Detection of F1 antibody against Yersinia pestis in flushing fluid of heart blood of Rhombomys opimus with ELISA: a feasibility study

Objective To analyse the feasibility of detecting F1 antibody to Yersinia pestis in flushing fluid of heart blood of Rhombomys opimus with enzyme linked immunosorbent assay(ELISA) method and its application value in surveillance of the disease. Methods Serum, flushing fluid of heart blood and infusion fluid of liver and spleen of Rhombomys opimus, which were caught by capture in the plague focus of Zunger basin in 2007, were taken to carry out detection for F1 antibodies to Yersinia pestis with ELISA method. The data were processed with SPSS 17.0. Results Positive rate and average titer of serum were 12.35%(11/162) and 25.35, of flushing fluid of heart blood were 10.49%(17/162) and 23.75 and of the infusion fluid of liver and spleen 6.79%(17/162) and 2240,respectively. No statistical difference was found in positive detection rate when it was compared between serum and flushing fluid of heart blood(χ2 = 1.333, P ＞ 0.05), but it was obviously different between serum and infusion fluid of liver and spleen(χ2 = 7.111, P ＜ 0.01 ) and between flushing fluid of heart blood and infusion fluid of liver and spleen(x2 = 6.250, P ＜ 0.05). There was a significant difference in average titer between serum, flushing fluid of heart blood and infusion fluid of liver and spleen(t = 2.290, 3.612, P ＜ 0.05 or ＜ 0.01 ). The plague F1 antibody positive coincidence rate of serum and flushing fluid of heart blood was 85.0%(17/20), of serum and infusion fluid of liver and spleen was 55.0% (11/20), and of flushing fluid of heart blood and infusion fluid of liver and spleen was 64.7%(11/17). Conclusions The ELISA method can detect Fl antibody in flushing fluid of heart blood,and the method is feasible in plague surveillance. Key words: Rhombmys opimus; Plague; F1 antibody; Enzyme linked immunosorbent assay