Molecular identification of Trichinella isolates from wildlife animals of the Russian Arctic territories

The parasitic nematodes of genus Trichinella are infective to a wide range of hosts, including humans, and have global distribution from tropic to arctic areas. Muscle samples from animals, collected in two areas of the Russian Federation, Chukotka Peninsula and Arkhangelsk Oblast, were tested for the presence of Trichinella spp. larvae. Trichinella spp. larvae were recovered from tissues of eleven wild and domestic animals: 1 polar bear, 1 wolverine, 3 arctic foxes, 1 ringed seal, 1 brown bear, 1 cat, 1 sled dog, 1 domestic pig and 1 northern sea lion.

Two molecular methods, multiplex PCR and inter-simple sequence repeat polymerase chain reaction (ISSR PCR), were utilized for species identification. T. nativa was identified in the majority of tested animals and mixed infections with two Trichinella species were detected in four animals. T. spiralis/T. pseudospiralis mixed infection was found in a domestic pig and T. spiralis/T. nativa in two arctic foxes and a northern sea lion.

Here, for the first time, Trichinella spp. infection in a northern sea lion and the northern sea lion as a new host for T. spiralis and T. nativa is reported. Discovery of Trichinella spp. infection in a new host, such as a northern sea lion, which is an opportunistic marine predator, mainly feeding on fish, indicates environmental contamination. Leaving of carcasses or waste from animals and improper management of livestock operations is important for spreading Trichinella spp. infection in free living animals. Therefore, further extensive epidemiological and environmental research and molecular studies are needed to investigate the local fauna.