Resistance of Mongolian Gerbils (Meriones unguiculatus) to chlorophacinone-Na based on blood clotting response tests

Abstract

The aim of this study was to develop a quick, simple and inexpensive anticoagulant rodenticide resistance test method. The blood clotting response (BCR) test for resistance to chlorophacinone-Na in Mongolian Gerbils was prepared using small-volume blood samples. The normal Prothrombin time for Mongolian Gerbils was 9.92 ± 0.96 s using MDC Haemostasis thromboplastin-s (ISI: 1.86) reagent. Percent coagulation activity (PCA) calibration curves fitted the S curve and the PCA of 17% was found to correspond to a coagulation time International Normalized Ratio of 2.5. Dose–response baselines for BCR were obtained using susceptible Mongolian Gerbils and the ED₉₉ values estimated for a quantal response were 0.27710 mg kg⁻¹ for males and 0.26228 mg kg⁻¹ for females. Based on the BCR test for resistance in wild Mongolian Gerbils from Zhenglanqi, Zhengxiangbaiqi, Kezhen in the Inner Mongolia Autonomous Region, we found that the populations of three areas have developed chlorophacinone-Na resistance populations with resistance ratios (%) of 34.0, 30.0 and 40.9, respectively.

Keywords:

• anticoagulant resistance
• blood clotting response test
• Prothrombin time
• Mongolian Gerbils (Meriones unguiculatus)
• chlorophacinone-Na

Acknowledgements

The authors acknowledge the funding from the project, NO2007CB109105 of the Ministry of Science and Technology and the project, NO2005BA529A05 of the Ministry of Agriculture, and the provision of chlorophacinone-Na product by the Institute for Control of Agrochemicals, the Ministry of Agriculture. The Plant Protection Station of Inner Mongolia is also gratefully acknowledged for its assistance throughout the field work.