The bacterial species Vibrio vulnifiucs from the family Vibrionaceae belongs to the order Proteobacteria and falls under it in the class Gammaproteobacteria and the genus Vibrio. The bacterial species mainly colonizes water bodies and is considered to be human pathogenic. The bacteria cause subcutaneous inflammation, which can be fatal if the pathogen enters the bloodstream.
What is Vibrio vulnifiucs?
Vibrions are bacteria with Gram-negative staining behavior that engage in facultative anaerobic metabolism and are known by their shape as curved rod bacteria. Many species of the genus are unipolar flagellated and thus have active motility. One species among the vibrios is Vibrio vulnificus. The species is classified as human pathogenic and is closely related to the species Vibrio cholerae, which is also known as the causative agent of cholera. Infection with the bacterial species Vibrio vulnificus does not result in cholera, but it can cause sepsis (blood poisoning). This type of bacterial infection became particularly relevant after the flooding caused by Hurricane Katrina. In New Orleans at that time, numerous people with Vibrio vulnificus infections were evacuated.
Occurrence, distribution, and characteristics
The preferred habitat of Vibrio vulnificus bacteria is water. Thus, the bacteria occur primarily in marine environments and, in addition to river estuaries, colonize brackish ponds or coastal areas, for example. According to a study, the Baltic Sea coast is one of the areas with the highest Vibrio vulnificus colonization in Germany. The low salinity and the strong warming of water in this area seem to be responsible for this. The bacteria often pass in the water to seafood or other aquatic life. Since zoonosis exists, they can also pass to humans. This can be the case, for example, when contaminated seafood is consumed. Oyster consumption is particularly dangerous in this context, as these are usually eaten raw. Open wounds can also provide an entry point for the bacterium. Wounds from swimming and wading, for example, allow the bacteria to enter the human organism if the body of water is contaminated. In addition, another infection possibility is a puncture wound from spiny fish such as tilapia. Since the bacteria species are facultative anaerobic bacteria, they survive in the absence of oxygen. Their growth progresses most rapidly in an oxygen-free environment because they do not require oxygen for their metabolism. The presence of oxygen does not necessarily kill facultative anaerobes, but mostly makes it more difficult for them to grow. The bacterial species Vibrio vulnificus is always pathogenic. In the human body, detection is therefore always associated with disease value, since the bacteria are not naturally commensal. This distinguishes them from many other bacteria found in the human body. Commensals neither benefit nor harm humans. Pathogenic bacteria such as those of the species Vibrio vulnificus, on the other hand, harm humans, in favor of their own growth. Therefore, the infection always requires treatment. Infection is particularly dangerous for immunodeficient patients such as HIV patients, immunosuppressed patients (with artificially lowered immune system) or elderly people with age-related weakness of the immune system. In these cases, infection with Vibrio vulnificus can develop into an acutely life-threatening condition.
Diseases and symptoms
Following infection with Vibrio vulnificus, symptoms of the gastrointestinal tract initially present themselves. In addition to vomiting, these symptoms include diarrhea. Associated with the gastrointestinal symptoms of patients are often more or less severe abdominal pain. Characteristic for the pathogen Vibrio vulnificus are especially the skin symptoms. A blistering dermatitis sets in, which is often misdiagnosed and thus confused with pemphigus vulgaris. A more or less extensive cellulitis is also a common symptom. This is an inflammation of the subcutaneous tissue, which is also noticeable on the surface of the skin in the form described. Tumors may develop. For people with a weakened immune system, especially an infected cut or other wound is a great danger. The bacteria enter the bloodstream via the wounds.In healthy people, the resulting bacteremia is immediately fought by the immune system. In the absence of immunological attacks, bacterial sepsis or septic shock rapidly develops. This systemic inflammatory response can cause circulatory failure or even death. Infections with Vibrio vulnificus are associated with relatively high mortality, so especially those that have already caused sepsis. Death often occurs in the first 48 hours after infection. The ideal treatment remains controversial. Third-generation cephalosporin seems most likely to be effective, for example, in the form of ceftriaxone or doxycycline. The bacterial growths of the skin may require surgical intervention or amputation. Infections with Vibrio vulnificus occur with higher than average frequency in men. Males also appear to be at increased risk of shock and thus overall risk of mortality in the setting of the infection. Medical science now believes that female estrogen is protective against Vibrio vulnificus. Thus, women are generally less at risk from the infection as long as they do not suffer from hormonal estrogen deficiency.
