Development of a novel immunochromatographic lateral flow assay specific for Mycobacterium bovis cells and its application in combination with immunomagnetic separation to test badger faeces

BMC Veterinary Research

Research Article

Roland Ashford¹  Nuria Tort²  Paul Meakin²  Irene R. Grant³  Jose M. Argudo³  Linda D. Stewart³  Ruramayi Nzuma³  W. Ian Montgomery⁴  Neil Reid⁴  Richard J. Delahay⁵ 

[1] Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, Surrey, UK;Forsite Diagnostics Limited (now Abingdon Health), National Innovation Campus, Sand Hutton, York, UK;Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, Northern Ireland, UK;Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, Northern Ireland, UK;Quercus, School of Biological Sciences, Belfast, Northern Ireland, UK;National Wildlife Management Centre, Animal and Plant Health Agency, Woodchester Park, Nympsfield, Gloucestershire, UK;

关键词: Mycobacterium bovis;    Meles meles;    Faeces;    immunomagnetic separation;    Lateral flow device;    Non-invasive test;    Diagnostic specificity;    Diagnostic sensitivity;   

DOI  :  10.1186/s12917-017-1048-x

 received in 2017-02-28, accepted in 2017-05-04,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe European badger is an important wildlife reservoir of Mycobacterium bovis implicated in the spread of bovine tuberculosis in the United Kingdom and Ireland. Infected badgers are known to shed M. bovis in their urine and faeces, which may contaminate the environment. To aid bovine tuberculosis control efforts novel diagnostic tests for detecting infected and shedding badgers are needed. We proposed development of a novel, rapid immunochromatographic lateral flow device (LFD) as a non-invasive test to detect M. bovis cells in badger faeces. Its application in combination with immunomagnetic separation (IMS) to detect Mycobacterium bovis cells in badger faeces is reported here.ResultsA novel prototype LFD for M. bovis cells was successfully developed, with unique specificity for M. bovis and a limit of detection 50% (LOD50%) of 1.7 × 104 M. bovis cells/ml. When IMS was employed to selectively capture and concentrate M. bovis cells from badger faeces prior to LFD testing, the LOD50% of the IMS-LFD assay was 2.8 × 105 M. bovis cells/ml faecal homogenate. Faeces samples collected from latrines at badger setts in a region of endemic bovine tuberculosis infection were tested; 78 (18%) of 441 samples tested IMS-LFD assay positive, whereas 140 (32%) tested IMS-qPCR positive (Kappa agreement −0.009 ± 0.044, p = 0.838). Subsequently, when 130 faeces samples from live captured, or captive, badgers of known infection status (on the basis of StatPak, interferon-γ and/or culture results) were tested, the IMS-LFD assay had higher relative diagnostic specificity (Sp 0.926), but poorer relative diagnostic sensitivity (Se 0.081), than IMS-qPCR (Sp 0.706, Se 0.581) and IMS-culture (Sp 0.794, Se 0.436).ConclusionsThe novel IMS-LFD assay, although very specific for M. bovis, has low analytical sensitivity (indicated by the LOD50%) and would only detect badgers shedding high numbers of M. bovis (>104–5 cells/g) in their faeces. The novel LFD would, therefore, have limited value as a non-invasive test for badger TB surveillance purposes but it may have value for alternative veterinary diagnostic applications.

【 授权许可】

CC BY   
© The Author(s). 2017