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

Heiko Nathues , Elisabeth Grosse Beilage , Lothar Kreienbrock (1) , Renate Rosengarten (2) , Joachim Spergser (2)

1 Institute for Biometry
2 Institute of Bacteriology

Since differences in the virulence of () strains have been described, the isolation of field strains followed by genotypic and phenotypic characterisation has become a major goal in epidemiological studies. The aim of this study was to compare various isolates from different pig herds and numerous pigs within the same herd. Therefore, pigs of 109 herds located in North-Western Germany were sampled either on-farm or during necropsies. Overall, 52 isolates of were recovered from 45 pigs originating from 21 herds. The identity of cultures was confirmed by PCR targeting the 16S-23S intergenic spacer region. Typing of isolates was achieved by random amplified polymorphic DNA (RAPD) analysis and multi-locus analysis of variable number of tandem repeats (VNTR) and demonstrated a high degree of heterogeneity of isolates. Differences among isolates recovered from animals of the same herd or even from the same pig revealed a grouping into different genotypic clusters. This outcome was observed with both methods. It was concluded that more than one strain of might be present in a pig herd and even in a single pig, suggesting high genetic heterogeneity between isolates of the same epidemiological source. These factors should be considered when applying nucleic amplification techniques for characterising strains to specify the epidemiology of infection and to evaluate virulence factors triggering the corresponding disease.

Domaines: Médecine vétérinaire et santé animale

Heiko Nathues, Elisabeth Grosse Beilage, Lothar Kreienbrock, Renate Rosengarten, Joachim Spergser. RAPD and VNTR analyses demonstrate genotypic heterogeneity of isolates from pigs housed in a region with high pig density. Veterinary Microbiology, 2011, 152 (3-4), pp.338. ⟨10.1016/j.vetmic.2011.05.029⟩. ⟨hal-00724200⟩