In vivovirulence ofMycoplasma hyopneumoniaeisolates does not correlate within vitroadhesion assessed by a microtitre plate adherence assay

Abstract

Aims: Adherence of Mycoplasma hyopneumoniae to the ciliated epithelial cells of the porcine respiratory tract is considered an important first step in the pathogenesis of enzootic pneumonia. It was the aim of this study to verify the usefulness of in vitro adhesion as a virulence marker. Methods and Results: Adherence capacity to immobilized cilia from porcine tracheal epithelial cells of three low, two moderately and two highly virulent M. hyopneumoniae field isolates was determined by a microtitre plate adherence assay. Conclusions: No significant differences between the isolates were demonstrated. Significance and Impact of the Study: The results suggest that mechanisms other than adherence might be responsible for the observed differences in virulence of these field isolates or that the in vitro assay does not adequately reproduce in vivo adherence conditions.

RAPD and VNTR analyses demonstrate genotypic heterogeneity of Mycoplasma hyopneumoniae isolates from pigs housed in a region with high pig density

“…Based on these findings, the genotypic characterisation and/or phenotypic determination of isolates from different farms remained a major goal in epidemiological studies, at least to assess routes of infection and, if possible, to describe virulence markers (Calus et al, 2009;de Castro et al, 2006). The main aim of our study was to apply established and easy to perform typing methods with sufficient discriminatory power for comparing M. hyopneumoniae isolates, namely RAPD and multi-locus VNTR analyses, to a large number of A c c e p t e d M a n u s c r i p t 5 epidemiologically well-defined M. hyopneumoniae isolates (de Castro et al, 2006;Stakenborg et al, 2006a).…”