Development of colloidal gold-based immunochromatographic assay for rapid detection of Streptococcus suis serotype 2.
To develop colloidal gold immunochromatographic strips for the direct detection of the Streptococcus suis serotype 2 antigen, colloidal gold was prepared by reduction of a gold salt with sodium citrate and coupled with polyclonal antibody against S. suis serotype 2. The optimal concentrations of the capture antibody and the coating antibody were determined to be 22mug/mL and 2.0mg/mL, respectively, and that of the blocking buffer was determined to be 1.5% bovine serum albumin. Different serotypes of S. suis and other related bacteria were used to evaluate the sensitivity, specificity, and stability of the immunochromatographic strips. The detection sensitivity was found to be as high as 10(6)CFU/mL. There was no cross-reaction of the antibodies with other serotypes of S. suis (except with SS1/2, which shares some common sugar residues or antigenic determinants with serotype 2) and other related bacteria. In conclusion, we developed colloidal gold immunochromatographic strips that had high sensitivity and specificity. This method proved to be feasible, convenient, rapid, and effective for detecting S. suis serotype 2.
Ju
Ying
Y
State Key Laboratory of Pathogen and Biosecurity, The Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Fengtai District, Beijing 100071, People's Republic of China.
Hao
Huai-Jie
HJ
Xiong
Guo-Hua
GH
Geng
Hong-Ran
HR
Zheng
Yu-Ling
YL
Wang
Jing
J
Cao
Yuanyin
Y
Yang
Yin-Hui
YH
Cai
Xue-Hui
XH
Jiang
Yong-Qiang
YQ
D000818:Animals; D000907:Antibodies, Bacterial; D002417:Cattle; D002845:Chromatography / Q000379:methods*; D017979:Gold Colloid; D007118:Immunoassay / Q000379:methods*; D012703:Serotyping / Q000379:methods; D013290:Streptococcal Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D017011:Streptococcus suis / Q000145:classification / Q000276:immunology / Q000302:isolation & purification*; D013552:Swine / Q000382:microbiology; D013553:Swine Diseases / Q000175:diagnosis* / Q000382:microbiology
D000907:Antibodies, Bacterial; D017979:Gold Colloid