Epidemiological aspects and molecular characterization of Borrelia burgdorferi s.l. from southern Germany with special respect to the new species Borrelia spielmanii sp. nov.

In 475 Borrelia-infected Ixodes ricinus (2155 ticks investigated) from southern Germany the most common Borrelia burgdorferi sensu lato species was B. garinii (34.3%) followed by B. afzelii (25.1%), B. burgdorferi sensu stricto (22.0%), and B. valaisiana (12.7%). B. spielmanii sp. nov. was detected in 5.9% of the 475 infected ticks. Hints for a focal distribution were found for B. spielmanii sp. nov. and B. garinii OspA type 4. In 242 patient isolates, dominance (66.9%) of B. afzelii for skin could be confirmed, while frequency of B. garinii in cerebrospinal fluid (CSF) isolates (51.1%) was comparable to the frequency in nymphal ticks (51.6%). Four patient isolates from southern Germany and two from Slovenia, all isolated from erythema migrans, could be assigned to B. spielmanii sp. nov. Within this new species high sequence identities were found for rrs, fla, and ospA while rrf-rrl, ospC, and dbpA were less conserved: three new ospC and two new dbpA sequence types were found. This genetic heterogeneity reveals that B. spielmanii sp. nov. did not evolve just recently.