Correlations between Clinical Features and Mortality in Patients with Vibrio vulnificus Infection

Early diagnosis and application of hemopurification combined with antibiotic therapy and surgical debridement for successful treatment of a child with Vibrio vulnificus necrotizing fasciitis and septic shock: a case report

BACKGROUND

Vibrio vulnificus (V. vulnificus) is a halophilic marine Gram-negative bacterium. Necrotizing fasciitis caused by V. vulnificus is a rapidly progressing clinical emergency often accompanied by septic shock. Despite advances in antibiotics and infection control measures, it remains a highly fatal and disabling infection. The incidence of V. vulnificus infection has increased due to climate warming and expanded global seafood trade in recent years. However, pediatric cases of V. vulnificus infection remain rare, leading to limited clinical experience in their management.

METHODS

This report analyzes the clinical data of a pediatric case of V. vulnificus necrotizing fasciitis with septic shock, treated at Zhuhai Center for Maternal and Child Health Care in April 2024. The report also reviews the literature on pediatric V. vulnificus infection.

RESULTS

A 26-month-old boy developed a V. vulnificus infection after being scratched by a sea bass. The patient experienced an acute onset of illness that quickly worsened, presenting with a fever, mental fatigue, soft tissue edema, and pain, necrosis of the fascia and foot, coagulation dysfunction, and even shock. Laboratory results revealed white blood cell count(5.0 × 109/L), neutrophilia %(65%), thrombocytopenia (56 × 109/L), elevated CRP (200 mg/L), PCT (67.4 ng/mL), and IL-6 (> 4000 pg/mL), hypoalbuminemia (17.4 g/L), prolonged PT (17.5 s), reduced total T and NK cell counts, and a significantly reduced proportion of Treg cells. Initial treatment included surgical debridement and drainage, empirical antibiotic therapy, and rapid diagnosis of V. vulnificus via bacterial wound culture. Next-generation sequencing (NGS) of the blood microbial macrogenome and high-throughput sequencing of wound microbial pathogens (MetCap) were performed. Antibiotics were selected based on drug sensitivity testing, accompanied by hemopurification and measures to prevent disseminated intravascular coagulation. The patient's condition stabilized gradually post-treatment, and he was discharged.

CONCLUSION

Prompt diagnosis is important for children with seafood exposure. Early hemopurification, surgical intervention, effective antibiotic therapy, and DIC prevention significantly improve prognosis and survival rates. These findings provide a practical reference for managing pediatric V. vulnificus infections.

Emerging Vibrio vulnificus-Associated Infections After Seawater Exposure-Cases from the Bulgarian Black Sea Coast

Objectives: The aim of the current report is to present three cases of necrotizing fasciitis and sepsis caused by Vibrio vulnificus on the Bulgarian Black Sea coast. Materials and Methods: Two of the patients are males, 70 and 86 years of age, respectively, and one is an 86-year-old female. Data were collected from the patients' examination records. V. vulnificus was isolated on 5% sheep blood agar from wound and blood samples and identified by the automated system Phoenix M50 (BD, Franklin Lakes, NJ, USA). Antimicrobial susceptibility was tested with two well-known methods (disk diffusion and broth microdilution). Results: All of the patients were admitted to our hospital due to pain, swelling, ulceration, and bullae on the legs and were febrile. They underwent surgery and received intensive care support. One of the patients developed septicemia and septic shock; one of his legs was amputated, but the outcome was fatal. The other patient received immediate approptiate antibiotic and surgical treatment, and the outcome was favorable. The third patient underwent emergency fasciotomy but died a few hours after admission. Conclusions: Global climate change is affecting the distribution of Vibrio spp., and their incidence is expected to increase. It is important to highlight the need for awareness among immunocompromised and elderly patients of the potential threat posed by V. vulnificus infections.

Better Performance of Modified Scoring Systems to Predict the Clinical Outcomes of Vibrio Bacteremia in the Emergency Department: An Observational Study

BACKGROUND

Vibrio is a genus of Gram-negative bacteria found in various aquatic environments, including saltwater and freshwater. Vibrio bacteremia can lead to sepsis, a potentially life-threatening condition in which the immune system enters overdrive in response to the disease, causing widespread inflammation and damage to tissues and organs. V. vulnificus had the highest case fatality rate (39%) of all reported foodborne infections in the United States and a high mortality rate in Asia, including Taiwan. Numerous scoring systems have been created to estimate the mortality risk in the emergency department (ED). However, there are no specific scoring systems to predict the mortality risk of Vibrio bacteremia. Therefore, this study modified the existing scoring systems to better predict the mortality risk of Vibrio bacteremia.

METHODS

Cases of Vibrio bacteremia were diagnosed based on the results from at least one blood culture in the ED. Patient data were extracted from the electronic clinical database, covering January 2012 to December 2021. The primary outcome was in-hospital mortality.This study used univariate and multivariate analyses to evaluate the mortality risk.

RESULTS

This study enrolled 36 patients diagnosed with Vibrio bacteremia, including 23 males (63.9%) and 13 females (36.1%), with a mean age of 65.1 ± 15.7 years. The in-hospital mortality rate amounted to 25% (9/36), with 31.5% in V. vulnificus (6/19) and 17.6% in V. non-vulnificus (3/17). The non-survivors demonstrated higher MEDS (10.3 ± 2.4) than the survivors (6.2 ± 4.1) (p = 0.002). Concerning the qSOFA, the survivors scored 0.3 ± 0.5, and the non-survivors displayed a score of 0.6 ± 0.7 (p = 0.387). The AUC of the ROC for the MEDS and qSOFA was 0.833 and 0.599, respectively. This study modified the scoring systems with other predictive factors, including BUN and pH. The AUC of the ROC for the modified MEDS and qSOFA reached up to 0.852 and 0.802, respectively.

CONCLUSION

The MEDS could serve as reliable indicators for forecasting the mortality rate of patients grappling with Vibrio bacteremia. This study modified the MEDS and qSOFA to strengthen the predictive performance of mortality risk for Vibrio bacteremia. We advocate the prompt initiation of targeted therapeutic interventions and judicious antibiotic treatments to curb fatality rates.

Insight into the mechanism of gallstone disease by proteomic and metaproteomic characterization of human bile

Introduction

Cholesterol gallstone disease is a prevalent condition that has a significant economic impact. However, the role of the bile microbiome in its development and the host's responses to it remain poorly understood.

Methods

In this study, we conducted a comprehensive analysis of microbial and human bile proteins in 40 individuals with either gallstone disease or gallbladder polyps. We employed a combined proteomic and metaproteomic approach, as well as meta-taxonomic analysis, functional pathway enrichment, and Western blot analyses.

Results

Our metaproteomic analysis, utilizing the lowest common ancestor algorithm, identified 158 microbial taxa in the bile samples. We discovered microbial taxa that may contribute to gallstone formation, including β-glucuronidase-producing bacteria such as Streptococcus, Staphylococcus, and Clostridium, as well as those involved in biofilm formation like Helicobacter, Cyanobacteria, Pseudomonas, Escherichia coli, and Clostridium. Furthermore, we identified 2,749 human proteins and 87 microbial proteins with a protein false discovery rate (FDR) of 1% and at least 2 distinct peptides. Among these proteins, we found microbial proteins crucial to biofilm formation, such as QDR3, ompA, ndk, pstS, nanA, pfIB, and dnaK. Notably, QDR3 showed a gradual upregulation from chronic to acute cholesterol gallstone disease when compared to polyp samples. Additionally, we discovered other microbial proteins that enhance bacterial virulence and gallstone formation by counteracting host oxidative stress, including sodB, katG, rbr, htrA, and ahpC. We also identified microbial proteins like lepA, rtxA, pckA, tuf, and tpiA that are linked to bacterial virulence and potential gallstone formation, with lepA being upregulated in gallstone bile compared to polyp bile. Furthermore, our analysis of the host proteome in gallstone bile revealed enhanced inflammatory molecular profiles, including innate immune molecules against microbial infections. Gallstone bile exhibited overrepresented pathways related to blood coagulation, folate metabolism, and the IL-17 pathway. However, we observed suppressed metabolic activities, particularly catabolic metabolism and transport activities, in gallstone bile compared to polyp bile. Notably, acute cholelithiasis bile demonstrated significantly impaired metabolic activities compared to chronic cholelithiasis bile.

Conclusion

Our study provides a comprehensive metaproteomic analysis of bile samples related to gallstone disease, offering new insights into the microbiome-host interaction and gallstone formation mechanism.

Pathogenetic detection, retrospective and pathogenicity analysis of a fatal case of Vibrio vulnificus in Shenzhen, China

We report a 36-year-old male patient died of V. vulnificus-induced septicaemia and multiple organ failure syndrome after oyster consumption at a restaurant. We isolated and identified V. vulnificus vv16015 from the patient's blood sample and antibiotic susceptibility tests indicated sensitivity to all 21 antibiotics. Oyster samples were subsequently collected from the restaurant's supplier and three strains of V. vulnificus were isolated. Whole genome sequencing and analysis revealed vv16015 to be distantly related to these strains and confirmed that V. vulnificus contamination was present in the seafood of the restaurant and supplier. Using a Galleria mellonella larvae infection model, the virulence of vv16015 was determined to be higher than that of comparison strains isolated from a surviving patient (vv15018) and an oyster (vv220015). The human and environment distribution of V. vulnificus in Shenzhen is sporadic and heterogeneous, and vv16015 is highly virulent compared to other strains.

A case report of Vibrio vulnificus sepsis in a diabetic patient

Vibrio vulnificus is a facultative anaerobic, alkalophilic, halophilic, mesophilic, Gram-negative bacterium that can cause severe wound infection, sepsis and diarrhea. This paper reported a case of 85-year-old male patient infected with Vibrio vulnificus due to being stabbed by a sea shrimp. This patient also had diabetes with a long history of alcoholism. Due to bacterial pathogenicity and the patient's underlying diseases, his condition deteriorated rapidly. Based on the rapid diagnosis of Vibrio vulnificus using the next-generation sequencing（NGS）technology and blood culture method, as well as the selection of the most effective antibiotics via drug sensitivity test, this patient underwent precise antimicrobial treatment, thorough debridement and drainage within the shortest possible time, and thus the prognosis of this patient was greatly improved. In this paper, we have systematically explored the epidemiology, clinical features, diagnosis and treatment of Vibrio vulnificus infection, thus providing a practical reference for the clinicians to quickly identify and treat possible Vibrio vulnificus infection in diabetic patients after contacting with sea water or seafood.

Prediction model of in-hospital mortality in intensive care unit patients with cardiac arrest: a retrospective analysis of MIMIC -IV database based on machine learning

BACKGROUND

Both in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) have higher incidence and lower survival rates. Predictors of in-hospital mortality for intensive care unit (ICU) admitted cardiac arrest (CA) patients remain unclear.

METHODS

The Medical Information Mart for Intensive Care IV (MIMIC-IV) database was used to perform a retrospective study. Patients meeting the inclusion criteria were identified from the MIMIC-IV database and randomly divided into training set (n = 1206, 70%) and validation set (n = 516, 30%). Candidate predictors consisted of the demographics, comorbidity, vital signs, laboratory test results, scoring systems, and treatment information on the first day of ICU admission. Independent risk factors for in-hospital mortality were screened using the least absolute shrinkage and selection operator (LASSO) regression model and the extreme gradient boosting (XGBoost) in the training set. Multivariate logistic regression analysis was used to build prediction models in training set, and then validated in validation set. Discrimination, calibration and clinical utility of these models were compared using the area under the curve (AUC) of the receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA). After pairwise comparison, the best performing model was chosen to build a nomogram.

RESULTS

Among the 1722 patients, in-hospital mortality was 53.95%. In both sets, the LASSO, XGBoost,the logistic regression(LR) model and the National Early Warning Score 2 (NEWS 2) models showed acceptable discrimination. In pairwise comparison, the prediction effectiveness was higher with the LASSO,XGBoost and LR models than the NEWS 2 model (p < 0.001). The LASSO,XGBoost and LR models also showed good calibration. The LASSO model was chosen as our final model for its higher net benefit and wider threshold range. And the LASSO model was presented as the nomogram.

CONCLUSIONS

The LASSO model enabled good prediction of in-hospital mortality in ICU admission CA patients, which may be widely used in clinical decision-making.

Detection of V. vulnificus septic shock with ARDS using mNGS

The latest surveillance from the Centers for Disease Control and Prevention shows that the annual incidence of V. vulnificus infection is increasing. Unfortunately, in less well-known high-risk groups, this infection is usually excluded from differential diagnosis. Transmitted through wound exposure or ingestion, the mortality rate of foodborne diseases of V. vulnificus is the highest of all V. vulnificus. V. vulnificus is as lethal early diagnosis as Ebola and bubonic plague, so timely treatment is imperative. Sepsis caused by V. vulnificus infection mainly exists in the United States and is rarely reported in Southeast Asia. We report a 78-year-old man who went to the local hospital and complained of swelling in his right hand with severe pain. He ate raw salmon 2 days ago and denied other recognized seafood stab or trauma history and other seafood contact history. He was in septic shock at the time of treatment, so we immediately transferred to the emergency intensive care unit and tested for metagenomic next-generation sequencing (mNGS). The diagnosis was confirmed the second day after admission, and eventually he was cured and discharged from the hospital only after medical treatment, thus avoiding the risk of surgical debridement or even amputation. mNGS is helpful for early clinical diagnosis and effective early intervention for etiology, so that patients can get a good prognosis.

Pathogenic mechanism of Vibrio vulnificus infection

Vibrio vulnificus is a fatal, opportunistic human pathogen transmitted through the consumption of raw/undercooked seafood or direct contact. V. vulnificus infection progresses rapidly and has severe consequences; some cases may require amputation or result in death. Growing evidence suggests that V. vulnificus virulence factors and regulators play a large role in disease progression, involving host resistance, cellular damage, iron acquisition, virulence regulation and host immune responses. Its disease mechanism remains largely undefined. Further evaluation of pathogenic mechanisms is important for selecting appropriate measures to prevent and treat V. vulnificus infection. In this review, the possible pathogenesis of V. vulnificus infection is described to provide a reference for treatment and prevention.

Genetic Divergence of Vibrio vulnificus Clinical Isolates with Mild to Severe Outcomes

The marine bacterium Vibrio vulnificus infects humans via food or water contamination, leading to serious manifestations, including gastroenteritis, wound infections, and septic shock. Previous studies suggest phylogenetic Lineage 1 isolates with the vcgC allele of the vcg gene cause human infections, whereas Lineage 2 isolates with the vcgE allele are less pathogenic. Mouse studies suggest that some variants of the primary toxin could drive more serious infections. A collection of 109 V. vulnificus United States human clinical isolates from 2001 to 2019 with paired clinical outcome data were assembled. The isolates underwent whole-genome sequencing, multilocus-sequence phylogenetic analysis, and toxinotype analysis of the multifunctional autoprocessing repeats-in-toxin (MARTX) toxin. In contrast to prior reports, clinical isolates were equally distributed between lineages. We found no correlation between phylogenetic lineage or MARTX toxinotype and disease severity. Infections caused by isolates in Lineage 1 demonstrated a borderline statistically significant higher mortality. Lineage 1 isolates had a trend toward a higher proportion of M-type MARTX toxins compared with Lineage 2, although this was not statistically significant. IMPORTANCE Vibrio vulnificus is an aquatic pathogen that is capable of causing severe disease in humans. Previous studies have suggested that pathogenic isolates were restricted to certain phylogenetic lineages and possibly toxinotype. Our study demonstrated that phylogenetic lineage and multifunctional autoprocessing repeats-in-toxin (MARTX) toxinotype do not predict severity of infection. V. vulnificus strains capable of causing severe human disease are not concentrated in Lineage 1 but are genetically diverse. Thus, food surveillance based on lineage type or toxinotype may not be an appropriate intervention measure to control this rare but serious infection.

Biomimetic Nanosponges Enable the Detoxification of Vibrio vulnificus Hemolysin

Vibrio vulnificus (V. vulnificus) infection-associated multiple antibiotic resistance has raised serious public health concerns. Recently, nanosponges (NSs) have been expected to provide innovative platforms for addressing antibacterial and drug-resistant challenges by targeting various pore-forming toxins (PFTs). In the present study, we constructed NSs to explore the effects and possible mechanism of recombinant V. vulnificus hemolysin (rVvhA)-induced injuries. In vitro, NSs significantly reversed rVvhA-induced apoptosis and necrosis, and improved toxin-induced intracellular reactive oxygen species (ROS) production, adenosine triphosphate (ATP) depletion, and apoptosis signaling pathway disruption. To explore the clinical translation potential of NSs, we established VvhA-induced septicemia and wound infection mouse models, respectively, and further found NSs could notably attenuate rVvhA-induced acute toxicity and septicemia-associated inflammation, as well as local tissue damage. In a conclusion, NSs showed excellent protective effects against rVvhA-induced toxicity, thus providing useful insights into addressing the rising threats of severe V. vulnificus infections.

Analysis of Gene Expression Profiles, Cytokines, and Bacterial Loads Relevant to Alcoholic Liver Disease Mice Infected With V. vulnificus

Patients with liver disease are susceptible to infection with Vibrio vulnificus (V. vulnificus), but the specific reasons remain elusive. Through RNA-seq, we found that when mice with alcoholic liver disease (ALD) were infected with V. vulnificus by gavage, compared with the Pair group, the small intestinal genes affecting intestinal permeability were upregulated; and the number of differentially expressed genes related to immune functions (e.g., such as cell chemotaxis, leukocyte differentiation, and neutrophil degranulation) decreased in the liver, spleen, and blood. Further analysis showed that the number of white blood cells decreased in the Pair group, whereas those in the ALD mice did not change significantly. Interestingly, the blood bacterial load in the ALD mice was about 100 times higher than that of the Pair group. After the ALD mice were infected with V. vulnificus, the concentrations of T cell proliferation-promoting cytokines (IL-2, IL-23) decreased. Therefore, unlike the Pair group, ALD mice had weaker immune responses, lower T cell proliferation-promoting cytokines, and higher bacterial loads post-infection, possibly increasing their susceptibility to V. vulnificus infection. These new findings we presented here may help to advance the current understanding of the reasons why patients with liver disease are susceptible to V. vulnificus infection and provides potential targets for further investigation in the context of treatment options for V. vulnificus sepsis in liver disease patient.

The Role of TSC1 in the Macrophages Against Vibrio vulnificus Infection

Vibrio vulnificus (V. vulnificus) is an estuarine bacterium that is capable of causing rapidly fatal infection in humans. Proper polarization and bactericidal activity of macrophages play essential roles in defending against invading pathogens. How macrophages limit V. vulnificus infection remains not well understood. Here we report that tuberous sclerosis complex 1 (TSC1) is crucial for the regulation of V. vulnificus-induced macrophage polarization, bacterial clearance, and cell death. Mice with myeloid-specific deletion of TSC1 exhibit a significant reduction of survival time after V. vulnificus infection. V. vulnificus infection induces both M1 and M2 polarization. However, TSC1 deficient macrophages show enhanced M1 response to V. vulnificus infection. Interestedly, the absence of TSC1 in myeloid cells results in impaired bacterial clearance both in vivo and in vitro after V. vulnificus infection. Inhibition of the mammalian target of rapamycin (mTOR) activity significantly reverses V. vulnificus-induced hypersensitive M1 response and resistant bactericidal activity both in wild-type and TSC1-deficient macrophages. Moreover, V. vulnificus infection causes cell death of macrophages, possibly contributes to defective of bacterial clearance, which also exhibits in a mTORC1-dependent manner. These findings highlight an essential role for the TSC1-mTOR signaling in the regulation of innate immunity against V. vulnificus infection.

NLRP3 and mTOR Reciprocally Regulate Macrophage Phagolysosome Formation and Acidification Against Vibrio vulnificus Infection

The marine bacterium Vibrio vulnificus causes potentially fatal bloodstream infections, typically in patients with chronic liver diseases. The inflammatory response and anti-bacterial function of phagocytes are crucial for limiting bacterial infection in the human hosts. How V. vulnificus affects macrophages after phagocytosis is unclear. In this report, we found that the bactericidal activity of macrophages to internalize V. vulnificus was dependent on mammalian target of rapamycin (mTOR) and NOD-like receptor (NLR) family pyrin domain containing 3 (NLRP3) interaction. Additionally, the NLRP3 expression was dependent on mTORC1 activation. Inhibited mTORC1 or absence of NLRP3 in macrophages impaired V. vulnificus-induced phagosome acidification and phagolysosome formation, leading to a reduction of intracellular bacterial clearance. mTORC1 signaling overactivation could increase NLRP3 expression and restore insufficient phagosome acidification. Together, these findings indicate that the intracellular bactericidal activity of macrophages responding to V. vulnificus infection is tightly controlled by the crosstalk of NLRP3 and mTOR and provide critical insight into the host bactericidal activity basis of clearance of V. vulnificus through lyso/phagosome.

Outcomes of Third-Generation Cephalosporin Plus Ciprofloxacin or Doxycycline Therapy in Patients with Vibrio vulnificus Septicemia: A Propensity Score-Matched Analysis

Background

Combination therapy with a third-generation cephalosporin (TGC) and a tetracycline analogue is recommended for Vibrio vulnificus infection. The combination of a TGC and ciprofloxacin has synergistic in vitro bactericidal activity against V. vulnificus. No clinical study has compared the standard regimen with TGC plus ciprofloxacin therapy for V. vulnificus infection.

Methods

Patients with a confirmed V. vulnificus infection at two medical centers in Korea from 1991 to 2016 were enrolled in this study. The patients were grouped according to the type of antibiotic administered. A retrospective propensity-score-matched case-control study of patients treated with TGC plus doxycycline or TGC plus ciprofloxacin was performed. The clinical characteristics and outcomes of the patients were analyzed.

Results

A total of 218 patients were confirmed to have V. vulnificus septicemia during the study, and the 30-day survival rate was 39% (85/218). The patients were classified into the following six treatment groups: TGC monotherapy (n = 82), TGC plus doxycycline therapy (n = 42), TGC plus ciprofloxacin therapy (n = 39), ciprofloxacin monotherapy (n = 14), other β-lactam monotherapy (n = 10), and other (n = 31). The survival rates of these groups were as follows: TGC monotherapy (35%), TGC plus doxycycline (38%), TGC plus ciprofloxacin (54%), ciprofloxacin monotherapy (29%), other β-lactam (20%), and other (39%). The 30-day survival rate showed no significant difference between the TGC plus doxycycline and TGC plus ciprofloxacin groups (log-rank test, P = 0.18). Among the 81 patients treated with TGC plus doxycycline or TGC plus ciprofloxacin, 12 per treatment group were selected by propensity-score matching. There was no significant difference in the baseline characteristics or the frequency of fasciotomy between the two groups. The 30-day survival rate showed no significant difference between the TGC plus doxycycline (50%) and TGC plus ciprofloxacin (67%) groups (log-rank test, P = 0.46).

Conclusion

Our data suggest that the outcome of TGC plus ciprofloxacin therapy was comparable to that of TGC plus doxycycline therapy in patients with V. vulnificus septicemia.

The combination of a third-generation cephalosporin (TGC) and ciprofloxacin has synergy in vitro bactericidal activity against V. vulnificus. No clinical study has compared the standard regimen with TGC plus ciprofloxacin therapy for V. vulnificus infection. A total of 218 patients were enrolled who are confirmed to have V. vulnificus septicemia in two medical centers in Korea from 1991 to 2016. The 30-day survival rate was 39% (85/218) for all patients, 38% (16/42) for TGC plus doxycycline and 54% (21/39) for TGC plus ciprofloxacin (log rank test, P = 0.18). A propensity score-matched analysis was performed and 12 per treatment groups were selected. The 30-day survival rate showed no significant difference between the TGC plus doxycycline (50%, 6/12) and TGC plus ciprofloxacin (67%, 4/12) groups (log-rank test, P = 0.46). The outcome of TGC plus ciprofloxacin therapy was comparable to that of TGC plus doxycycline therapy in patients with V. vulnificus septicemia.

Late-onset Vibrio vulnificus septicemia without cirrhosis

Recent surveillance from the Centers for Disease Control and Prevention indicates rising annual incidence rates of Vibrio vulnificus infection. Unfortunately, this infection is often excluded from the differential diagnosis in lesser known at-risk populations. Transmission occurs via wound exposure or ingestion, with V. vulnificus foodborne illness having the highest mortality rate of all Vibrio species. Fatality rates of V. vulnificus rival those of Ebola and bubonic plague, so timely treatment is imperative. Current literature favors surgical debridement with a third-generation cephalosporin plus intravenous doxycycline or fluoroquinolone. Cephalosporin monotherapy is discouraged due to rising resistance. This case features V. vulnificus septicemia with prolonged incubation time in a noncirrhotic patient.

Vibrio spp. infections

Vibrio is a genus of ubiquitous bacteria found in a wide variety of aquatic and marine habitats; of the >100 described Vibrio spp., ~12 cause infections in humans. Vibrio cholerae can cause cholera, a severe diarrhoeal disease that can be quickly fatal if untreated and is typically transmitted via contaminated water and person-to-person contact. Non-cholera Vibrio spp. (for example, Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus) cause vibriosis - infections normally acquired through exposure to sea water or through consumption of raw or undercooked contaminated seafood. Non-cholera bacteria can lead to several clinical manifestations, most commonly mild, self-limiting gastroenteritis, with the exception of V. vulnificus, an opportunistic pathogen with a high mortality that causes wound infections that can rapidly lead to septicaemia. Treatment for Vibrio spp. infection largely depends on the causative pathogen: for example, rehydration therapy for V. cholerae infection and debridement of infected tissues for V. vulnificus-associated wound infections, with antibiotic therapy for severe cholera and systemic infections. Although cholera is preventable and effective oral cholera vaccines are available, outbreaks can be triggered by natural or man-made events that contaminate drinking water or compromise access to safe water and sanitation. The incidence of vibriosis is rising, perhaps owing in part to the spread of Vibrio spp. favoured by climate change and rising sea water temperature.

Complete genome sequence of the Vibrio vulnificus strain VV2014DJH, a human-pathogenic bacterium isolated from a death case in China

Background

Vibrio vulnificus, an opportunistic pathogen, is the causative agent of life-threatening septicemia and severe wound infections. However, the pathogenicity and virulence factors of V. vulnificus are not fully understood. Here we report the complete genome sequence of V. vulnificus VV2014DJH, which was isolated from a death case.

Results

The genome of the V. vulnificus VV2014DJH contains two circular chromosomes with a mean G+C content of 46.8%, but does not consists of any plasmids. The chromosome I and chromosome II consist of 3,303,590 and 1,770,972 bp, respectively. In addition, the genome consists of 4617 protein coding genes, 172 RNA genes and type I, II and III secretion systems were predicted.

Conclusions

In this study, the genomic information of the V. vulnificus VV2014DJH has been described. The information would contribute to the increasing scope and depth of Vibrio genome database, and provide insights into the pathogenicity and virulence factors of V. vulnificus.

Electronic supplementary material

The online version of this article (10.1186/s13099-017-0216-7) contains supplementary material, which is available to authorized users.

Efficacy of Ceftriaxone, Cefepime, Doxycycline, Ciprofloxacin, and Combination Therapy for Vibrio vulnificus Foodborne Septicemia

Foodborne Vibrio vulnificus infections are associated with higher rates of sepsis and mortality than wound infections; however, antibiotic efficacy studies have not been performed in foodborne infection models. The efficacies of ceftriaxone, cefepime, doxycycline, ciprofloxacin, and combination therapy were assessed in V. vulnificus intestinal infection in mice in order to model foodborne infections. In accordance with prior studies of cefotaxime, cefepime was synergistic with doxycycline and ciprofloxacin in vitro; combination therapy significantly decreased bacterial growth, by ≥2 log₁₀ units, from that with antibiotic monotherapy (P < 0.01). In vivo, survival rates in the ceftriaxone (50%), doxycycline (79%), and ciprofloxacin (80%) groups were significantly higher than those in the control group (0%) (P < 0.0001). Survival was significantly higher with ceftriaxone-doxycycline (91%) or ceftriaxone-ciprofloxacin (100%) therapy than with ceftriaxone (50%) (P ≤ 0.05). Survival with cefepime-doxycycline (96%) or cefepime-ciprofloxacin (90%) therapy was significantly higher than that with cefepime alone (20%) (P < 0.001). There was no difference in survival between the combination therapy groups. Thus, we conclude that combination therapy was the most effective treatment for foodborne V. vulnificus septicemia. In a septic patient with a recent ingestion of raw seafood, cefepime in combination with doxycycline or ciprofloxacin should be initiated for coverage of resistant Gram-negative organisms and V. vulnificus pending a microbiological diagnosis. Once a diagnosis of foodborne V. vulnificus septicemia is established, treatment can safely transition to ceftriaxone in combination with doxycycline or ciprofloxacin.

Clinical features and treatment of patients with Vibrio vulnificus infection

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.