Enterotoxigenic Escherichia coli

Last updated
Enterotoxigenic Escherichia coli
Specialty Infectious disease

Enterotoxigenic Escherichia coli (ETEC) is a type of Escherichia coli and one of the leading bacterial causes of diarrhea in the developing world, [1] as well as the most common cause of travelers' diarrhea. [2] Insufficient data exist, but conservative estimates suggest that each year, about 157,000 deaths occur, mostly in children, from ETEC. [3] [4] [5] A number of pathogenic isolates are termed ETEC, but the main hallmarks of this type of bacteria are expression of one or more enterotoxins and presence of fimbriae used for attachment to host intestinal cells. The bacteria was identified by the Bradley Sack lab in Kolkata in 1968.

<i>Escherichia coli</i> species of Gram-negative, rod-shaped bacterium

Escherichia coli, also known as E. coli, is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus Escherichia that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in their hosts, and are occasionally responsible for product recalls due to food contamination. The harmless strains are part of the normal microbiota of the gut, and can benefit their hosts by producing vitamin K2, and preventing colonization of the intestine with pathogenic bacteria, having a symbiotic relationship. E. coli is expelled into the environment within fecal matter. The bacterium grows massively in fresh fecal matter under aerobic conditions for 3 days, but its numbers decline slowly afterwards.

Diarrhea Loose or liquid bowel movements

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.

In biology, a pathogen, in the oldest and broadest sense, is anything that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ.

Contents

Signs and symptoms

Infection with ETEC can cause profuse, watery diarrhea with no blood or leukocytes and abdominal cramping. Fever, nausea with or without vomiting, chills, loss of appetite, headache, muscle aches and bloating can also occur, but are less common. [2]

Enterotoxins

Enterotoxins produced by ETEC include heat-labile enterotoxin (LT) and heat-stable enterotoxin (ST). [6]

Heat-stable enterotoxin

Heat-stable enterotoxins (STs) are secretory peptides produced by some bacterial strains, such as enterotoxigenic Escherichia coli which are in general toxic to animals.

Prevention and treatment

To date, no licensed vaccines specifically target ETEC, though several are in various stages of development. [1] [7] Studies indicate that protective immunity to ETEC develops after natural or experimental infection, suggesting that vaccine-induced ETEC immunity should be feasible and could be an effective preventive strategy. [1] [8] Prevention through vaccination is a critical part of the strategy to reduce the incidence and severity of diarrheal disease due to ETEC, particularly among children in low-resource settings. The development of a vaccine against this infection has been hampered by technical constraints, insufficient support for coordination, and a lack of market forces for research and development. Most vaccine development efforts are taking place in the public sector or as research programs within biotechnology companies. [9] ETEC is a longstanding priority and target for vaccine development for the World Health Organization.

World Health Organization Specialised agency of the United Nations

The World Health Organization (WHO) is a specialized agency of the United Nations that is concerned with international public health. It was established on 7 April 1948, and is headquartered in Geneva, Switzerland. The WHO is a member of the United Nations Development Group. Its predecessor, the Health Organisation, was an agency of the League of Nations.

Treatment for ETEC infection includes rehydration therapy and antibiotics, although ETEC is frequently resistant to common antibiotics. [2] Improved sanitation is also key. Since the transmission of this bacterium is fecal contamination of food and water supplies, one way to prevent infection is by improving public and private health facilities. Another simple prevention of infection is by drinking factory bottled water—this is especially important for travelers and traveling military—though it may not be feasible in developing countries, which carry the greatest disease burden.

Sanitation public health conditions related to clean drinking water and adequate disposal of human excreta and sewage

Sanitation refers to public health conditions related to clean drinking water and adequate treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation systems aim to protect human health by providing a clean environment that will stop the transmission of disease, especially through the fecal–oral route. For example, diarrhea, a main cause of malnutrition and stunted growth in children, can be reduced through sanitation. There are many other diseases which are easily transmitted in communities that have low levels of sanitation, such as ascariasis, cholera, hepatitis, polio, schistosomiasis, trachoma, to name just a few.

See also

Related Research Articles

Shigellosis Human disease

Shigellosis is an infection of the intestines caused by Shigella bacteria. Symptoms generally start one to two days after exposure and include diarrhea, fever, abdominal pain, and feeling the need to pass stools even when the bowels are empty. The diarrhea may be bloody. Symptoms typically last five to seven days. Complications can include reactive arthritis, sepsis, seizures, and hemolytic uremic syndrome.

<i>Shigella</i> genus of bacteria

Shigella is a genus of Gram-negative, facultative aerobic, non-spore-forming, nonmotile, rod-shaped bacteria genetically closely related to E. coli. The genus is named after Kiyoshi Shiga, who first discovered it in 1897.

Whooping cough human disease caused by the bacteria Bordetella pertussis

Whooping cough is a highly contagious bacterial disease. Initially, symptoms are usually similar to those of the common cold with a runny nose, fever, and mild cough. This is followed by weeks of severe coughing fits. Following a fit of coughing, a high-pitched whoop sound or gasp may occur as the person breathes in. The coughing may last for 10 or more weeks, hence the phrase "100-day cough". A person may cough so hard that they vomit, break ribs, or become very tired from the effort. Children less than one year old may have little or no cough and instead have periods where they do not breathe. The time between infection and the onset of symptoms is usually seven to ten days. Disease may occur in those who have been vaccinated, but symptoms are typically milder.

Gastroenteritis Inflammation of the stomach and small intestine

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".

Lower respiratory tract infection

Lower respiratory tract infection (LRTI), while often used as a synonym for pneumonia, can also be applied to other types of infection including lung abscess and acute bronchitis. Symptoms include shortness of breath, weakness, fever, coughing and fatigue.

Travelers diarrhea disease

Traveler's diarrhea (TD) is a stomach and intestinal infection. TD is defined as the passage of unformed stool while traveling. It may be accompanied by abdominal cramps, nausea, fever, and bloating. Occasionally bloody diarrhea may occur. Most travelers recover within four days with little or no treatment. About 10% of people may have symptoms for a week.

Ceftazidime chemical compound

Ceftazidime, sold under the brand names Fortaz among others, is an antibiotic useful for the treatment of a number of bacterial infections. Specifically it is used for joint infections, meningitis, pneumonia, sepsis, urinary tract infections, malignant otitis externa, Pseudomonas aeruginosa infection, and vibrio infection. It is given by injection into a vein or muscle.

Global health Health of populations in a global context

Global health is the health of populations in the global context; it has been defined as "the area of study, research and practice that places a priority on improving health and achieving equity in health for all people worldwide". Problems that transcend national borders or have a global political and economic impact are often emphasized. Thus, global health is about worldwide health improvement, reduction of disparities, and protection against global threats that disregard national borders. Global health is not to be confused with international health, which is defined as the branch of public health focusing on developing nations and foreign aid efforts by industrialized countries. Global health can be measured as a function of various global diseases and their prevalence in the world and threat to decrease life in the present day.

Bacillary dysentery is a type of dysentery, and is a severe form of shigellosis.

Meningococcal disease Human disease

Meningococcal disease describes infections caused by the bacterium Neisseria meningitidis. It has a high mortality rate if untreated but is vaccine-preventable. While best known as a cause of meningitis, it can also result in sepsis, which is an even more damaging and dangerous condition. Meningitis and meningococcemia are major causes of illness, death, and disability in both developed and under-developed countries.

Paratyphoid fever bacterial infection caused by one of the three types of Salmonella enterica

Paratyphoid fever, also known simply as paratyphoid, is a bacterial infection caused by one of the three types of Salmonella enterica. Symptoms usually begin 6–30 days after exposure and are the same as those of typhoid fever. Often, a gradual onset of a high fever occurs over several days. Weakness, loss of appetite, and headaches also commonly occur. Some people develop a skin rash with rose-colored spots. Without treatment, symptoms may last weeks or months. Other people may carry the bacteria without being affected; however, they are still able to spread the disease to others. Both typhoid and paratyphoid are of similar severity. Paratyphoid and typhoid fever are types of enteric fever.

The discovery of disease-causing pathogens is an important activity in the field of medical science. Many viruses, bacteria, protozoa, fungi, helminthes and prions are identified as a confirmed or potential pathogen. In the United States, a Centers for Disease Control program, begun in 1995, identified over a hundred patients with life-threatening illnesses that were considered to be of an infectious cause, but that could not be linked to a known pathogen. The association of pathogens with disease can be a complex and controversial process, in some cases requiring decades or even centuries to achieve.

Meningitis inflammation of membranes around the brain and spinal cord

Meningitis is an acute inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or altered consciousness, vomiting, and an inability to tolerate light or loud noises. Young children often exhibit only nonspecific symptoms, such as irritability, drowsiness, or poor feeding. If a rash is present, it may indicate a particular cause of meningitis; for instance, meningitis caused by meningococcal bacteria may be accompanied by a characteristic rash.

Enteroinvasive Escherichia coli (EIEC) is a type of pathogenic bacteria whose infection causes a syndrome that is identical to shigellosis, with profuse diarrhea and high fever. EIEC are highly invasive, and they use adhesin proteins to bind to and enter intestinal cells. They produce no toxins, but severely damage the intestinal wall through mechanical cell destruction.

IOMAI was a Biotech company founded in 1997 by Gregory Glenn M.D. of the Walter Reed Army Institute of Research and Dean Lewis, a World Bank employee. The company was the first to develop the concept of transcutaneous immunization, delivery of vaccines to the skin using a patch or similar method. This provided a means to stimulate robust immune responses safely as the skin patch-based immunization targeted Langerhans cells in the skin. The patch technology underwent extensive evaluation in the context of a traveler's diarrhea vaccine which entered Phase 3 pivotal trials in 2009. IOMAI was acquired by Intercell in 2008 and the technology was the subject of a development license to GSK in 2009. Dr. Glenn pioneered needle free delivery to the skin and spawned general interest in skin-targeting vaccine technologies, including intradermal delivery and the use of the heat labile toxin as an adjuvant and the adjuvant patch.

Pathogenic <i>Escherichia coli</i>

Escherichia coli ( Anglicized to ; commonly abbreviated E. coli) is a gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Most E. coli strains are harmless, but some serotypes are pathogenic and can cause serious food poisoning in humans, and are occasionally responsible for product recalls. E. coli are also responsible for a majority of cases of urinary tract infections. The harmless strains are part of the normal flora of the gut, and can benefit their hosts by producing vitamin K2, and by preventing the establishment of pathogenic bacteria within the intestine.

Heat-labile enterotoxin family

In molecular biology, the heat-labile enterotoxin family includes Escherichia coli heat-labile enterotoxin (Elt) and cholera toxin (Ctx) secreted by Vibrio cholerae.

Enteroaggregative <i>Escherichia coli</i>

Enteroaggregative Escherichia coli are a pathotype of Escherichia coli associated with acute and chronic diarrhea in both the developed and developing world. EAEC are defined by their "stacked-brick" pattern of adhesion to the human laryngeal epithelial cell line HEp-2. The pathogenesis of EAEC involves the aggregation of and adherence of the bacteria to the intestinal mucosa, where they elaborate enterotoxins and cytotoxins that damage host cells and induce inflammation that results in diarrhea.

References

  1. 1 2 3 Bourgeois, A Louis; Wierzba, Thomas F; Walker, Richard I (2016). "Status of vaccine research and development for enterotoxigenic Escherichia coli". Vaccine. 34 (26): 2880–2886. doi:10.1016/j.vaccine.2016.02.076. PMID   26988259.
  2. 1 2 3 US Centers for Disease Control and Prevention (2014). "Enterotoxigenic E. coli (ETEC)".
  3. Lozano, Rafael; Naghavi, Mohsen; Foreman, Kyle; et al. (2012). "Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010". The Lancet. 380 (9859): 2095–2128. doi:10.1016/S0140-6736(12)61728-0. PMID   23245604.
  4. Gupta, SK; Keck J; Ram PK; et al. (2008). "Analysis of Data Gaps Pertaining to Enterotoxigenic Escherichia coli Infections in Low and Medium Human Development Index Countries, 1984-2005". Epidemiology and Infection. 136 (6): 721–738. doi:10.1017/S095026880700934X. PMC   2870873 .
  5. Kotloff, Karen L; Nataro, James P; Blackwelder, William C; et al. (2013). "Burden and aetiology of diarrhoeal disease in infants and young children in developing countries (the Global Enteric Multicenter Study, GEMS): a prospective, case-control study". The Lancet. 382 (9888): 209–222. doi:10.1016/s0140-6736(13)60844-2. PMID   23680352.
  6. Qadri, F.; Svennerholm, A. M.; Faruque, A. S. G.; Bradley Sack, R. (2005). "Enterotoxigenic Escherichia coli in Developing Countries: Epidemiology, Microbiology, Clinical Features, Treatment, and Prevention". Clinical Microbiology Reviews. 18 (3): 465–483. doi:10.1128/CMR.18.3.465-483.2005. PMC   1195967 . PMID   16020685.
  7. "WHO vaccine pipeline tracker". World Health Organization. Retrieved 2016-07-21.
  8. Girard, M.; Steele, D.; Chaignat, C. L.; Kieny, M. P. (2006). "A review of vaccine research and development: human enteric infections". Vaccine. 24 (15): 2732–2750. doi:10.1016/j.vaccine.2005.10.014. PMID   16483695.
  9. PATH, bvgh (March 2011). "The Case for Investment in Enterotoxigenic Escherichia coli Vaccines" (PDF). Retrieved 2 May 2012.
Classification
D