The development, validation and application of an indirect enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Streptococcus dysgalactiae subspecies dysgalactiae in lamb and ewe sera

IF 2.2 3区农林科学 Q1 VETERINARY SCIENCES

Research in veterinary science Pub Date : 2025-03-03 DOI:10.1016/j.rvsc.2025.105604

L.P. Jackson , D. Timofte , K.T. Ballingall , J.S. Duncan

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引用次数: 0

Abstract

Background

Neonatal infectious arthritis (NIA) is a bacterial disease of lambs caused by Streptococcus dysgalactiae sub species dysgalactiae (SDSD). NIA negatively impacts animal welfare; whilst its control entails widespread antibiotic use. The aims of this study are to develop, validate and apply an indirect, ELISA assay to inform SDSD vaccine development and epidemiology studies.

Methods

The antigen (inactivated isolate of SDSD) was incubated with sera from SDSD infected sheep, negative control sheep and serum from sheep flocks with outbreaks of SDSD NIA. SDSD antibody was detected with rabbit anti-sheep IgG conjugated with horseradish peroxidase. Antibody levels were estimated using peroxidase substrate and detection of colour change.

Test performance was determined by receiver operating characteristic (ROC) curve analysis and by comparison with the animals' concurrent infection status, as determined by a Real Time PCR assay for SDSD bacterial DNA.

Results

Using ROC curve analysis, a median test sensitivity of 85.71 % (95 % CI, 77.51–93.91) and a median test specificity of 73.68 % (95 % CI, 53.89–93.48), with a positive predictive value of 92.31 % (95 % CI, 86.07–98.55), and a negative predictive value of 58.33 % (95 % CI, 36.16–80.50).

ELISA test performance was reduced when serum ELISA status (n = 362 sheep) was compared with concurrent SDSD infection status. The SDSD ELISA sensitivity was 39.74 % (95 % CI, 28.83–51.46), the specificity 60.92 % (95 % CI, 54.97–66.63), the PPV 21.83 % (95 % CI, 15.34–29.53), and the NPV was 78.64 % (95 % CI, 72.62–83.86).

Conclusion

This ELISA assay could be applied to estimate flock sero-prevalences for SDSD and changing SDSD antibody titres in vaccine trials.

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来源期刊

Research in veterinary science 农林科学-兽医学

CiteScore

4.40

自引率

4.20%

发文量

312

审稿时长

75 days

期刊介绍： Research in Veterinary Science is an International multi-disciplinary journal publishing original articles, reviews and short communications of a high scientific and ethical standard in all aspects of veterinary and biomedical research. The primary aim of the journal is to inform veterinary and biomedical scientists of significant advances in veterinary and related research through prompt publication and dissemination. Secondly, the journal aims to provide a general multi-disciplinary forum for discussion and debate of news and issues concerning veterinary science. Thirdly, to promote the dissemination of knowledge to a broader range of professions, globally. High quality papers on all species of animals are considered, particularly those considered to be of high scientific importance and originality, and with interdisciplinary interest. The journal encourages papers providing results that have clear implications for understanding disease pathogenesis and for the development of control measures or treatments, as well as those dealing with a comparative biomedical approach, which represents a substantial improvement to animal and human health. Studies without a robust scientific hypothesis or that are preliminary, or of weak originality, as well as negative results, are not appropriate for the journal. Furthermore, observational approaches, case studies or field reports lacking an advancement in general knowledge do not fall within the scope of the journal.