ABSTRACT
In Chile, studies of parasites from the family Sarcocystidae (Apicomplexa) have mostly been related to domestic animals. We aimed to assess the presence of Sarcocystidae taxa in cricetid rodents from Central and Southern Chile. We studied 207 rodents, encompassing six species, from 13 localities. We isolated DNA from tissue samples, amplified the Sarcocystidae 18S rRNA gene with polymerase chain reaction, and performed phylogenetic analyses using maximum likelihood and Bayesian inferences. In addition, we examined blood smears and performed histological studies in organs from Sarcocystidae DNA-positive animals. Three specimens were DNA-positive and three genotypes were retrieved and named: Sarcocystis sp. P61, related to Sarcocystis strixi, was detected in two Abrothrix olivacea. Toxoplasmatinae gen. sp. P99 was retrieved from those same two specimens, and was related to Toxoplasma and other genera, although it branched independently. Besnoitia sp. R34 was detected in one Abrothrix hirta, and was clustered with congeneric species associated with rodents. No protozoa were found during microscopic studies; thus, it was not possible to confirm parasitic interactions rather than accidental encounters. However, the close relatedness of the retrieved genotypes to parasites of rodents supports the hypothesis of host-parasite associations. All three genotypes are suggested as potential new taxa, including a putative new genus.
ABSTRACT
Invasive populations are a threat to biodiversity, resulting in the loss of species, and also a threat to human health, participating in the reservoir of diseases. Rodents are among the most important invasive species worldwide. Chile is a country that features island conditions in terms of geography and has been widely invaded by allochthonous rodents. In this mini-review, we updated the literature on macro-parasites infecting both native and invasive rodents and of vector-borne pathogens in continental Chile in order to assess the relative importance of invasive rodents from both ecological and public health points of view. A total of 174 parasite species were found, with Siphonaptera representing the most diverse group. When examining how parasites are shared between native and introduced rodents, the analysis suggests that parasites circulate freely within recipient populations, and are not significantly transmitted from source populations. Further, generalist parasites are typically more prone to being shared between native and introduced rodents. Most zoonotic parasites were reported in invasive rodents, suggesting that these rodents must represent a public health concern. Although several vector-borne pathogens have been reported in rodents or ectoparasites, most of the recently emerging research has illustrated that there is a lack of evidence on rodent-vector-borne zoonoses in most pathogens.
