Silver staining combined with alcian blue and hematoxylin-eosin for the detection of Lawsonia intracelullaris in swine proliferative enteropathy.

Fragments of ileum from 663 pigs were collected in abattoirs, prepared with the use of standard histological methods and stained with a novel sensitive histochemical method for the detection of porcine proliferative enteropathy. The method is a combination of the following 3 well-known methods, the Warthin-Starry method, alcian blue and hematoxylin-eosin. In 11 cases, mucus-producing cells were completely absent, severe adenomatous proliferation was observed and intracellular bacteria were found in enterocytes. Disappearance of goblet cells and the presence of adenomatous proliferation without any detectable intracellular bacteria were observed in 16 cases. In the remaining 636 cases, histological changes and intracellular bacteria were not found. When comparing the conventional Warthin-Starry method with the modified staining method presented here, the same 16 cases were found. However, the method presented here enables examination of large numbers of sections in a relatively short period of time.