Heterologous strategy enhancing the sensitivity of the fluorescence polarization immunoassay of clinafloxacin in goat milk.
BACKGROUND
Clinafloxacin is used for the treatment of disease in food-producing animals, e.g. Brucella melitensis, which often occurs in goats; however, the clinafloxacin residue in goat milk may harm human health and result in the development of drug-resistant bacterial strains or allergies. Despite this, there is not a rapid, sensitive and accurate analytical method in goat milk for rapid screening or monitoring purposes.


RESULTS
One homologous and five heterologous tracers were designed and compared for fluorescence polarization immunoassay (FPIA) optimization. Based on the combination of a heterologous tracer (PAZ-FITC, synthesized with pazufloxacin and FITC) and the antibody against clinafloxacin, a highly sensitive FPIA was established for the detection of clinafloxacin residue in goat milk for the first time. The IC50 value was 29.3 µg L(-1) for clinafloxacin in the heterologous format - six times lower than that of the combination of the homologous tracers and the antibody. The recoveries ranged from 86.8% to 104.5%, with the relative standard deviation ranging from 4.1% to 7.2%. Validation by high-performance liquid chromatography (HPLC) confirmed that the results obtained from the proposed FPIA were in agreement with those of HPLC.


CONCLUSIONS
This proposed heterologous strategy for enhanced FPIA is sensitive and rapid enough for the high-throughput detection of clinafloxacin residue in goat milk.
Guangdong Provincial Key Laboratory of Food Quality and Safety/Guangdong Provincial Engineering and Technique Research Centre of Food Safety Detection and Risk Assessment, South China Agricultural University, Guangzhou, 510642, China.
Jiahong
J
Chen
Faculty of Chemistry, MV Lomonosov Moscow State University, 119991, Moscow, Russia.|AN Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
Ilya A
IA
Shanin
Guangdong Provincial Key Laboratory of Food Quality and Safety/Guangdong Provincial Engineering and Technique Research Centre of Food Safety Detection and Risk Assessment, South China Agricultural University, Guangzhou, 510642, China.
Shuwei
S
Lv
South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China.
Qiang
Q
Wang
Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, OK, 73019, USA.
Chuanbin
C
Mao
Guangdong Provincial Key Laboratory of Food Quality and Safety/Guangdong Provincial Engineering and Technique Research Centre of Food Safety Detection and Risk Assessment, South China Agricultural University, Guangzhou, 510642, China.
Zhenlin
Z
Xu
Guangdong Provincial Key Laboratory of Food Quality and Safety/Guangdong Provincial Engineering and Technique Research Centre of Food Safety Detection and Risk Assessment, South China Agricultural University, Guangzhou, 510642, China.
Yuanming
Y
Sun
Guangdong Provincial Key Laboratory of Food Quality and Safety/Guangdong Provincial Engineering and Technique Research Centre of Food Safety Detection and Risk Assessment, South China Agricultural University, Guangzhou, 510642, China.
Qing
Q
Wu
Faculty of Chemistry, MV Lomonosov Moscow State University, 119991, Moscow, Russia.|AN Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
Sergei A
SA
Eremin
Guangdong Provincial Key Laboratory of Food Quality and Safety/Guangdong Provincial Engineering and Technique Research Centre of Food Safety Detection and Risk Assessment, South China Agricultural University, Guangzhou, 510642, China.
Hongtao
H
Lei
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D004350:Drug Residues / Q000032:analysis; D016231:Fluorescence Polarization Immunoassay; D024841:Fluoroquinolones / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D006041:Goats; D006801:Humans; D008892:Milk / Q000737:chemistry*; D010078:Oxazines; D015203:Reproducibility of Results
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D010078:Oxazines; C078052:pazufloxacin; C057477:clinafloxacin
clinafloxacin; fluorescence polarization immunoassay; goat milk; heterologous