Listeria Listeriosis

Order: Bacillales
Class: Bacilli
Genus: Listeria

Species: There are 6 species of Listeria.
L. monocytogenes, L. ivanovii, L. innocua, L. welshimeri, L. seeligeri, and L. grayi
Only L. monocytogenes infects humans and makes us ill.

Serotypes: There are 13 serotypes of L. monocytogenes that can cause disease in humans. More than 90 percent of human isolates belong to only three serotypes: 1/2a, 1/2b, and 4b.

Listeriosis
- is the disease caused by Listeria monocytogenes (L. monocytogenes)

Manifestations of listeriosis
- febrile gastroenteritis
- septicemia
- meningitis
- corneal ulcer
- pneumonia
- miscarriage
- spontaneous abortion
- premature delivery
- stillbirth

Listeria monocytogenes
- named after Joseph Lister
- Gram positive bacterium (rod shape)
- motile (flagellate with actin rockets/comet tails) - tumbling motility (tergolek-golek)
- flagellate & aflagellate forms; grows flagella at 30C and below; no flagella at 37C (body temperature)
- peritrichous flagella at RT (20-25C)
- nonspore-forming (doesn't form spores) - no spores to disseminate the bacteria
- found in human gut or gastrointestinal (GI) system - up to 10% is L. monocytogenes
- virulent food-borne pathogen - can infect humans and cause 20-30% death
- facultatively anaerobic - can survive with & without oxygen (ie inside cells)

Transmission
- vertical transmission: mother to child when giving birth (childbirth) - transvaginal - fetomaternal listeriosis
- newborns can get the disease from their mothers if their mothers ate contaminated food
- expectant mothers to avoid soft cheeses which may be contaminated with L. monocytogenes

Food contamination
- many sources - raw food, fruits and vegetables, fruit salads, salads, coleslaw, unpasteurized milk & food
- sheep manure can contaminate cabbage - cabbage is made into coleslaw (raw cabbage) - contaminated coleslaw may cause consumers to become ill (foodborne listeriosis)

Development of listeriosis
- from days to weeks

Pathogenicity
-  causes meningitis in newborns (rengsa selaput otak bayi) - 3rd most common cause of meningitis in newborns

Recent outbreaks
- South Africa - ready-to-eat meat (cold meats)
- Australia - rock melons or cantaloupes

Industries affected
- food industry
- import & export
- tourism
- business travels

Detection in the clinical diagnostic labs
- old way - hemolysin test
- modern way - DNA methods

Treatment
- antibiotics


External links
Encyclopedia of Life (EOL)
http://eol.org/pages/974245/details
https://www.sowetanlive.co.za/news/south-africa/2018-03-22-who-no-need-to-ban-sa-meats/
https://mg.co.za/article/2018-03-21-three-major-mistakes-tiger-brands-made-in-response-to-the-listeriosis-crisis
http://punchng.com/who-warns-nigeria-15-other-african-countries-of-listeriosis-outbreak/
https://www.webmd.com/food-recipes/food-poisoning/tc/listeriosis-topic-overview
https://en.wikipedia.org/wiki/Listeriosis