Listeria

Listeria is a genus of bacteria that, until 1992, contained 10 known species, each containing two subspecies. As of 2020, another five species were identified. Named after the British pioneer of sterile surgery Joseph Lister, the genus received its current name in 1940. Listeria species are Gram-positive, rod-shaped, and facultatively anaerobic, and do not produce endospores.

Characteristics

The major human pathogen in the Listeria genus is Listeria monocytogenes. It is usually the causative agent of the relatively rare bacterial disease listeriosis, a serious infection caused by eating food contaminated with the bacteria. The disease affects primarily pregnant women, newborns, older adults, and adults with weakened immune systems. It is a serious disease in those with a weakened immune system and is rarely found in people otherwise healthy. In the European Union listeriosis is on the rise, with 2,161 confirmed cases in 2014 and 2,206 confirmed cases in 2015.

Pathogenesis

Listeria monocytogenes is a pathogen commonly found in various raw food products, soil, plants and even in animals. Listeria is responsible for listeriosis, a serious infection for humans; the overt form of the disease has a case-fatality rate around 20%. The two main clinical manifestations are sepsis and meningitis. Meningitis is often complicated by encephalitis, a pathology not usually seen in other causes of bacterial meningitis. Listeria ivanovii is a pathogen of mammals, specifically ruminants, and has rarely caused listeriosis in humans.

Treatment

Listeriosis treatment involves intravenous delivery of antibiotics and, depending on the severity of the infection, may require the removal of dead tissue. The most effective treatment for listeriosis is early diagnosis followed by antibiotics.

See also

• Listeriosis
• Listeria monocytogenes
• Listeria ivanovii

Listeria

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  Listeria monocytogenes 01
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  Listeria monocytogenes grown on Listeria Selective Agar
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  Listeria monocytogenes PHIL 2287 lores