Seroprevalence of bovine theileriosis in northern China.

Yaqiong Li,Jianxun Luo,Zhijie Liu,Youquan Li,Qian Li,Junlong Liu,Jifei Yang,Hong Yin,Guangyuan Liu,Pengfei Guo,Guiquan Guan

doi:10.1186/s13071-016-1882-x

Abstract

BackgroundBovine theileriosis is a common disease transmitted by ticks, and can cause loss of beef and dairy cattle worldwide. Here, an indirect enzyme-linked immunosorbent assay (iELISA) based on Theileria luwenshuni surface protein (TlSP) was developed and used to carry out a seroepidemiological survey of bovine theileriosis in northern China.MethodsWe used the BugBuster Ni-NTA His•Bind Purification Kit to purify recombinant TlSP (rTlSP), which was subsequently analyzed by Western Blotting to evaluate cross-reactivity with other pathogen-positive sera. The iELISA method based on rTlSP was successfully developed. Sera from 2005 blood samples were tested with the rTlSP-iELISA method, and blood smears from these samples were observed by microscopy.ResultsThe specificity of iELISA was 98.9%, the sensitivity was 98.5%, and the cut-off was selected as 24.6%. Western Blot analysis of rTlSP confirmed that there were cross-reactions with Theileria luwenshuni, Theileria uilenbergi, Theileria ovis, Theileria annulata, Theileria orientalis and Theileria sinensis. The epidemiological survey showed that the highest positive rate of bovine theileriosis was 98.3%, the lowest rate was 84.1%, and the average positive rate was 95.4% by iELISA. With microscopy, the highest positive rate was 38.9%, the lowest rate was 5.1%, and the relative average positive rate was 13.7%.ConclusionsAn rTlSP-iELISA was developed to detect circulating antibodies against bovine Theileria in northern China. This is the first report on the seroprevalence of bovine theileriosis in northern China, and it also provides seroepidemiological data on bovine theileriosis in China.

Highlights

Bovine theileriosis is a common disease transmitted by ticks, and can cause loss of beef and dairy cattle worldwide
Western blotting of recombinant Theileria luwenshuni surface protein (TlSP) (rTlSP) confirmed that there was specific recognition of the recombinant antigen rTlSP by the positive sera of T. luwenshuni, T. uilenbergi, T. ovis, T. annulata, T. orientalis and T. sinensis; but there was no specific recognition of rTlSP with the positive sera of B. bovis, B. bigemina, B. major, A. marginale, Br. abortus and Bovine epizootic fever virus (Fig. 2)
Cut-off, sensitivity and specificity of indirect enzyme-linked immunosorbent assay (iELISA) The cut-off, sensitivity and specificity were determined by 736 positive sera and 92 negative sera

Summary

Introduction

Bovine theileriosis is a common disease transmitted by ticks, and can cause loss of beef and dairy cattle worldwide. An indirect enzyme-linked immunosorbent assay (iELISA) based on Theileria luwenshuni surface protein (TlSP) was developed and used to carry out a seroepidemiological survey of bovine theileriosis in northern China. Bovine theileriosis can be diagnosed based on observing ticks feeding on cattle, superficial lymph node enlargement, Theileria schizonts in lymphocytes with microscopic examination, and other clinical symptoms [3, 9]. Theileria parasites can be detected and identified in animals and ticks by polymerase chain reaction (PCR) [13, 14], reverse line blot (RLB) hybridization assay [15, 16], and loop-mediated isothermal amplification (LAMP) [17, 18]. Some enzyme-linked immunosorbent assays (ELISAs) to detect circulating antibodies against T. annulata were developed based on recombinant protein T. annulata surface protein (TaSP) or Tams1 [22,23,24]. The ELISA method is widely applied as a cheap, fast and high-throughput method to screen and diagnose large numbers of clinical and field specimens

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