A robust PCR for the differentiation of potential virulent strains of Haemophilus parasuis

N. Galofré-Milà, F. Correa-Fiz, S. Lacouture, M. Gottschalk, K. Strutzberg-Minder, A. Bensaid, S. Pina-Pedrero, V. Aragon

    Research output: Contribution to journalArticleResearchpeer-review

    19 Citations (Scopus)


    © 2017 The Author(s). Background: Haemophilus parasuis is the etiological agent of Glässer's disease in swine. H. parasuis comprises strains with heterogeneous virulence capacity, from non-virulent to highly virulent. Determination of the pathogenic potential of the strains is important for diagnosis and disease control. The virulence-associated trimeric autotransporters (vtaA) genes have been used to predict H. parasuis virulence by PCR amplification of their translocator domains. Here, we report a new and improved PCR designed to detect a different domain of the vtaA genes, the leader sequence (LS) as a diagnostic tool to predict virulence. Methods: A collection of 360 *H. parasuis *strains was tested by PCR with LS specific primers. Results of the PCR were compared with the clinical origin of the strains and, for a subset of strains, with their phagocytosis and serum resistance using a Chi-square test. Results: LS-PCR was specific to H. parasuis, and allowed the differential detection of the leader sequences found in clinical and non-clinical isolates. Significant correlation was observed between the results of the LS-PCR and the clinical origin (organ of isolation) of the strains, as well as with their phagocytosis and serum susceptibility, indicating that this PCR is a good predictor of the virulence of the strains. In addition, this new PCR showed a full correlation with the previously validated PCR based on the translocator domain. LS-PCR could be performed in a wide range of annealing temperatures without losing specificity. Conclusion: This newly described PCR based on the leader sequence of the vtaA genes, LS-PCR, is a robust test for the prediction of the virulence potential of H. parasuis strains.
    Original languageEnglish
    Article number124
    JournalBMC veterinary research
    Issue number1
    Publication statusPublished - 8 May 2017


    • Bacterial virulence
    • Glässer's disease diagnosis
    • Haemophilus parasuis
    • PCR diagnosis


    Dive into the research topics of 'A robust PCR for the differentiation of potential virulent strains of Haemophilus parasuis'. Together they form a unique fingerprint.

    Cite this