Genotyping of strains by Multilocus VNTR Analysis

Karine Laroucau , Fabien Vorimore , Claire Bertin , Khalil Yousef Mohamad , Simon Thierry , Willems Hermann , Cyril Maingourd , Christine Pourcel , David Longbottom , Simone Magnino , Konrad Sachse , Evangelia Vretou , Annie Rodolakis

(C.) is the causative agent of ovine enzootic abortion with zoonotic potential whose epidemiology has been held back because of the obligate intracellular habitat of the bacterium. In the present study we report on a molecular typing method termed Multiple Loci Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) for exploring the diversity of . An initial analysis performed with 34 selected genetic loci on 34 ruminant strains including the variant Greek strains LLG and POS resulted in the identification of 5 polymorphic loci, confirming the widely held notion that is a very homogeneous species. Analysis of additional 111 samples with the selected 5 loci resulted in the classification of all strains into 6 genotypes with distinct molecular patterns termed genotypes [1] through [6]. Interestingly, the classification of the isolates in the 6 genotypes was partly related to their geographical origin. Direct examination of clinical samples proved the MLVA to be suitable for direct typing. Analysis of the genomic sequences in 6 prototypes of amplicons generated with each of the 5 selected VNTR primers revealed that variation between genotypes was caused by the presence or absence of coding tandem repeats in 3 loci. Amplification of reference strains with the 5 selected VNTR primers and of the 6 prototype strains with the 8 VNTR primers established for the typing of (Laroucau ., 2008) showed that both MLVA typing systems were species-specific when all respective VNTR primer sets were used.

Mots clés: Intra-species differentiation; MLVA typing; Molecular epidemiology

Domaines: Sciences du Vivant [q-bio]

Karine Laroucau, Fabien Vorimore, Claire Bertin, Khalil Yousef Mohamad, Simon Thierry, et al.. Genotyping of strains by Multilocus VNTR Analysis. Veterinary Microbiology, 2009, 137 (3-4), pp.335. ⟨10.1016/j.vetmic.2009.01.029⟩. ⟨hal-00485537⟩