Diversity within <i>Borrelia burgdorferi</i> sensu lato genospecies in Switzerland by <i>recA</i> gene sequence

A total of 874 <i>Ixodes ricinus</i> ticks were collected in Switzerland to investigate the genetic diversity of the <i>Borrelia</i> population. We integrated to the RT-PCR method the DNA sequence analysis of a 162-bp fragment of the <i>recA</i> gene. Five genospecies were detected: <i>Borrelia afzelii</i>, <i>Borrelia burgdorferi</i> s.s., <i>Borrelia garinii</i>, <i>Borrelia valaisiana</i>, and <i>Borrelia lusitaniae</i>. A heterogeneous distribution was observed within the <i>B. burgdorferi</i> s.l. genospecies. The most prevalent and diverse genospecies found in Switzerland was <i>Borrelia afzelii</i>, which might suggest a rapid evolution of this genospecies.