriosis is an infectious disease that generates large economic losses in Mediterranean aquaculture. Vibrio harveyi is one of the marine bacteria causing this disease,...
Vibriosis is an infectious disease that generates large economic losses in Mediterranean aquaculture. Vibrio harveyi is one of the marine bacteria causing this disease, it is widespread in the Mediterranean Sea and causes ulcers on the skin of the fish it infects. In addition, the skin is a route of entry and colonization of this pathogen. In this study, one group of fish was injected intraperitoneally with phosphate buffered saline (control group) and another with V. harveyi (infected group). At 4 h after injection, samples of skin mucus, blood, skin, head kidney, liver, and spleen were collected to study the immune response generated. Liver histology showed notable alterations in hepatocyte morphology, such as increased vacuolization. Bactericidal activity was measured in skin mucus and serum against V. harveyi and V. anguillarum, different changes in this activity were recorded depending on the bacteria target and sample (skin mucus or serum) used. Gene expression of genes encoding hepcidins and piscidins (antimicrobial peptides) was performed in the mentioned organs. The results indicated a different expression according to the type of AMP and the tissue studied. Hepcidin appeared involved in all tissues studied while piscidins were in the spleen. In this study we have integrated hepcidin-piscidin modulation with the effects of infection on skin mucosa, serum and hepatocyte morphology. Knowing the changes produced in all these parameters improves the understanding of the infection in the first hours in sea bream and could have applications in the diagnosis or treatment of vibriosis in fish farms.
Topics: Animals; Sea Bream; Hepcidins; Vibrio; Vibrio Infections; Anti-Bacterial Agents
PubMed: 37353061
DOI: 10.1016/j.fsi.2023.108899 -
Journal of Bacteriology May 2024() 's initial rise to fame derived from its alluring production of blue-green light. Subsequent studies to probe the mechanisms underlying this bioluminescence helped... (Review)
Review
() 's initial rise to fame derived from its alluring production of blue-green light. Subsequent studies to probe the mechanisms underlying this bioluminescence helped the field discover the phenomenon now known as quorum sensing. Orthologs of quorum-sensing regulators (i.e., LuxR and LuxI) originally identified in were subsequently uncovered in a plethora of bacterial species, and analogous pathways were found in yet others. Over the past three decades, the study of this microbe has greatly expanded to probe the unique role of as the exclusive symbiont of the light organ of the Hawaiian bobtail squid, . Buoyed by this optically amenable host and by persistent and insightful researchers who have applied novel and cross-disciplinary approaches, has developed into a robust model for microbe-host associations. It has contributed to our understanding of how bacteria experience and respond to specific, often fluxing environmental conditions and the mechanisms by which bacteria impact the development of their host. It has also deepened our understanding of numerous microbial processes such as motility and chemotaxis, biofilm formation and dispersal, and bacterial competition, and of the relevance of specific bacterial genes in the context of colonizing an animal host. Parallels in these processes between this symbiont and bacteria studied as pathogens are readily apparent, demonstrating functional conservation across diverse associations and permitting a reinterpretation of "pathogenesis." Collectively, these advances built a foundation for microbiome studies and have positioned to continue to expand the frontiers of our understanding of the microbial world inside animals.
Topics: Aliivibrio fischeri; Animals; Decapodiformes; Quorum Sensing; Symbiosis; Gene Expression Regulation, Bacterial; Bacterial Proteins; Host Microbial Interactions
PubMed: 38695522
DOI: 10.1128/jb.00035-24 -
Environmental Microbiology Reports Dec 2023Vibrio aestuarianus is a bacterium related to mass mortality outbreaks of the Pacific oyster, Crassostrea gigas in Europe. In this study, the role of different...
Vibrio aestuarianus is a bacterium related to mass mortality outbreaks of the Pacific oyster, Crassostrea gigas in Europe. In this study, the role of different planktonic substrates (phytoplankton cells, marine aggregates and chitin fragments) in mediating V. aestuarianus 02/041 infection of oysters was evaluated by controlled infection experiments. It was shown that phytoplankton cells and, to a greater extent, marine aggregates, significantly promote V. aestuarianus 02/041 intake by C. gigas maintained under stressful conditions in the laboratory. Such intake is associated with higher concentration of the pathogen in the bivalve hemolymph and compromised health status of infected oysters. In contrast, chitin particles do not play a significant role as transmission vector for V. aestuarianus 02/041 infecting its bivalve host. Interestingly, incorporation into marine aggregates foster extracellular proteases (ECPs) activity and a higher expression of bacterial virulence genes, that are potentially involved in bivalve infection. Results from this study contribute to elucidate transmission patterns of V. aestuarianus 02/041 to C. gigas that may be useful for the development of efficient measures to prevent and control oyster disease outbreaks.
Topics: Animals; Crassostrea; Plankton; Vibrio; Europe; Hemolymph; Chitin
PubMed: 37776112
DOI: 10.1111/1758-2229.13206