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Gastrointestinal nematode (GIN) infections have negative impacts on animal health, welfare and production. Information from molecular studies can highlight the underlying genetic mechanisms that enhance host resistance to GIN. However, such information often lacks for traditionally managed indigenous livestock. Here, we analysed 600 K single nucleotide polymorphism genotypes of GIN infected and non-infected traditionally managed autochthonous Tunisian sheep grazing communal natural pastures. Population structure analysis did not find genetic differentiation that is consistent with infection status. However, by contrasting the infected versus non-infected cohorts using ROH, LR-GWAS, FST and XP-EHH, we identified 35 candidate regions that overlapped between at least two methods. Nineteen regions harboured QTLs for parasite resistance, immune capacity and disease susceptibility and, ten regions harboured QTLs for production (growth) and meat and carcass (fatness and anatomy) traits. The analysis also revealed candidate regions spanning genes enhancing innate immune defence (SLC22A4, SLC22A5, IL-4, IL-13), intestinal wound healing/repair (IL-4, VIL1, CXCR1, CXCR2) and GIN expulsion (IL-4, IL-13). Our results suggest that traditionally managed indigenous sheep have evolved multiple strategies that evoke and enhance GIN resistance and developmental stability. They confirm the importance of obtaining information from indigenous sheep to investigate genomic regions of functional significance in understanding the architecture of GIN resistance. [ABSTRACT FROM AUTHOR]

Dirofilaria immitis and Dirofilaria repens are mosquito-borne nematodes which infect primarily dogs as their main definitive hosts. They cause cardiopulmonary ( D. immitis) or cutaneous ( D. repens) dirofilariasis in canids and other carnivores and can accidentally be transmitted to humans where they can induce a variety of clinical outcomes depending on organ localization. Dirofilaria spp. infection in dogs was assessed using molecular methods ( PCR and sequencing) to identify the different Dirofilaria species occurring in 200 dogs from Northern and Central Tunisia. The overall molecular prevalence of Dirofilaria spp. was 17.5% (35/200). The prevalence of D. immitis (14.5%) was significantly higher than for D. repens (3%). Molecular prevalence of D. immitis was significantly higher in suburban compared to urban and rural regions. There was no difference in molecular prevalence of D. immitis or D. repens according to the dogs' (sex or use). Dirofilaria immitis amplicons (accession numbers ) fall into the same clade with D. immitis from China, India and Taiwan. Comparison of the partial sequences of D. repens ITS2 rDNA gene () revealed 99.6% similarity with D. repens reported in dogs from USA. It had also 97.6% similarity with D. repens from mosquitoes in Czech Republic. High dog parasite burdens should motivate both medical doctors and veterinarians to consider these frequent infections. [ABSTRACT FROM AUTHOR]

Summary: Sarcocystosis is a parasitic disease caused by varying Sarcocystis species infecting humans and animals. It is commonly found in small ruminants causing pathogenic effects. This contributes to detrimental economic loss for local farmers and the local economy due this disease. Although the distribution of Sarcocystis can be found all over the world, the species infecting small ruminants in Tunisia is still unknown. Through this study, we aim to estimate the molecular prevalence of natural infection with Sarcocystis spp. in sheep and goats using molecular identification. Also, phylogenetic analyses were used to identify the different species of this parasite infecting small ruminants in northern Tunisia for the first time. DNA was extracted from 198 and 121, sheep and goats meat samples, respectively. The molecular prevalence of Sarcocystis spp. in sheep and goats was 58.6% (116/198) and 50.4% (61/121), respectively. Compared to the Noire de Thibar and cross‐breeds, the Barbarine sheep had the highest infection prevalence (63.4%) (p = .004). Five of the 116 positive samples were sequenced identifying Sarcocystis tenella from sheep. For goats, the sequencing results showed that five positive PCR products belonged to Sarcocystis capracanis species. [ABSTRACT FROM AUTHOR]