CMAVE Detachment, Navy Entomology Center of Excellence, Gainesville, FL, United States of America.
Mosquito and Fly Research Unit, United States Department of Agriculture, Agricultural Research Service, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL, United States of America.
PLoS Negl Trop Dis. 2018 Oct 24;12(10):e0006544. doi: 10.1371/journal.pntd.0006544. eCollection 2018 Oct.
Recent outbreaks of locally transmitted dengue and Zika viruses in Florida have placed more emphasis on integrated vector management plans for Aedes aegypti (L.) and Aedes albopictus Skuse. Adulticiding, primarily with pyrethroids, is often employed for the immediate control of potentially arbovirus-infected mosquitoes during outbreak situations. While pyrethroid resistance is common in Ae. aegypti worldwide and testing is recommended by CDC and WHO, resistance to this class of products has not been widely examined or quantified in Florida. To address this information gap, we performed the first study to quantify both pyrethroid resistance and genetic markers of pyrethroid resistance in Ae. aegypti and Ae. albopictus strains in Florida. Using direct topical application to measure intrinsic toxicity, we examined 21 Ae. aegypti strains from 9 counties and found permethrin resistance (resistance ratio (RR) = 6-61-fold) in all strains when compared to the susceptible ORL1952 control strain. Permethrin resistance in five strains of Ae. albopictus was very low (RR<1.6) even when collected from the same containers producing resistant Ae. aegypti. Characterization of two sodium channel kdr alleles associated with pyrethroid-resistance showed widespread distribution in 62 strains of Ae. aegypti. The 1534 phenylalanine to cysteine (F1534C) single nucleotide polymorphism SNP was fixed or nearly fixed in all strains regardless of RR. We observed much more variation in the 1016 valine to isoleucine (V1016I) allele and observed that an increasing frequency of the homozygous V1016I allele correlates strongly with increased RR (Pearson corr = 0.905). In agreement with previous studies, we observed a very low frequency of three kdr genotypes, IIFF, VIFF, and IIFC. In this study, we provide a statewide examination of pyrethroid resistance, and demonstrate that permethrin resistance and the genetic markers for resistance are widely present in FL Ae. aegypti. Resistance testing should be included in an effective management program.
最近在佛罗里达州爆发的本地传播登革热和寨卡病毒，使人们更加重视埃及伊蚊（Aedes aegypti）（L.）和白纹伊蚊（Aedes albopictus Skuse）的综合媒介管理计划。在疫情爆发期间，通常采用除虫菊酯类药剂进行成虫杀灭，以立即控制可能感染虫媒病毒的蚊子。尽管在全球范围内埃及伊蚊对拟除虫菊酯类杀虫剂的抗药性很常见，美国疾病控制与预防中心和世界卫生组织也建议进行检测，但在佛罗里达州，尚未广泛研究或量化该类产品的抗药性。为了解决这一信息空白，我们首次对佛罗里达州埃及伊蚊和白纹伊蚊的拟除虫菊酯类杀虫剂抗药性及其遗传标记进行了定量研究。我们采用直接表面涂抹法来测量内在毒性，共检测了来自 9 个县的 21 株埃及伊蚊，与敏感对照品系 ORL1952 相比，所有菌株均表现出拟除虫菊酯类杀虫剂的抗药性（抗性比（RR）为 6-61 倍）。尽管从产生抗性埃及伊蚊的相同容器中采集了 5 株白纹伊蚊，但它们的拟除虫菊酯类杀虫剂抗药性非常低（RR<1.6）。对与拟除虫菊酯类杀虫剂抗药性相关的两个钠离子通道 kdr 等位基因的特征分析表明，62 株埃及伊蚊广泛分布着这两种等位基因。1534 位苯丙氨酸到半胱氨酸（F1534C）单核苷酸多态性（SNP）在所有菌株中均为固定或几乎固定，而不论 RR 如何。我们观察到 1016 位缬氨酸到异亮氨酸（V1016I）等位基因的变异更大，并且观察到杂合子 V1016I 等位基因的频率增加与 RR 呈强相关性（皮尔逊相关系数=0.905）。与之前的研究一致，我们观察到非常低的三种 kdr 基因型，即 IIFF、VIFF 和 IIFC 的频率。在本研究中，我们对佛罗里达州的拟除虫菊酯类杀虫剂抗药性进行了全州范围的检测，证明了佛罗里达州埃及伊蚊广泛存在拟除虫菊酯类杀虫剂抗药性及其遗传标记。抗药性检测应纳入有效的管理计划。
