Campylobacter jejuni
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Campylobacter jejuni
Campylobacter jejuni is a species of curved, rod-shaped, non-spore forming, Gram-negative microaerophilic, bacteria commonly found in animal feces. It is one of the most common causes of human gastroenteritis in the world. Food poisoning caused by Campylobacter species can be severely debilitating but is rarely life-threatening. It has been linked with subsequent development of Guillain-Barré syndrome (GBS), which usually develops two to three weeks after the initial illness.[citation needed]
C. jejuni is commonly associated with poultry and naturally colonises the digestive tract of many bird species. It has also been isolated from wombat and kangaroo feces, being a cause of bushwalkers' diarrhea. Contaminated drinking water and unpasteurized milk provide an efficient means for distribution. Contaminated food is a major source of isolated infections, with incorrectly prepared meat and poultry normally the source of the bacteria.
Infection with C. jejuni usually results in enteritis, which is characterised by abdominal pain, diarrhea, fever, and malaise. The symptoms usually persist for between 24 hours and a week, but may be longer. Diarrhea can vary in severity from loose stools to bloody stools. No antibiotics are usually given as the disease is self-limiting, however, severe (accompanying fevers, blood in stools) or prolonged cases may require ciprofloxacin, erythromycin, azithromycin or norfloxacin. The drug of choice is Erythromycin. 90% of cases respond to ciprofloxacin treatment. Fluid and electrolyte replacement may be required for serious cases.
The first full-genome sequence of C. jejuni was performed in 2000 (strain NCTC11168 with a circular chromosome of 1,641,481 base pairs).
| Kingdom | Bacteria |
|---|---|
| Phylum | Proteobacteria |
| Class | Epsilon proteobacteria |
| Order | Campylobacterales |
| Family | Campylobacteraceae |
| Genus | Campylobacter |
| Species | C. jejuni |
| Binomial | Campylobacter jejuni |
Contents |
[edit] Surface Characteristics
Campylobacter jejuni is a Gram-negative bacteria like bacilli. It is microaerophilic and non-fermentive organism. Its structure is similar to most Gram-negative bacteria. It has one flagellum at one pole or both poles of the cell. The cell contains an outer membrane and an inner membrane with periplasm in between the two membranes. The outer membrane consist of lipopolysaccharide which are endotoxic. Membrane proteins are embedded on the outer membrane surface; they are antigenic and are used for invation of the host
[edit] Pathogenic Activity
Campylobacter jejuni is an interesting bacterium because it contains some eukaryotic-like system for N-linked protein glycosylation. The disease Camylobacter jejuni causes is known as campylobacer enteritis or gasteroenteritis. The bacteria use their flagella at both poles for adhesion and invasion of the host. The illness leads to severe diarrhea and fecal leukocytes. These symptoms are usually combined with fever, headaches and muscle pain. Children under 5 and young adults are more vulnerable to get the disease more than other groups. Although Campylobacter is the number one cause of food-borne illness, it is the least deadly. The case/fatality ratio is about 1/1000 which is very low.
[edit] Virulence
The Campylobacter bacteria is found in the intestines of many animals and some humans. They cycle through the intestinal environment and lead to diarrhea. Clinical evidence suggests that the site of Campylobacter infection seems to be the ileum and jejunum in the small intestines rather than in the large intestines. Although it is the leading cause of food-borne illness in the United States, Campylobacter can be easily killed by cooking or heating. In most cases, Campylobacter can contaminate water, milk or undercooked meat, especially chicken. It only takes a small amount of bacteria to cause infection. The illness usually lasts 2 to 5 days, and most of these cases will disappear without treatment. However, 25% of these patients are likely to have a relapse.
The early symptom of Campylobacter infection is usually abnormal abdominal pain and is then followed by bloody diarrhea. Other common accompanying symptoms are fever, headache, muscle pain, and sometimes vomiting and dehydration may occur. Although vomiting and dehydration are not usually prominent, they may be severe enough to lead to death. Complication of Campylobacter infection may also contribute to mortality. For example, deaths have occurred in patients who also have cirrhosis, malnutrition, and lymphoma
