|False-color SEM image of Vibrio vulnificus|
Vibrio vulnificus is a species of Gram-negative, motile, curved rod-shaped (bacillus), pathogenic bacteria of the genus Vibrio . Present in marine environments such as estuaries, brackish ponds, or coastal areas, V. vulnificus is related to V. cholerae , the causative agent of cholera.
Vibrio is a genus of Gram-negative bacteria, possessing a curved-rod shape, several species of which can cause foodborne infection, usually associated with eating undercooked seafood. Typically found in salt water, Vibrio species are facultative anaerobes that test positive for oxidase and do not form spores. All members of the genus are motile and have polar flagella with sheaths. Vibrio species typically possess two chromosomes, which is unusual for bacteria. Each chromosome has a distinct and independent origin of replication, and are conserved together over time in the genus. Recent phylogenies have been constructed based on a suite of genes.
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea.
Vibrio cholerae is a Gram-negative, comma-shaped bacterium. The bacterium's natural habitat is brackish or saltwater. Some strains of V. cholerae cause the disease cholera. V. cholerae is a facultative anaerobe and has a flagellum at one cell pole as well as pili. V. cholerae can undergo respiratory and fermentative metabolism. When ingested, V. cholerae can cause diarrhoea and vomiting in a host within several hours to 2–3 days of ingestion. V. cholerae was first isolated as the cause of cholera by Italian anatomist Filippo Pacini in 1854, but his discovery was not widely known until Robert Koch, working independently 30 years later, publicized the knowledge and the means of fighting the disease.
Infection with V. vulnificus leads to rapidly expanding cellulitis or sepsis. 279 It was first isolated as a source of disease in 1976. The capsule, made of polysaccharides, is thought to protect against phagocytosis. The observed association of the infection with liver disease (associated with increased serum iron) might be due to the capability of more virulent strains to capture iron bound to transferrin.:
Cellulitis is a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of the area of redness are generally not sharp and the skin may be swollen. While the redness often turns white when pressure is applied, this is not always the case. The area of infection is usually painful. Lymphatic vessels may occasionally be involved, and the person may have a fever and feel tired.
Sepsis is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. Common signs and symptoms include fever, increased heart rate, increased breathing rate, and confusion. There may also be symptoms related to a specific infection, such as a cough with pneumonia, or painful urination with a kidney infection. In the very young, old, and people with a weakened immune system, there may be no symptoms of a specific infection and the body temperature may be low or normal, rather than high. Severe sepsis is sepsis causing poor organ function or insufficient blood flow. Insufficient blood flow may be evident by low blood pressure, high blood lactate, or low urine output. Septic shock is low blood pressure due to sepsis that does not improve after fluid replacement.
Phagocytosis is the process by which a cell uses its plasma membrane to engulf a large particle, giving rise to an internal compartment called the phagosome. It is one type of endocytosis.
V. vulnificus is an extremely virulent bacterium that can cause three types of infections:
Gastroenteritis, also known as infectious diarrhea, is inflammation of the gastrointestinal tract—the stomach and small intestine. Symptoms may include diarrhea, vomiting and abdominal pain. Fever, lack of energy and dehydration may also occur. This typically lasts less than two weeks. It is not related to influenza, though it has been called the "stomach flu".
Seafood is any form of sea life regarded as food by humans. Seafood prominently includes fish and shellfish. Shellfish include various species of molluscs, crustaceans, and echinoderms. Historically, sea mammals such as whales and dolphins have been consumed as food, though that happens to a lesser extent in modern times. Edible sea plants, such as some seaweeds and microalgae, are widely eaten as seafood around the world, especially in Asia. In North America, although not generally in the United Kingdom, the term "seafood" is extended to fresh water organisms eaten by humans, so all edible aquatic life may be referred to as seafood. For the sake of completeness, this article includes all edible aquatic life.
Diarrhea is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behaviour. This can progress to decreased urination, loss of skin color, a fast heart rate, and a decrease in responsiveness as it becomes more severe. Loose but non-watery stools in babies who are exclusively breastfed, however, are normal.
Among healthy people, ingestion of V. vulnificus can cause vomiting, diarrhea, and abdominal pain. In someone with a compromised immune system, particularly those with chronic liver disease, it can infect the bloodstream, causing a severe and life-threatening illness characterized by fever and chills, decreased blood pressure (septic shock), and blistering skin lesions.
Liver disease is a type of damage to or disease of the liver.
V. vulnificus wound infections have a mortality rate around 25%. In people in whom the infection worsens into septicemia, typically following ingestion, the mortality rate rises to 50%. The majority of these people die within the first 48 hours of infection. The optimal treatment is not known, but in one retrospective study of 93 people in Taiwan, use of a third-generation cephalosporin and a tetracycline (e.g., ceftriaxone and doxycycline, respectively) was associated with an improved outcome.Prospective clinical trials are needed to confirm this finding, but in vitro data support the supposition that this combination is synergistic against V. vulnificus. Likewise, the American Medical Association and the Centers for Disease Control and Prevention (CDC) recommend treating the person with a quinolone or intravenous doxycycline with ceftazidime. The first successful documented treatment of fulminant V. vulnificus sepsis was in 1995. Treatment was Fortaz and intravenous (IV) Cipro and IV doxycycline, which proved successful. Prevention of secondary infections from respiratory failure and acute renal failure is crucial. Key to the diagnosis and treatment were the early recognition of bullae in an immunocompromised person with liver cirrhosis and oyster ingestion within the previous 48 hours, and the request by the physician for STAT Gram staining and blood cultures for V. vulnificus.
The cephalosporins are a class of β-lactam antibiotics originally derived from the fungus Acremonium, which was previously known as "Cephalosporium".
Tetracycline, sold under the brand name Sumycin among others, is an antibiotic used to treat a number of infections. This includes acne, cholera, brucellosis, plague, malaria, and syphilis. It is taken by mouth.
Ceftriaxone, sold under the trade name Rocephin, is an antibiotic used for the treatment of a number of bacterial infections. These include middle ear infections, endocarditis, meningitis, pneumonia, bone and joint infections, intra-abdominal infections, skin infections, urinary tract infections, gonorrhea, and pelvic inflammatory disease. It is also sometimes used before surgery and following a bite wound to try to prevent infection. Ceftriaxone can be given by injection into a vein or into a muscle.
V. vulnificus often causes large, disfiguring ulcers that require extensive debridement or even amputation.
An ulcer is a discontinuity or break in a bodily membrane that impedes the organ of which that membrane is a part from continuing its normal functions. According to Robins pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughing out of inflamed necrotic tissue." Common forms of ulcers recognized in medicine include:
Debridement is the medical removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue. Removal may be surgical, mechanical, chemical, autolytic (self-digestion), and by maggot therapy.
The worst prognosis is in those people arriving at hospital in a state of shock. Total mortality in treated people (ingestion and wound) is around 33%.
People especially vulnerable are those with liver disease (especially cirrhosis and hepatitis) or immunocompromised states (some kinds of 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.About half of those who contract blood infections die.
V. vulnificus infections also disproportionately affect males; 85% of those developing endotoxic shock from the bacteria are male. Females having had an oophorectomy experienced increased mortality rates, as estrogen has been shown experimentally to have a protective effect against V. vulnificus.
V. vulnificus is commonly found in the Gulf of Mexico, where more than a dozen people have died from the infection since 1990.Most deaths at that time were occurring due to fulminant sepsis, either in the area of oyster harvest and ingestion, or in tourists returning home. Lack of disease recognition, and also of the risk factors, presentation, and cause, were and are major obstacles to good outcome and recovery.
After the successful treatment of the first person, the Florida Department of Health was able to trace the origin of the outbreak to Apalachicola Bay oysters and their harvesting in water prone to excessive growth of the organism. This contamination was due to warmth of the water and change in freshwater dilution because of a change in flow of the Chattahoochee River into the Apalachicola River, and in turn into Apalachicola Bay. A similar situation occurred after Hurricane Katrina in New Orleans.
The pathogen was first isolated in 1976 from a series of blood culture samples submitted to the CDC in Atlanta.It was described as a "lactose-positive vibrio". It was subsequently given the name Beneckea vulnifica, and finally Vibrio vulnificus by Farmer in 1979.
Increasing seasonal temperatures and decreasing coastal salinity levels seem to favor a greater concentration of Vibrio within filter-feeding shellfish of the US Atlantic seaboard and the Gulf of Mexico, especially oysters ( Crassostrea virginica ). Scientists have frequently demonstrated the presence of V. vulnificus in the gut of oysters and other shellfish and in the intestines of fish that inhabit oyster reefs. The vast majority of people who develop sepsis from V. vulnificus became ill after they ate raw oysters; most of these cases have been men.
In 2005, health officials clearly identified strains of V. vulnificus infections among evacuees from New Orleans due to the flooding there caused by Hurricane Katrina.
In 2015 in Florida, eight cases of V. vulnificus infection with two resulting in death were reported.
Natural transformation is a bacterial adaptation for DNA transfer between individual cells. V. vulnificus was found to become naturally transformable during growth on chitin in the form of crab shells.The ability to now carry out transformation experiments in the laboratory should facilitate molecular genetic analysis of this opportunistic pathogen.
Cholera is an infection of the small intestine by some strains of the bacterium Vibrio cholerae. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This may result in sunken eyes, cold skin, decreased skin elasticity, and wrinkling of the hands and feet. Dehydration can cause the skin to turn bluish. Symptoms start two hours to five days after exposure.
Gangrene is a type of tissue death caused by a lack of blood supply. Symptoms may include a change in skin color to red or black, numbness, swelling, pain, skin breakdown, and coolness. The feet and hands are most commonly affected. Certain types may present with a fever or sepsis.
Necrotizing fasciitis (NF), commonly known as flesh-eating disease, is an infection that results in the death of parts of the body's soft tissue. It is a severe disease of sudden onset that spreads rapidly. Symptoms include red or purple skin in the affected area, severe pain, fever, and vomiting. The most commonly affected areas are the limbs and perineum.
Bacteremia is the presence of bacteria in the blood. Blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal. It is distinct from sepsis, which is the host response to the bacteria.
Septicemic plague is one of the three main forms of plague. It is caused by Yersinia pestis, a gram-negative species of bacterium. Septicemic plague is a life-threatening infection of the blood, most commonly spread by bites from infected fleas.
Septic shock is a potentially fatal medical condition that occurs when sepsis, which is organ injury or damage in response to infection, leads to dangerously low blood pressure and abnormalities in cellular metabolism. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) defines septic shock as a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone. Patients with septic shock can be clinically identified by a vasopressor requirement to maintain a mean arterial pressure of 65 mm Hg or greater and serum lactate level greater than 2 mmol/L in the absence of hypovolemia. This combination is associated with hospital mortality rates greater than 40%.
Foodborne illness is any illness resulting from the spoilage of contaminated food, pathogenic bacteria, viruses, or parasites that contaminate food, as well as toxins such as poisonous mushrooms and various species of beans that have not been boiled for at least 10 minutes.
The Vibrionaceae are a family of Proteobacteria given their own order. Inhabitants of fresh or salt water, several species are pathogenic, including the type species Vibrio cholerae, which is the agent responsible for cholera. Most bioluminescent bacteria belong to this family, and are typically found as symbionts of deep-sea animals.
Vibrio parahaemolyticus is a curved, rod-shaped, Gram-negative bacterium found in brackish, saltwater, which, when ingested, causes gastrointestinal illness in humans. V. parahaemolyticus is oxidase positive, facultatively aerobic, and does not form spores. Like other members of the genus Vibrio, this species is motile, with a single, polar flagellum.
Gas gangrene is a bacterial infection that produces gas in tissues in gangrene. This deadly form of gangrene usually is caused by Clostridium perfringens bacteria. About 1,000 cases of gas gangrene are reported yearly in the United States.
Bartonellosis is an infectious disease produced by bacteria of the genus Bartonella. Bartonella species cause diseases such as Carrión's disease, trench fever, cat-scratch disease, bacillary angiomatosis, peliosis hepatis, chronic bacteremia, endocarditis, chronic lymphadenopathy, and neurological disorders.
Yersiniosis is an infectious disease caused by a bacterium of the genus Yersinia. In the United States, most yersiniosis infections among humans are caused by Yersinia enterocolitica.
Anaplasma phagocytophilum is a Gram-negative bacterium that is unusual in its tropism to neutrophils. It causes anaplasmosis in sheep and cattle, also known as tick-borne fever and pasture fever, and also causes the zoonotic disease human granulocytic anaplasmosis.
Vibrio anguillarum is a species of Gram-negative bacteria with a curved-rod shape and one polar flagellum. Classified under three biotypes, before scientists discovered that different strains of Vibrio anguillarum could be differentiated using serotypes. Vibrio anguillarum are halophiles that prefer warmer temperatures and neutral pH conditions. Vibrio anguillarum are able to compete for iron before the host can absorb it through iron acquisition mechanisms. It is an important pathogen of cultured salmonid fish, and causes the disease known as vibriosis or red pest of eels. This disease has the ability to impact brackish water, marine water, and freshwater species and may greatly impact cultured salmonid fish. Vibriosis has been observed in salmon, bream, eel, mullet, catfish, oysters, tilapia, and shrimp amongst others. The bacteria is most prevalent in late summer in salt or brackish water and gene transmission is mainly horizontal. Infection in humans is most commonly through the skin, but also through the mouth via contaminated food or water. It is widely distributed across the world. Vibrio anguillarum are damaging to the economy of aquaculture sector and fishing industries.
Vibrio tubiashii is a Gram-negative, rod-shaped (0.5 um-1.5 um) marine bacterium that uses a single polar flagellum for motility. It has been implicated in several diseases of marine organisms.
There are several different types of skin conditions that may result from flooding.