Prevalence of tick-borne haemoparasites in small ruminants in Turkey and diagnostic sensitivity of single-PCR and RLB

Huseyin Bilgin Bilgic,Tulin Karagenc,Serkan Bakırcı,Onur Kose,William Weir,Ahmet Hakan Unlu,Selin Hacılarlıoglu,Hasan Eren

doi:10.1186/s13071-017-2151-3

Huseyin Bilgin Bilgic, Tulin Karagenc + Show 6 more

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https://doi.org/10.1186/s13071-017-2151-3

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Abstract

BackgroundTick-borne haemoparasitic diseases (TBHDs), caused by Theileria, Babesia, Anaplasma and Ehrlichia, are common in regions of the world where the distributions of host, pathogen and vector overlap. Many of these diseases threaten livestock production and some also represent a concern to human public health. The primary aim of this study was to determine the prevalence of the above-mentioned pathogens in a large number of blood samples (n = 1979) collected from sheep (n = 1727) and goats (n = 252) in Turkey. A secondary aim was to assess the diagnostic sensitivity of a number of species-specific polymerase chain reaction (PCR) tests and the reverse line blotting (RLB) assay. DNA samples were screened using species-specific PCR for the presence of Theileria ovis, Theileria sp. MK, T. lestoquardi, T. uilenbergi, T. luwenshuni, Babesia ovis, Anaplasma ovis and A. phagocytophilum while RLB was undertaken to test for the presence of all known Theileria, Babesia, Anaplasma and Ehrlichia species. The diagnostic sensitivity of these two approaches was then compared in terms of their ability to detect single species and mixed infections.ResultsOverall, 84 and 74.43% of the small ruminants sampled were identified as hosting one or more pathogen(s) by species-specific PCR and RLB respectively. The presence of Theileria sp. OT1, T. luwenshuni and T. uilenbergi in Turkey was revealed for the first time while the presence of Babesia motasi, B. crassa and T. separata in Turkish small ruminants was confirmed using molecular methods. A high prevalence of mixed infection was evident, with PCR and RLB approaches indicating that 52.24 and 35.42% of animals were co-infected with multiple species, respectively. More than 80% of the mixed infections contained T. ovis and/or A. ovis. The RLB approach was found to be capable of detecting mixed infections with species such as Theileria sp. OT1, Theileria sp. OT3, T. separata, B. crassa and Babesia spp.ConclusionThe results indicated that pathogens causing TBHDs are highly prevalent in sheep and goats in Turkey. The diagnostic sensitivity of species-specific single PCR was generally higher than that of RLB. However, the latter approach was still capable of identifying a high proportion of individuals containing mixed-species infections. The use of species-specific single PCR is recommended to accurately estimate pathogen prevalence and to identify co-infected hosts.

Highlights

Tick-borne haemoparasitic diseases (TBHDs), caused by Theileria, Babesia, Anaplasma and Ehrlichia, are common in regions of the world where the distributions of host, pathogen and vector overlap
B. motasi, A. phagocytophilum, T. lestoquardi, T. luwenshuni and T. uilenbergi are considered to be pathogenic, while T. ovis, T. separata and B. crassa are considered to be non-pathogenic in sheep and goats
Prevalence of Theileria, Babesia, Ehrlichia and Anaplasma spp. determined by reverse line blotting (RLB) The prevalence and distribution of single and mixedspecies infections are summarised in Table 1 and in Additional file 4: Table S4, respectively

Summary

Introduction

Tick-borne haemoparasitic diseases (TBHDs), caused by Theileria, Babesia, Anaplasma and Ehrlichia, are common in regions of the world where the distributions of host, pathogen and vector overlap. Many of these diseases threaten livestock production and some represent a concern to human public health. Tick-borne haemoparasitic diseases (TBHDs) caused by protozoans (Theileria, Babesia) and bacteria (Anaplasma/ Ehrlichia) impose a serious constraint upon livestock health and production in tropical and sub-tropical regions where the distributions of host, pathogen and vector overlap [1]. B. motasi, A. phagocytophilum, T. lestoquardi, T. luwenshuni and T. uilenbergi are considered to be pathogenic, while T. ovis, T. separata and B. crassa are considered to be non-pathogenic in sheep and goats. MK [2, 5, 7, 9,10,11,12,13,14]

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