PCR confirmation of Trichinella spiralis isolated from small mammals trapped in Buenos Aires Province

CASTAÑO ZUBIETA, R.; RUIZ, MARCELA; MORICI, GABRIEL; MARTÍNEZ, M.; CAVIA, REGINO; LOVERA, ROSARIO

Conferencia; 23rd. International Conference of the World Association for the Advancement of Veterinary Parasitology; 2011

To date, there are few published reports in Argentina about the existence of Trichinella spiralis in wild animals. Knowledge of its presence in this kind of animals is important, especially in those endemic areas where pigs are raised outdoors and potentially in contact with them. Wild animals infected with Trichinella represent a risk not only for being a reservoir but also for helping the potential introduction of this parasite into a domestic swine population. Therefore, to know the occurrence of Trichinella in wild animals, we collected 220 samples in outer suburbs of Buenos Aires from six different species of small rodents (Rattus rattus, Rattus norvegicus, Mus musculus, Akodon azarae, Calomys laucha, Oligoryzomys flavescens) and a marsupial (Didelphis albiventris). Muscle samples from the trapped wild animals were then artificially digested to potentially isolate Trichinella. As a result, a low burden of putative T. spiralis could be isolated from three R. rattus, one R. norvegicus and a single D. albiventris. However, no larva was isolated from the other species. Larvae obtained from the positive samples were then identified as T. spiralis after performing a nested-multiplex PCR. Three of these larvae could further be identified to the genotype level through DNA sequencing. Although the burden of Trichinella spiralis found in the wildlife population was low (it varied from 0.6-3 larvae per gram among the different species), and Trichinella was not present in all the trapped wild animals, this finding confirms the presence of this parasite among feral animals and thus, this may represent a risk to the swine and human populations under the current pig management practices held in some areas of Argentina.