Isolation of infectious Theileria parva sporozoites secreted by infected Rhipicephalus appendiculatus ticks into an in vitro tick feeding system

Parasites & Vectors

George Chaka¹  Maxime Madder²  Rubikah Vimonish³  Donald P. Knowles³  Reginaldo G. Bastos³  Kelcey D. Dinkel³  Janaina Capelli-Peixoto³  Lindsay M. Fry⁴  Massaro W. Ueti⁵  Wendell C. Johnson⁶  Glen A. Scoles⁷ 

[1] Centre for Ticks and Tick-Borne Diseases, 309200, Lilongwe, Malawi;Clinglobal, Black River, 90903, Tamarin, Mauritius;Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, 99164-7040, Pullman, WA, USA;Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, 99164-7040, Pullman, WA, USA;USDA-ARS-Animal Diseases Research Unit, 99164-6630, Pullman, WA, USA;Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, 99164-7040, Pullman, WA, USA;USDA-ARS-Animal Diseases Research Unit, 99164-6630, Pullman, WA, USA;Paul G. Allen School for Global Animal Health, Washington State University, 99164, Pullman, WA, USA;USDA-ARS-Animal Diseases Research Unit, 99164-6630, Pullman, WA, USA;USDA-ARS-Animal Diseases Research Unit, 99164-6630, Pullman, WA, USA;Invasive Insect Biocontrol and Behavior Lab, USDA, ARS, 20705, Beltsville, MD, USA;

关键词: In vitro tick feeding system;    Theileria parva;    Rhipicephalus appendiculatus;   

DOI  :  10.1186/s13071-021-05120-7

来源: Springer

【 摘 要 】

BackgroundVector-borne diseases pose an increasing threat to global food security. Vaccines, diagnostic tests, and therapeutics are urgently needed for tick-borne diseases that affect livestock. However, the inability to obtain significant quantities of pathogen stages derived from ticks has hindered research. In vitro methods to isolate pathogens from infected tick vectors are paramount to advance transcriptomic, proteomic, and biochemical characterizations of tick-borne pathogens.MethodsNymphs of Rhipicephalus appendiculatus were infected with Theileria parva by feeding on a calf during an acute infection. Isolation of sporozoites was accomplished by feeding infected adult ticks on an in vitro tick feeding system. Sporozoite viability was tested using in vitro bovine lymphocytes.ResultsWe isolated infectious T. parva sporozoites secreted into an in vitro tick feeding system. Infected adult R. appendiculatus ticks attached to and successfully fed on silicone membranes in the in vitro tick feeding system. Bovine blood in the receptacle was replaced with cell-free medium and the ticks were allowed to feed for 3 h to collect secreted T. parva sporozoites. Secreted sporozoites infected in vitro bovine lymphocytes, demonstrating that isolated sporozoites remained viable and infectious.ConclusionsThis work is the first to report the isolation of mature infectious T. parva sporozoites using an in vitro tick feeding system, which represents a significant step towards the development of a more efficient control strategy for T. parva. Isolation of infectious tick-stage parasites will facilitate the examination of the vector-pathogen interface, thereby accelerating the development of next-generation vaccines and treatment interventions for tick-borne pathogens.Graphical Abstract

【 授权许可】

CC BY