Vibrio vulnificus infection in Taiwan: report of 28 cases and review of clinical manifestations and treatment

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.

Successful surgical treatment of polybacterial gas gangrene confirmed by metagenomic next-generation sequencing detection: A case report

BACKGROUND

We report on a case of Vibrio vulnificus (V. vulnificus) detected by metagenomics next-generation sequencing (mNGS) in a 53-year-old male patient with polymicrobial gas gangrene and successful treatment by surgery. This report raises awareness among dermatologists that when a patient is clinically suspected of a special type of pathogenic infection, the mNGS method should be preferred to identify the patient’s pathogen infection as soon as possible and then take effective treatment in time to save patients’ lives.

CASE SUMMARY

A 53-year-old male who worked in the aquatic market complained of redness and swelling of the lower limbs, blisters and ulcers with fever for 3 d. We used mNGS to test the pathogens in ulcer secretions. The results were returned in 24 h and indicated: V. vulnificus, Fusobacterium necrophorum, Staphylococcus haemolyticus, Staphylococcus aureus, Streptococcus dysgalactiae and Klebsiella aerogenes. This patient was diagnosed with V. vulnificus infection. The emergency operation was performed immediately under combined lumbar and epidural anesthesia: Left leg expansion and exploration (August 10, 2021). After surgery, we continued to use piperacillin sodium tazobactam sodium 4.5 g every 8 h and levofloxacin 0.5 g for anti-infection treatment. The patient underwent further surgery under lumbar anesthesia on August 17, 2021 and August 31, 2021: Left leg deactivation and skin grafting, negative pressure closed drainage and right thigh skin removal. After treatment, the transplanted flap survived.

CONCLUSION

We could confirm the diagnosis of Vibrio vulnificus infection within 24 h through mNGS detection and then immediately performed emergency surgery.

Rational Use of Antibiotics and Education Improved Aeromonas Necrotizing Fasciitis Outcomes in Taiwan: A 19-Year Experience

BACKGROUND

Aeromonas necrotizing fasciitis (NF) causes high rates of amputation and mortality, even after aggressive surgical debridement and antibacterial therapy. This study investigated the effects of rational use of antibiotics and education by infectious disease (ID) physicians on Aeromonas NF treatment outcomes.

METHODS

Retrospective review for conducted for four years (period I, without an ID physician, December 2001 to December 2005) and 15 years (period II, with an ID physician, January 2006 to March 2021). In period II, the hospital-wide computerized antimicrobial approval system (HCAAS) was also implemented. A pretest-posttest time series analysis compared the two periods. Differences in clinical outcomes, demographics, comorbidities, signs and symptoms, laboratory findings, Aeromonas antibiotic susceptibility, and antibiotic regimens were compared between the two periods.

RESULTS

There were 19 patients in period I and 53 patients in period II. Patients had a lower rate of amputation or mortality in period II (35.8%) compared with period I (63.2%). Forty-four patients (61.1%) had polymicrobial infections. In the emergency room, the rate of misdiagnosis decreased from 47.4% in period I to 28.3% in period II, while effective empiric antibiotic usage increased from 21.1% in period I to 66.0% in period II. After the ID physician's adjustment, 69.4% received monotherapy in period II compared to 33.3% in period I.

CONCLUSIONS

Because Aeromonas NF had a high mortality rate and was often polymicrobial, choosing an antibiotic regimen was difficult. Using the HCAAS by an experienced ID physician can improve rational antibiotic usage and clinical outcomes in Aeromonas NF.

Identification and whole-genome sequencing analysis of Vibrio vulnificus strains causing pearl gentian grouper disease in China

Vibrio vulnificus is a pathogenic bacterium that causes disease in marine fish, affecting fish farming and human health worldwide. In May 2021, in the Bohai Bay region, a disease broke out in commercially farmed pearl gentian grouper (♀Epinephelus fuscoguttatus × ♂Epinephelus lanceolatus), causing huge economic losses. The diseased fish had skin lesions, water accumulation in their abdomens, and showed tissue and organ damage. V. vulnificus biotype 2 has been reported in eels and other marine fish, but it is less reported in pearl gentian grouper. In this study, the pathogenic strain isolated from diseased fish was identified as V. vulnificus EPL 0201 biotype 2 on the basis of physiological and biochemical characteristics and the results of 16S rRNA gene and gyrB sequencing, virulence gene detection, and recursive infection experiments. To gain a comprehensive understanding of the pathogenicity and drug resistance of this strain, whole-genome sequencing was performed. Whole-genome analysis showed that the gene map of this strain was complete. The Virulence Factor Database annotation results showed that this strain had the key virulence factor genes vvhA and rtxA, which cause host disease. In addition, this strain had genes conferring resistance against cephalosporins, aminoglycosides, tetracyclines, and sulfonamides. Antimicrobial susceptibility testing confirmed the presence of these resistance genes identified in the genome. The results of this study show that V. vulnificus EPL 0201 biotype 2 is a multi-drug resistant strain with high pathogenicity.

Vibrio vulnificus necrotizing fasciitis with sepsis presenting with pain in the lower legs in winter: a case report

Background

Vibrio vulnificus infections develop rapidly and are associated with a high mortality rate. The rates of diagnosis and treatment are directly associated with mortality.

Case presentation

We describe an unusual case of a 61-year-old male patient with chronic liver disease and diabetes who presented with a chief complaint of pain in both lower legs due to V. vulnificus infection in winter. Within 12 h of arrival, typical skin lesions appeared, and the patient rapidly developed primary sepsis. Despite prompt appropriate antibiotic and surgical treatment, the patient died 16 days after admission.

Conclusion

Our case findings suggest that V. vulnificus infection should be suspected in patients with an unclear infection status experiencing pain of unknown origin in the lower legs, particularly in patients with liver disease or diabetes, immunocompromised status, and alcoholism.

In-hospital mortality associated with necrotizing soft tissue infection due to Vibrio vulnificus: a matched-pair cohort study

Background

It remains unclear whether Vibrio vulnificus necrotizing soft tissue infection (NSTI) is associated with higher mortality compared with non-Vibrio NSTI. This study’s objective was to compare outcomes including in-hospital mortality and prognosis between patients with V. vulnificus NSTI and those with non-Vibrio NSTI.

Method

A retrospective 1:2 matched-pair cohort study of hospitalized patients with NSTI diagnosed by surgical finding was conducted in two tertiary hospitals in southern Taiwan between January 2015 and January 2020. In-hospital outcomes (mortality, length of stay) were compared between patients with and without V. vulnificus infection. We performed multiple imputation using chained equations followed by multivariable regression analyses fitted with generalized estimating equations to account for clustering within matched pairs. All-cause in-hospital mortality and length of stay during hospitalization were compared for NSTI patients with and without V. vulnificus.

Result

A total of 135 patients were included, 45 in V. vulnificus NSTI group and 90 in non-Vibrio group. The V. vulnificus NSTI patients had higher mortality and longer hospital stays. Multivariable logistic regression analysis revealed that V. vulnificus NSTI was significantly associated with higher in-hospital mortality compared with non-Vibrio NSTI (adjusted odds ratio = 1.52; 95% confidence interval 1.36–1.70; p < 0.01).

Conclusion

Vibrio vulnificus NSTI was associated with higher in-hospital mortality and longer hospital stay which may increase health care costs, suggesting that preventing V. vulnificus infection is essential.

Molecular Mechanism of Iron Transport Systems in Vibrio

The ability to acquire iron from the environment is often an important virulence factor for pathogenic bacteria and Vibrios are no exception to this. Vibrios are reported mainly from marine habitats and most of the species are pathogenic. Among those, the pathogenic vibrios eg. V cholerae, V. parahaemolyticus, V. vulnificus causes foodborne illnesses. Vibrios are capable of producing all different classes of siderophores like hydroxamate (aerobactin), catecholate (vibriobactin, fluvibactin), carboxylate (vibrioferrin), and amphiphilic (amphibactin). Every different species of vibrios are capable of utilizing some endogenous or xenosiderophores. Being Gram-negative bacteria, Vibrios import iron siderophore via TonB dependent transport system and unlike other Gamma proteobacteria these usually possess two or even three partially redundant TonB systems for iron siderophore transport. Other than selected few iron siderophores, most pathogenic Vibrios are known to be able to utilize heme as the sole iron source, while some species are capable of importing free iron from the environment. As per the present knowledge, the spectrum of iron compound transport and utilization in Vibrios is better understood than the siderophore biosynthetic capability of individual species.

Rapid and Sensitive Detection of Vibrio vulnificus Using CRISPR/Cas12a Combined With a Recombinase-Aided Amplification Assay

Vibrio vulnificus is an important zoonotic and aquatic pathogen and can cause vibriosis in humans and aquatic animals (especially farmed fish and shrimp species). Rapid and sensitive detection methods for V. vulnificus are still required to diagnose human vibriosis early and reduce aquaculture losses. Herein, we developed a rapid and sensitive diagnostic method comprising a recombinase-aided amplification (RAA) assay and the CRISPR/Cas12a system (named RAA-CRISPR/Cas12a) to detect V. vulnificus. The RAA-CRISPR/Cas12a method allows rapid and sensitive detection of V. vulnificus in 40 min without a sophisticated instrument, and the limit of detection is two copies of V. vulnificus genomic DNA per reaction. Meanwhile, the method shows satisfactory specificity toward non-target bacteria and high accuracy in the spiked blood, stool, and shrimp samples. Therefore, our proposed rapid and sensitive V. vulnificus detection method, RAA-CRISPR/Cas12a, has great potential for early diagnosis of human vibriosis and on-site V. vulnificus detection in aquaculture and food safety control.

Genomic and Phenotypic Characteristics for Vibrio vulnificus Infections

Background

Vibrio vulnificus (VV) is a causative agent of foodborne diseases with high mortality. The aim of this study was to investigate the genomic and phenotypic profiles of VV.

Methods

Six VV isolates were collected and conducted whole-genome sequencing. Biofilm formation and anti-complement killing test were performed to evaluate the pathogenicity. Subsequently, 157 publicly available genomes of VV isolates were selected to determine the evolutionary relationship.

Results

The resistant genes norM and tet34 were identified in six isolates. A total of 156 virulence genes were identified. However, there is no obvious difference between strains isolated from blood and puncture fluid. The tendency of growth for six isolates decreased with the lapse of time, while the biofilm formation increased. The genes tadC and flp related to Flp pili were found in isolate 25506 and 30896, resulting in more obvious biofilm formation. In addition, the survival rate of 19656 was less than 20% due to lack of one genomic island including virulence genes (impD-H, clpV-1) relevant to type VI secretion system (T6SS). Multi-locus sequence typing (MLST) revealed 95 different STs and 19 novel STs, indicating that the tendency of 163 isolates was sporadic. Further comparative genomics analysis clearly classified 163 isolates into three distinct evolutionary lineages.

Conclusion

VV infections were sporadic in humans and the environment. Virulence genes impD-H and clpV-1 related to T6SS were associated with pathogenicity phenotype of VV.

Different types of bullae of limbs with necrotizing fasciitis predict different outcome: a prospective study

Study objective

Necrotizing fasciitis (NF) is an uncommon life-threatening necrotizing skin and soft tissue infection. Bullae are special skin manifestations of NF. This study was conducted to analyze the differences between different types of bullae of limbs with NF for providing the information to emergency treatment.

Methods

From April 2015 to August 2018, patients were initially enrolled based on surgical confirmation of limbs with NF. According to the presence of different bullae types, patients were divided into no bullae group (Group N), serous-filled bullae group (Group S), and hemorrhagic bullae group (Group H). Data such as demographics, clinical outcomes, microbiological results, presenting symptoms/signs, and laboratory findings were compared among these groups.

Results

In total, 187 patients were collected, with 111 (59.4%) patients in Group N, 35 (18.7%) in Group S, and 41 (21.9%) in Group H. Group H had the highest incidence of amputation, required intensive care unit care, and most patients infected with Vibrio species. In Group N, more patients were infected with Staphylococcus spp. than Group H. In Group S, more patients were infected with β-hemolytic Streptococcus than Group H. Patients with bacteremia, shock, skin necrosis, anemia, and longer prothrombin time constituted higher proportions in Group H and S than in Group N.

Conclusions

In southern Taiwan, patients with NF accompanied by hemorrhagic bullae appear to have more bacteremia, Vibrio infection, septic shock, and risk for amputation. If the physicians at the emergency department can detect for the early signs of NF as soon as possible, and more patient’s life and limbs may be saved.

Phenotypic Discovery of an Antivirulence Agent against Vibrio vulnificus via Modulation of Quorum-Sensing Regulator SmcR

An antivirulence agent against Vibrio vulnificus named quoromycin (QM) was discovered by a phenotype-based elastase inhibitor screening. Using the fluorescence difference in two-dimensional gel electrophoresis (FITGE) approach, SmcR, a quorum-sensing master regulator and homologue of LuxR, was identified as the target protein of QM. We confirmed that the direct binding of QM to SmcR inhibits the quorum-sensing signaling pathway by controlling the DNA-binding affinity of SmcR and thus effectively alleviates the virulence of V. vulnificus in vitro and in vivo. QM can be regarded as a novel antivirulence agent for the treatment of V. vulnificus infection.

Phylogeography of the marine pathogen, Vibrio vulnificus, revealed the ancestral scenarios of its evolution

Vibrio vulnificus is the leading cause of seafood‐associated deaths worldwide. Despite the growing knowledge about the population structure of V. vulnificus, the evolutionary history and the ancestral relationships of strains isolated from various regions around the world have not been determined. Using the largest collection of sequence and isolate data of V. vulnificus to date, we applied ancestral character reconstruction to study the phylogeography of V. vulnificus. Multilocus sequence typing data from 10 housekeeping genes were used for the inference of ancestral states and reconstruction of the evolutionary history. The findings showed that the common ancestor of all V. vulnificus populations originated from East Asia, and later evolved into two main clusters that spread with time and eventually evolved into distinct populations in different parts of the world. While we found no meaningful insights concerning the evolution of V. vulnificus populations in the Middle East; however, we were able to reconstruct the ancestral scenarios of its evolution in East Asia, North America, and Western Europe.

Independent Predictors of Mortality for Aeromonas Necrotizing Fasciitis of Limbs: An 18-year Retrospective Study

Necrotizing fasciitis (NF) of the limbs caused by Aeromonas species is an extremely rare and life-threatening skin and soft tissue infection. The purpose of this study was to evaluate the specific characteristics and the independent predictors of mortality in patients with Aeromonas NF. Sixty-eight patients were retrospectively reviewed over an 18-year period. Differences in mortality, demographics data, comorbidities, symptoms and signs, laboratory findings, microbiological analysis, empiric antibiotics treatment and clinical outcomes were compared between the non-survival and the survival groups. Twenty patients died with the mortality rate of 29.4%. The non-survival group revealed significant differences in bacteremia, monomicrobial infection, cephalosporins resistance, initial ineffective empiric antibiotics usage, chronic kidney disease, chronic hepatic dysfunction, tachypnea, shock, hemorrhagic bullae, skin necrosis, leukopenia, band polymorphonuclear neutrophils >10%, anemia, and thrombocytopenia. The multivariate analysis identified four variables predicting mortality: bloodstream infection, shock, skin necrosis, and initial ineffective empirical antimicrobial usage against Aeromonas. NF caused by Aeromonas spp. revealed high mortality rates, even through aggressive surgical debridement and antibacterial therapies. Identifying those independent predictors, such as bacteremia, shock, progressive skin necrosis, monomicrobial infection, and application of the effective antimicrobial agents against Aeromonas under the supervision of infectious doctors, may improve clinical outcomes.

Predictors for gram-negative monomicrobial necrotizing fasciitis in southern Taiwan

BACKGROUND

Necrotizing fasciitis (NF) is a rare and life-threatening necrotizing skin and soft-tissue infection. Infectious pathogens of NF must be detected early and treated rapidly to prevent loss of limb or a fatal outcome. This study aimed to detect more reliable predictors between gram-negative and gram-positive monomicrobial NF of limbs.

METHODS

A total of 100 patients with limb monomicrobial NF were diagnosed prospectively from April 2015 to July 2018. These monomicrobial NF pathogens can be divided into gram-negative and gram-positive groups according to the result of Gram staining and final bacterial reports. Data such as demographics, seawater or seafood contact history, infectious location, comorbidities, presenting signs and symptoms, and laboratory findings were recorded and compared.

RESULTS

A total of 55 patients were infected with gram-negative organisms and 45 patients with gram-positive organisms. Among the 55 cases of monomicrobial gram-negative NF, 48 (87.3%) were caused mainly by Vibrio spp. (38, 69.1%) and Aeromonas spp. (10, 18.2%). A higher incidence of chronic kidney disease, cerebrovascular accident, tachypnea, and septic shock; a higher rate of band forms of leukocytes of more than 3%, serum lactate of more than 20 mg/dL, and C-reactive protein level of less than 150 mg/dL; prolonged prothrombin time; and a lower fibrinogen level were observed in patients with gram-negative infection. In a multivariate analysis, a higher incidence of seawater or seafood contact history (odds ratio [OR]: 66.301; 95% confidence interval [CI]: 7.467-588.702), a higher rate of hyperlactatemia (OR: 7.904; 95% CI: 1.231-50.744), and a low fibrinogen level (OR: 1.013; 95% CI: 1.004-1.023) indicated gram-negative infection.

CONCLUSIONS

In southern Taiwan, NF of limbs mainly affected the lower limbs, exhibited monomicrobial infection, and was predominated by gram-negative bacteria. Gram-negative monomicrobial NF of limbs often occurred in individuals with the more seawater or seafood contact history, hyperlactatemia, and low fibrinogen levels.

Hepatic disease and the risk of mortality of Vibrio vulnificus necrotizing skin and soft tissue infections: A systematic review and meta-analysis

Background

Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs) are associated with a high mortality rate that varies remarkably with host susceptibility. Hepatic disease (HD) is considered the key risk factor for high VNSSTIs incidence and mortality; however, there is limited evidence in the literature to support this observation.

Methodology

We examined all reported cases of VNSSTIs and associated mortality rates between 1966 and mid-2018. The PubMed, Medline and Cochrane Library databases were systematically searched for observational studies on patients with VNSSTIs. Twelve studies with 1157 total patients with VNSSTIs were included in the analysis. From the pooled dataset, nearly half (46.8%) of the patients with VNSSTIs had HD. The mortality rate in HD patients with VNSSTIs was 53.9% (n = 292/542), which was considerably higher than the mortality rate of 16.1% (n = 99/615) in non-HD patients. Patients with HD contracted VNSSTIs were found to be two or more times (RR = 2.61, 95% CI = 2.14–3.19) as likely to die compared with those without HD. Besides, liver cirrhosis (LC), the end-stage HD, was confirmed to be a significant risk factor, with risk ratios of 1.84 (95% CI 1.21–2.79) and 2.00 (95% CI 1.41–2.85) when compared to non-LC and non-HD, respectively.

Conclusions

HD with or without LC can be associated with infections and complications from V. vulnificus. Clinicians should aggressively approach care and management of acutely and/or critically ill patients with VNSSTIs.

Application of gyrB targeted SYBR green based qPCR assay for the specific and rapid detection of Vibrio vulnificus in seafood

A SYBR green based qPCR assay targeting a unique region of gyrB was developed for the detection of Vibrio vulnificus. The specificity of the assay was studied using V. vulnificus and other bacterial strains belonging to Vibrio and non-Vibrio species. The assay unambiguously distinguished V.vulnificus with a sensitivity of 10¹ CFU/mL in pure culture while 10²CFU/g was detected in clam meat homogenate with an efficiency of ≥98%.The utility of the qPCR assay was validated with naturally incurred seafood samples, where 24 out of 59(40.67%) seafood samples tested positive for V. vulnificus after 6-8 h enrichment in APW-P broth. In contrast, conventional PCR could detect only 11 samples (18.64%). Our results showed that qPCR assay developed in this study could be used as a rapid method for screening seafood samples for the presence of V. vulnificus, as the assay can be completed within 9-12 h including the enrichment of seafood in APW-P broth. The gyrB targeted qPCR developed in this study can provide excellent results on the presence and load of V. vulnificus in naturally contaminated samples quickly and efficiently; thus it could find application as a routine test in the seafood industry for the analysis V. vulnificus.

Fatal case of necrotising fasciitis due to Vibrio vulnificus in a patient with alcoholic liver disease and diabetes mellitus

Vibrio vulnificus is a halophilic Vibrio found globally. They are thought to be normal microbiome in the estuaries along the coasts associated with seawater and seashells. Infection usually results from consumption of raw oysters or shellfish or exposure of broken skin or open wounds to contaminated salt or brackish water. Clinical manifestations range from gastroenteritis to skin and subcutaneous infection and primary sepsis. Pathogen has the ability to cause infections with significant mortality in high-risk populations, including patients with chronic liver disease, immunodeficiency, diabetes mellitus and iron storage disorders. There is often a lack of clinical suspicion in cases due to Vibrio vulnificus leading to delay in treatment and subsequent mortality. Herein we report a case of necrotising fasciitis in a diabetic patient with alcoholic liver disease caused by Vibrio vulnificus which ended fatally.

Vibrio vulnificus infection: a persistent threat to public health

Vibrio vulnificus is a gram-negative bacterium that can cause serious, potentially fatal infections. V. vulnificus causes three distinct syndromes: an overwhelming primary septicemia caused by consuming contaminated seafood, wound infections acquired when an open wound is exposed to contaminated warm seawater, and gastrointestinal tract-limited infections. Case-fatality rates are higher than 50% for primary septicemia, and death typically occurs within 72 hours of hospitalization. Risk factors for V. vulnificus infection include chronic liver disease, alcoholism, and hematological disorders. When V. vulnificus infection is suspected, appropriate antibiotic treatment and surgical interventions should be performed immediately. Third-generation cephalosporin with doxycycline, or quinolone with or without third-generation cephalosporin, may be potential treatment options for patients with V. vulnificus infection.

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.

Uncovering the geographical and host impacts on the classification of Vibrio vulnificus

Vibrio vulnificus causes human sickness throughout the world via the consumption of undercooked seafood or exposure to contaminated water. Previous attempts at phylogenetic analyses of V. vulnificus have proven unsuccessful, mainly due to the poorly understood impact of factors on its divergence. In this study, we used advanced statistical and phylogenetic methods to strengthen the classification of V. vulnificus. This updated classification included the impact of geographical and host factors. The results demonstrate the existence of hierarchies and multidimensional effects in the classification of V. vulnificus, from the molecular level using biotypes, to the distributional level using geographical location, to the adaptational level through host immune response. These findings have implications for the classification of bacteria, bacterial evolution, and public health.

Lrp, a global regulator, regulates the virulence of Vibrio vulnificus

Background

An attenuated mutant (designated NY303) of Vibrio vulnificus, which causes serious wound infection and septicemia in humans, was isolated fortuitously from a clinical strain YJ016. This mutant was defective in cytotoxicity, migration on soft agar and virulence in the mouse. The purpose of this study was to map the mutation in this attenuated mutant and further explore how the gene thus identified is involved in virulence.

Methods

The whole genome sequence of mutant NY303 determined by next-generation sequencing was compared with that of strain YJ016 to map the mutations. By isolating and characterizing the specific gene-knockout mutants, the gene associated with the phenotype of mutant NY303 was identified. This gene encodes a global regulator, Lrp. A mutant, YH01, deficient in Lrp was isolated and examined in vitro, in vivo and ex vivo to find the affected virulence mechanisms. The target genes of Lrp were further identified by comparing the transcriptomes, which were determined by RNA-seq, of strain YJ016 and mutant YH01. The promoters bound by Lrp were identified by genome footprinting-sequencing, and those related with virulence were further examined by electrophoretic mobility shift assay.

Results

A mutation in lrp was shown to be associated with the reduced cytotoxicity, chemotaxis and virulence of mutant NY303. Mutant YH01 exhibited a phenotype resembling that of mutant NY303, and was defective in colonization in the mouse and growth in mouse serum, but not the antiphagocytosis ability. 596 and 95 genes were down- and up-regulated, respectively, in mutant YH01. Many of the genes involved in secretion of the MARTX cytotoxin, chemotaxis and iron-acquisition were down-regulated in mutant YH01. The lrp gene, which was shown to be negatively autoregulated, and 7 down-regulated virulence-associated genes were bound by Lrp in their promoters. A 14-bp consensus sequence, mkCrTTkwAyTsTG, putatively recognized by Lrp was identified in the promoters of these genes.

Conclusions

Lrp is a global regulator involved in regulation of cytotoxicity, chemotaxis and iron-acquisition in V. vulnificus. Down-regulation of many of the genes associated with these properties may be responsible, at least partly, for loss of virulence in mutant NY303.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-017-0361-9) contains supplementary material, which is available to authorized users.

Vibrio vulnificus: An Environmental and Clinical Burden

Vibrio vulnificus is a Gram negative, rod shaped bacterium that belongs to the family Vibrionaceae. It is a deadly, opportunistic human pathogen which is responsible for the majority of seafood-associated deaths worldwide. V. vulnificus infection can be fatal as it may cause severe wound infections potentially requiring amputation or lead to sepsis in susceptible individuals. Treatment is increasingly challenging as V. vulnificus has begun to develop resistance against certain antibiotics due to their indiscriminate use. This article aims to provide insight into the antibiotic resistance of V. vulnificus in different parts of the world as well as an overall review of its clinical manifestations, treatment, and prevention. Understanding the organism's antibiotic resistance profile is vital in order to select appropriate treatment and initiate appropriate prevention measures to treat and control V. vulnificus infections, which should eventually help lower the mortality rate associated with this pathogen worldwide.

Soft tissue infections from fish spike wounds: normal commensal bacteria are more common than marine pathogens

BACKGROUND

A fish spike injury can be sustained by anyone handling fish; during fishing, meal preparation or in retail. Case reports of fish spikes inoculating victims with virulent marine-specific pathogens and causing systemic illness led us to question whether empirical treatment of these injuries with amoxicillin and clavulanic acid is adequate.

METHODS

This 2-year prospective observational study was conducted at Middlemore Hospital, Auckland, New Zealand. Wound swabs and tissue samples belonging to patients presenting to the Department of Plastic and Reconstructive Surgery with an upper limb fish spike injury were sent to the laboratory (n = 60). A series of stains and cultures were performed to look specifically for marine bacteria not typically isolated in other soft tissue injuries. Patient demographic data and injury details were collected.

RESULTS

Of the patients with adequate microbiology samples, 12% (6/50) grew clinically relevant bacteria resistant to amoxicillin and clavulanic acid. These included methicillin-resistant Staphylococcus aureus (8%, 4/50), Enterobacter cloacae (2%, 1/50) and an anaerobic sporing bacillus (2%, 1/50). Only one patient grew a true marine-specific bacteria, Photobacterium damselae, which was susceptible to amoxicillin and clavulanic acid.

CONCLUSION

The authors concluded that amoxicillin and clavulanic acid is an adequate first-line antibiotic for fish spike injuries but that flucloxacillin may be more appropriate given most bacteria were from patients' own skin flora. The authors suggest that clinicians consider the presence of resistant marine-specific bacteria in cases where there is sepsis or inadequate response to initial therapy.

Distribution of Fatal Vibrio Vulnificus Necrotizing Skin and Soft-Tissue Infections: A Systematic Review and Meta-Analysis

Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs), which have increased significantly over the past few decades, are still highly lethal and disabling diseases despite advancing antibiotic and infection control practices. We, therefore, examined the spatiotemporal distribution of worldwide reported episodes and associated mortality rates of VNSSTIs between 1966 and 2014. The PubMed and Cochrane Library databases were systematically searched for observational studies on patients with VNSSTIs. The primary outcome was all-cause mortality. We did random-effects meta-analysis to obtain estimates for primary outcomes; the estimates are presented as means plus a 95% confidence interval (CI). Data from the selected studies were also extracted and pooled for correlation analyses.Nineteen studies of 2227 total patients with VNSSTIs were analyzed. More than 95% of the episodes occurred in the subtropical western Pacific and Atlantic coastal regions of the northern hemisphere. While the number of cases and the number of deaths were not correlated with the study period (rs = 0.476 and 0.310, P = 0.233 and 0.456, respectively), the 5-year mortality rate was significantly negatively correlated with them (rs = -0.905, P = 0.002). Even so, the pooled estimate of total mortality rates from the random-effects meta-analysis was as high as 37.2% (95% CI: 0.265-0.479).These data suggest that VNSSTIs are always an important public health problem and will become more critical and urgent because of global warming. Knowing the current distribution of VNSSTIs will help focus education, policy measures, early clinical diagnosis, and appropriate medical and surgical treatment for them.

pH level as a marker for predicting death among patients with Vibrio vulnificus infection, South Korea, 2000-2011

Initial pH level at hospital admission was the most accurate and simple predictor of death.

Vibrio vulnificus infection can progress to necrotizing fasciitis and death. To improve the likelihood of patient survival, an early prognosis of patient outcome is clinically important for emergency/trauma department doctors. To identify an accurate and simple predictor for death among V. vulnificus–infected persons, we reviewed clinical data for 34 patients at a hospital in South Korea during 2000–2011; of the patients, 16 (47%) died and 18 (53%) survived. For nonsurvivors, median time from hospital admission to death was 15 h (range 4–70). For predicting death, the areas under the receiver operating characteristic curves of the Acute Physiology and Chronic Health Evaluation (APACHE) II score and initial pH were 0.746 and 0.972, respectively (p = 0.005). An optimal cutoff pH of <7.35 had a sensitivity of 100% and specificity of 83%. Compared with the APACHE II score, the initial arterial blood pH level in V. vulnificus-infected patients was a more accurate predictive marker for death.

Vibrio Vulnificus Necrotizing Fasciitis Associated with Acupuncture

Necrotizing fasciitis is a severe life-threatening infection of the deep subcutaneous tissues and fascia. Infection with Vibrio vulnificus, a halophilic Gram-negative bacillus found worldwide in warm coastal waters, can lead to severe complications, particularly among patients with chronic liver diseases. We herein present an unusual case of necrotizing fasciitis caused by V. vulnificus triggered by acupuncture needle insertion. The patient, who suffered from diabetes mellitus and nonalcoholic fatty liver disease and worked at a fish hatchery, denied any injury prior to acupuncture. This is the first ever reported case of V. vulnificus infection triggered by acupuncture needle insertion, clearly emphasizing the potential hazards of the prolonged survival of V. vulnificus on the skin. The potential infectious complications of acupuncture needle insertion are discussed.

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

Vibrio vulnificus is a common gram-negative bacterium, which might cause morbidity and mortality in patients following consumption of seafood or exposure to seawater in Southeast China. We retrospectively analyzed clinical data of patients with laboratory confirmed V. vulnificus infection. Twenty one patients were divided into a survival group and a non-surviving (or death) group according to their clinical outcome. Clinical data and measurements were statistically analyzed. Four patients (19.05%) died and five patients gave positive cultures from bile fluid, and 16 other patients gave positive culture from blood or blisters. Ten patients (47.62%) had an underlying liver disease and marine-related events were found in sixteen patients (76.2%). Patients with heavy drinking habits might be at increased mortality (p = 0.028). Clinical manifestations of cellulitis (47.6%), septic shock (42.9%) and multiple organ failure (28.6%) were statistically significant when comparing survivors and non-survivors (p = 0.035, p = 0.021 and p = 0.003, respectively). The laboratory results, including hemoglobin < 9.0 g/L (p = 0.012), platelets < 2.0×10⁹ /L, prothrombin time activity (PTA) <20%, decreased serum creatinine and increased urea nitrogen were statistically significant (p = 0.012, p = 0.003, p = 0.028 and p = 0.028, respectively). Patients may be at a higher risk of mortality under situations where they have a history of habitual heavy alcoholic drink consumption (p = 0.028, OR = 22.5, 95%CI 1.5–335.3), accompanied with cellulitis, shock, multiple organ failure, and laboratory examinations that are complicated by decreased platelets, hemoglobin and significantly prolonged prothrombin time (PT).

Occurrence of Vibrio parahaemolyticus, Vibrio cholerae, and Vibrio vulnificus in the Aquacultural Environments of Taiwan

The occurrence of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae in a total of 72 samples from six aquaculture ponds for groupers, milk fish, and tilapia in southern Taiwan was examined by the membrane filtration and colony hybridization method. The halophilic V. parahaemolyticus was only recovered in seawater ponds, with a high isolation frequency of 86.1% and a mean density of 2.6 log CFU/g. V. cholerae was found in both the seawater and freshwater ponds but preferentially in freshwater ponds, with a frequency of 72.2% and a mean density of 1.65 log CFU/g. V. vulnificus was identified mainly in seawater ponds, with an isolation frequency of 27.8%. The density of V. parahaemolyticus in seawater ponds was positively related to water temperature (Pearson correlation coefficient, r = 0.555) and negatively related to salinity (r = 2 0.333). The density of V. cholerae in all six ponds was positively related to water temperature (r = 0.342) and negatively related to salinity (r = 2 0.432). Two putatively pathogenic tdh(+) V. parahaemolyticus isolates (1.4% of the samples) and no ctx(+) V. cholerae isolates were identified. The experimental results may facilitate assessments of the risk posed by these pathogenic Vibrio species in Taiwan, where aquaculture provides a large part of the seafood supply.

Comparative genomic analysis of clinical and environmental Vibrio vulnificus isolates revealed biotype 3 evolutionary relationships

In 1996 a common-source outbreak of severe soft tissue and bloodstream infections erupted among Israeli fish farmers and fish consumers due to changes in fish marketing policies. The causative pathogen was a new strain of Vibrio vulnificus, named biotype 3, which displayed a unique biochemical and genotypic profile. Initial observations suggested that the pathogen erupted as a result of genetic recombination between two distinct populations. We applied a whole genome shotgun sequencing approach using several V. vulnificus strains from Israel in order to study the pan genome of V. vulnificus and determine the phylogenetic relationship of biotype 3 with existing populations. The core genome of V. vulnificus based on 16 draft and complete genomes consisted of 3068 genes, representing between 59 and 78% of the whole genome of 16 strains. The accessory genome varied in size from 781 to 2044 kbp. Phylogenetic analysis based on whole, core, and accessory genomes displayed similar clustering patterns with two main clusters, clinical (C) and environmental (E), all biotype 3 strains formed a distinct group within the E cluster. Annotation of accessory genomic regions found in biotype 3 strains and absent from the core genome yielded 1732 genes, of which the vast majority encoded hypothetical proteins, phage-related proteins, and mobile element proteins. A total of 1916 proteins (including 713 hypothetical proteins) were present in all human pathogenic strains (both biotype 3 and non-biotype 3) and absent from the environmental strains. Clustering analysis of the non-hypothetical proteins revealed 148 protein clusters shared by all human pathogenic strains; these included transcriptional regulators, arylsulfatases, methyl-accepting chemotaxis proteins, acetyltransferases, GGDEF family proteins, transposases, type IV secretory system (T4SS) proteins, and integrases. Our study showed that V. vulnificus biotype 3 evolved from environmental populations and formed a genetically distinct group within the E-cluster. The unique epidemiological circumstances facilitated disease outbreak and brought this genotype to the attention of the scientific community.

Comparison of skin and soft tissue infections caused by Vibrio and Aeromonas species

BACKGROUND

The aim of this study was to compare skin and soft tissue infections (SSTIs) caused by Vibrio and Aeromonas spp.

METHODS

Patients whose cultures yielded Vibrio or Aeromonas spp. from July 2004 to June 2010 were retrieved from the computerized database of the bacteriology laboratory at a hospital in southern Taiwan. The medical records were reviewed for all patients fulfilling the criteria of monomicrobial Vibrio or Aeromonas spp. SSTIs and the clinical characteristics were analyzed.

RESULTS

During the study period, there were 28 patients with Vibrio spp. and 26 patients with Aeromonas spp., respectively. Vibrio vulnificus (n=25) and A. hydrophila (n=14) were the most common spp. There were no significant differences in age, gender, underlying diseases between patients with Vibrio and Aeromonas SSTIs. In comparison to Aeromonas SSTIs, more patients with Vibrio SSTIs were complicated with acute respiratory failure (39.3% vs. 3.8%, p=0.002) and required intensive care unit admission (50.0% vs. 7.7%, p<0.001). Furthermore, patients with Aeromonas SSTIs had a higher likelihood of discharge alone within 30 days than Vibrio SSTIs (p=0.049). The difference in in-hospital mortality among the two groups was not statistically significant (p=0.11).

CONCLUSION

Both Aeromonas and Vibrio spp. cause SSTIs in southern Taiwan and the pathogenicity of Vibrio spp. might be higher than Aeromonas spp.

Monomicrobial Aeromonas and Vibrio bacteremia in cirrhotic adults in southern Taiwan: Similarities and differences

BACKGROUND/PURPOSE

Aeromonas and Vibrio are important water-borne pathogens causing substantial morbidity and mortality in cirrhotic patients in Taiwan, but the differences in clinical manifestations of Aeromonas and Vibrio bacteremia have not been reported in detail.

METHODS

From January 2003 to September 2013, cirrhotic patients with monomicrobial Aeromonas or Vibrio bacteremia at a medical center in Taiwan were included in this study.

RESULTS

The study population consisted of 77 cirrhotic patients with Aeromonas bacteremia and 48 patients with Vibrio bacteremia. Both pathogens clustered during the summer season; Vibrio bacteremia was more correlated with higher temperatures (Vibrio: r(2) = 0.95, p < 0.0001; Aeromonas: r(2) = 0.74, p = 0.006) and was associated with ingestion of undercooked seafood (p = 0.03) or cutaneous exposure (p < 0.001). Vibrio bacteremia mainly occurred in mildly or moderately decompensated cirrhosis (Child-Pugh class A and B: 45.8% vs. 20.8%, p = 0.003), and caused more soft-tissue infections (31.3% vs. 5.2%; p < 0.001) and renal dysfunction (1.6 ± 1.2 mg/dL vs. 1.3 ± 0.8 mg/dL, p = 0.006). Sepsis-related mortality was similar in the cases of Vibrio and Aeromonas bacteremia (14.6% vs. 14.3%, p = 0.96), but those with Vibrio bacteremia underwent a fulminant course, as evidenced by a shorter time from bacteremia onset to death (3.1 days vs. 8.2 days, p = 0.04).

CONCLUSION

In cirrhotic patients, bacteremia caused by Aeromonas and Vibrio species clustered in summer months and caused similar mortality, but Vibrio bacteremia led to a more severe and fulminant sepsis.

Vibrio vulnificus outbreaks in Dutch eel farms since 1996: strain diversity and impact

Vibrio vulnificus is a potentially zoonotic bacterial pathogen of fish, which can infect humans (causing necrotic fasciitis). We analysed 24 V. vulnificus isolates (from 23 severe eel disease outbreaks in 8 Dutch eel farms during 1996 to 2009, and 1 clinical strain from an eel farmer) for genetic correlation and zoonotic potential. Strains were typed using biotyping and molecular typing by high-throughput multilocus sequence typing (hiMLST) and REP-PCR (Diversilab®). We identified 19 strains of biotype 1 and 5 of biotype 2 (4 from eels, 1 from the eel farmer), that were subdivided into 8 MLST types (ST) according to the international standard method. This is the first report of V. vulnificus biotype 1 outbreaks in Dutch eel farms. Seven of the 8 STs, of unknown zoonotic potential, were newly identified and were deposited in the MLST database. The REP-PCR and the MLST were highly concordant, indicating that the REP-PCR is a useful alternative for MLST. The strains isolated from the farmer and his eels were ST 112, a known potential zoonotic strain. Antimicrobial resistance to cefoxitin was found in most of the V. vulnificus strains, and an increasing resistance to quinolones, trimethoprim + sulphonamide and tetracycline was found over time in strain ST 140. Virulence testing of isolates from diseased eels is recommended, and medical practitioners should be informed about the potential risk of zoonotic infections by V. vulnificus from eels for the prevention of infection especially among high-risk individuals. Additional use of molecular typing methods such as hiMLST and Diversilab® is recommended for epidemiological purposes during V. vulnificus outbreaks.

Prognostic factor of mortality and its clinical implications in patients with necrotizing fasciitis caused by Vibrio vulnificus

In Taiwan, the aquatic environment and endemic hepatitis contribute to the high susceptibility of Vibrio vulnificus infection. A multidisciplinary treatment protocol for necrotizing fasciitis caused by V. vulnificus was developed in our institute, namely, ceftriaxone or ceftazidime combined with doxycycline or minocycline followed by an emergency fasciotomy and intensive care unit admission. We retrospectively reviewed 100 cases to evaluate the effectiveness of our treatment protocol and identify independent predictors of mortality to improve clinical outcomes. Cases of culture-confirmed V. vulnificus infection between January 1996 and December 2011 were reviewed. Necrotizing fasciitis was surgically diagnosed if these criteria were met: necrotic fascia, "dishwater discharge", and loss of resistance while doing finger dissection along the fascia plane. One hundred cases met these criteria and were included for analysis. Eighteen patients died (18 % mortality). Unknown injury events, presence of multiple skin lesions, leukocytes < 10,000 cells/mm(3), platelets < 100,000/mm(3), serum creatinine ≥1.3 mg/dL, serum albumin < 2.5 mg/dL, and delayed treatment beyond 3 days post-injury or symptom onset were associated with significantly higher mortality. Multivariate analysis showed that treatment delayed beyond 3 days is an independent factor indicating a poor prognosis (OR 10.75, 95 % CI 1.02-113.39, p = 0.048). Early diagnosis and prompt treatment within 3 days post-injury or symptom onset should be the goal for treating patients with necrotizing fasciitis caused by V. vulnificus. Additional investigations to rescue patients with a prolonged disease course of necrotizing fasciitis (≥3 days) may be important.

Vibrio parahaemolyticus Induced Necrotizing Fasciitis: An Atypical Organism Causing an Unusual Presentation

Background necrotizing fasciitis (NF) represents a life-threatening bacterial infection characterized by a rapid necrosis of deep subcutaneous tissue and facia underlying the skin. Despite its lethal nature, NF occurs infrequently, leaving many physicians unfamiliar with the disease process, common pathogens, and treatment strategies. Here we present a case of NF caused by an unlikely organism, Vibrio parahaemolyticus. We highlight the innocuous nature of initial presentation and the potentially devastating sequela.

Necrotizing fasciitis: eight-year experience and literature review

Objectives

To describe clinical, laboratory, microbiological features, and outcomes of necrotizing fasciitis.

Methods

From January 1, 2004 to December 31, 2011, 115 patients (79 males, 36 females) diagnosed with necrotizing fasciitis were admitted to Mackay Memorial Hospital in Taitung. Demographic data, clinical features, location of infection, type of comorbidities, microbiology and laboratory results, and outcomes of patients were retrospectively analyzed.

Results

Among 115 cases, 91 survived (79.1%) and 24 died (20.9%). There were 67 males (73.6%) and 24 females (26.4%) with a median age of 54 years (inter-quartile ranges, 44.0–68.0 years) in the survival group; and 12 males (50%) and 12 females (50%) with a median age of 61 years (inter-quartile ranges, 55.5–71.5 years) in the non-surviving group. The most common symptoms were local swelling/erythema, fever, pain/tenderness in 92 (80%), 87 (76%) and 84 (73%) patients, respectively. The most common comorbidies were liver cirrhosis in 54 patients (47%) and diabetes mellitus in 45 patients (39%). A single organism was identified in 70 patients (61%), multiple pathogens were isolated in 20 patients (17%), and no microorganism was identified in 30 patients (26%). The significant risk factors were gender, hospital length of stay, and albumin level.

Discussion

Necrotizing fasciitis, although not common, can cause notable rates of morbidity and mortality. It is important to have a high index of suspicion and increase awareness in view of the paucity of specific cutaneous findings early in the course of the disease. Prompt diagnosis and early operative debridement with adequate antibiotics are vital.

The Laboratory Risk Indicator for Necrotizing Fasciitis score for discernment of necrotizing fasciitis originated from Vibrio vulnificus infections

BACKGROUND

The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score has been verified as a useful diagnostic tool for detecting necrotizing fasciitis (NF). Its application, however, is mainly for NF types I and II. The practical relevance of the LRINEC score for Vibro vulnificus-related skin and soft tissue infection (SSTI) was hardly ever investigated. The aim of this study was to assess the applicability of the LRINEC scoring system and to identify NF-predicting factors in patients with V. vulnificus-caused SSTI.

METHODS

A retrospective study was conducted, enrolling 125 consecutive patients diagnosed with V. vulnificus-related SSTI who were admitted to a teaching hospital between January 2003 and December 2011. Demographics, laboratory data, comorbidities, treatment, and outcomes were collected for each patient and extracted for analysis. Logistic regression and receiver operating characteristic curve analyses were performed.

RESULTS

The mean (SD) age of the 125 patients was 63.0 (10.9) years; 58% of the patients were male. The mean (SD) LRINEC score at admission was 2.4 (1.9) points. Of the 125 patents, 72 (58%) had NF. Multivariate analysis revealed that the presence of hemorrhagic bullous lesions (p = 0.002) and higher LRINEC scores at admission (p < 0.0001) were significantly associated with the presence of NF. In addition, the area under the receiver operating characteristic curve for the LRINEC scoring model for detecting NF was 0.783 (p < 0.0001). An optimal cutoff LRINEC score of 2 or greater had a sensitivity of 71%, a specificity of 83%, and a positive predictive value of 85%, with an 11.9-fold increased risk for the presence of NF (p < 0.0001).

CONCLUSION

We have demonstrated that the LRINEC score and hemorrhagic bullous/blistering lesions are significant predictors of NF in patients with V. vulnificus-related SSTI. V. vulnificus-infected patients having hemorrhagic bullous/blistering lesions or with an LRINEC score of 2 or greater should be thoughtfully evaluated for the presence of NF.

LEVEL OF EVIDENCE

Diagnostic test study, level II.

Acute Otitis due to Vibrio fluvialis after Swimming

A 40-year-old female presented with purulent exudate through the left auditive duct and pain in the left ear region, which intensified during mastication. After collection of the pus from the left ear lesion, amoxicillin-clavulanic acid for seven days was prescribed for a presumed diagnosis of acute otitis. Four days later, the pus culture grew V. fluvialis which is further identified by API 20E identification system (bioMérieux). Following the successful completion of a course of antibiotics, the patient recovered completely and without complication. To the best of our knowledge, this is the first case of Vibrio fluvialis otitis after swimming in an immunocompetent patient.

Expression of Vibrio vulnificus insulin-degrading enzyme is regulated by the cAMP-CRP complex

Components of the bacterial phosphoenolpyruvate (PEP) : carbohydrate phosphortransferase system (PTS) have multiple regulatory roles in addition to PEP-dependent transport/phosphorylation of numerous carbohydrates. We have recently shown that, in an opportunistic human pathogen, Vibrio vulnificus, enzyme IIA(Glc) (EIIA(Glc)) interacts with a peptidase that has high sequence similarity to mammalian insulin-degrading enzymes, called Vibrio insulin-degrading enzyme (vIDE). Although the vIDE-EIIA(Glc) interaction is independent of the phosphorylation state of EIIA(Glc), vIDE shows no peptidase activity unless complexed with the unphosphorylated form of EIIA(Glc). A deletion mutant of ideV, the gene encoding vIDE, shows remarkably lower degrees of survival and virulence than the wild-type strain in mice, implying that vIDE is a virulence factor. In this study, we investigated regulation of ideV expression at the transcriptional level. Primer extension analysis identified two different transcriptional start sites of ideV: P(L) for the longer transcript and P(S) for the shorter transcript. We performed ligand fishing experiments by using the promoter region of ideV and found that the cAMP receptor protein (CRP) specifically binds to the promoter. DNase I footprinting experiments revealed that CRP binds to a region between the two promoters. In vitro transcription assays showed that CRP activates ideV P(S) transcription in the presence of cAMP whose concentration is regulated by EIIA(Glc). These results suggest that EIIA(Glc) regulates the expression level of vIDE as well as its activity.

Injection of Acanthaster planci with thiosulfate-citrate-bile-sucrose agar (TCBS). II. Histopathological changes

We assessed histological changes in the tissues of the crown-of-thorns starfish Acanthaster planci (COTS) after injection of thiosulfate-citrate-bile-sucrose agar (TCBS) which was used as a disease inducer (potential outbreak control method), by conventional and scanning electron microscopy. Digestive glands were processed and stained with hematoxylin and eosin to describe the histological architecture of the intestinal epithelium. Subsequently comparison of healthy versus infected tissues and Gram stains were carried out to confirm bacterial occurrence on infected tissues, characterize the structural changes induced by bacterial communities in COTS tissues, and to determine if the histopathological changes of intestinal tissues were consistent with vibrio infection. TCBS injections induced marked epithelial desquamation, hypertrophy and hypersecretion of glandular cells, epithelial cell destruction, pyknosis, reduction of thickness and disorganization of connective tissue and associated nerve plexus, presence of bacterial colonies, irregular eosinophilic foci in glandular cells, brush border disruption, atrophy and detachment of intestinal microvilli and cell debris in the lumen. All these changes were attributed to a fulminating systemic dysbiosis and were consistent with vibrio infections.

Soft tissue infections caused by marine bacterial pathogens: epidemiology, diagnosis, and management

Skin and soft tissue infections (SSTIs) are one of the most common infection syndromes and may be caused by a large number of microorganisms. Some principles of aquatic injuries are different than those of land-based trauma. Wounds sustained in marine environment are exposed to a milieu of bacteria rarely encountered in different settings. These include Vibrio spp., Aeromonas spp., Shewanella spp., Erysipelothrix rhusiopathiae, Mycobacterium marinum, Streptococcus iniae, and other microbes. Failure to recognize and treat these uncommon pathogens in a timely manner may result in significant morbidity or death. These infections are frequently contracted as a result of recreational swimming, fishing injuries, or seafood handling. The spectrum of manifestations is wide, varying from cases of mild cellulitis, to severe life-threatening necrotizing fasciitis requiring radical surgery, to sepsis and death. This review will focus on the epidemiology, clinical manifestations, and treatment of SSTIs caused by the most important marine pathogens.

Vibrio vulnificus Diarrhea in a Child with Respiratory Infection

Vibrio vulnificus is a rare cause of disease and it is often unrecognized and underreported. It is a lactose-fermenting, halophilic vibrio causing severe disease in immunocompromised patients, but causing a mild type of gastroenteritis in healthy people, usually associated with consumption of seafood. We report here a case of diarrhea due to V. vulnificus in a male child who was admitted for fever, loose motions and productive cough. There was no history of consumption of any seafood; so, the source of infection could not be traced. As V. vulnificus is a rare entity, clinicians should have a high index of suspicion for the bacteria, when patients present with gastrointestinal illness, fever or shock, with or without ingestion of raw seafood. Pediatricians should also be alert as the bacterium causes a potentially fatal disease in children.