Effects of Artemisia annua on experimentally induced leucocytozoonosis in chickens

Abstract

The biting midge Culicoides arakawae is the vector for the parasite Leucocytozoon caulleryi. Birds infected with L. caulleryi develop leucocytozoonosis. Given the food safety concern regarding drug residue in eggs, discovering a natural alternative to antibiotics is a worthy of exploration. Thus, we investigated the effects of the antimalarial herb Artemisia annua on experimentally induced leucocytozoonosis in chickens. We reared C. arakawae in the laboratory. Eggs were cultured, developing into larvae, pupae, and imagoes. Female midges sucked the blood of sick chickens and then were ground into a solution injected into healthy chickens. The control group was given empty capsules daily, whereas the 2 experimental groups were given 40 mg/kg sulfadimethoxine or 0.5 g of A. annua powder. Leucocytozoon gametocytes were detected in chicken blood through Giemsa staining. PCR detected the cytochrome b gene of L. caulleryi in the infected chickens. No significant among-group differences in body weight gain were observed before d 14 postinoculation (P > 0.05). Body weight gain in the control group was significantly lower from day 14 to 28 postinoculation (P < 0.05). After day 14, rectal temperature in the experimental groups decreased significantly compared with that in the control group. Lower rates of pale comb and green feces were observed in the animals receiving treatment from day 0. The experimental groups had a higher recovery rate and recovered earlier than did the control group. By day 31, all the animals had recovered. PCR detected L. caulleryi in the infected chickens with high sensitivity and accuracy. The animals receiving A. annua exhibited increased weight gain and reduced parasite concentrations in the blood. This in turn reduced mortality and the occurrence of pale comb and green feces. The findings are informative for research on leucocytozoonosis.

Keywords: Artemisia annua; Culicoides arakawae; Leucocytozoon caulleryi; leucocytozoonosis; molecular diagnosis.