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Fibrinosuppurative meningitis:
Fibrinosuppurative meningitis may be caused by a number of
bacteria in the pig including Streptococcus spp,
Escherichia coli, Haemophilus parasuis and Erysipelothrix
rhusiopathiae. Typically it is characterised by meningeal opacity due
to the presence of purulent (neutrophil containing) exudate in the leptomeninges
which include the subarachnoid space. There is also hyperaemia and vasculitis
with the formation of thrombi within the meningeal vessels.
Erysipelothrix was diagnosed in this case based on the occurrence of arthritis
and skin lesions within the group of pigs. While none of these is definitively
diagnostic of Erysipelothrix they are all commonly associated with this
infection. The longevity of Erysipelothrix in the environment means that
once it has entered a pig farm it is likely to remain and re-emerge in
young growers. Arthritis occurs from localisation of bacteria from the
blood into joints and the skin lesions are a result of vascular thrombosis
in the dermal tissues.
Ancillary tests:
Bacterial culture of the CSF and blood cultures from
newly infected bacteraemic animals should yield short gram positive, rod
organisms.
 
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