OspA heterogeneity of Borrelia valaisiana confirmed by phenotypic and genotypic analyses

This study describes a mAb that targets OspA of B. valaisiana and primers targeting the OspA gene of this species. As the monoclonal antibody A116k did not react with strains NE231, M7, M53 and Frank and no amplification was observed with strains NE231, M7 and M53, the existence of two subgroups among European B. valaisiana species was confirmed.The association of both monoclonal antibody A116k and primers Bval 1F and Bval 1R allows to specific identification of the B. valaisiana isolates belonging to subgroup 1.Lyme borreliosis (LB) caused by a spirochetal species Borrelia burgdorferi sensu lato (sl.) is a multisystemic illness distributed worldwide [1]. In North America and Eurasia, LB is the most common tick-borne disease [2]. On the basis of protein profiles, DNA-DNA relatedness and rRNA gene restriction pattern, B. burgdorferi sl. strains have been previously divided into three species: B. burgdorferi sensu stricto (ss.), B. garinii and B. afzelii [3,4]. B. burgdorferi ss. was found in ticks and patients infected in Europe as well as in North America, whereas B. garinii and B. afzelii were only found in ticks and patients infected in Eurasia [4,5]. B. andersonii and B. bissettii were described in North America [6,7], while B. japonica has been defined in Japan [8] and B. lusitaniae in Portugal [9].First isolated in Valais-CH, from an I. ricinus tick, VS116 was characterized as B. valaisiana novel species [10]. As other species, it appeared that its geographical distribution was not uniform. In Switzerland, Scandinavia and the Netherlands, B. valaisiana was less frequently isolated than B. garinii and B. afzelii. In Ireland however, B. valaisiana was described as the most prevalent genospecies [11]. More recently, B. valaisiana has been isolated in Japan and East Asia from I. nipponensis, I. columnae and I. granulatus [12,13].An association between clinical outcome and infection by strains of different genospecies has been suggested and suspicion of a pathogenic