| Vibrio vulnificus | |
|---|---|
| False-color SEM image of Vibrio vulnificus | |
| Scientific classification | |
| Kingdom: | Bacteria |
| Phylum: | Proteobacteria |
| Class: | Gammaproteobacteria |
| Order: | Vibrionales |
| Family: | Vibrionaceae |
| Genus: | Vibrio |
| Species: | V. vulnificus |
| Binomial name | |
| Vibrio vulnificus (Reichelt et al. 1979) Farmer 1980 |
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Vibrio vulnificus is a species of Gram-negative, motile, curved, rod-shaped bacteria of the Vibrio Genus. It was first reported (as the "Lactose-positive vibrio") by Hollis et al. (J. Clin. Microbiol.) in 1976. It was subsequently given the name Beneckea vulnifica by Reichelt et al. in 1976 (Archives Microbiology), and finally Vibrio vulnificus by Farmer in 1979 (Lancet). Present in marine environments such as estuaries, brackish ponds, or coastal areas, V. vulnificus is related to V. cholerae, the causative agent of cholera.[1],[2] Infection with V. vulnificus leads to rapidly expanding cellulitis or septicemia.[3]:279
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Vibrio vulnificus causes an infection often incurred after eating seafood, especially raw or undercooked oysters; the bacteria can also enter the body through open wounds when swimming or wading in infected waters,[2] or via puncture wounds from the spines of fish such as tilapia.
Symptoms include vomiting, diarrhea, abdominal pain, and a blistering dermatitis that is sometimes mistaken for pemphigus or pemphigoid.
In people with compromised immune systems such as in chronic liver disease, a cut infected with Vibrio bacteria can quickly become worse and spread into the bloodstream. Severe symptoms and even death can then occur.[4]
Vibrio vulnificus wound infections have a mortality of ca. 25%. In patients in which the infection worsens into septicaemia, typically following ingestion, the mortality rate rises dramatically to 50%. The majority of these patients die within the first 48 hours of infection. The optimal treatment is not known, but, in one retrospective study of 93 patients in Taiwan, use of a third-generation cephalosporin and a tetracycline (e.g., ceftriaxone and doxycycline, respectively) were associated with an improved outcome.[5] Prospective clinical trials are needed to confirm this finding, but in vitro data supports the supposition that this combination is synergistic against Vibrio vulnificus. Similarly, the American Medical Association and the Centers for Disease Control and Prevention recommend treating the patient with tetracycline and intravenous doxycycline with ceftazidime.[6]
Vibrio vulnificus often causes large, disfiguring ulcers that require extensive debridement or even amputation.
Vibrio vulnificus is commonly found in Pacific Northwesterns.
The worst prognosis is in those patients that arrive at hospital in a state of shock. Total mortality in treated patients (ingestion and wound) is around 33%.[5]
Patients especially vulnerable are those with liver disease (especially chirrhosis and hepatitis) or immunocompromised states (cancer, bone marrow suppression, HIV, diabetes, etc.). With these cases, V. vulnificus usually enters the bloodstream where it may cause fever and chills, septic shock (with sharply decreased blood pressure), and blistering skin lesions.[7] According to the CDC, about half of those who contract blood infections die.
Vibrio vulnificus infections also disproportionately affect males; 85% of those that develop endotoxic shock from the bacteria are male. Females that have had an oophorectomy experienced increased mortality rates, as estrogen has been shown experimentally to have a protective effect against V. vulnificus.[8]
Health officials clearly identified strains of V. vulnificus infections among evacuees from New Orleans due to the flooding there caused by Hurricane Katrina.[9]
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