Identification and Molecular Characterization of Trematode and Nematode in Fleas Infesting Small Ruminants in Egypt

The present study aimed to determine the prevalence and distribution of flea-infested ruminants in Egypt's Northern West Coast (NWC) and South Sinai Governorate (SSG), besides the molecular characterization and genotypes of Nematode and Trematode in the identified flea species. In total, 765 animals of both sexes and ages (471 from NWC and 294 from SSG) were examined for flea infestation, including 460 sheep and 305 goats. Microscopically, flea species were identified; while nematodes and trematodes were identified using sequence analysis of purified PCR fragments of the small subunits 18S of nuclear ribosomal DNA (18S rDNA) and the internal transcribed spacer region of the ribosomal RNA (ITS2) gene primers. The results revealed that the cat flea, Ctenocephalides felis, and the dog flea, Ctenocephalides canis, were widely distributed in sheep and goat flocks throughout the corresponding areas. While age, sex, and host had no significant differences (P > 0.5), the location, flea species, and season of flea collection all had an impact on the predominance of the two flea species. Additionally, there were significant differences between C. felis and C. canis infestations in the two areas, and only among the sexes of both flea species in the NWC. Molecular data confirmed one trematode (Fasciola hepatica) in both C. felis and C. canis, whereas two nematode species were identified: Haemonchus contortus only in sheep in both areas and Trichostrongylus colubriformis only in C. canis infesting goats in SSG. Sequenced isolates were assigned in the GenBank database under accession numbers ON123999, ON123994, ON123995, and ON123993 (F. hepatica), ON113484, ON113485, and ON113486 (H. contortus), and ON113498 (T. colubriformis). We conclude that the presence of those pathogens in fleas in the two areas required special attention to periodic flea control programmes and anthelmintic treatments, as well as further evaluation of the epidemiology and role of fleas.