A European inter-laboratory trial to evaluate the performance of three serological methods for diagnosis of Mycoplasma bovis infection in cattle using latent class analysis

Anna-Maria Andersson,Anna Aspán,Jane Kensø,Sinikka Pelkonen,Tiina Autio,Klara Tølbøll Lauritsen,Florence Tardy,Anne Ridley,Patrice Gaurivaud,Bregtje Smid,Henk J Wisselink

doi:10.1186/s12917-019-2117-0

Abstract

BackgroundMycoplasma bovis (M. bovis) is an emerging bovine pathogen, leading to significant economic losses in the livestock industry worldwide. Infection can result in a variety of clinical signs, such as arthritis, pneumonia, mastitis and keratoconjunctivitis, none of which are M. bovis-specific. Laboratory diagnosis is therefore important. Serological tests to detect M. bovis antibodies is considered an effective indicator of infection in a herd and often used as a herd test. Combined with clinical judgement, it can also be used to implement control strategies and/or to estimate the disease prevalence within a country. However, due to lack of harmonisation of approaches to testing, and serological tests used by different laboratories, comparisons of prevalence data between countries is often difficult. A network of researchers from six European countries designed and participated in an inter-laboratory trial, with the aim of evaluating the sensitivity (Se) and specificity (Sp) of two commercially available ELISA tests (ID Screen® ELISA (IDvet) and BIO K302 ELISA (BIO-X Diagnostics)) for diagnosis of M. bovis infection. Each laboratory received a blinded panel of bovine sera and tested independently, according to manufacturer’s instructions. Western blot analyses (WB) performed by one of the participating laboratories was used as a third diagnostic test in the statistical evaluation of Se and Sp values using latent class analysis.ResultsThe Se of WB, the ID Screen® ELISA and the BIO K302 ELISA were determined to be 91.8, 93.5 and 49.1% respectively, and corresponding Sp of the three tests were 99.6, 98.6 and 89.6%, respectively.ConclusionsThe present study is, to our knowledge, the first to present an inter-laboratory comparison of the BIO K302 ELISA and the ID Screen® ELISA. Based on our results, the ID Screen® ELISA showed high consistency with WB and performed with higher precision and accuracy than the BIO K302 ELISA.

Highlights

Mycoplasma bovis (M. bovis) is an emerging bovine pathogen, leading to significant economic losses in the livestock industry worldwide
enzyme-linked immunosorbent assays (ELISA) I: ID screen® ELISA Forty-four percent of the serum samples had an S/P % of ≥60% and were categorised as seropositive using the cut-off recommended by the manufacturer
ELISA II: the BIO K302 ELISA With the BIO K302 ELISA, 29% of the samples had an S/P % > 37% and were categorised as seropositive using the cut-off recommended by the manufacturer

Summary

Introduction

Mycoplasma bovis (M. bovis) is an emerging bovine pathogen, leading to significant economic losses in the livestock industry worldwide. Mycoplasma bovis has emerged as a pathogen of increasing importance in many industrialised countries around the world, causing significant economic and production losses in the beef and dairy industries [1,2,3,4]. Pneumonia, mastitis, otitis media, and reproductive problems have been observed [1, 4, 5] Since none of these clinical signs are pathognomonic, definitive and accurate diagnosis requires laboratory confirmation. This is important for implementation of control strategies such as enabling immediate separation of infected livestock and early administration of appropriate treatment, as the spread of disease is difficult to contain once present on a farm [6, 7]

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