( ( ( ( ( ( Lyme Disease ) ( is ( caused ( by ( ( a bacterium ) ( that ( 's ( transmitted ( by ( tick bite ) ) ) ) ) ) ) ) ) ) , ) but ) ( ( many ( infected people ) ) ( ( do n't ) ( remember ( a bite ) ) ) ) ) . )
(ROOT (S (S (NP (NNP Lyme) (NNP Disease)) (VP (VBZ is) (VP (VBN caused) (PP (IN by) (NP (NP (DT a) (NN bacterium)) (SBAR (WHNP (WDT that)) (S (VP (VBZ 's) (VP (VBN transmitted) (PP (IN by) (NP (NN tick) (NN bite)))))))))))) (, ,) (CC but) (S (NP (JJ many) (JJ infected) (NNS people)) (VP (VBP do) (RB n't) (VP (VB remember) (NP (DT a) (NN bite))))) (. .)))
Lyme  Disease is caused by a bacterium that's transmitted by tick bite, but many infected people don't remember a bite.
(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.