Listeria Flashcards
Is listeria gram positive or negative?
Gram positive rods- usually occur in chains
Catalase _____Oxidase_____
catalase positive oxidase negative
True/False: Listeria is spore forming and non motile?
False! Listeria is non spore forming and motile
Is listeria an anerobe or aerobe?
Facultative anaerobe
Listeria are facultative _____ parasites
intracellular- survival in macrophages or hepatocytes
What pathogenesis does Listeria cause?
septicemia, encephalitis, and abortions
What does ActA do?
intracellular movement
What are the adhesions of listeria?
internalins, ActA, and protein 60
What is the main virulence factor of Listeria and what does it do?
Listeriolysin OVERY IMPORTANT- can induce apoptosis of the cell- lysis of ferritin vacuolespore forming lysis factor. They create pores and the bacteria gets into the phagosome. To get out of the phagosome, Listeria punches a hole in the membrane and is able to escape. Then the bacteria uses ActA to travel through the cytoplasm to the next cell
What is a cellular product of Listeria that breaks down phospholipids for membrane lysis?
Phospholipase C
How does Listeria surivie in the intestinal lumen?
Bile salt hydrolase
Intestinal Pathogenesis for Listeria
- bacteria is ingested in decaying soil2. Many are killed by gastric acids3. If they survive, attach to epithelium,M cells, and phagocytic cells4. Once in the phagocytes, they move through the blood stream
What can listeria cause in Pregnant females?
abortion or calves will be born with CNS signs- this is deterined by host immunity
How does Listeria cause outbreaks in humans?
Food borne diseasemeningitis is the most common manifestationpregnant women- still births, preterm labor, infant with systemic infection
What products may humans ingest that are contaminated?
dairy products that are infected with listeria from and asymptomatic cowListeria can withstand refrigeration
Who are predisposed to disease from Listeria?
humans- immunosupressedanimals- neonates and preganat animals
What kind of immune response do we want against Listeria?
mainly cell mediataed- since bacteria lives in cellshumoral can play a role
Is there a vaccine for Listeria?
No
What will you see in a gram stain of Listeria
Gram positive short rods with rounded ends. Some cells may be curved
What lowtemperature is Listeria still mobile at?
25 degrees celsiusUmbrella pattern of motility
How do you treat Listeria?
antimicrobial treatmentThere are NO vaccinesTherapy is often of little use
