应用凝血反应检测杀鼠灵抗药性褐家鼠的可行性研究

Feasibility of blood clotting response (BCR) to discriminate the warfarin-resi s ta nt and susceptible Rattus norvegicus (Berk)

为探讨凝血反应在鼠类抗药性检测中的应用前景,以褐家鼠为对象,在摄食实验基础上筛选抗药性褐家鼠,并在区分剂量12mg/kg作用下分析抗药性和敏感性褐家鼠的凝血能力的变化情况。结果显示,抗药性个体在区分剂量作用下,凝血酶活动度虽有所下降,下降幅度可达正常水平的17%,但在2～3d内可恢复到正常凝血水平;而敏感性褐家鼠的凝血酶下降到很低,且在随后不能恢复。另外,对褐家鼠凝血酶活动度的分布及其存活的关系研究也提示,区分剂量可促使凝血酶活动度的种群分布从单峰型向双峰型分化,其中敏感个体的凝血酶活动度在0～3.16之间,而抗药性个体则在17～100之间。并发现用药4d后的凝血酶活动度基本上可代表其未来的存活率,这提示了凝血反应与摄食实验结果的一致性。因此,以施药后4d凝血酶活动度PCA=17或INR=5.0作为阈值来区分抗药性和敏感性个体的凝血反应状况,进行家栖鼠抗药性测定是可行的。

To determine the feasibility of a blood clotting response （BCR） method for monitoring the resistance of commensal rodents, Rattus norvegicus were sampled from suburbs of Beijing and discriminated into resistant and susceptible individuals by non-alternative feed test appraised by World Health Organization. When administered with a discrimination dose of Warfarin （ 12 mg/kg body weight） , both resistant and susceptible R. norvegicus individuals decreased their percentage clotting activity （PCA） the following day. While PCA of resistant individuals only decreased to 17% of normal level and soon increased to normal level within 2 - 3 days. In contrast the PCA of susceptible individuals decreased dramatically and no subsequent increase was observed. As a whole population, the distribution pattern of PCA four days of post-treatment R. norvegicus also changes form one peak type of pre-treatment population into double peaks type, one peak stands for resistant individuals and the other for resistance individuals. The peak of the resistant covers PCA range from 0 to 3.16 and that of susceptible individuals PCA ranges from 17 to 100. In the same time, PCA four days post-treatment also was found to be related to survival of R. norvegicus and can predict survival in subsequent feed test which indicate the consistency of BCR method and non-alternative feed test in monitoring the resistance of R. norvegicus. Therefore, PCA = 17 （INR =5. 0） should be a threshold in determining ＂responders＂ to discriminate the resistant and susceptible rodent. So BCR might be an applicable method to monitor the resistance against anticoagulant rodenticides of commensal rodents.