4.4.4 Porcine salmonellosis

In some occasions, enteric salmonellosis may occur in fattening pigs. In those cases small and large intestine both can be involved. A fibrinous to necrotizing ulcerative colitis is one of the features of porcine salmonellosis. Especially in enteric infections with Salmonellaspp., a necrotizing to ulcerative typhlocolitis is obvious at sites, where lymphoglandular complexes are present.

Diagnostic methods for the detection of Salmonella spp.:

Faecal or organ samples are directly inoculated on at least 2 selective solid media for identification of salmonella-suspect colonies. Phage typing of a salmonella isolate is based on the sensitivity of a particular isolate to several bacteriophages at appropriate dilutions. In recent publications, PCR are described to detect the phage type of salmonella.

PCR methods are available to detect salmonella in clinical specimens or identify isolates. Serological test directed against salmonella anti-bodies are ELISA, agglutination tests, antiglobulin and complement fixation tests. Especially the ELISA is suitable for monitoring the status of a pig herd.

Due to subclinical infections, the detection of salmonella in faeces (especially after enrich­ment) or the detection of antibodies against salmonella alone do not prove salmonella as the causative agent in an acute disease. Histological examination of multiple samples of small and large intestines and liver to differentiate salmonellosis from proliferative enteritis and swine dysentery is a valuable supplemental procedure.