Email updates

Keep up to date with the latest news and content from Parasites & Vectors and BioMed Central.

Open Access Highly Accessed Research

Population genetic analysis and sub-structuring of Theileria parva in the northern and eastern parts of Zambia

Walter Muleya12, Boniface Namangala3, Martin Simuunza4, Ryo Nakao5, Noboru Inoue6, Takashi Kimura1, Kimihito Ito78, Chihiro Sugimoto58 and Hirofumi Sawa18*

Author Affiliations

1 Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, N20, W10, Kita-ku, Sapporo, 001-0020, Japan

2 Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, P.O Box 32379, Lusaka, 10101, Zambia

3 Department of Para-clinical Studies, School of Veterinary Medicine, University of Zambia, P.O Box 32379, Lusaka, 10101, Zambia

4 Department of Disease Control, School of Veterinary Medicine, University of Zambia, P.O Box 32379, Lusaka, 10101, Zambia

5 Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, N20, W10, Kita-ku, Sapporo, 001-0020, Japan

6 National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Hokkaido, 080-8555, Japan

7 Division of Bioinformatics, Research Center for Zoonosis Control, Hokkaido University, N20, W10, Kita-ku, Sapporo, 001-0020, Japan

8 Global COE program, Research Center for Zoonosis Control, Hokkaido University, N20, W10, Kita-ku, Sapporo, 001-0020, Japan

For all author emails, please log on.

Parasites & Vectors 2012, 5:255  doi:10.1186/1756-3305-5-255

Published: 12 November 2012

Abstract

Background

Theileriosis, caused by Theileria parva, is an economically important disease in Africa. It is a major constraint to the development of the livestock industry in some parts of eastern, central and southern Africa. In Zambia, theileriosis causes losses of up to 10,000 cattle annually.

Methods

Cattle blood samples were collected for genetic analysis of Theileria parva from Isoka and Petauke districts in Zambia. Microsatellite analysis was then performed on all Theileria parva positive samples for PCR using a panel of 9 microsatellite markers. Microsatellite data was analyzed using microsatellite toolkit, GenAlEx ver. 6, Fstat ver. 2.9.3.2, and LIAN computer softwares.

Results

The combined percentage of positive samples in both districts determined by PCR using the p104 gene primers was 54.9% (95% CI: 46.7 – 63.1%, 78/142), while in each district, it was 44.8% (95% CI: 34.8 – 54.8%) and 76.1% (95% CI = 63.9 – 88.4%) for Isoka and Petauke districts, respectively. We analyzed the population genetic structure of Theileria parva from a total of 61 samples (33 from Isoka and 28 from Petauke) using a panel of 9 microsatellite markers encompassing the 4 chromosomes of Theileria parva. Wright’s F index (FST = 0.178) showed significant differentiation between the Isoka and Petauke populations. Linkage disequilibrium was observed when populations from both districts were treated as a single population. When analyzed separately, linkage disequilibrium was observed in Kanyelele and Kalembe areas in Isoka district, Isoka district overall and in Petauke district. Petauke district had a higher multiplicity of infection than Isoka district.

Conclusion

Population genetic analyses of Theileria parva from Isoka and Petauke districts showed a low level of genotype exchange between the districts, but a high level of genetic diversity within each district population, implying genetic and geographic sub-structuring between the districts. The sub-structuring observed, along with the lack of panmixia in the populations, could have been due to low transmission levels at the time of sampling. However, the Isoka population was less diverse than the Petauke population.

Keywords:
Theileria parva; Genetic diversity; Sub-structuring; Zambia