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Journal of Bacteriology Nov 2020Pathogenic species use many different approaches to subvert, attack, and undermine the host response. The toxins they produce are often responsible for the devastating... (Review)
Review
Pathogenic species use many different approaches to subvert, attack, and undermine the host response. The toxins they produce are often responsible for the devastating effects associated with their diseases. These toxins target a variety of host proteins, which leads to deleterious effects, including dissolution of cell organelle integrity and inhibition of protein secretion. Becoming increasingly prevalent as cofactors for toxins are proteins of the small GTPase families. ADP-ribosylation factor small GTPases (ARFs) in particular are emerging as a common host cofactor necessary for full activation of toxins. While ARFs are not the direct target of cholera toxin (CT), ARF binding is required for its optimal activity as an ADP-ribosyltransferase. The makes caterpillars floppy (MCF)-like and the domain X (DmX) effectors of the multifunctional autoprocessing repeats-in-toxin (MARTX) toxin also both require ARFs to initiate autoprocessing and activation as independent effectors. ARFs are ubiquitously expressed in eukaryotes and are key regulators of many cellular processes, and as such they are ideal cofactors for pathogens that infect many host species. In this review, we cover in detail the known toxins that use ARFs as cross-kingdom activators to both stimulate and optimize their activity. We further discuss how these contrast to toxins and effectors from other bacterial species that coactivate, stimulate, or directly modify host ARFs as their mechanisms of action.
Topics: ADP-Ribosylation Factors; Animals; Bacterial Toxins; Host-Pathogen Interactions; Humans; Multigene Family; Vibrio Infections; Vibrio vulnificus
PubMed: 32900828
DOI: 10.1128/JB.00278-20 -
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 -
Microbiology and Immunology Sep 2020Vibrio vulnificus is a foodborne pathogen causing septicemia with high mortality rate. In this study, we explored how Escherichia coli, one of the commensal bacteria in...
Vibrio vulnificus is a foodborne pathogen causing septicemia with high mortality rate. In this study, we explored how Escherichia coli, one of the commensal bacteria in the human gastrointestinal tract, can interact with V. vulnificus. Our study results show that the amount of biofilm produced by V. vulnificus was reduced in the presence of E. coli ATCC 35218, although the growth of V. vulnificus L-180 remained unaffected. We also detected an antibiofilm effect of E. coli culture supernatant against V. vulnificus, which could not be reduced even after heat treatment. These findings indicate that E. coli and its culture supernatant may be suitable to prevent biofilm formation by V. vulnificus. By contrast, live cells of V. vulnificus could reduce the amount of preformed E. coli biofilm, but its culture supernatant could not. This suggests that the cell-associated factors contribute toward reduction in E. coli biofilm. Therefore, we speculate that ingestion of an infectious dose of V. vulnificus might induce dislodging of the commensal bacteria from the intestinal epithelia and thus can colonize to initiate the infection.
Topics: Biofilms; Culture Media, Conditioned; Escherichia coli; Microbial Interactions; Microbial Viability; Vibrio vulnificus
PubMed: 32603487
DOI: 10.1111/1348-0421.12829 -
Journal of Applied Microbiology Apr 2016In New Zealand, there have been no known cases of foodborne diseases linked to Vibrio vulnificus and shellfish consumption, but two cases of wound infection have been...
AIMS
In New Zealand, there have been no known cases of foodborne diseases linked to Vibrio vulnificus and shellfish consumption, but two cases of wound infection have been reported. We evaluated the distribution, the effect of environmental parameters, the pheno-genotypic profile and the growth characteristics of strains isolated from shellfish.
METHODS AND RESULTS
Vibrio vulnificus was present in 13·6% of Pacific oysters and not found in any dredge oyster or Greenshell(™) mussel samples. Eleven isolates belonged to biotype 1 while nine appeared to be variants of biotype 1. Nineteen isolates were genotype E (type A) and just one was genotype C (type B). Some isolates were more resistant to high salt concentrations (>30‰) than others, but not different from ATCC 27562.
CONCLUSIONS
Vibrio vulnificus were low in numbers, mostly belonging to genotype E, 16S rRNA type A and biotype 1. No relationship or adaptability to high salinity was observed, but seawater temperature was a strong predictor of bacterial numbers in shellfish.
SIGNIFICANCE AND IMPACT OF THE STUDY
We report, for the first time, the characterization of V. vulnificus isolated from New Zealand shellfish and its long-term distribution and prevalence. This information will help the authorities on risk assessments.
Topics: Animals; Bivalvia; Ecology; New Zealand; Ostreidae; RNA, Ribosomal, 16S; Salinity; Seawater; Shellfish; Temperature; Vibrio vulnificus; Wound Infection
PubMed: 26788798
DOI: 10.1111/jam.13064 -
Infection and Immunity Nov 2014Vibrio vulnificus causes rapidly progressing septicemia with an extremely high mortality rate (≥50%), even with aggressive antibiotic treatment. The bacteria secrete...
Vibrio vulnificus causes rapidly progressing septicemia with an extremely high mortality rate (≥50%), even with aggressive antibiotic treatment. The bacteria secrete multifunctional autoprocessing repeats-in-toxin (MARTX) toxins, which are involved in the pathogenesis of Gram-negative Vibrio species. Recently, we reported that immunization with the C-terminal region of V. vulnificus RtxA1/MARTXVv, RtxA1-C, elicits a protective immune response against V. vulnificus through a poorly defined mechanism. In this study, we generated a panel of new monoclonal antibodies (MAbs) against V. vulnificus RtxA1-C and investigated their protective efficacies and mechanisms in a mouse model of infection. Prophylactic administration of seven MAbs strongly protected mice against lethal V. vulnificus infection (more than 90% survival). Moreover, three of these MAbs (21RA, 24RA, and 47RA) demonstrated marked efficacy as postexposure therapy. Notably, 21RA was therapeutically effective against lethal V. vulnificus infection by a variety of routes. Using Fab fragments and a neutropenic mouse model, we showed that 21RA and 24RA mediate protection from V. vulnificus infection through an Fc-independent and/or neutrophil-independent pathway. In contrast, 47RA-mediated protection was dependent on its Fc region and was reduced to 50% in neutropenic mice compared with 21RA-mediated and 24RA-mediated protection. Bacteriological study indicated that 21RA appears to enhance the clearance of V. vulnificus from the blood. Overall, these studies suggest that humoral immunity controls V. vulnificus infection through at least two different mechanisms. Furthermore, our panel of MAbs could provide attractive candidates for the further development of immunoprophylaxis/therapeutics and other therapies against V. vulnificus that target the MARTX toxin.
Topics: Animals; Antibodies, Bacterial; Antibodies, Monoclonal; Bacterial Load; Bacterial Proteins; Bacterial Vaccines; Female; Immunization, Passive; Mice; Vibrio Infections; Vibrio vulnificus
PubMed: 25156730
DOI: 10.1128/IAI.02130-14 -
Proceedings of the National Academy of... Oct 2021Pathogen emergence is a complex phenomenon that, despite its public health relevance, remains poorly understood. , an emergent human pathogen, can cause a deadly...
Pathogen emergence is a complex phenomenon that, despite its public health relevance, remains poorly understood. , an emergent human pathogen, can cause a deadly septicaemia with over 50% mortality rate. To date, the ecological drivers that lead to the emergence of clinical strains and the unique genetic traits that allow these clones to colonize the human host remain mostly unknown. We recently surveyed a large estuary in eastern Florida, where outbreaks of the disease frequently occur, and found endemic populations of the bacterium. We established two sampling sites and observed strong correlations between location and pathogenic potential. One site is significantly enriched with strains that belong to one phylogenomic cluster (C1) in which the majority of clinical strains belong. Interestingly, strains isolated from this site exhibit phenotypic traits associated with clinical outcomes, whereas strains from the second site belong to a cluster that rarely causes disease in humans (C2). Analyses of C1 genomes indicate unique genetic markers in the form of clinical-associated alleles with a potential role in virulence. Finally, metagenomic and physicochemical analyses of the sampling sites indicate that this marked cluster distribution and genetic traits are strongly associated with distinct biotic and abiotic factors (e.g., salinity, nutrients, or biodiversity), revealing how ecosystems generate selective pressures that facilitate the emergence of specific strains with pathogenic potential in a population. This knowledge can be applied to assess the risk of pathogen emergence from environmental sources and integrated toward the development of novel strategies for the prevention of future outbreaks.
Topics: Animals; Biodiversity; Ecosystem; Endemic Diseases; Florida; Genetic Markers; Humans; Ostreidae; Phenotype; Phylogeny; Vibrio Infections; Vibrio vulnificus; Virulence
PubMed: 34593634
DOI: 10.1073/pnas.2103470118 -
Molecular Medicine Reports Nov 2016The halophilic marine bacterium, Vibrio vulnificus, occasionally causes fatal septicemia in immunocompromised patients. Mice are commonly used as experimental animals to...
The halophilic marine bacterium, Vibrio vulnificus, occasionally causes fatal septicemia in immunocompromised patients. Mice are commonly used as experimental animals to investigate the virulence of V. vulnificus, however, a large number of mice are generally required for bioassays. The present study examined whether the invertebrate species, silkworms, can be used instead of mice to investigate V. vulnificus virulence. When the silkworms were inoculated with 1.2x107 colony forming units of V. vulnificus OPU1‑Rf, a virulent strain of V. vulnificus, all injected silkworms died within 48 h, however, those injected with culture filtrate or diluent did not. This silkworm infection model was then used to isolate attenuated V. vulnificus mutants from 1,016 transposon‑inserted mutants. Consequently, a harmless mutant, SW998, was isolated. In this strain, the transposon was inserted into the rtxA gene, which is a known V. vulnificus virulence gene. In conclusion, the present study demonstrated that silkworms are useful animals for investigating the virulence of V. vulnificus.
Topics: Animals; Bombyx; DNA Transposable Elements; Disease Models, Animal; Humans; Mice; Sepsis; Vibrio vulnificus
PubMed: 27748924
DOI: 10.3892/mmr.2016.5782 -
MicrobiologyOpen Jan 2020In gram-negative bacteria, energy-dependent active transport of iron-bound substrates across the outer membrane is achieved through the TonB systems of proteins. Three...
In gram-negative bacteria, energy-dependent active transport of iron-bound substrates across the outer membrane is achieved through the TonB systems of proteins. Three TonB systems have been identified in the human pathogen Vibrio vulnificus. The TonB1 system contains three proteins: TonB1, ExbB1, and ExbD1. Both the TonB2 and TonB3 systems have been shown to also contain a fourth protein, TtpC2 and TtpC3, respectively. Here, we report and begin to characterize two additional proteins in the TonB2 and TonB3 systems: TtpB and TtpD. Both TtpB2 and TtpD2 are absolutely required for the function of the TonB2 system in V. vulnificus. However, although both TtpB3 and TtpD3 in the TonB3 system are related to the proteins in the TonB2 system, neither are active in iron transport. All six protein components of the TonB2 system-TonB2, ExbB2, ExbD2, TtpB2, TtpC2, and TtpD2-are essential for the uptake of both endogenously produced iron-bound siderophores and exogenous siderophores produced from other organisms. Through complementation, we have shown that V. vulnificus is capable of using different TtpD2 proteins from other Vibrio species to bring in multiple siderophores. In contrast, we also demonstrate that TtpB2 must come from V. vulnificus, and not other species within the genus, to complement mutations in the TonB2 system.
Topics: Amino Acid Sequence; Bacterial Proteins; Biological Transport; Iron; Membrane Proteins; Sequence Alignment; Siderophores; Vibrio vulnificus; Virulence
PubMed: 31595707
DOI: 10.1002/mbo3.947 -
International Journal of Food... Aug 2019The present study aimed to investigate the presence of Vibrio vulnificus in fish captured at the Lagoa dos Patos estuary (RS, Brazil), to establish a correlation between...
Ability of Vibrio vulnificus isolated from fish of the Lagoa dos Patos estuary in south Brazil to form biofilms after sublethal stress and bacterial resistance to antibiotics and sanitizers.
The present study aimed to investigate the presence of Vibrio vulnificus in fish captured at the Lagoa dos Patos estuary (RS, Brazil), to establish a correlation between bacterial biofilm formation and sublethal stress, and to assess the resistance of the isolates to antimicrobials and sanitizers. A total of 217 isolates characteristic of Vibrio sp. were analyzed. Isolates were identified and subsequently their ability to form biofilm, the impact of exposure to sublethal stress on their biofilm formation ability, and their resistance to antimicrobial and to sodium hypochlorite and chlorine dioxide sanitizers were evaluated. V. vulnificus was isolated from the fish Paralichthys orbignyanus and Micropogonias furnieri. The bacterial isolates examined were able to form biofilms. Biofilm formation ability of these strains was decreased or inhibited after being exposed to sublethal stress. The isolates were resistant to most antimicrobials. The sanitizer concentrations necessary to eliminate V. vulnificus were higher than those usually used in the fishing industry.
Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Biofilms; Brazil; Estuaries; Fishes; Stress, Physiological; Vibrio vulnificus
PubMed: 31112793
DOI: 10.1016/j.ijfoodmicro.2019.05.007 -
Letters in Applied Microbiology Sep 2010To develop an effective multiplex PCR for simultaneous and rapid detection of Vibrio cholerae, Vibrio vulnificus and Vibrio parahaemolyticus, the three most important...
AIMS
To develop an effective multiplex PCR for simultaneous and rapid detection of Vibrio cholerae, Vibrio vulnificus and Vibrio parahaemolyticus, the three most important Vibrio species that can cause devastating health hazards among human.
METHODS AND RESULTS
Species-specific PCR primers were designed based on toxR gene for V. cholerae and V. parahaemolyticus, and vvhA gene for V. vulnificus. The multiplex PCR was validated with 488 Vibrio strains including 322 V. cholerae, 12 V. vulnificus, and 82 V. parahaemolyticus, 20 other Vibrio species and 17 other bacterial species associated with human diseases. It could detect the three target bacteria without any ambiguity even among closely related species. It showed good efficiency in detection of co-existing target species in the same sample. The detection limit of all the target species was ten cells per PCR tube.
CONCLUSIONS
Specificity and sensitivity of the multiplex PCR is 100% each and sufficient for simultaneous detection of these potentially pathogenic Vibrio species in clinical and environmental samples.
SIGNIFICANCE AND IMPACT OF THE STUDY
This simple, rapid and cost-effective method can be applicable in a prediction system to prevent disease outbreak by these Vibrio species and can be considered as an effective tool for both epidemiologist and ecologist.
Topics: Bacterial Proteins; Bacteriological Techniques; DNA-Binding Proteins; Humans; Polymerase Chain Reaction; Sensitivity and Specificity; Transcription Factors; Vibrio Infections; Vibrio cholerae; Vibrio parahaemolyticus; Vibrio vulnificus
PubMed: 20666989
DOI: 10.1111/j.1472-765X.2010.02895.x