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Elati K, Nijhof AM, Mwamuye MM, Ameen V, Mhadhbi M, Darghouth MA, Obara I. Sequence polymorphisms in a Theileria annulata surface protein (TaSP) known to augment the immunity induced by live attenuated cell line vaccine. Transbound Emerg Dis 2022; 69:3350-3359. [PMID: 36043476 DOI: 10.1111/tbed.14687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 07/03/2022] [Accepted: 08/18/2022] [Indexed: 02/07/2023]
Abstract
Theileria annulata is a tick-borne protozoan causing tropical theileriosis in cattle. The use of attenuated cell line vaccines in combination with subunit vaccines has been relatively successful as a control method, as exemplified by a recent study in which immunization with a local cell line followed by booster vaccinations with recombinant T. annulata surface protein (TaSP) resulted in 100% protection upon field challenge in Sudan. However, these findings cannot be directly extrapolated to other countries as culture-attenuated live vaccines are generated using local strains and no systematic evaluation of genotype differences between countries has been undertaken. In this study, we sequenced the TaSP gene from T. annulata cell lines and field isolates from Tunisia (n = 28) and compared them to genotypes from Sudan (n = 25) and Morocco (n = 1; AJ316259.1). Our analyses revealed 20 unique TaSP genotypes in the Tunisian samples, which were all novel but similar to genotypes found in Asia. The impact of these polymorphisms on the ability of the TaSP antigen to boost the immunity engendered by live cell line vaccines, especially in Tunisia where studies with TaSP have not been conducted, remains to be examined. Interestingly, phylogenetic analyses of publicly available TaSP sequences resolved the sequences into two clusters with no correlation to the geographical origin of the isolates. The availability of candidate vaccines that were recently attenuated using local strains from Sudan, Tunisia, Egypt and Morocco should be exploited to generate a comprehensive catalogue of genetic variation across this regional collection of attenuated live vaccines.
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Affiliation(s)
- Khawla Elati
- Laboratoire de Parasitologie, Institution de la Recherche et de l'Enseignement Supérieur Agricoles & Université de Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet, Tunisia.,Freie Universität Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Berlin, Germany
| | - Ard Menzo Nijhof
- Freie Universität Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Berlin, Germany
| | - Micky M Mwamuye
- Freie Universität Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Berlin, Germany.,Department of Environment and Natural Resource Management, Africa Nazarene University, Nairobi, Kenya
| | - Vahel Ameen
- Freie Universität Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Berlin, Germany
| | - Moez Mhadhbi
- Laboratoire de Parasitologie, Institution de la Recherche et de l'Enseignement Supérieur Agricoles & Université de Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet, Tunisia
| | - Mohamed Aziz Darghouth
- Laboratoire de Parasitologie, Institution de la Recherche et de l'Enseignement Supérieur Agricoles & Université de Manouba, École Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet, Tunisia
| | - Isaiah Obara
- Freie Universität Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Berlin, Germany
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