Listeria monocytogenes animated Listeria monocytogenes infections

Listeria monocytogenes appearance

  • small, Gram-positive, short rods or coccobacilli
  • motile at 30°C (flagella, a characteristic tumbling motility in fluid media), nonmotile at 37°C
  • non-spore-forming

Infections caused by Listeria monocytogenes

Listeria monocytogenes is the bacterium that causes the infection listeriosis. Listeriosis primarily causes infections of the central nervous system (meningitis, meningoencephalitis, brain abscess, cerebritis) and bacteremia in those who are immunocompromised, pregnant women, and those at the extremes of age (newborns and the elderly), as well as gastroenteritis in healthy persons who have ingested a large inoculum of the organism. Listeria is ubiquitous in the environment and is primarily transmitted via the oral route after ingestion of contaminated food products, after which the organism penetrates the intestinal tract to cause systemic infections (Wikipedia).

Listeria monocytogenes treatment

Selection of appropriate antibiotics depends on diagnosis!!




Colony appearance

Listeria monocytogenes morphology Listeria monocytogenes cell morphology Listeria monocytogenes Gram-stain