Secretory microRNA Profiles of Third- and Fourth-Stage Dirofilaria immitis Larvae with Different Macrocyclic Lactone Susceptibility: In Search of Biomarkers for Early Detection of Infection

The canine heartworm, Dirofilaria immitis, is among the most important parasites of dogs in United States and worldwide, may cause severe potentially fatal disease. Current diagnostic recommendations rely on serological detection an adult female antigen, visualization microfilariae blood. Therefore, a reliable diagnosis can be only performed approximately six months post-infection. There growing need to characterize novel markers that are capable detecting early stages heartworm infection, special associated with third-stage larvae (L3) fourth-stage (L4). infection would guide medical interventions could impede development patent infections further parasite transmission. We cultured D. immitis L3 L4 two laboratorial strains different susceptibility statuses macrocyclic lactone drugs vitro. Excretory/secretory microRNAs were sequenced analyzed. identified miRNA candidates secreted abundantly by both strains. These previously detected secretions other one them was found blood immitis-infected dogs. miRNAs have not been nematodes immitis-specific biomarkers, which allow for infection.