[Borrelia strains that cause erythema migrans in Alsace, France].

INTRODUCTION: In Europe, Borrelia burgdorferi sensu stricto, Borrelia afzelii and Borrelia garinii are known as pathogens among the Borrelia burgdorferi sensu lato group. Since it is not yet known which Borrelia are responsible for Lyme borreliosis in France, the objective of this study was to identify the species of Borrelia responsible for erythema migrans in the region of Alsace, France. PATIENTS AND METHODS: Eighteen patients with erythema migrans (EM) of more than 5 cm of diameter were included in this prospective study. All patients were investigated at the Strasbourg University Hospital. Patients were biopsied on the active border of their lesion. Cutaneous biopsies of the active border of the lesion were cultivated in BSK-H medium (Sigma) and analysed in vitro by PCR after 8 weeks of culture, using flagellin consensus sequences which are present in all species of Borrelia burgdorferi sensu lato group as primers. Species-specific oligotyping was used for species identification. RESULTS: Among the 18 patients biopsied, 7 had evidence of borrelia infection revealed by culture and/or PCR. Borrelia afzelii was detected in 4 patients and Borrelia garinii in three. CONCLUSION: These preliminary results appear to confirm that Borrelia afzelii and Borrelia garinii are the predominant borrelial species in EM lesions in our geographic area, as in other European countries.