VIBRIO VULNIFICUS: CHARACTERISTICS, MORPHOLOGY, DISEASES, TREATMENTS - BIOLOGY - 2024

Vibrio vulnificus is a bacillus-shaped bacterium that belongs to the Proteobacteria phylum, specifically the Vibrionaceae family. It is a bacterium that has been known for a short time, as it was first described in 1976 by John Reichelt.

However, it was not until three years later that it was assigned to the genus Vibrio and identified as a potential pathogen for humans, like other bacteria of the same genus.

Vibrio vulnificus. By CDC / James Gathany (PHIL # 7815) - Obtained from the CDC Public Health Image Library, Public domain, Pathogenicity in humans is represented by wound infections, sepsis and to a lesser extent, gastrointestinal infections. If these infections are not treated in time, the infection progresses and in a high percentage of patients, it is fatal.

General characteristics

-Species: Vibrio vulnificus.

Morphology

On the other hand, wound infection can occur through two mechanisms. It may be that a person who already had an open wound bathed in the sea, in water contaminated by the bacteria, or that a perfectly healthy person made a cut or wound when bathing in seawater contaminated with the microorganism.

Finally, sepsis is considered an infection that is also known by the name of Systemic Inflammatory Response Syndrome. It consists of a disproportionate reaction of the body to the presence of a pathogen, such as Vibrio vulnificus.

In general, the symptoms that accompany sepsis are not the product of the bacteria as such, but rather the body begins to release a series of chemicals that generate a response.

Transmission

Vibrio vulnificus is a bacterium that, as mentioned, is found in bodies of salty water at warm temperatures. Taking this into account, there are several ways through which it can reach the human being.

The most common form of transmission is through ingestion of marine animals such as mollusks or undercooked fish. These animals may have acquired the bacteria by feeding on contaminated algae or by passing contaminated water through the gills. When a person feeds on an animal contaminated by Vibrio vulnificus, it passes into their digestive tract and can subsequently pass into the blood.

Another way of transmission of this bacterium is the contamination of an open wound. This can occur from bathing on a beach where the bacteria are present. A wound is a gateway to the body that bacteria can very well take advantage of to enter the bloodstream and begin to cause damage.

Symptoms

The symptoms that a person presents when infected with Vibrio vulnificus depend on the organs that are affected.

- Enteritis

When the organs affected by the bacteria are those of the digestive tract (stomach, intestine), the symptoms that may occur are the following:

-Intense abdominal pain

-Frequent watery stools

-Nausea and vomiting

-General discomfort.

- Infection of a wound

When a wound comes into contact with Vibrio vulnificus, the skin cells surrounding the wound are affected by the bacteria and begin to undergo certain changes that result in the following signs and symptoms:

-Increased erythema (redness)

-Increased edema (swelling) in the area around the wound

-Intense pain

-Significant increase in body temperature

- Blisters on the skin surface near the wound.

In cases in which the infection is not treated in time or when there is a poor response to treatment, it is possible that it intensifies and other pathologies such as cellulitis and, in the most serious cases, necrotizing fasciitis may occur.

Cellulite Cases

Among the symptoms of cellulite we can mention:

-Very high fever

-Almost unbearable pain and irritability in the affected area

-Inflammation, edema and redness that are not only limited to the wound area, -but that progress, spreading to healthy tissues

Very painful fluid-filled blisters

-Sensation of heat in the affected area.

Necrotizing fasciitis cases

When Vibrio vulnificus infection progresses further and necrotizing fasciitis develops, the most representative signs and symptoms are as follows:

-High fever

-Significant changes in skin color

-Blisters and ulcers around the wound

-Black spots on the skin

-Secretions in the affected area, mainly pus

-General discomfort

It is important to note that necrotizing fasciitis is a very serious and serious infection that, in general, progresses very quickly through the tissues. Sometimes, doctors find it necessary to amputate a limb (finger, arm, leg), to prevent the progression of the infection. In other cases, the response to treatment is poor, and the patient unfortunately dies.

- Sepsis

In the case of Vibrio vulnificus infections, sepsis is generally localized in the bloodstream. However, the symptoms that manifest are general. These include:

-Variations in body temperature. There may be hyperthermia (fever) or hypothermia.

-Nervous involvement. There may be manifestations such as delirium or confusion.

-Abnormalities in the heartbeat, mainly tachycardia.

-Dizziness

-Skin manifestations such as changes in the color of the skin and its texture.

Diagnosis

The most practical and common way to diagnose bacterial infections is through a culture of the affected tissues to identify the bacteria in question.

If the Vibrio vulnificus infection has manifestations coinciding with enteritis, the culture is done from a stool sample. This procedure is generally done in a culture medium that contains bile salts, sucrose, citrate, and thiosulfate, in addition to agar.

On the other hand, when the presence of Vibrio vulnificus is suspected in a wound or in the blood, a culture is also performed to identify the microorganism.

The culture is the definitive procedure for the diagnosis, since the doctor, only seeing the symptoms cannot give an accurate diagnosis, since these are similar to those that occur in other pathologies.

Treatments

Because Vibrio vulnificus is a bacterium, the most commonly used treatment when an infection is diagnosed with it is the supply of antibiotics. This can be through the oral or intravenous route.

The most commonly used antibiotics are doxycillin and ceftazidine. So-called fluoroquinolones such as levofloxacin and gatifloxacin are also used.

Likewise, when the bacteria affect a wound, other procedures other than drug therapy are also recommended. Among these procedures, the most used is the debridement of the affected tissue. This consists of removing all the necrotic and damaged tissue. It is done with the aim of protecting the underlying tissues that still remain intact.

References

1. Bross, M., Soch, K., Morales, R. and Mitchell, R. (2007). Vibrio vulnificus infection: Diagnosis and treatment. American Family Physician 76 (4).
2. Curtis, H., Barnes, S., Schneck, A. and Massarini, A. (2008). Biology. Medical Editorial
3. Dávalos, M. and Selene G. (2005). Opportunistic pathogen Vibrio vulnificus. University Digital Magazine 6 (4).
4. Drake, S., Depaola, A. and Jaykus, L. (2007). An overview of Vibrio vulnificus and Vibrio parahaemolyticus. Comprehensive Reviews in Food Science and Foot Safety 6 (4).
5. Oliver, J. (2006). Vibrio vulnificus. Chapter in the book: Oceans and Health: Pathogens in the Marine Enviroment.
6. Peng, S., Letchumanan, V., Yan, C. and Syakima, N. (2017). Frontiers in Microbiology 8.