A quantum dot fluorescent microsphere based immunochromatographic strip for detection of brucellosis

Yufang Kong,Shaoqiang Wu,Huiyu Wang,Lin Mei,Jizhou Lv,Huifang Zhou,Xiangmei Lin,Xueqing Han

doi:10.1186/s12917-021-02760-w

Yufang Kong, Shaoqiang Wu + Show 6 more

Open Access

https://doi.org/10.1186/s12917-021-02760-w

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Abstract

BackgroundBrucellosis is a serious zoonosis disease that frequently causes significant economic loss in animal husbandry and threatens human health. Therefore, we established a rapid, accurate, simple and sensitive fluorescent immunochromatographic strip test (ICST) based on quantum dots (QDs) for detection the antibodies of Brucella infection animals serum.ResultsThe test strips were successfully prepared by quantum dot fluorescent microspheres (QDFM) as tracers, which were covalently coupled to an outer membrane protein of Brucella OMP22. The outer membrane protein OMP28 and monoclonal antibodies of OMP22 were separately dispensed onto a nitrocellulose membrane as test and quality control lines, respectively. The critical threshold for determining negative or positive through the ratio of the fluorescent signal of the test line and the control line (HT / HC) is 0.0492. The repeatability was excellent with an overall average CV of 8.78%. Under optimum conditions, the limit of detection was 1.05 ng/mL (1:512 dilution). With regard to the detection of brucellosis in 150 clinical samples, the total coincidence rate of ICST and Rose Bengal plate test (RBPT) was 97.3%, the coincidence rate of positive samples was 98.8%, the coincidence rate of negative samples was 95.3%, the sensitivity of RBPT is 1:32, and no cross reaction with the sera of other related diseases was observed.ConclusionIn our present study, the QDFM has promising application for on-site screening of brucellosis owing to its high detection speed, high sensitivity, high specificity and low cost.

Highlights

Brucellosis is a serious zoonosis disease that frequently causes significant economic loss in animal husbandry and threatens human health
Optimization of the coating concentration for the NC membrane The optimal coating concentration of the test line and control line were selected as 1 mg/mL and 0.5 mg/L, respectively
Repeatability assay of the immunochromatographic strip test (ICST) for brucellosis The results showed that the ICST maximum coefficient of variation (CV) value of all samples was 8.78%, and the average value was 6.16%

Summary

Introduction

Brucellosis is a serious zoonosis disease that frequently causes significant economic loss in animal husbandry and threatens human health. We established a rapid, accurate, simple and sensitive fluorescent immunochromatographic strip test (ICST) based on quantum dots (QDs) for detection the antibodies of Brucella infection animals serum. Brucellosis is a highly infectious zoonosis and poses serious threats to human health [1]. Infertility, placenta retention, still birth or weak offspring, and poor reproductive performance of animals, which results in huge economic losses for livestock farmers [6]. There is no effective method to prevent this disease, early diagnosis and monitoring are very essential. Traditional detection methods of Brucella are pathogen isolation identification, serological diagnosis and molecular biology, which have a few defects [7].

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