Dynamics and within-host interaction of Theileria lestoquardi and T. ovis among naive sheep in Oman

Awad, H. et al. (2020) Dynamics and within-host interaction of Theileria lestoquardi and T. ovis among naive sheep in Oman. Scientific Reports, 10, 19802. (doi: 10.1038/s41598-020-76844-2) (PMID:33188233) (PMCID:PMC7666211)

Abstract

Mixed species infections of Theileria spp. are common in nature. Experimental and epidemiological data suggest that mixed species infections elicit cross-immunity that can modulate pathogenicity and disease burden at the population level. The present study examined within-host interactions, over a period of 13 months during natural infections with two Theileria spp., pathogenic (T. lestoquardi) and non-pathogenic (T. ovis), amongst a cohort of naive sheep in Oman. In the first two months after exposure to infection, a high rate of mortality was seen among sheep infected with T. lestoquardi alone. However, subsequently mixed-infections of T. lestoquardi and T. ovis prevailed, and no further death occurred. The overall densities of both parasite species were significantly higher as single infection vs mixed infection and the higher relative density of pathogenic T. lestoquardi indicated a competitive advantage over T. ovis in mixed infection. The density of both species fluctuated significantly over time, with no difference in density between the very hot (May to August) and warm season (September to April). A high degree of genotype multiplicity was seen among T. lestoquardi infections, which increased with rising parasite density. Our results illustrate a potential competitive interaction between the two ovine Theileria spp., and a substantial reduction in the risk of mortality in mixed parasite infections, indicating that T. ovis confers heterologous protection against lethal T. lestoquardi infection.

• Item Type: Articles
• Additional Information: This research is supported by Gulf States Cooperation Council grant (GCC)CL/SQU-GCC/17/01.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Shiels, Professor Brian
• Authors: Awad, H., Gadalla, A. A.H., Postigo, M., Al-Hamidhi, S., Tageldin, M. H., Skariah, S., Sultan, A. A., Johnson, E. H., Shiels, B., Pain, A., Thompson, J., and Babiker, H. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Scientific Reports
• Publisher: Nature Research
• ISSN: 2045-2322
• ISSN (Online): 2045-2322
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Scientific Reports 10: 19802
• Publisher Policy: Reproduced under a Creative Commons License