TolCV1 Has Multifaceted Roles During Vibrio vulnificus Infection

RtxA1 is a major cytotoxin of Vibrio vulnificus (V. vulnificus) causing fatal septicemia and necrotic wound infections. Our previous work has shown that RpoS regulates the expression and secretion of V. vulnificus RtxA1 toxin. This study was conducted to further investigate the potential mechanisms of RpoS on RtxA1 secretion. First, V. vulnificus TolCV1 and TolCV2 proteins, two Escherichia coli TolC homologs, were measured at various time points by Western blotting. The expression of TolCV1 was increased time-dependently, whereas that of TolCV2 was decreased. Expression of both TolCV1 and TolCV2 was significantly downregulated in an rpoS deletion mutation. Subsequently, we explored the roles of TolCV1 and TolCV2 in V. vulnificus pathogenesis. Western blot analysis showed that RtxA1 toxin was exported by TolCV1, not TolCV2, which was consistent with the cytotoxicity results. Furthermore, the expression of TolCV1 and TolCV2 was increased after treatment of the host signal bile salt and the growth of tolCV1 mutant was totally abolished in the presence of bile salt. A tolCV1 mutation resulted in significant reduction of V. vulnificus induced-virulence in mice. Taken together, TolCV1 plays key roles in RtxA1 secretion, bile salt resistance, and mice lethality of V. vulnificus, suggesting that TolCV1 could be an attractive target for the design of new medicines to treat V. vulnificus infections.

Successful Treatment of Necrotizing Fasciitis of the Upper Extremity Caused by Vibrio vulnificus: Two Case Reports and Literature Review

Background: Vibrio vulnificus infection patients are more common in China's coastal areas and military activities, but there have been very rare reports successful treatment and limb salvage patients. Case presentation: We present two cases of patients with the successful treatment of necrotizing fasciitis caused by V. vulnificus and review the pathogenetic mechanism, epidemiology, clinical characteristics, and treatment of this infection.Conclusion: When Vibrio vulnificus patients develop bacteraemia and necrotizing fasciitis symptoms,emergency surgical debridement combined with anti-infection therapy should be considered.

Protective Effects of Chicken Egg Yolk Immunoglobulins (IgYs) against Vibrio vulnificus Infections

Vibrio (V.) vulnificus infection is a rare disease whose death rates exceed 50% despite aggressive antibiotic treatment and surgical debridement. The aim of this study was to assess the ability of specific anti-V. vulnificus immunoglobulins Y (IgYs) for preventing and treating V. vulnificus infections. IgYs were produced by immunizing egg laying hens with inactivated whole cell bacteria. Peritoneal cytokines, blood’s bacterial load, and survival curves were obtained from both prophylactic and therapeutic mouse models. The results showed that the specific IgYs (i) inhibited the growth of V. vulnificus in vitro, (ii) dramatically reduced the inflammatory response and blood’s bacterial load, and (iii) improved the survival rate of V. vulnificus-infected mice. These results prove that anti-V. vulnificus IgYs can be markedly effective means for the prophylaxis and the therapy of V. vulnificus infections.

An Uncommon Case of Necrotizing Fasciitis and Septic Shock Caused by Vibrio vulnificus Infection–Related Freshwater Shrimp Stung

Vibrio vulnificus is a deadly marine pathogen that can cause necrotizing fasciitis, septic shock, and even death in severe cases. The relatively low incidence and atypical early-stage symptoms may hinder many physicians from carrying out surgical intervention effectively, thus leading to an increase of mortality in infected patients. This article reported a patient who developed necrotizing fasciitis and septic shock after the exposure to freshwater shrimp stabbed on the limb. By reviewing and analyzing previous studies, it was found out that the timing of surgery could have a significant impact on the patients for their necrotizing fasciitis caused by Vibrio vulnificus infection. The mortality among patients undergoing early-stage surgical treatment (≤12 hours from the time of admission) was significantly lower than that of patients undergoing late surgical treatment (>12 hours).