Presence of gastrointestinal and bronchopulmonary parasites in Cantabrian brown bears

Abstract

The Cantabrian brown bear (Ursus arctos) population is threatened although in a constant process of recovery during the last 20 years. Since data on the parasitological status of this bear is still limited, the objective of the present study was to assess the diversity and prevalence of parasites in this population. Thus, 111 bear faecal samples were collected in north-western Spain and analysed for estimating the occurrence of gastrointestinal and bronchopulmonary parasites. Samples were processed by flotation in saline and sucrose solution, sedimentation and Baermann-Wetzel techniques. In addition, a commercial immunofluorescent assay was performed for detecting Giardia duodenalis and Cryptosporidium spp. Dicrocoelium dendriticum was the most prevalent parasite (58.6%), followed by Baylisascaris transfuga (43.2%) and nematodes of the Suborder Strongylida (18.9%) and Spirurida (2.7%). Mixed infections were detected in the 41.4% of the samples. The presence of D. dendriticum was significantly highest in bears from the autonomous region of Castile and León as well as in those in which grass or nuts/acorns were the predominant food item. Moreover, the risk of being positive to B. transfuga was significantly higher during autumn–winter, and in those, faecal samples were mainly composed of fleshy fruit. Some of the parasites detected could infect other wildlife and even humans, and therefore, the risk of pathogen transmission deserves further investigation. Since the impact of endoparasites in the health status of bears is poorly understood, the establishment of a disease surveillance protocol is strongly recommended in order to assess the potential risk of these infections for bears.

Non-invasive surveillance of shared pathogens in the Eurasian brown bear (Ursus arctos) human interface

“…Nevertheless, assemblage A (unknown sub-assemblage) was previously identified in a brown bear fecal sample collected in the same region (GenBank accession number: PP312933), being the first report on the molecular diversity of Giardia infection in wild bears globally. Giardia cysts were identified in resident polar bears ( Ursus maritimus ) in Alaska [ 37 ], but the parasite was not detected in brown bears from Croatia, the United States, and Spain [ 15 , 38 , 39 ]. Of note, Cryptosporidium spp., E. bieneusi , and Blastocystis sp.…”

“…and Baylisascaris spp. have been described [ 9 , 15 , 16 ]. All those pathogens are shared between domestic animals, wildlife and in some cases humans, and in most instances are transmitted through indirect contacts (i.e., shared habitats and resources) at the interface [ 1 , 13 ].…”