Development and application of a quantitative PCR assay for the detection and enumeration of Lawsonia intracellularis

摘要

Proliferative enteropathy (PE) is caused by an obligate intracellular bacterium, Lawsonia intracellularis, and is clinically manifested in several forms. The chronic form is known as porcine intestinal adenomatosis (PIA), the acute form is known as proliferative hemorrhagic enteropathy (PHE) and the sub-clinical form is most characterized by poor performance (Lawson and Geb-hart, 2000; McOrist and Gebhart, 2006). The amount of shedding of Lawsonia that is present when an animal presents with PIA, PHE, or sub-clinical infections is unknown. This quantitative information could be used to correlate shedding to performance loss or clinical manifestation of the disease. Therefore, the objective of this study was to develop a quantitative PCR assay, validate its sensitivity and specificity, and apply it to field samples for investigating the amount of Lawsonia shed per gram of feces in the field.