Molecular Detection and Characterization of Rickettsia Species in Ixodid Ticks Collected From Cattle in Southern Zambia

Simbarashe Chitanga; Kennedy Chibesa; Karen Sichibalo; Benjamin Mubemba; King S Nalubamba; Walter Muleya; Katendi Changula; Edgar Simulundu

doi:10.3389/fvets.2021.684487

Molecular Detection and Characterization of Rickettsia Species in Ixodid Ticks Collected From Cattle in Southern Zambia

Front Vet Sci. 2021 Jun 7:8:684487. doi: 10.3389/fvets.2021.684487. eCollection 2021.

Authors

Simbarashe Chitanga^{1

2

3}, Kennedy Chibesa^{1

4}, Karen Sichibalo¹, Benjamin Mubemba^{5

6}, King S Nalubamba⁷, Walter Muleya⁸, Katendi Changula⁹, Edgar Simulundu^{10

11}

Affiliations

¹ Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka, Zambia.
² Department of Pathobiology, School of Veterinary Medicine, University of Namibia, Windhoek, Namibia.
³ School of Life Sciences, College of Agriculture, Engineering and Sciences, University of KwaZulu-Natal, Durban, South Africa.
⁴ Centre for Infectious Diseases Research in Zambia, Lusaka, Zambia.
⁵ Department of Wildlife Sciences, School of Natural Resources, Copperbelt University, Kitwe, Zambia.
⁶ Department of Biomedical Sciences, School of Medicine, Copperbelt University, Ndola, Zambia.
⁷ Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia.
⁸ Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia.
⁹ Department of Paraclinical Studies, School of Veterinary Sciences, University of Zambia, Lusaka, Zambia.
¹⁰ Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia.
¹¹ Macha Research Trust, Choma, Zambia.

Abstract

Tick-borne zoonotic pathogens are increasingly becoming important across the world. In sub-Saharan Africa, tick-borne pathogens identified include viruses, bacteria and protozoa, with Rickettsia being the most frequently reported. This study was conducted to screen and identify Rickettsia species in ticks (Family Ixodidae) infesting livestock in selected districts of southern Zambia. A total of 236 ticks from three different genera (Amblyomma, Hyalomma, and Rhipicephalus) were collected over 14 months (May 2018-July 2019) and were subsequently screened for the presence of Rickettsia pathogens based on PCR amplification targeting the outer membrane protein B (ompB). An overall Rickettsia prevalence of 18.6% (44/236) was recorded. Multi-locus sequencing and phylogenetic characterization based on the ompB, ompA, 16S rRNA and citrate synthase (gltA) genes revealed the presence of Rickettsia africae (R. africae), R. aeschlimannii-like species and unidentified Rickettsia species. While R. aeschlimannii-like species are being reported for the first time in Zambia, R. africae has been reported previously, with our results showing a wider distribution of the bacteria in the country. Our study reveals the potential risk of human infection by zoonotic Rickettsia species and highlights the need for increased awareness of these infections in Zambia's public health systems.

Keywords: Rickettsia; Zambia; febrile illness; tick-borne zoonoses; ticks.

Grants and funding

R01 AI136035/AI/NIAID NIH HHS/United States