( ( Lyme disease ) ( ( is ( caused ( by ( ( ( Borrelia burgdorferi ) , ) ( ( a ( corkscrew-shaped bacterium ) ) ( of ( the ( spirochete group ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Lyme) (NN disease)) (VP (VBZ is) (VP (VBN caused) (PP (IN by) (NP (NP (NNP Borrelia) (NNP burgdorferi)) (, ,) (NP (NP (DT a) (JJ corkscrew-shaped) (NN bacterium)) (PP (IN of) (NP (DT the) (JJ spirochete) (NN group)))))))) (. .)))
Lyme disease is caused by Borrelia burgdorferi, a corkscrew-shaped bacterium of the spirochete group.
(ROOT (S (NP (JJ Lyme) (NN disease)) (VP (VBZ is) (VP (VBN caused) (PP (IN by) (NP (NNS bacteria))))) (. .)))
Lyme disease is caused by bacteria.