IDENTIFICATION OF BORRELIA-BURGDORFERI SENSU-LATO SPECIES IN EUROPE

Characterisation at the species level of 142 Borrelia isolates obtaine d from ticks, humans and rodents in Western Europe was carried out and their geographical distribution was described. Borrelia garinii was t he predominant species representing 44% of the isolates and B. afzelii and B. burgdorferi sensu stricto constituted 27% and 19% of isolates respectively. B. valaisiana, [formerly group VS116) constituted 10.5% of isolates. Some differences in the Borrelia species distribution wer e observed from one country to another, possibly linked to different s ources of samples. In the human samples, which were mostly collected i n Austria, B. afzelii was preferentially isolated from skin and B. gar inii from CSF B. afzelii was consistently isolated from rodents captur ed in Switzerland, but one isolate of B. garinii was obtained from a r odent in Austria. B. garinii was by far the most abundant species isol ated from Ixodes ricinus ticks in all studied countries. B. valaisiani a was isolated from I. ricinus ticks collected from vegetation and fro m I. ricinus engorged on birds.