The Effect of the Environmental Temperature on the Adaptation to Host in the Zoonotic Pathogen Vibrio vulnificus

Wildfire Ashes from the Wildland-Urban Interface Alter Vibrio vulnificus Growth and Gene Expression

Climate change-induced stressors are contributing to the emergence of infectious diseases, including those caused by marine bacterial pathogens such as Vibrio spp. These stressors alter Vibrio temporal and geographical distribution, resulting in increased spread, exposure, and infection rates, thus facilitating greater Vibrio-human interactions. Concurrently, wildfires are increasing in size, severity, frequency, and spread in the built environment due to climate change, resulting in the emission of contaminants of emerging concern. This study aimed to understand the potential effects of urban interface wildfire ashes on Vibrio vulnificus (V. vulnificus) growth and gene expression using transcriptomic approaches. V. vulnificus was exposed to structural and vegetation ashes and analyzed to identify differentially expressed genes using the HTSeq-DESeq2 strategy. Exposure to wildfire ash altered V. vulnificus growth and gene expression, depending on the trace metal composition of the ash. The high Fe content of the vegetation ash enhanced bacterial growth, while the high Cu, As, and Cr content of the structural ash suppressed growth. Additionally, the overall pattern of upregulated genes and pathways suggests increased virulence potential due to the selection of metal- and antibiotic-resistant strains. Therefore, mixed fire ashes transported and deposited into coastal zones may lead to the selection of environmental reservoirs of Vibrio strains with enhanced antibiotic resistance profiles, increasing public health risk.

Sources and contamination routes of seafood with human pathogenic Vibrio spp.: A Farm-to-Fork approach

Vibrio spp., known human foodborne pathogens, thrive in freshwater, estuaries, and marine settings, causing vibriosis upon ingestion. The rising global vibriosis cases due to climate change necessitate a deeper understanding of Vibrio epidemiology and human transmission. This review delves into Vibrio contamination in seafood, scrutinizing its sources and pathways. We comprehensively assess the contamination of human-pathogenic Vibrio in the seafood chain, covering raw materials to processed products. A "Farm-to-Fork" approach, aligned with the One Health concept, is essential for grasping the complex nature of Vibrio contamination. Vibrio's widespread presence in natural and farmed aquatic environments establishes them as potential entry points into the seafood chain. Environmental factors, including climate, human activities, and wildlife, influence contamination sources and routes, underscoring the need to understand the origin and transmission of pathogens in raw seafood. Once within the seafood chain, the formation of protective biofilms on various surfaces in production and processing poses significant food safety risks, necessitating proper cleaning and disinfection to prevent microbial residue. In addition, inadequate seafood handling, from inappropriate processing procedures to cross-contamination via pests or seafood handlers, significantly contributes to Vibrio food contamination, thus warranting attention to reduce risks. Information presented here support the imperative for proactive measures, robust research, and interdisciplinary collaboration in order to effectively mitigate the risks posed by human pathogenic Vibrio contamination, safeguarding public health and global food security. This review serves as a crucial resource for researchers, industrials, and policymakers, equipping them with the knowledge to develop biosecurity measures associated with Vibrio-contaminated seafood.

Validation of the Thermo Scientific™ SureTect™ Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus PCR Assay for the Detection of Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus in Seafood Matrixes: AOAC Performance Tested MethodsSM 022301

BACKGROUND

The Thermo Scientific™ SureTect™ Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus PCR Assay method is a real-time PCR method for the multiplex detection of Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus in seafood.

OBJECTIVE

The Thermo Scientific SureTect Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus Assay was evaluated for AOAC Performance Tested MethodsSM certification.

METHOD

Inclusivity/exclusivity, matrix, product consistency/stability, and robustness studies were conducted to assess the method's performance. For the matrix study, the method was validated using the Applied Biosystems™ QuantStudio™ 5 Real-Time PCR Food Safety Instrument and the Applied Biosystems™ 7500 Fast Real-Time PCR Food Safety Instrument against the U.S. Food and Drug Administration Bacteriological Analytical Manual, Chapter 9 (2004), Vibrio and ISO 21872-1:2017 Microbiology of the food chain-Horizontal method for the determination of Vibrio spp.-Part 1: Detection of potentially enteropathogenic Vibrio parahaemolyticus, Vibrio cholerae, and Vibrio vulnificus reference methods.

RESULTS

Matrix studies showed equivalent or superior performance of the candidate method compared to the reference method and, overall, no difference between presumptive and confirmed results, except for one matrix due to high background flora. The inclusivity/exclusivity study correctly identified/excluded all strains analyzed. Robustness testing showed no statistically significant differences in assay performance under varied test conditions. Product consistency and stability studies demonstrated no statistically significant differences between assay lots with different expiration dates.

CONCLUSIONS

The data presented show that the assay constitutes a rapid and reliable workflow for the detection of V. cholerae, V. parahaemolyticus, and V. vulnificus in seafood matrixes.

HIGHLIGHTS

The SureTect PCR Assay method allows for fast, reliable detection of stipulated strains in seafood matrixes with results obtained in as little as 80 min post-enrichment.

Meteorological associations of Vibrio vulnificus clinical infections in tropical settings: Correlations with air pressure, wind speed, and temperature

V. vulnificus is one of the deadliest waterborne pathogens, yet little is known of the ecological and environmental forces that drive outbreaks. As a nationally notifiable disease, all cases of V. vulnificus diagnosed in the United States are reported to the state in which they occurred, as well as to the Centers for Disease Control (CDC) in Atlanta, Georgia. Given that the state of Florida is a 'hotspot' for V. vulnificus in the United States, we examined the prevalence and incidence of cases reported to the Florida Department of Health (2008-2020). Using a dataset comprised of 448 cases of disease caused by V. vulnificus infection, we identified meteorological variables that were associated with clinical cases and deaths. Combined with data from the National Oceanic and Atmospheric Administration (NOAA), we first utilized correlation analysis to examine the linear relationships between satellite meteorological measurements such as wind speed, air temperature, water temperature, and sea-level pressure. We then measured the correlation of those meteorological variables with coastal cases of V. vulnificus, including the outcome, survival, or death. We also constructed a series of logistic regression models to analyze the relationship between temporal and meteorological variables during months that V. vulnificus cases were reported versus months when V. vulnificus cases were not reported. We report that between 2008 and 2020, V. vulnificus cases generally increased over time, peaking in 2017. As water temperature and air temperature increased, so too did the likelihood that infection with V. vulnificus would lead to patient death. We also found that as mean wind speed and sea-level pressure decreased, the probability that a V. vulnificus case would be reported increased. In summary, we discuss the potential factors that may contribute to the observed correlations and speculate that meteorological variables may increase in their public health relevance in light of rising global temperatures.

Vibrio vulnificus, an Underestimated Zoonotic Pathogen

V. vulnificus, continues being an underestimated yet lethal zoonotic pathogen. In this chapter, we provide a comprehensive review of numerous aspects of the biology, epidemiology, and virulence mechanisms of this poorly understood pathogen. We will emphasize the widespread role of horizontal gene transfer in V. vulnificus specifically virulence plasmids and draw parallels from aquaculture farms to human health. By placing current findings in the context of climate change, we will also contend that fish farms act as evolutionary drivers that accelerate species evolution and the emergence of new virulent groups. Overall, we suggest that on-farm control measures should be adopted both to protect animals from Vibriosis, and also as a public health measure to prevent the emergence of new zoonotic groups.

Vibrio parahaemolyticus and Vibrio vulnificus in vitro colonization on plastics influenced by temperature and strain variability

Marine bacteria often exist in biofilms as communities attached to surfaces, like plastic. Growing concerns exist regarding marine plastics acting as potential vectors of pathogenic Vibrio, especially in a changing climate. It has been generalized that Vibrio vulnificus and Vibrio parahaemolyticus often attach to plastic surfaces. Different strains of these Vibrios exist having different growth and biofilm-forming properties. This study evaluated how temperature and strain variability affect V. parahaemolyticus and V. vulnificus biofilm formation and characteristics on glass (GL), low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS). All strains of both species attached to GL and all plastics at 25, 30, and 35°C. As a species, V. vulnificus produced more biofilm on PS (p ≤ 0.05) compared to GL, and biofilm biomass was enhanced at 25°C compared to 30° (p ≤ 0.01) and 35°C (p ≤ 0.01). However, all individual strains' biofilm biomass and cell densities varied greatly at all temperatures tested. Comparisons of biofilm-forming strains for each species revealed a positive correlation (r = 0.58) between their dry biomass weight and OD₅₇₀ values from crystal violet staining, and total dry biofilm biomass for both species was greater (p ≤ 0.01) on plastics compared to GL. It was also found that extracellular polymeric substance (EPS) chemical characteristics were similar on all plastics of both species, with extracellular proteins mainly contributing to the composition of EPS. All strains were hydrophobic at 25, 30, and 35°C, further illustrating both species' affinity for potential attachment to plastics. Taken together, this study suggests that different strains of V. parahaemolyticus and V. vulnificus can rapidly form biofilms with high cell densities on different plastic types in vitro. However, the biofilm process is highly variable and is species-, strain-specific, and dependent on plastic type, especially under different temperatures.

Depuration of live oysters to reduce Vibrio parahaemolyticus and Vibrio vulnificus: A review of ecology and processing parameters

Consumption of raw oysters, whether wild-caught or aquacultured, may increase health risks for humans. Vibrio vulnificus and Vibrio parahaemolyticus are two potentially pathogenic bacteria that can be concentrated in oysters during filter feeding. As Vibrio abundance increases in coastal waters worldwide, ingesting raw oysters contaminated with V. vulnificus and V. parahaemolyticus can possibly result in human illness and death in susceptible individuals. Depuration is a postharvest processing method that maintains oyster viability while they filter clean salt water that either continuously flows through a holding tank or is recirculated and replenished periodically. This process can reduce endogenous bacteria, including coliforms, thus providing a safer, live oyster product for human consumption; however, depuration of Vibrios has presented challenges. When considering the difficulty of removing endogenous Vibrios in oysters, a more standardized framework of effective depuration parameters is needed. Understanding Vibrio ecology and its relation to certain depuration parameters could help optimize the process for the reduction of Vibrio. In the past, researchers have manipulated key depuration parameters like depuration processing time, water salinity, water temperature, and water flow rate and explored the use of processing additives to enhance disinfection in oysters. In summation, depuration processing from 4 to 6 days, low temperature, high salinity, and flowing water effectively reduced V. vulnificus and V. parahaemolyticus in live oysters. This review aims to emphasize trends among the results of these past works and provide suggestions for future oyster depuration studies.

Vibrio spp. and Their Vibriocin as a Vibriosis Control Measure in Aquaculture

Vibriosis disease is a major threat to the aquaculture industry caused by Vibrio spp. that are often resistant to antibiotics. Alternative controlling measures such as bacteriocins could be effective due to their narrow-spectrum activity. Hence, this systematic literature review (SLR) was carried out to review the feasibility of Vibrio spp. and their vibriocins to be used as a vibriosis control measure in aquaculture. A literature search using the web of science (WOS) and SCOPUS databases resulted in 42 unique articles which were reviewed. The results showed that Vibrio spp. could be used as a probiotic to control vibriosis, but not recommended due to their opportunistic nature and pathogenesis. Vibriocin showed narrow-spectrum activity against Vibrio spp. including highly pathogenic strains such as V. alginolyticus, V. harveyi, and V. parahaemolyticus. This supported this review's hypothesis of using vibriocin as a targeted vibriosis control measure. Vibrio cholerae was the most studied and showed the highest inhibition range, inhibiting 13 different vibrio and non-vibrio species. Various innovations were reported in the field and vibriocins can now be produced on large scales using whole-cell culture. Vibriocins were structurally diverse, large molecular weight, and relatively heat stable. These vibriocins mainly inhibited the cell wall but could have other novel mechanisms. These properties could affect the extraction process as well as applications in aquaculture, hence, should be considered in future research.

A Transcriptomic Study Reveals That Fish Vibriosis Due to the Zoonotic Pathogen Vibrio vulnificus Is an Acute Inflammatory Disease in Which Erythrocytes May Play an Important Role

Vibrio vulnificus is a marine zoonotic pathogen associated with fish farms that is considered a biomarker of climate change. Zoonotic strains trigger a rapid death of their susceptible hosts (fish or humans) by septicemia that has been linked to a cytokine storm in mice. Therefore, we hypothesize that V. vulnificus also causes fish death by triggering a cytokine storm in which red blood cells (RBCs), as nucleated cells in fish, could play an active role. To do it, we used the eel immersion infection model and then analyzed the transcriptome in RBCs, white BCs, and whole blood using an eel-specific microarray platform. Our results demonstrate that V. vulnificus triggers an acute but atypical inflammatory response that occurs in two main phases. The early phase (3 h post-infection [hpi]) is characterized by the upregulation of several genes for proinflammatory cytokines related to the mucosal immune response (il17a/f1 and il20) along with genes for antiviral cytokines (il12β) and antiviral factors (ifna and ifnc). In contrast, the late phase (12 hpi) is based on the upregulation of genes for typical inflammatory cytokines (il1β), endothelial destruction (mmp9 and hyal2), and, interestingly, genes related to an RNA-based immune response (sidt1). Functional assays revealed significant proteolytic and hemolytic activity in serum at 12 hpi that would explain the hemorrhages characteristic of this septicemia in fish. As expected, we found evidence that RBCs are transcriptionally active and contribute to this atypical immune response, especially in the short term. Based on a selected set of marker genes, we propose here an in vivo RT-qPCR assay that allows detection of early sepsis caused by V. vulnificus. Finally, we develop a model of sepsis that could serve as a basis for understanding sepsis caused by V. vulnificus not only in fish but also in humans.

Transcriptomic Analysis Reveals That Municipal Wastewater Effluent Enhances Vibrio vulnificus Growth and Virulence Potential

Vibrio vulnificus is an opportunistic pathogen indigenous to estuarine and marine environments and associated with aquatic organisms. Vibrio vulnificus is of utmost importance because it causes 95% of the seafood-related deaths in the United States due to rapid progression of septicemia. Changes in environmental parameters associated with climate change and coastal population expansion are altering geographical constraints, resulting in increased Vibrio spread, exposure, and rates of infection. In addition, coastal population expansion is resulting in increased input of treated municipal sewage into areas that are also experiencing increased Vibrio proliferation. This study aimed to better understand the influence of treated sewage effluent on effluent-receiving microbial communities using Vibrio as a model of an opportunistic pathogen. Integrated transcriptomic approaches were used to analyze the changes in overall gene expression of V. vulnificus NBRC 15645 exposed to wastewater treatment plant (WWTP) effluent for a period of 6h using a modified seawater yeast extract media that contained 0, 50, and 100% filtered WWTP effluent. RNA-seq reads were mapped, annotated, and analyzed to identify differentially expressed genes using the Pathosystems Resource Integration Center analysis tool. The study revealed that V. vulnificus responds to wastewater effluent exposure by activating cyclic-di-GMP-influenced biofilm development. Also, genes involved in crucial functions, such as nitrogen metabolism and bacterial attachment, were upregulated depending on the presence of treated municipal sewage. This altered gene expression increased V. vulnificus growth and proliferation and enhanced genes and pathways involved in bacterial survival during the early stages of infection in a host. These factors represent a potential public health risk due to exposure to environmental reservoirs of potentially Vibrio strains with enhanced virulence profiles in coastal areas.

Whole genome sequencing reveals great diversity of Vibrio spp in prawns at retail

Consumption of prawns as a protein source has been on the rise worldwide with seafood identified as the predominant attributable source of human vibriosis. However, surveillance of non-cholera Vibrio is limited both in public health and in food. Using a population- and market share-weighted study design, 211 prawn samples were collected and cultured for Vibrio spp. Contamination was detected in 46 % of samples, and multiple diverse Vibrio isolates were obtained from 34 % of positive samples. Whole genome sequencing (WGS) and phylogenetic analysis illustrated a comprehensive view of Vibrio species diversity in prawns available at retail, with no known pathogenicity markers identified in Vibrio parahaemolyticus and V. cholerae. Antimicrobial resistance genes were found in 77 % of isolates, and 12 % carried genes conferring resistance to three or more drug classes. Resistance genes were found predominantly in V. parahaemolyticus, though multiple resistance genes were also identified in V. cholerae and V. vulnificus. This study highlights the large diversity in Vibrio derived from prawns at retail, even within a single sample. Although there was little evidence in this study that prawns are a major source of vibriosis in the UK, surveillance of non-cholera Vibrio is very limited. This study illustrates the value of expanding WGS surveillance efforts of non-cholera Vibrios in the food chain to identify critical control points for food safety through the production system and to determine the full extent of the public health impact.

Behavior of Vibrio spp. in Table Olives

The presence of Vibrio species in table olive fermentations has been confirmed by molecular biology techniques in recent studies. However, there has been no report of any foodborne outbreak caused by Vibrio due to the consumption of table olives, and their role as well as the environmental conditions allowing their survival in table olives has not been elucidated so far. The aims of this work were to model the behavior of an inoculated Vibrio cocktail in diverse table olive environments and study the possible behavior of an inoculated Vibrio cocktail in table olives. First, an in vitro study has been performed where the microbial behavior of a Vibrio cocktail was evaluated in a laboratory medium and in olive brines using predictive models at different NaCl concentrations (2-12%) and pH levels (4.0-9.0). Afterward, a challenge testing was done in lye-treated olives inoculated at the beginning of fermentation with the Vibrio cocktail for 22 days. The Vibrio cocktail inoculated in table olives has not been detected in olive brines during fermentation at different pH levels. However, it was observed that this microorganism in a laboratory medium could reach an optimal growth at pH 9 and 2% salt, without time of constant absorbance (t _A), and the maximum absorbance value (y _end) observed was at pH 8 and 2% salt conditions. The statistical analysis demonstrated that the effect of salt concentration was higher than pH for the kinetic growth parameters (μ_max, t _A, and y _end). On the other hand, it was confirmed that no growth of the Vibrio cocktail on any sample was noticed in lye-treated olive fermentations. Thus, it was concluded that the presence of olive compounds (unknown) did not allow the development of Vibrio strains, so it is a very safety product as it has a natural antimicrobial compound, but the possibility that a native Vibrio sp. is able to acquire the capacity to adapt to this compound should be considered in further studies.

Draft Genome Sequences of Vibrio vulnificus Strains Recovered from Moribund Tilapia

Potentially zoonotic Vibrio vulnificus strains were isolated from vibriosis outbreaks occurring on eastern Mediterranean tilapia farms between 2016 and 2019. In this work, the draft genome sequences of three representative isolates are presented.

Probing the physiological roles of the extracellular loops of chitoporin from Vibrio campbellii

VhChiP, a sugar-specific porin found on the outer membrane of Vibrio campbellii, is responsible for the transport of chitooligosaccharides, allowing the bacterium to thrive in aquatic environments using chitin as a nutrient. We previously showed that VhChiP is composed of three identical subunits, each containing a 16-stranded β-barrel connected by eight extracellular loops and eight short periplasmic turns. This study is focused on the specific roles of three prominent extracellular loops of VhChiP-L2, L3, and L8. The deletion of L2 completely disrupted the L2-L2 interactions, thus destabilizing the protein trimers as well as the integrity of the secondary structure. The deletion of L3 caused a drastic loss in the binding affinity for sugar substrates because of the absence of a cluster of key amino acid residues that form the affinity sites. The removal of L8 induced pronounced gating, which is highly responsive to elevated potentials. Our data provide further information on the important roles of the three prominent loops of VhChiP: loop L2 maintains the trimeric structure and the integrity of secondary structure, loop L3 controls the binding affinity for sugar substrates, and loop L8 retains the stably open state of the channel.

Who rules over immunology? Sseasonal variation in body temperature,, steroid hormones, and immune variables in a tegu lizard

Multiple factors can influence the immune response of ectothermic vertebrates, including body temperature, gonadal steroids, and seasonality, in ways that are thought to reflect trade-offs between energetic investment in immunity vs. reproduction. Hibernating tegu lizards (Salvator merianae) are a unique model to investigate how immunocompetence might be influenced by different factors during their annual cycle. We assessed immunological measures (plasma bacterial killing ability, total and differential leukocyte count), plasma hormone levels (testosterone in males, estradiol and progesterone in females, and corticosterone in both sexes), body temperature, and body condition from adult tegus during each stage of their annual cycle: reproduction, post-reproduction/preparation for hibernation, and hibernation. Our hypothesis that immune traits present higher values during the reproductive phase, and a sharp decrease during hibernation, was partially supported. Immune variables did not change between life history stages, except for total number of leukocytes, which was higher at the beginning of the reproductive season (September) in both males and females. Average body temperature of the week prior to sampling was positively correlated with number of eosinophils, basophils, monocytes and azurophils, corroborating other studies showing that when animals maintain a high Tb, there is an increase in immune activity. Surprisingly, no clear relationship between immune traits and gonadal steroids or corticosterone levels was observed, even when including life history stage in the model. When gonadal hormones peaked in males and females, heterophil:lymphocyte ratio (which often elevates during physiological stress) also increased. Additionally, we did not observe any trade-off between reproduction and immunity traits, sex differences in immune traits or a correlation between body condition and immune response. Our results suggest that variation in patterns of immune response and correlations with body condition and hormone secretion across the year can depend upon the specific hormone and immune trait, and that experienced Tb is an important variable determining immune response in ectotherms.

Effect of Seawater Temperature Increase on the Occurrence of Coastal Vibrio vulnificus Cases: Korean National Surveillance Data from 2003 to 2016

The purpose of this study was to assess the association between seawater temperature and Vibrio vulnificus cases in coastal regions of Korea. All V. vulnificus cases in coastal regions notified to the Korea Disease Control and Prevention Agency between 2003 and 2016 were included in this work. Data for seawater temperature on the south, west, and east coast during the study period were provided by the Korea Oceanographic Data Center of the National Institute of Fisheries Science. We used a generalized additive model and performed a negative binomial regression analysis. In total, 383 notified cases were analyzed (west coast: 196 cases, south coast: 162, and east coast: 25). The maximum seawater temperature was the most significant predictor of V. vulnificus cases on the south and east coasts (relative risk according to the 1 °C increase in seawater temperature (RR) = 1.35 (95% confidence interval (CI): 1.19–1.53) and 1.30 (95% CI: 1.06–1.59), respectively). However, the mean seawater temperature was the most significant predictor for the west coast (RR = 1.34 (95% CI: 1.20–1.51)). These results indicate that continuously monitoring seawater temperature increase in each coastal area is crucial to prevent V. vulnificus infections and protect high-risk groups, such as persons with liver disease.

Comparative transcriptome analysis reveals ectopic delta-5 and delta-6 desaturases enhance protective gene expression upon Vibrio vulnificus challenge in Tilapia (Oreochromis niloticus)

Background

Tilapia (Oreochromis niloticus) cultures are frequently infected by Vibrio vulnificus, causing major economic losses to production units. Previously, tilapia expressing recombinant delta-5 desaturase and delta-6 desaturase (D56) were found to be resistant to V. vulnificus infection. In this report, we profile the D56-mediated molecular changes underlying this resistance in tilapia. A comparative transcriptome analysis was performed on V. vulnificus-infected wild-type and D56-transgenic tilapia using Illumina’s sequencing-by-synthesis approach. Gene enrichment analysis on differentially expressed unigenes was performed, and the expression patterns were validated by real-time PCR.

Results

Comparative transcriptome analysis was performed on RNA-sequence profiles obtained from wild-type and D56-transgenic tilapia at 0, 6 and 24 h post-infection with V. vulnificaus. GO and KEGG gene enrichment analyses showed that D56 regulates several pathways and genes, including fatty acid (FA) metabolism associated, and inflammatory and immune response. Expression of selected FA metabolism-associated, inflammatory and immune responsive genes was validated by qPCR. The inflammatory and immune responsive genes that are modulated by FA-associated D56 likely contribute to the enhanced resistance against V. vulnificus infection in Tilapia.

Conclusions

Transcriptome profiling and filtering for two-fold change variation showed that 3795 genes were upregulated and 1839 genes were downregulated in D56-transgenic tilapia. These genes were grouped into pathways, such as FA metabolism, FA elongation, FA biosynthesis, biosynthesis of unsaturated FA, FA degradation, inflammation, immune response, and chemokines. FA-associated genes and immune-related genes were modulated by D56 at 6 h and 24 h post infection with V. vulnificus. The expression patterns of FA-related genes, inflammatory genes, antimicrobial peptide genes and immune responsive genes at 0, 3, 6, 12, 24 and 48 h post-infection suggests these genes are involved in the enhanced resistance of D56 transgenic tilapia to V. vulnificus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07521-5.

Phylogeny and life cycle of the zoonotic pathogen Vibrio vulnificus

Vibrio vulnificus is a zoonotic pathogen able to cause diseases in humans and fish that occasionally result in sepsis and death. Most reviews about this pathogen (including those related to its ecology) are clearly biased towards its role as a human pathogen, emphasizing its relationship with oysters as its main reservoir, the role of the known virulence factors as well as the clinic and the epidemiology of the human disease. This review tries to give to the reader a wider vision of the biology of this pathogen covering aspects related to its phylogeny and evolution and filling the gaps in our understanding of the general strategies that V. vulnificus uses to survive outside and inside its two main hosts, the human and the eel, and how its response to specific environmental parameters determines its survival, its death, or the triggering of an infectious process.