Iberian wild leporidae as hosts of zoonotic enteroparasites in Mediterranean ecosystems of Southern Spain

Wild lagomorphs including rabbits and hares can act as natural carriers or reservoirs of bacterial and parasitic zoonotic diseases. However, little is known on the epidemiology and potential public health significance of intestinal eukaryotes in wild leporids. We examined faecal samples from European wild rabbits (Oryctolagus cuniculus, n = 438) and Iberian hares (Lepus granatensis, n = 111) collected in the Autonomous Region of Andalusia in southern Spain during 2012-2021. We searched for the presence of DNA from the main intestinal protist and microsporidial pathogens of veterinary and public health concerns using molecular methods (PCR followed by Sanger and next-generation sequencing). Giardia duodenalis was the most prevalent species found (27.8%, 153/550; 95% CI: 24.1-31.8), followed by Cryptosporidium spp. (1.3%, 7/550; 95% CI: 0.5-2.6), Blastocystis sp. (1.1%, 6/550; 95% CI: 0.4-2.4) and Encephalitozoon intestinalis (0.2%, 1/550; 95% CI: 0.0-10.1). All samples tested negative for Enterocytozoon bieneusi. Sequence analyses revealed the presence of sub-assemblage BIV (n = 1) within G. duodenalis, and Cryptosporidium cuniculus (n = 6) and Cryptosporidium andersoni (n = 1) within Cryptosporidium. The presence of ruminant-adapted C. andersoni is indicative of a potential cross-species transmission event, although a spurious infection (mechanical carriage) cannot be ruled out. Samples assigned to C. cuniculus belonged to the gp60 subtype families Va (n = 3) and Vb (n = 2). The six Blastocystis-positive samples were identified as ST2 (n = 3) and ST1 + ST2 (n = 3). Our molecular results suggest that wild rabbits and hares were primarily infected by leporid-adapted species of eukaryotic pathogens. However, the occasional findings of zoonotic G. duodenalis sub-assemblage BIV, Blastocystis sp. ST1 and ST2, and Encephalitozoon intestinalis could be of public health relevance.

Wild micromammal host spectrum of zoonotic eukaryotic parasites in Spain. Occurrence and genetic characterisation

Micromammals have historically been recognized as highly contentious species in terms of the maintenance and transmission of zoonotic pathogens to humans. Limited information is currently available on the epidemiology and potential public health significance of intestinal eukaryotes in wild micromammals. We examined 490 faecal samples, grouped into 155 pools, obtained from 11 micromammal species captured in 11 Spanish provinces for the presence of DNA from Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and Blastocystis sp. The presence of Leishmania spp. was investigated in individual spleen samples. All micromammal species investigated harboured infections by at least one eukaryotic parasite, except Apodemus flavicollis, Myodes glareolus, Sorex coronatus and Sciurus vulgaris, but the sample size for these host species was very low. Cryptosporidium spp. was the most prevalent species found (3.7%, 95% confidence interval [CI]: 2.2-5.7), followed by G. duodenalis (2.8%, 95% CI: 1.6-4.6) and E. bieneusi (2.6%, 95% CI: 1.4-4.3). All pooled faecal samples tested negative for Blastocystis sp. Leishmania infantum was identified in 0.41% (95% CI: 0.05-1.46) of the 490 individual spleen samples analysed. Sequence analyses allowed the identification of Cryptosporidium andersoni (5.9%), C. ditrichi (11.7%), C. muris (5.9%), C. parvum (5.9%), C. tyzzeri (5.9%), rat genotypes CR97 (5.9%) and W19 (5.9%), vole genotypes V (11.7%) and VII (5.9%) and Cryptosproridium spp. (35.3%) within Cryptosporidium (n = 17). Known genotypes C (66.7%) and Peru11 (25.0%) and a novel genotype (named MouseSpEb1, 8.3%) were detected within E. bieneusi (n = 12). None of the G. duodenalis-positive samples could be genotyped at the assemblage level. Molecular data indicate that wild micromammals were primarily infected by rodent-adapted species/genotypes of eukaryotic pathogens and thereby have a limited role as a source of human infections. The presence of ruminant-adapted species C. andersoni along with finding C. parvum is indicative of an overlap between domestic/peri-domestic and sylvatic transmission cycles of these agents.