1. A robust PCR for the differentiation of potential virulent strains of Haemophilus parasuis.
- Author
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Galofré-Milà, N., Correa-Fiz, F., Lacouture, S., Gottschalk, M., Strutzberg-Minder, K., Bensaid, A., Pina-Pedrero, S., and Aragon, V.
- Subjects
GLAESSER'S disease ,HAEMOPHILUS disease treatment ,MICROBIAL virulence ,POLYMERASE chain reaction ,CHI-squared test - Abstract
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. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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