Molecular Characterization and Prevalence of Intestinal Parasites in Oreochromis niloticus (Nile Tilapia) from Ureje Reservoir, Ado-Ekiti, Nigeria

Abstract

Oreochromis niloticus commonly known as Nile Tilapia, is a widely distributed freshwater fish, largely consumed in Nigeria. Intestinal parasites pose a significant threat to its cultivation and consumption. This study aimed at determining the prevalence and molecular characterization of parasites isolated from Nile Tilapia collected from Ureje reservoir, in Ado-Ekiti, Nigeria. A total of two hundred and forty live Tilapia fishes were examined for intestinal parasites using a combination of microscopy and molecular techniques. The Oreochromis niloticus samples were examined for intestinal parasites using a combination of microscopy and molecular techniques. The parasitological examination of Oreochromis niloticus from Ureje Reservoir revealed the presence of five different species of intestinal parasites namely Schistosoma japonicum, Schistosoma mansoni, Ascaris lumbricoides, Eustrongylides sp., and Ancylostoma duodenale. Among the identified species Schistosoma japonicum had the highest number of occurrences (189) and Ancylostoma duodenale had the lowest number of occurrences (6). Microscopic analysis of fecal samples further confirmed the presence of parasitic eggs and cysts. The PCR and sequencing results confirmed the presence of Schistosoma japonicum, Schistosoma mansoni, Ascaris lumbricoides, and Eustrongylides sp. in the fish samples. The phylogenetic analysis (Fig. 1) further showed that the parasite isolates clustered closely with known reference strains, indicating that the identified species are consistent with those reported in other studies. The study concluded that a high prevalence of parasitic infection of Tilapia fish can pose a significant threat to human health. It is therefore recommended that proper hygiene and proper cooking conditions are maintained in the preparation of Tilapia fish for consumption.