Investigation of Drug Susceptibility in Rats Experimentally Infected with Trypanosoma evansi Isolated from Camels in Sudan

Abstract

A number of 18 adults male outbred albino rats, weighing between 133-137g were used to investigate the drug susceptibility of Trypanosoma evansi strain isolated from naturally infected dromedary camels in Umbadir area, North Kordofan State, Sudan. The rats were divided into 3 groups (C, D and F) of 6 animals each. Group C and D were infected intraperitoneally with T. evansi (Umbadir stabilate) with 1×10 4 Trypanosome for the inoculum. Group D rats were given quinapyramine sulphate (20 mg/Kg bwt) after parasitaemia was evident. Group F was left as healthy uninfected control for the stabilate. When parasite counts were one or more parasites per field, counting in haemocytometer were used for exact number of parasite per cubic millimeter using Neubaeur's counter. Parasites from tail blood were first fixed, stained and diluted in trypanosome diluting reagent. The parasites were diluted to the level that can be easily counted in WBC counting chamber in the haemocytometer. The total number of parasites was expressed as log 10 number of parasites per ml of blood. The presence and degree of parasitaemia were determined daily for each rat by examining tail blood. The identity of the local stabilates of Trypanosoma evansi was confirmed through adopting PCR where primers that target the internal transcribed spacer one (ITS1) of the ribosomal DNA were used. There was significant reduction in serum glucose and potassium as well as significant increase in total protein, urea, calcium, albumin and cholesterol in group C. The Umbadir stabilate showed low mortality and high sensitivity to quinapyramine sulphate.