# European Pine Marten (Martes martes) as Natural Definitive Host of Sarcocystis Species in Latvia: Microscopic and Molecular Analysis

## TL;DR

European pine martens in Latvia host multiple Sarcocystis species, some of which can infect livestock and cause food poisoning.

## Contribution

First molecular identification of Sarcocystis species in European pine martens from Latvia, including a novel species.

## Key findings

- Nine Sarcocystis species were identified in pine marten intestinal samples, including a new species.
- Several Sarcocystis species found can infect livestock or cervids and may cause food poisoning.
- Co-infections with multiple Sarcocystis species were detected in 30% of the samples.

## Abstract

The pine marten (Martes martes) is a species of the family Mustelidae, widely distributed in the Baltic States. This predatory species can harbor a range of pathogens; however, its role in transmitting protozoan Sarcocystis parasites remains understudied. In the current investigation, we aimed to molecularly identify Sarcocystis species from intestinal samples of European pine martens from Latvia, focusing on the diagnosis of zoonotic and pathogenic ones. This is the first study to establish the richness of Sarcocystis species in the intestines of predators from Latvia. Overall, nine Sarcocystis species were identified: eight known ones, using cervids and livestock as their intermediate hosts, and a genetically new species, Sarcocystis sp. 25MmLV, closely related to S. wenzeli, which is known to be pathogenic for chickens. We report the first detection of S. entzeorthi, S. hjorti, S. truncata, and Sarcocystis sp. 25MmLV in European pine martens. Several of the Sarcocystis species that have been found can be pathogenic to farm animals or cervids. Furthermore, the detected S. truncata has been linked to food poisoning due to venison consumption.

Apicomplexan parasites of the genus Sarcocystis utilize a wide range of vertebrate hosts, including reptiles, birds, and mammals, and follow a complex two-host prey–predator life cycle. Sarcocysts develop within the muscle tissue of intermediate hosts, while oocyst sporulation occurs in the intestines of definitive hosts. Despite their broad host range, the role of Mustelidae predators in the transmission and maintenance of Sarcocystis species remains poorly understood, highlighting the need for targeted studies in this area. In 2023, 20 intestinal samples were collected from European pine martens (Martes martes) in Latvia. Light microscopy revealed sporocysts of Sarcocystis spp. in 70.0% of the samples. Sarcocystis species were identified by using the analysis of obtained cox1 and ITS1 sequences. Using molecular methods, Sarcocystis spp. were confirmed in 85.0% of the samples examined, and co-infections with two or more different parasite species were established in 30.0% samples. We detected eight Sarcocystis species (S. arieticanis, S. bertrami, S. capracanis, S. cruzi, S. entzerothi, S. hjorti, S. morae, and S. truncata) associated with intermediate hosts such as cervids, cattle, sheep, goats, and horses. Additionally, a genetically novel species, Sarcocystis sp. 25MmLV, was detected in a single European pine marten. These findings suggest that European pine martens serve as definitive hosts for multiple Sarcocystis species, particularly those infecting cervids.