Specific detection of Lawsonia intracellularis in porcine proliferative enteropathy inferred from fluorescent rRNA in situ hybridization

Fluorescent in situ hybridization targeting 16S ribosomal RNA was used for specific detection of the obligate intracellular bacterium Lawsonia intrace llularis in enterocytes from pigs affected by proliferative enteropathy. A specific oligonucleotide probe was designed and the specificity of the prob e was determined by simultaneous comparison with indirect immunofluorescenc e assay for detection of L. intracellularis in formalin-fixed tissue sample s from 15 pigs affected by porcine proliferative enteropathy. We used 10 ti ssue samples from pigs without proliferative mucosal changes as negative co ntrols. The results showed that the oligonucleotide probe is specific for L . intracellularis and that fluorescent in situ hybridization targeting ribo somal RNA is a suitable and fast method for specific detection and histolog ical recognition of L. intracellularis in formalin-fixed tissue.