Lab 4- Listeria Flashcards
Habitat
Soil, sewage, plants, silage, gut and food
Morphology
1-2 um thick rods
Flagella - 22 degrees
Staining
Gram positive
Culture
Simple
B-haemolysis
4-45 degrees
pH: 5.5-9.6
Selective: cattle serum, trypaflavin, nalidixic acid
Selective enrichment:
Cold enrichment; 4 degrees
U-tube
Biochemistry
Catalase +
Oxidase -
Fermentative
Virulence factors:
Listeriolysin O ( haemolysin): intracellular replication !
Monocytosis factor: cell wall, lipoid
Antigens
Cell wall polysaccharides
Flagellar protein
13 serotypes, most common: 1/2a, 4b
Resistance
Months in soil
Propagation in soil !
Pathogenicity
Facultative pathogenic
Virulence
Haemolysis
Lipolysis
Monocytosis factor
Cell wall lipoids
Pathogenicity in different species.
Sheep: mainly CNS signs Cattle: mainly abortion Rabbit: septicaemia, abortion Humans: abortion, newborn septicaemia, encephalitis Birds: septicaemia
Species
L. Monocytogens
L. Ivanovoii
Factulative intracellular agents
Saprophytic species
L. Ivanovii
Better hemolysis
Serotype 5
When can the bacteria be found flagellated?
At room temp !
What is special about the motility ?
Tumbling motility (rolls)
What kind of hemolysis does it cause?
Weak, complete beta hemolysis
Can listeria propagate in the fridge ?
Yes, 4-45 degrees
What is important concerning listeria and silage production?
The ph of the silage must be under 5.5, or the bacteria will spread in the fermented feedstuff
How can you differentiate (alternative method) listeria from other bacteria’s?
Leave in fridge for several weeks, only listeria will survive
Causes what disease ?
Listeriosis
Symptoms of CNS damage ivy listeria in sheep?
Tilting of head, paresis of tongue, salivation (also ru)
L. Monocytogens cause what disease in ov and ru ?
Encephalitis (circling disease), abortion, septicaemia
L. Monocytogens cause what disease in ru?
Mastitis
L. Monocytogens cause what disease in hu?
Septicaemia, abortion
Mainly from raw milk, vegetables, plants
L. Monocytogens cause what disease in fe, ca, eq?
Abortion, encephalitis
