Morphological and molecular characterization of Linguatula serrata and evaluation of the health status of the infested dogs

Linguatula serrata is a neglected parasitic zoonosis with less research recorded throughout the globe on the physiological and immunological alteration of dogs infested by these zoonotic parasites. This study aimed to evaluate the effects of L. serrata infestation on the dogs after experimental infestation with the nymphs by determining oxidative stress levels and immunological genes of cellular immunity. Larvae of L. serrata were collected from the infested goat mesenteric lymph nodes by cutting it, and the nymphs were liberated; these nymphs were mixed with saline at 37–40 °C for experimental infestation of dogs and observed infestation to puppies using viable nymphal stages (movable, not traumatized or dead). Blood and sera samples were sampled from the dog after 6 months of infestation. The nasal mucosa and its mucus were collected from the infested dogs as well as negative controls for evaluation of gene expression such as tumor necrosis factor-alpha (TNF-α) and gamma interferon (IFN-γ) activity and interleukin (1β and 6). Infested dogs exhibited lower hemoglobin concentration, packed cell volume (PCV), and total erythrocyte count than non-infested control dogs. Dogs had high AST and ALT levels, leukocytosis with prominent eosinophilia, and low hematological values. The oxidative stress was higher in experimentally infested dogs than control non-infested dogs. The genetic characterization of the nymphal stage of L. serrata was recorded as the first confirmation in Egypt. The four examined genes were expressed regularly against nasopharynx linguatulosis in experimentally infested dogs. This study is the first report on the genetic characterization of L. serrata from goat origin in Egypt.