14th ICID - Poster Abstracts - International Society for Infectious ...

When citing these abstracts please use the following reference:
Author(s) of abstract. Title of abstract [abstract]. Int J Infect Dis 2010;14S1: Abstract number.
Please note that the official publication of the International Journal of Infectious Diseases 2010, Volume 14, Supplement 1
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Final Abstract Number: 34.013
Session: Zoonoses and Infectoins in Animals
Date: Wednesday, March 10, 2010
Time: 12:30-13:30
Room: Poster & Exhibition Area/Ground Level
Type: Poster Presentation
The micro-adenomatous lesions associated with Lawsonia intracellularis in the pig intestine
M. Sueyoshi, R. Uemura, H. Nagatomo
University of Miyazaki, Miyazaki, Japan
Background: Lawsonia intracellularis orally infects and causes marked hyperplasia of
enterocytes in pigs. The infected intestinal wall makes thickening remarkable. This disease is
called porcine proliferative enteropathy (PPE) or porcine intestinal adenomatosis(PIA). L.
intracellularis was spreads all over the world and that the microbes were infected with pigs of a lot
of farms have been reported. The characteristic pathological lesion of PIA is well known, but the
pathogenesis mechanism is not clear. In this study, the localization of L. intracellularis and the
mucosal lesions were investigated on the intestine with onset or healthy pigs.
Methods: The histopathological examination of the intestines of the 25 poor-growth piglets and
67 healthy pigs at the meat inspection station were examined by Hematoxylin-Eosin staining,
Warthin-Starry(WS) staining and immunohistochemical(IHC) method used the anti-L.
intracellularis antibody. In addition, it was examined detection of a specific gene of L.
intracellularis by PCR method about an intestinal frozen-, a formalin- and a paraffin-specimen.
Results: In necropsy, no thickened intestinal wall was found in 25 poor-growth piglets, however,
in two of them, the typical PIA histological lesions were found in from the jejunum to the rectum.
These cases were diagnosed as atypical PIA. In addition, in the other two of them, an islandshaped
micro-PIA lesion was distributed in the intestinal mucosa. The comma-shaped small
bacteria were observed by WS staining, and the antigens of L. intracellularis were detected with
IHC methods in the enterocytes of the micro-adenomatous lesions. The antigen of L.
intracellularis was also detected in the intact superficial enterocytes. In 67 healthy pigs, the
thickened intestinal wall was not found macroscopically. However, the focal adenomatous lesions
with clear boundaries were observed to three pigs in them. A specific gene of L. intracellularis
was detected by PCR method in the intestinal frozen-, the formalin- and the paraffin-specimen.
Conclusion: In this study, it was confirmed that there was atypical PIA, and the island-shaped or
the focal adenomatous lesions were also distributed in a normal intestine macroscopically. The
microlesions was suggested on the stage of an early infection or the subclinical infection with L.
intracellularis.