( Pathogens ( ( are ( ( disease-causing organisms ) ( such ( as ( viruses ( , ( bacteria ( , ( and parasites ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Pathogens)) (VP (VBP are) (NP (NP (JJ disease-causing) (NNS organisms)) (PP (JJ such) (IN as) (NP (NNS viruses) (, ,) (NNS bacteria) (, ,) (CC and) (NNS parasites))))) (. .)))
Pathogens are disease-causing organisms such as viruses, bacteria, and parasites.
(ROOT (S (NP (NNS Pathogens)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (JJ disease-causing) (NNS agents))) (, ,) (PP (JJ such) (IN as) (NP (NNS bacteria) (CC and) (NNS viruses))))) (. .)))