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Infection and Immunity May 2009
Review
Topics: Animals; Humans; Vibrio Infections; Vibrio vulnificus; Virulence; Virulence Factors
PubMed: 19255188
DOI: 10.1128/IAI.01046-08 -
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 -
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 -
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 -
Frontiers in Cellular and Infection... 2021is a deadly human pathogen for which infections occur seafood consumption (foodborne) or direct contact with wounds. Virulence is not fully characterized for this...
is a deadly human pathogen for which infections occur seafood consumption (foodborne) or direct contact with wounds. Virulence is not fully characterized for this organism; however, there is evidence of biochemical and genotypic correlations with virulence potential. In this study, biochemical profiles and virulence genotype, based on 16S rRNA gene () and virulence correlated gene () types, were determined for 30 clinical and 39 oyster isolates. Oyster isolates were more biochemically diverse than the clinical isolates, with four of the 20 tests producing variable (defined as 20-80% of isolates) results. Whereas, for clinical isolates only mannitol fermentation, which has previously been associated with virulence potential, varied among the isolates. Nearly half (43%) of clinical isolates were the more virulent genotype (B/C); this trend was consistent when only looking at clinical isolates from blood. The majority (64%) of oyster isolates were the less virulent genotype (A or AB/E). These data were used to select a sub-set of 27 isolates for virulence testing with a subcutaneously inoculated, iron-dextran treated mouse model. Based on the mouse model data, 11 isolates were non-lethal, whereas 16 isolates were lethal, indicating a potential for human infection. Within the non-lethal group there were eight oyster and three clinical isolates. Six of the non-lethal isolates were the less virulent genotype (A/E or AB/E) and two were B/C with the remaining two of mixed genotype (AB/C and B/E). Of the lethal isolates, five were oysters and 11 were clinical. Eight of the lethal isolates were the less virulent genotype and seven the more virulent genotype, with the remaining isolate a mixed genotype (A/C). A discordance between virulence genotype and individual mouse virulence parameters (liver infection, skin infection, skin lesion score, and body temperature) was observed; the variable most strongly associated with mouse virulence parameters was season (warm or cold conditions at time of strain isolation), with more virulent strains isolated from cold conditions. These results indicate that biochemical profiles and genotype are not significantly associated with virulence potential, as determined by a mouse model. However, a relationship with virulence potential and seasonality was observed.
Topics: Animals; Mice; Ostreidae; RNA, Ribosomal, 16S; Vibrio Infections; Vibrio vulnificus; Virulence
PubMed: 33718284
DOI: 10.3389/fcimb.2021.637019 -
International Journal of Infectious... Jun 2017Infections with Vibrio vulnificus are commonly fatal, and the speed and accuracy of diagnosis and treatment is directly linked to mortality. The main aims of this study...
OBJECTIVES
Infections with Vibrio vulnificus are commonly fatal, and the speed and accuracy of diagnosis and treatment is directly linked to mortality. The main aims of this study were to investigate the clinical characteristics of six patients with V. vulnificus infections retrospectively and to determine the effect of treatment with tigecycline (TGC) alone compared with doxycycline plus ceftazidime (DOX/CAZ).
METHODS
The medical records of patients were reviewed. The species-specific and pathogenic gene markers were detected by PCR, and multilocus sequence typing (MLST) was performed. Furthermore, the effects of TGC and of DOX/CAZ were determined using time-kill assays.
RESULTS
MLST revealed six different sequence types and five of them were novel. The complete clinical pattern (vcg type C, CPS operon allele 1, 16S-rRNA type B) was found in one strain and the others had a mixed pattern. The lesion was mainly located at the distal end of the extremities and the most common clinical symptoms were fever, pain, erythema, and local swelling. The in vitro time-kill assay indicated that TGC monotherapy at a concentration of 0.1mg/l had a rapid bactericidal effect against the six tested V. vulnificus strains at 24h.
CONCLUSIONS
TGC alone might be a better potential therapeutic option than the traditional combination of DOX/CAZ against V. vulnificus.
Topics: Adult; Aged; Bacterial Typing Techniques; Female; Humans; Male; Middle Aged; Multilocus Sequence Typing; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Vibrio Infections; Vibrio vulnificus
PubMed: 28347850
DOI: 10.1016/j.ijid.2017.03.017 -
MSphere Aug 2020To understand toxin-stimulated host-pathogen interactions, we performed dual-transcriptome sequencing experiments using human epithelial (HT-29) and differentiated THP-1...
To understand toxin-stimulated host-pathogen interactions, we performed dual-transcriptome sequencing experiments using human epithelial (HT-29) and differentiated THP-1 (dTHP-1) immune cells infected with the sepsis-causing pathogen (either the wild-type [WT] pathogen or a ultifunctional-utoprocessing epeats-in-oin [MARTX] toxin-deficient strain). Gene set enrichment analyses revealed MARTX toxin-dependent responses, including negative regulation of extracellular related kinase 1 (ERK1) and ERK2 (ERK1/2) signaling and cell cycle regulation in HT-29 and dTHP-1 cells, respectively. Further analysis of the expression of immune-related genes suggested that the MARTX toxin dampens immune responses in gut epithelial cells but accelerates inflammation and nuclear factor κB (NF-κB) signaling in immune cells. With respect to the pathogen, siderophore biosynthesis genes were significantly more highly expressed in WT than in the MARTX toxin-deficient mutant upon infection of dTHP-1 cells. Consistent with these results, iron homeostasis genes that limit iron levels for invading pathogens were overexpressed in WT -infected dTHP-1 cells. Taken together, these results suggest that MARTX toxin regulates host inflammatory responses during infection while also countering host defense mechanisms such as iron limitation. is an opportunistic human pathogen that can cause life-threatening sepsis in immunocompromised patients via seafood poisoning or wound infection. Among the toxic substances produced by this pathogen, the MARTX toxin greatly contributes to disease progression by promoting the dysfunction and death of host cells, which allows the bacteria to disseminate and colonize the host. In response to this, host cells mount a counterattack against the invaders by upregulating various defense genes. In this study, the gene expression profiles of both host cells and were analyzed by RNA sequencing to gain a comprehensive understanding of host-pathogen interactions. Our results suggest that uses the MARTX toxin to subvert host cell immune responses as well as to oppose host counterattacks such as iron limitation.
Topics: Bacterial Toxins; Epithelial Cells; Gene Expression Profiling; HT29 Cells; Host-Pathogen Interactions; Humans; Iron; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Siderophores; THP-1 Cells; Vibrio vulnificus; Virulence Factors
PubMed: 32817457
DOI: 10.1128/mSphere.00659-20 -
Biocontrol Science Mar 2011Bacteria of the genus Vibrio are normal habitants of the aquatic environment but the some species are believed to be human pathogens. Pathogenic vibrios produce various... (Review)
Review
Bacteria of the genus Vibrio are normal habitants of the aquatic environment but the some species are believed to be human pathogens. Pathogenic vibrios produce various pathogenic factors, and the proteases are also recognized to play pathogenic roles in the infection: the direct roles by digesting many kinds of host proteins or indirect roles by processing other pathogenic protein factors. Especially VVP from Vibrio vulnificus is thought to be a major pathogenic factor of the vibrio. Although HA/P, the V. cholerae hemagglutinin/protease, is not a direct toxic factor of cholera vibrio, its significance is an undeniable fact. Production of HA/P is regulated together with major pathogenic factors such as CT (cholera toxin) or TCP (toxin co-regulated pilus) by a quorum-sensing system. HA/P is necessary for full expression of pathogenicity of the vibrio by supporting growth and translocation in the digestive tract. Processing of protein toxins such as CT or El Tor hemolysin is also an important pathogenic role.
Topics: Bacterial Proteins; Cholera Toxin; Fimbriae, Bacterial; Hemolysin Proteins; Metalloendopeptidases; Peptide Hydrolases; Quorum Sensing; Vibrio cholerae; Vibrio vulnificus; Virulence Factors
PubMed: 21467624
DOI: 10.4265/bio.16.1 -
Journal of Microbiology, Immunology,... Feb 2018The aim of this study is to investigate the role of tigecycline in Vibrio vulnificus infection.
BACKGROUND/PURPOSE
The aim of this study is to investigate the role of tigecycline in Vibrio vulnificus infection.
METHODS
Eight randomly selected clinical V. vulnificus isolates were studied to obtain the minimal inhibitory concentrations (MICs) of minocycline, cefotaxime, and tigecycline, and the time-kill curves of tigecycline alone or in combination with other drugs. A peritonitis mouse model was used for the evaluation of the therapeutic efficacy of tigecycline alone or cefotaxime in combination with minocycline or tigecycline.
RESULTS
The MIC of minocycline, cefotaxime, and tigecycline for eight clinical V. vulnificus isolates was 0.06-0.12 μg/mL, 0.03-0.06 μg/mL, and 0.03-0.06 μg/mL, respectively. In time-killing studies, at the concentration of 1 × MIC, the inhibitory effect of tigecycline persisted for 24 hours in five of eight isolates. With 2 × MIC and trough level, the inhibitory effect was noted in all isolates for 24 hours. With the combination of minocycline plus cefotaxime and tigecycline plus cefotaxime at 1/2 × MIC, the bactericidal effect was noted in 25% and 62.5% of eight isolates and synergism in 50% and 75% of isolates. With a low (1.25 × 10 CFU/mL) inoculum, all infected mice survived with tigecycline alone, tigecycline plus cefotaxime, or minocycline plus cefotaxime on the 14 day. At the inoculum of 1.25 × 10 CFU, the survival rate was 33.3% on the 14 day in the tigecycline plus cefotaxime-treated group, but none of the mice treated by tigecycline alone or minocycline plus cefotaxime survived (33.3% vs. 0%, p = 0.01 by Fisher's exact test).
CONCLUSION
Our in vitro combination and animal studies indicate that tigecycline could be an option for the treatment of invasive V. vulnificus infections.
Topics: Animals; Anti-Bacterial Agents; Cefotaxime; Colony Count, Microbial; Disease Models, Animal; Drug Combinations; Drug Synergism; Drug Therapy, Combination; Humans; Mice; Microbial Sensitivity Tests; Minocycline; Peritonitis; Survival Rate; Taiwan; Tigecycline; Time Factors; Vibrio Infections; Vibrio vulnificus
PubMed: 27260781
DOI: 10.1016/j.jmii.2016.04.009 -
International Journal of Molecular... May 2020populates coastal waters around the world, where it exists freely or becomes concentrated in filter feeding mollusks. It also causes rapid and life-threatening sepsis... (Review)
Review
populates coastal waters around the world, where it exists freely or becomes concentrated in filter feeding mollusks. It also causes rapid and life-threatening sepsis and wound infections in humans. Of its many virulence factors, it is the capsule, composed of capsular polysaccharide (CPS), that plays a critical role in evasion of the host innate immune system by conferring antiphagocytic ability and resistance to complement-mediated killing. CPS may also provoke a portion of the host inflammatory cytokine response to this bacterium. CPS production is biochemically and genetically diverse among strains of , and the carbohydrate diversity of CPS is likely affected by horizontal gene transfer events that result in new combinations of biosynthetic genes. Phase variation between virulent encapsulated opaque colonial variants and attenuated translucent colonial variants, which have little or no CPS, is a common phenotype among strains of this species. One mechanism for generating acapsular variants likely involves homologous recombination between repeat sequences flanking the phosphatase gene within the Group 1 CPS biosynthetic and transport operon. A considerable number of environmental, genetic, and regulatory factors have now been identified that affect CPS gene expression and CPS production in this pathogen.
Topics: Antigens, Bacterial; Bacterial Capsules; Gene Expression; Gene Expression Regulation, Bacterial; Humans; Operon; Phenotype; Polysaccharides, Bacterial; Structure-Activity Relationship; Vibrio Infections; Vibrio vulnificus; Virulence; Virulence Factors
PubMed: 32380667
DOI: 10.3390/ijms21093259