Changes

==Overview==

==Overview==

   

   

There are 6 species of Listeria bacteria. They are saprophytes in soil.''L. monocytogenes'' and ''L. ivanovii'' are pathogens and are carried by sheep and goats and shed in faeces and milk especially during stress. They can cause septicaemia, encephalitis, abortion and endophthalmitis in ruminants. Outbreaks of listeriosis often linked to silage feeding

There are 6 species of Listeria bacteria. They are known as saprophytes in soil. ''L. monocytogenes'' and ''L. ivanovii'' are pathogens carried by sheep and goats and shed in faeces and milk especially during stress. They can cause septicaemia, encephalitis, abortion and endophthalmitis in ruminants. Outbreaks of listeriosis often linked to silage feeding

==Characteristics==

==Characteristics==

Listeria are intracellular pathogens. They are Gram positive rods with catalase positive and oxidase negative activity. They are facultative anaerobes and have tumbling motility.

Listeria are intracellular pathogens. They are Gram positive rods with catalase positive and oxidase negative activity. They are facultative anaerobes and have tumbling motility.

''L. monocytogenes'' is haemolytic on blood agar due to a cytolytic protein, listeriolysin and grows at range of pH values and temperatures.''L. ivanovii'' produces a strong haemolytic zone. Listeria produces small, smooth, transparent colonies after 24 hours incubation. They are able to grow on non-enriched media.

''L. monocytogenes'' is haemolytic on blood agar due to a cytolytic protein, listeriolysin, and grows at range of pH values and temperatures. ''L. ivanovii'' produces a strong haemolytic zone. Listeria produces small, smooth, transparent colonies after 24 hours incubation. They are able to grow on non-enriched media.

==Pathogenesis and pathogenicity==

==Pathogenesis and pathogenicity==

==Diagnosis==

==Diagnosis==

*Specimens should include CSF in neural cases, cotyledons in abortion, liver, spleen and blood in septicaemia

Specimens for  should include CSF in neural cases, cotyledons in abortion, liver, spleen and blood in septicaemia

*Immunofluorescence using monoclonal antibodies

*Immunofluorescence using monoclonal antibodies

*Histology of brain demonstrates microabscesses and lymphocytic cuffing in brainstem

*Histology of brain demonstrates microabscesses and lymphocytic cuffing in brainstem