Anopheles sinensis mosquito insecticide resistance: comparison of three mosquito sample collection and preparation methods and mosquito age in resistance measurements

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• 作者：Tielong Xu (5)
  Daibin Zhong (6)
  Linhua Tang (5)
  Xuelian Chang (7)
  Fengyang Fu (8)
  Guiyun Yan (6)
  Bin Zheng (5)
  
• 关键词：Anopheles sinensis ; Pyrethroid resistance ; Mosquito preparation methods
• 刊名：Parasites & Vectors
• 出版年：2014
• 出版时间：December 2014
• 年：2014
• 卷：7
• 期：1
• 全文大小：231 KB
• 作者单位：Tielong Xu (5)
  Daibin Zhong (6)
  Linhua Tang (5)
  Xuelian Chang (7)
  Fengyang Fu (8)
  Guiyun Yan (6)
  Bin Zheng (5)
  
  5. National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, and WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Ministry of Public Health, Shanghai, China
  6. Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92697, USA
  7. Department of Pathogen Biology, Bengbu Medical College, Anhui, China
  8. Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, China
  
• ISSN：1756-3305

文摘

Background Insecticide resistance monitoring in malaria mosquitoes is essential for guiding the rational use of insecticides in vector control programs. Resistance bioassay is the first step for insecticide monitoring and it lays an important foundation for molecular examination of resistance mechanisms. In the literature, various mosquito sample collection and preparation methods have been used, but how mosquito sample collection and preparation methods affect insecticide susceptibility bioassay results is largely unknown. The objectives of this study were to determine whether mosquito sample collection and preparation methods affected bioassay results, which may cause incorrect classification of mosquito resistance status. Methods The study was conducted in Anopheles sinensis mosquitoes in two study sites in central China. Three mosquito sample collection and preparation methods were compared for insecticide susceptibility, kdr frequencies and metabolic enzyme activities: 1) adult mosquitoes collected from the field; 2) F1 adults from field collected, blood-fed mosquitoes; and 3) adult mosquitoes reared from field collected larvae. Results Mosquito sample collection and preparation methods significantly affected mortality rates in the standard WHO tube resistance bioassay. Mortality rate of field-collected female adults was 10-15% higher than in mosquitoes reared from field-collected larvae and F1 adults from field collected blood-fed females. This pattern was consistent in mosquitoes from the two study sites. High kdr mutation frequency (85-95%) with L1014F allele as the predominant mutation was found in our study populations. Field-collected female adults consistently exhibited the highest monooxygenase and GST activities. The higher mortality rate observed in the field-collected female mosquitoes may have been caused by a mixture of mosquitoes of different ages, as older mosquitoes were more susceptible to deltamethrin than younger mosquitoes. Conclusions Female adults reared from field-collected larvae in resistance bioassays are recommended to minimize the effect of confounding factors such as mosquito age and blood feeding status so that more reliable and reproducible mortality may be obtained.