摘要：We report the first record of Litomosoides pardinasi in native and exotic rodents from Chile. Litomosoidespardinasi, described in the Argentine Patagonia parasitizing Phyllotis xanthopygus and Oligoryzomys longicaudatus,was found in Chile parasitizing the peritoneal and thoracic cavities of O. longicaudatus (prevalence (P)= 18.9%, meanintensity (MI)= 57.3) and Phyllotis darwini (P= 4.2%, MI= 10), and in the peritoneal cavity of Rattus rattus (P=1.24%; MI= 22.5). Total P in native rodents from Chile was significantly lower than in Argentina, while the total MIwas higher. Prevalence and MI of L. pardinasi in O. longicaudatus from Chile and Argentina showed non-significantdifferences; prevalence in P. darwini from Chile was significantly lower than in P. xanthopygus from Argentina andthan in Chilean O. longicaudatus. Our results, together with those from Argentina, support the hypothesis that L.pardinasi is well established in O. longicaudatus, but seems to be recently acquired by P. darwini and the exotic R.rattus. Considering the known host distribution of Litomosoides species among the sigmodontines, our results alsosupport the hypothesis that L. pardinasi first colonized the Oryzomyini tribe and later, by different phenomena ofhost-switching, colonized the Phyllotini tribe and the exotic R. rattus.
关键词：host-switching;nematodes;filarioid;sigmodontine rodents;Oligoryzomys;Phyllotis;Rattus.;cambio de hospedero;nemátodos;filarias;roedores sigmodontinos;Oligoryzomys;Phyllotis;Rattus.
