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Frontiers in Microbiology 2023Fluctuations in environmental physicochemical parameters can affect the diversity and prevalence of microbial communities, including vibrios, associated with aquatic...
INTRODUCTION
Fluctuations in environmental physicochemical parameters can affect the diversity and prevalence of microbial communities, including vibrios, associated with aquatic species and their surrounding environments. This study aimed to investigate the population dynamics of two species as well as the microbial community diversity of whole crab and seawater from the Maryland Coastal Bays (MCBs), using 16S rRNA sequencing.
METHODS
During this study, three crabs and 1 L of seawater were collected monthly from two sites for 3 months. Crab tissue was extracted and pooled for each site. Extracted crab tissue and seawater were analyzed for and using Most Probable Number (MPN) real-time PCR. For 16S rRNA microbiome analysis, three different DNA extraction kits were evaluated to extract microbial DNA from individual crabs. Also, 500 mL of each seawater sample was filtered for DNA extraction.
RESULTS
Results indicated that sample types and sampling periods had a significant effect on the alpha diversity of the microbial community of crabs and seawater ( < 0.05); however, no statistical difference was found between DNA extraction kits. Beta diversity analysis also found that the microbial compositions between sample types and temporal distributions were statistically significant. Taxonomic classification revealed that Proteobacteria, Cyanobacteria, Actinobacteria, and Bacteroidetes were present in both crab and seawater samples. and were also detected in both crab and seawater samples, although crabs contained a higher concentration of the bacterium compared to the seawater samples. It was found that vibrios were not a dominant species in the microbial community of crab or seawater samples.
DISCUSSION
Results from this study provide further insight into species diversity and phylogenetic compositions of blue crabs and seawater from the MCBs. These approaches will help in risk assessments that are essential in the overall advancement of public health.
PubMed: 37854338
DOI: 10.3389/fmicb.2023.1235070 -
Frontiers in Microbiology 2023Growing concerns exist regarding human ingestion of contaminated seafood that contains biofilms on microplastics (MPs). One of the mechanisms enhancing biofilm related...
Growing concerns exist regarding human ingestion of contaminated seafood that contains biofilms on microplastics (MPs). One of the mechanisms enhancing biofilm related infections in humans is due to biofilm dispersion, a process that triggers release of bacteria from biofilms into the surrounding environment, such as the gastrointestinal tract of human hosts. Dispersal of cells from biofilms can occur in response to environmental conditions such as sudden changes in temperature, pH and nutrient conditions, as the bacteria leave the biofilm to find a more stable environment to colonize. This study evaluated how brief exposures to nutrient starvation, elevated temperature, different pH levels and simulated human media affect and biofilm dispersal and processes on and from low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS) MPs. Both species were able to adequately disperse from all types of plastics under most exposure conditions. was able to tolerate and survive the low pH that resembles the gastric environment compared to pH had a significantly ( ≤ 0.05) positive effect on overall biofilm biomass in microplates and cell colonization from PP and PS. pH also had a positive effect on cell colonization from LDPE and PP. However, most biofilm biomass, biofilm cell and dispersal cell densities of both species greatly varied after exposure to elevated temperature, pH, and nutrient starvation. It was also found that certain exposures to simulated human media affected both and biofilm biomass and biofilm cell densities on LDPE, PP and PS compared to exposure to traditional media of similar pH. Cyclic-di-GMP was higher in biofilm cells compared to dispersal cells, but exposure to more stressful conditions significantly increased signal concentrations in both biofilm and dispersal states. Taken together, this study suggests that human pathogenic strains of and can rapidly disperse with high cell densities from different plastic types . However, the biofilm dispersal process is highly variable, species specific and dependent on plastic type, especially under different human body related environmental exposures.
PubMed: 37854331
DOI: 10.3389/fmicb.2023.1236471 -
Foods (Basel, Switzerland) Sep 2023can cause disease in aquatic animals and humans, therefore, rapid and simple field detection of pathogenic is important for early disease prevention. In this study, a...
can cause disease in aquatic animals and humans, therefore, rapid and simple field detection of pathogenic is important for early disease prevention. In this study, a novel recombinase-aided amplification (RAA) combined test strip with double T-lines (RAA-TS-DTL) was developed for the rapid detection of in aquatic products. Pathogenic was detected using the virulence gene and the housekeeping gene gene as the dual target of the test strip. The RAA-TS-DTL method showed 100% specificity for , and no cross-reaction was observed with spp. or other bacteria ( = 14). Furthermore, sensitive detection of in oysters was achieved. The LODs of the and genes were 6 CFU/mL and 23 CFU/mL, respectively, which was about five times higher than that of the commercial test strip. The method was validated with spiked samples ( = 60) of fish, shrimp and oyster. The consistency between RAA-TS-DTL and the traditional culture method was 97.9%. In addition, the entire process of detection, including preparation of the sample, could be completed within 50 min. Our results indicated that the developed RAA-TS-DTL was a reliable and useful tool for rapid screening or on-site detection of pathogenic in aquatic products and aquaculture water.
PubMed: 37835259
DOI: 10.3390/foods12193605 -
Fish & Shellfish Immunology Nov 2023Vibrio vulnificus is an emerging zoonotic pathogen associated with fish farms that is capable of causing a hemorrhagic septicemia known as warm-water vibriosis....
Vibrio vulnificus is an emerging zoonotic pathogen associated with fish farms that is capable of causing a hemorrhagic septicemia known as warm-water vibriosis. According to a recent transcriptomic and functional study, the death of fish due to vibriosis is more related to the inflammatory response of the host than to the tissue lesions caused by the pathogen. In this work, we hypothesize that the RtxA1 toxin (a V. vulnificus toxin of the MARTX (Multifunctional Autoprocessing Repeats in Toxin) family) is the key virulence factor that would directly or indirectly trigger this fatal inflammatory response. Our hypothesis was based on previous studies that showed that rtxA1-deficient mutants maintained their ability to colonize and invade, but were unable to kill fish. To demonstrate this hypothesis, we infected eels (model of fish vibriosis) by immersion with a mutant deficient in RtxA1 production and analyzed their transcriptome in blood, red blood cells and white blood cells during early vibriosis (0, 3 and 12 h post-infection). The transcriptomic results were compared with those obtained in the previous study in which eels were infected with the V. vulnificus parental strain, and were functionally validated. Overall, our results confirm that fish death after V. vulnificus infection is due to an acute, early and atypical inflammatory response triggered by RtxA1 in which red blood cells seem to play a central role. These results could be relevant to other vibriosis as the toxins of this family are widespread in the Vibrio genus.
Topics: Animals; Bacterial Toxins; Vibrio Infections; Virulence Factors; Vibrio vulnificus
PubMed: 37832748
DOI: 10.1016/j.fsi.2023.109131 -
BioRxiv : the Preprint Server For... Sep 2023Members of the genus are ecologically significant bacteria native to aquatic ecosystems globally, and a few can cause diseases in humans. Vibrio-related illnesses have...
Members of the genus are ecologically significant bacteria native to aquatic ecosystems globally, and a few can cause diseases in humans. Vibrio-related illnesses have increased in recent years, primarily attributed to changing environmental conditions. Therefore, understanding the role of environmental factors in the occurrence and growth of pathogenic strains is crucial for public health. Water, oyster, and sediment samples were collected between 2009 and 2012 from Chester River and Tangier Sound sites in Chesapeake Bay, Maryland, USA, to investigate the relationship between water temperature, salinity, and chlorophyll with the incidence and distribution of (VP) and (VV). Odds ratio analysis was used to determine association between the likelihood of VP and VV presence and these environmental variables. Results suggested that water temperature threshold of 20°C or higher was associated with an increased risk, favoring the incidence of . A significant difference in salinity was observed between the two sampling sites, with distinct ranges showing high odds ratio for incidence, especially in water and sediment, emphasizing the impact of salinity on VP and VV incidence and distribution. Notably, salinity between 9-20 PPT consistently favored the incidence across all samples. Relationship between chlorophyll concentrations and VP and VV incidence varied depending on sample type. However, chlorophyll range of 0-10 μg/L was identified as critical in oyster samples for both vibrios. Analysis of odds ratios for water samples demonstrated consistent outcomes across all environmental parameters, indicating water samples offer a more reliable indicator of . incidence.
PubMed: 37808627
DOI: 10.1101/2023.09.25.559351 -
Journal, Genetic Engineering &... Oct 2023Vibrio species are among the autochthonous bacterial populations found in surface waters and associated with various life-threatening extraintestinal diseases,...
Polymorphism and mutational diversity of virulence (vcgCPI/vcgCPE) and resistance determinants (aac(3)-IIa, (aacC2, strA, Sul 1, and 11) among human pathogenic Vibrio species recovered from surface waters in South-Western districts of Uganda.
BACKGROUND
Vibrio species are among the autochthonous bacterial populations found in surface waters and associated with various life-threatening extraintestinal diseases, especially in human populations with underlying illnesses and wound infections. Presently, very diminutive information exists regarding these species' mutational diversity of virulence and resistance genes. This study evaluated variations in endonucleases and mutational diversity of the virulence and resistance genes of Vibrio isolates, harboring virulence-correlated gene (vcgCPI), dihydropteroate synthase type 1 and type II genes (Sul 1 and 11), (aadA) aminoglycoside (3'') (9) adenylyltransferase gene, (aac(3)-IIa, (aacC2)a, aminoglycoside N(3)-acetyltransferase III, and (strA) aminoglycoside 3'-phosphotransferase resistance genes.
METHODS
Using combinations of molecular biology techniques, bioinformatics tools, and sequence analysis.
RESULTS
Our result revealed various nucleotide variations in virulence determinants of V. vulnificus (vcgCPI) at nucleotide positions (codon) 73-75 (A → G) and 300-302 (N → S). The aminoglycosides resistance gene (aadA) of Vibrio species depicts a nucleotide difference at position 482 (A → G), while the aminoglycosides resistance gene (sul 1 and 11) showed two variable regions of nucleotide polymorphism (102 and 140). The amino acid differences exist with the nucleotide polymorphism at position 140 (A → E). The banding patterns produced by the restriction enzymes HinP1I, MwoI, and StyD4I showed significant variations. Also, the restriction enzyme digestion of protein dihydropteroate synthase type 1 and type II genes (Sul 1 and 11) differed significantly, while enzymes DpnI and Hinf1 indicate no significant differences. The restriction enzyme NlaIV showed no band compared to reference isolates from the GenBank. However, the resistant determinants show significant point nucleotide mutation, which does not produce any amino acid change with diverse polymorphic regions, as revealed in the restriction digest profile.
CONCLUSION
The described virulence and resistance determinants possess specific polymorphic locus relevant to pathogenomics studies, pharmacogenomic, and control of such water-associated strains.
PubMed: 37801152
DOI: 10.1186/s43141-023-00554-1 -
MBio Oct 2023Many free-swimming bacteria propel themselves through liquid using rotary flagella, and mounting evidence suggests that the inhibition of flagellar rotation initiates...
Many free-swimming bacteria propel themselves through liquid using rotary flagella, and mounting evidence suggests that the inhibition of flagellar rotation initiates biofilm formation, a sessile lifestyle that is a nearly universal surface colonization paradigm in bacteria. In general, motility and biofilm formation are inversely regulated by the intracellular second messenger bis-(3´-5´)-cyclic dimeric guanosine monophosphate (c-di-GMP). Here, we identify a protein, PlzD, bearing a conserved c-di-GMP binding PilZ domain that localizes to the flagellar pole in a c-di-GMP-dependent manner and alters the foraging behavior, biofilm, and virulence characteristics of the opportunistic human pathogen, . Our data suggest that PlzD interacts with components of the flagellar stator to decrease bacterial swimming speed and changes in swimming direction, and these activities are enhanced when cellular c-di-GMP levels are elevated. These results reveal a physical link between a second messenger (c-di-GMP) and an effector (PlzD) that promotes transition from a motile to a sessile state in .
Topics: Humans; Vibrio vulnificus; Bacterial Proteins; Virulence; Cyclic GMP; Biofilms; Gene Expression Regulation, Bacterial
PubMed: 37800901
DOI: 10.1128/mbio.01536-23 -
PeerJ 2023Biofloc technology improves water quality and promote the growth of beneficial bacteria community in shrimp culture. However, little is known about the bacteria...
Biofloc technology improves water quality and promote the growth of beneficial bacteria community in shrimp culture. However, little is known about the bacteria community structure in both water and gut of cultured organisms. To address this, the current study characterised the metagenomes derived from water and shrimp intestine samples of novel Rapid BFT with probiotic and clearwater treatments using 16S V4 region and full length 16S sequencing. Bacteria diversity of water and intestine samples of Rapid BFT and probiotic treatments were similar. Based on the 16S V4 region, water samples of >20 μm biofloc had the highest abundance of amplicon sequence variant (ASV). However, based on full length 16S, no clear distinction in microbial diversity was observed between water samples and intestine samples. Proteobacteria was the most abundant taxon in all samples based on both 16S V4 and full length 16S sequences. was among the highest genus based on 16S V4 region but only full length 16S was able to discern up to species level, with three s identified-, and . being the most abundant species in all treatments. Among water samples, biofloc water samples had the lowest abundance of all three s, with was present only in bioflocs of <20 μm. Predicted functional profiles of treatments support the beneficial impacts of probiotic and biofloc inclusion into shrimp culture system. This study highlights the potential displacement of opportunistic pathogens by the usage of biofloc technology (Rapid BFT) in shrimp culture.
Topics: Animals; Metagenome; Penaeidae; Seafood; Aquaculture; Probiotics
PubMed: 37790619
DOI: 10.7717/peerj.15758 -
NPJ Vaccines Sep 2023Flagellin, the TLR5 agonist, shows potent adjuvant activities in diverse vaccines and immunotherapies. Vibrio vulnificus flagellin B expressed in eukaryotic cells...
Flagellin, the TLR5 agonist, shows potent adjuvant activities in diverse vaccines and immunotherapies. Vibrio vulnificus flagellin B expressed in eukaryotic cells (eFlaB) could not stimulate TLR5 signaling. Enzymatic deglycosylation restored eFlaB's TLR5 stimulating functionality, suggesting that glycosylation interferes with eFlaB binding to TLR5. Site-directed mutagenesis of N-glycosylation residues restored TLR5 stimulation and adjuvanticity. Collectively, deglycosylated eFlaB may provide a built-in adjuvant platform for eukaryotic-expressed antigens and nucleic acid vaccines.
PubMed: 37752138
DOI: 10.1038/s41541-023-00738-3 -
Frontiers in Cellular and Infection... 2023, a foodborne pathogen, has a high mortality rate. Despite its relevance to public health, the identification of virulence genes associated with the pathogenicity of...
, a foodborne pathogen, has a high mortality rate. Despite its relevance to public health, the identification of virulence genes associated with the pathogenicity of currently known clinical isolates of is incomplete and its synergistic pathogenesis remains unclear. Here, we integrate whole genome sequencing (WGS), genome-wide association studies (GWAS), and genome-wide epistasis studies (GWES), along with phenotype characterization to investigate the pathogenesis and survival strategies of . GWAS and GWES identified a total of six genes (, , , , , and ) associated with the pathogenicity of clinical isolates related to nucleotide/amino acid transport and metabolism, cell membrane biogenesis, signal transduction mechanisms, and protein turnover. Of these, five were newly discovered potential specific virulence genes of in this study. Furthermore, GWES combined with phenotype experiments indicated that isolates were clustered into two ecological groups (EGs) that shared distinct biotic and abiotic factors, and ecological strategies. Our study reveals pathogenic mechanisms and their evolution in to provide a solid foundation for designing new vaccines and therapeutic targets.
Topics: Metagenomics; Vibrio vulnificus; Genome-Wide Association Study; Amino Acids; Biological Transport
PubMed: 37692161
DOI: 10.3389/fcimb.2023.1254379