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Applied and Environmental Microbiology Feb 2018and are naturally occurring estuarine bacteria and are the leading causes of seafood-associated infections and mortality in the United States. Though...
and are naturally occurring estuarine bacteria and are the leading causes of seafood-associated infections and mortality in the United States. Though multiple-antibiotic-resistant and strains have been reported, resistance patterns in vibrios are not as well documented as those of other foodborne bacterial pathogens. Salinity relaying (SR) is a postharvest processing (PHP) treatment to reduce the abundances of these pathogens in shellfish harvested during the warmer months. The purpose of this study was to evaluate the antimicrobial susceptibility (AMS), pathogenicity, and genetic profiles of and recovered from oysters during an oyster relay study. Isolates ( [ = 296] and [ = 94]) were recovered from oysters before and during the 21-day relaying study to detect virulence genes ( and ) and genes correlated with virulence () using multiplex quantitative PCR (qPCR). AMS to 20 different antibiotics was investigated using microbroth dilution, and pulsed-field gel electrophoresis (PFGE) was used to study the genetic profiles of the isolates. Twenty percent of isolates were , while 1 and 2% of were and , respectively. More than 77% of the isolates and 30% of the isolates were resistant to at least one antimicrobial. Forty-eight percent of and 8% of isolates were resistant to two or more antimicrobials. All isolates demonstrated a high genetic diversity, even among those isolated from the same site and having a similar AMS profile. No significant effects of the relaying process on AMS, virulence genes, or PFGE profiles of and were observed. Analysis of the antibiotic resistance profiles of and isolated from oysters during this study indicated that more than 48% of isolates were resistant to two or more antimicrobials, including those recommended by the CDC for treating infections. Also, the isolates showed high MICs for some of the infection treatment antibiotics. Monitoring of AMS profiles of this bacterium is important to ensure optimal treatment of infections and improve food safety. Our study showed no significant differences in the AMS profiles of ( = 0.26) and ( = 0.23) isolated from the oysters collected before versus after relaying. This suggests that the salinity of the relaying sites did not affect the AMS profiles of the isolates, although it did reduce the numbers of these bacteria in oysters (S. Parveen et al., J Food Sci 82:484-491, 2017, https://doi.org/10.1111/1750-3841.13584).
Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Colony Count, Microbial; Drug Resistance, Multiple, Bacterial; Food Handling; Food Safety; Genetic Variation; Microbial Sensitivity Tests; Ostreidae; Polymerase Chain Reaction; Salinity; Shellfish; Vibrio Infections; Vibrio parahaemolyticus; Vibrio vulnificus; Virulence
PubMed: 29150510
DOI: 10.1128/AEM.01790-17 -
Frontiers in Cellular and Infection... 2018The expression of virulence genes in bacteria is known to be regulated by various environmental and host factors. , an estuarine bacterium, experiences a dramatic...
The expression of virulence genes in bacteria is known to be regulated by various environmental and host factors. , an estuarine bacterium, experiences a dramatic environmental change during its infection process. We reported that RtxA1 toxin caused acute cell death only when close contact to host cells was allowed. A sigma factor RpoS is a very important regulator for the maximal survival of pathogens under stress conditions. Here, we studied the role of RpoS in cytotoxicity and mouse lethality. The growth of mutant strain was comparable to that of wild-type in heart infusion (HI) media and DMEM with HeLa cell lysate. An mutation resulted in decreased cytotoxicity, which was restored by complementation. Interestingly, host contact increased the expression and secretion of RtxA1 toxin, which was decreased and delayed by the mutation. Transcription of the cytotoxic gene and its transporter was significantly increased after host factor contact, whereas the activity was decreased by the mutation. In contrast, the mutation showed no effect on the transcriptional activity of a cytolytic heamolysin gene (). Additionally, the LD of the mutant was 15-fold higher than that of the wild-type in specific pathogen-free CD-1 female mice. Taken together, these results show that RpoS regulates the expression of RtxA1 toxin and its transporter upon host contact.
Topics: Animals; Bacterial Proteins; Bacterial Toxins; Cell Death; Disease Models, Animal; Female; Gene Expression Regulation, Bacterial; Genetic Complementation Test; HeLa Cells; Hemolysis; Host-Pathogen Interactions; Humans; Lethal Dose 50; Mice; Mutation; Sigma Factor; Vibrio Infections; Vibrio vulnificus; Virulence
PubMed: 29600196
DOI: 10.3389/fcimb.2018.00070 -
Applied and Environmental Microbiology Dec 2014Vibrio vulnificus, a bacterium ubiquitous in oysters and coastal water, is capable of causing ailments ranging from gastroenteritis to grievous wound infections or... (Review)
Review
Vibrio vulnificus, a bacterium ubiquitous in oysters and coastal water, is capable of causing ailments ranging from gastroenteritis to grievous wound infections or septicemia. The uptake of these bacteria into oysters is often examined in vitro by placing oysters in seawater amended with V. vulnificus. Multiple teams have obtained similar results in studies where laboratory-grown bacteria were observed to be rapidly taken up by oysters but quickly eliminated. This technique, along with suggested modifications, is reviewed here. In contrast, the natural microflora within oysters is notoriously difficult to eliminate via depuration. The reason for the transiency of exogenous bacteria is that those bacteria are competitively excluded by the oyster's preexisting microflora. Evidence of this phenomenon is shown using in vitro oyster studies and a multiyear in situ case study. Depuration of the endogenous oyster bacteria occurs naturally and can also be artificially induced, but both of these events require extreme conditions, natural or otherwise, as explained here. Finally, the "viable but nonculturable" (VBNC) state of Vibrio is discussed. This bacterial torpor can easily be confused with a reduction in bacterial abundance, as bacteria in this state fail to grow on culture media. Thus, oysters collected from colder months may appear to be relatively free of Vibrio but in reality harbor VBNC cells that respond to exogenous bacteria and prevent colonization of oyster matrices. Bacterial-uptake experiments combined with studies involving cell-free spent media are detailed that demonstrate this occurrence, which could explain why the microbial community in oysters does not always mirror that of the surrounding water.
Topics: Animals; Ostreidae; Seawater; Vibrio vulnificus
PubMed: 25261513
DOI: 10.1128/AEM.02042-14 -
Emerging Infectious Diseases Jan 2005The recent emergence of the human-pathogenic Vibrio vulnificus in Israel was investigated by using multilocus genotype data and modern molecular evolutionary analysis...
The recent emergence of the human-pathogenic Vibrio vulnificus in Israel was investigated by using multilocus genotype data and modern molecular evolutionary analysis tools. We show that this pathogen is a hybrid organism that evolved by the hybridization of the genomes from 2 distinct and independent populations. These findings provide clear evidence of how hybridization between 2 existing and nonpathogenic forms has apparently led to the emergence of an epidemic infectious disease caused by this pathogenic variant. This novel observation shows yet another way in which epidemic organisms arise.
Topics: Animals; Bacterial Proteins; Bacterial Typing Techniques; Chromosomes, Bacterial; Communicable Diseases, Emerging; Disease Outbreaks; Environmental Microbiology; Evolution, Molecular; Genotype; Humans; Israel; Recombination, Genetic; Sequence Analysis, DNA; Vibrio Infections; Vibrio vulnificus
PubMed: 15705319
DOI: 10.3201/eid1101.040440 -
European Journal of Pharmacology Oct 2020Vibrio vulnificus (V. vulnificus) infection, frequently resulting in fatal septicemia, has become a growing health concern worldwide. The present study aimed to explore...
Vibrio vulnificus (V. vulnificus) infection, frequently resulting in fatal septicemia, has become a growing health concern worldwide. The present study aimed to explore the potential agents that could protect against V. vulnificus cytotoxicity, and to analyze the possible underlying mechanisms. First, we observed that 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate (DIDS) significantly suppressed V. vulnificus cytotoxicity to host cells by using a lactate dehydrogenase (LDH) assay. DIDS did not exhibit any effect on host cell viability, bacterial growth, microbial adhesion and swarming motility. DIDS effectively lowered V. vulnificus RtxA1 toxin-induced calcium influx into host mitochondria and RtxA1 binding to host cells. To further elucidate the underlying mechanism, the synthesis and secretion of RtxA1 toxin were investigated by Western blotting. Intriguingly, DIDS selectively inhibited the secretion of RtxA1 toxin, but did not influence its synthesis. Consequently, the outer membrane portal TolC, a key conduit for RtxA1 export coupled with tripartite efflux pumps, was examined by RT-PCR and Western blotting. We found that DIDS significantly reduced the expression of TolCV1 protein at the transcriptional level. Taken together, these results suggest that DIDS is a promising new paradigm as an antimicrobial drug that targets TolC-mediated toxin.
Topics: 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; Anti-Bacterial Agents; Bacterial Outer Membrane Proteins; Bacterial Toxins; Female; Gene Expression Regulation, Bacterial; HeLa Cells; Host-Pathogen Interactions; Humans; Transcription, Genetic; Vibrio Infections; Vibrio vulnificus; Virulence Factors
PubMed: 32735984
DOI: 10.1016/j.ejphar.2020.173407 -
Microbial Ecology May 2013The human bacterial pathogen, Vibrio vulnificus, is found in brackish waters and is concentrated by filter-feeding molluscan shellfish, especially oysters, which inhabit... (Review)
Review
The human bacterial pathogen, Vibrio vulnificus, is found in brackish waters and is concentrated by filter-feeding molluscan shellfish, especially oysters, which inhabit those waters. Ingestion of raw or undercooked oysters containing virulent strains of V. vulnificus can result in rapid septicemia and death in 50 % of victims. This review summarizes the current knowledge of the environmental interactions between these two organisms, including the effects of salinity and temperature on colonization, uptake, and depuration rates of various phenotypes and genotypes of the bacterium, and host-microbe immunological interactions.
Topics: Animals; Humans; Ostreidae; Shellfish; Shellfish Poisoning; Sodium Chloride; Temperature; Vibrio Infections; Vibrio vulnificus
PubMed: 23280497
DOI: 10.1007/s00248-012-0162-3 -
Microbiology Spectrum May 2024is a genus of halophilic, gram-negative bacteria found in estuaries around the globe. Integral parts of coastal cultures often involve contact with vectors of...
UNLABELLED
is a genus of halophilic, gram-negative bacteria found in estuaries around the globe. Integral parts of coastal cultures often involve contact with vectors of pathogenic spp. (e.g., consuming raw shellfish). High rates of mortality from certain spp. infections demonstrate the need for an improved understanding of spp. dynamics in estuarine regions. Our study assessed meteorological, hydrographic, and biological correlates of and at 10 sites in the Eastern Mississippi Sound System (EMSS) from April to October 2019. During the sampling period, median abundances of and were 2.31 log MPN/L and 2.90 log MPN/L, respectively. spp. dynamics were largely driven by site-based variation, with sites closest to freshwater inputs having the highest abundances. The E-W wind scalar, which affects Ekman transport, was a novel spp. correlate observed. A potential salinity effect on bacterial-particle associations was identified, where was associated with larger particles in conditions outside of their optimal salinity. Additionally, abundances were correlated to those of harmful algal species that did not dominate community chlorophyll. Correlates from this study may be used to inform the next iteration of regionally predictive models and may lend additional insight to spp. ecology in similar systems.
IMPORTANCE
spp. are bacteria found in estuaries worldwide; some species can cause illness and infections in humans. Relationships between spp. abundance, salinity, and temperature are well documented, but correlations to other environmental parameters are less understood. This study identifies unique correlates (e.g., E-W wind scalar and harmful algal species) that could potentially inform the next iteration of predictive models for the EMSS region. Additionally, these correlates may allow existing environmental monitoring efforts to be leveraged in providing data inputs for future Vibrio risk models. An observed correlation between salinity and /particle-size associations suggests that predicted environmental changes may affect the abundance of spp. in certain reservoirs, which may alter which vectors present the greatest vibrio risk.
Topics: Vibrio parahaemolyticus; Vibrio vulnificus; Estuaries; Alabama; Population Dynamics; Salinity; Vibrio Infections; Seawater; Water Microbiology
PubMed: 38578091
DOI: 10.1128/spectrum.03674-23 -
Molecular and Cellular Probes Jun 2021Vibrio vulnificus (V. vulnificus) is a Gram-negative bacterium living in warm and salty water. This marine bacterium could produce hemolysin (VVH), which often causes...
Vibrio vulnificus (V. vulnificus) is a Gram-negative bacterium living in warm and salty water. This marine bacterium could produce hemolysin (VVH), which often causes serious gastroenteritis or septicemia when people contact to seawater or seafood containing V. vulnificus. Timely diagnosis is regard as essential to disease surveillance. In this paper, we aimed at developing a quick and sensitive method for the detection of Vibrio vulnificus using real time recombinase polymerase amplification (real time RPA). Specific primers and an exo probe were designed on the basis of the vvhA gene sequence available in GenBank. Target DNA could be amplified and labeled with specific fluorophore within 20 min at 38 °C. The method exhibited a high specificity, only detecting Vibrio vulnificus and not showing cross-reaction with other bacteria. The sensitivity of this method was 2 pg per reaction (20 μL) for DNA, or 200 copies per reaction (20 μL) for standard plasmid. The detection limit (LOD) stated as the target level that would be detected 95% of the time and estimated was 1.58 × 10 copies by fit of the probit to the results of 8 replicates in different concentration. For quantitative analysis of the real time RPA, the second order polynomial regression was adopted in our study. The results showed the correlation coefficients were raised above 0.98, which suggested this model might be a better choice for the quantitative analysis of real time RPA compared to the routine linear regression model. For artificially contaminated plasma samples, Vibrio vulnificus could be detected within 16 min by real time RPA at concentration as low as 1.2 × 10 CFU/mL or 2.4 CFU per reaction (20 μL). Thus, the real time RPA method established in this study shows great potential for detecting Vibrio vulnificus in the research laboratory and disease diagnosis.
Topics: DNA Primers; Humans; Polymerase Chain Reaction; Recombinases; Sensitivity and Specificity; Vibrio vulnificus
PubMed: 33789126
DOI: 10.1016/j.mcp.2021.101726 -
Transboundary and Emerging Diseases Jul 2019Vibrio vulnificus is an opportunistic human pathogen responsible for the majority of seafood-associated deaths worldwide and is also a relevant fish pathogen for the...
Vibrio vulnificus is an opportunistic human pathogen responsible for the majority of seafood-associated deaths worldwide and is also a relevant fish pathogen for the aquaculture industry. In addition to infections in aquatic livestock, V. vulnificus also represents a risk to aquarium animals. For the first time, this work describes an important mortality outbreak in Trachinotus goodei in a zoo aquarium, with the isolation of Vibrio vulnificus (Vv) from the internal organs of the diseased fish. The isolates were identified by MALDI-TOF MS, serotyped and characterized by pulsed-field gel electrophoresis (PFGE). Although the isolates from great pompanos did not belong to pathovar piscis (formerly biotype 2) or to any of the fish-related serovars, they all had identical phenotypes, antimicrobial susceptibility profiles and PFGE patterns, which together with their isolation in pure culture from internal organs is strongly indicative of their clinical significance. Moreover, Vv isolates harboured important genetic markers of human virulence potential: they had the clinical variant of the vcg gene, gave the 338 bp DNA amplification product of the pilF gene and resisted the bactericidal activity of human serum. All these results strongly suggest that these Vv isolates should be considered potentially virulent for humans. These results extend the range of fish species affected by V. vulnificus, confirm the threat that this pathogen represents to aquatic animals and highlight the risk that this bacterial pathogen poses to human health.
Topics: Animals; Aquaculture; Disease Outbreaks; Fish Diseases; Humans; Perciformes; Spain; Vibrio Infections; Vibrio vulnificus; Virulence
PubMed: 30927558
DOI: 10.1111/tbed.13190 -
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