Knockdown-resistance (kdr) against pyrethroids in bed bugs (Cimex lectularis) is associated with the presence of several point mutations in the voltage-sensitive sodium channel α-subunit gene and/or an increased metabolic detoxification by cytochrome P450 monooxygenases (CYPs). In the present study, pyrosequencing assays were developed to quantify the presence of the kdr substitutions (V419L or L925I substitution) in bed bugs in Berlin, Germany. In 14 of 17 bed bug field strains, pyrosequencing revealed the presence of the substitution L925I with allele frequencies between 30% and 100%. One field strain additionally carried the substitution V419L with allele frequencies of 40% in males and 96% in females. In seven of the 17 field strains, mRNA levels of four CYP genes were examined using RT-qPCR. Relative to a susceptible laboratory reference strain, five field strains showed significantly higher mRNA levels of cyp397a1 with 7.1 to 56-fold increases. One of these strains additionally showed a 4.9-fold higher mRNA level of cyp398a1 compared to the reference strain, while cyp4cm1 and cyp6dn1 showed no significant differences. Our findings indicate that multiple resistance mechanisms are present in German C. lectularius populations simultaneously.

臭虫（Cimex lectularis）中对拟除虫菊酯的抗击倒性 ( kdr ) 与电压敏感钠通道 α-亚基基因中存在几个点突变和/或细胞色素 P450 单加氧酶 (CYPs) 的代谢解毒增加有关。在本研究中，开发了焦磷酸测序分析来量化kdr的存在德国柏林的臭虫替代品（V419L 或 L925I 替代品）。在 17 个臭虫田间菌株中的 14 个中，焦磷酸测序显示存在替代 L925I，等位基因频率在 30% 到 100% 之间。一种田间菌株另外携带替代 V419L，等位基因频率在雄性中为 40%，在雌性中为 96%。在 17 个野外菌株中的 7 个中，使用 RT-qPCR 检查了四种 CYP 基因的 mRNA 水平。相对于易感的实验室参考菌株，五个野外菌株显示出显着更高的cyp397a1 mRNA 水平， 增加 了 7.1 至 56 倍。其中一个菌株的cyp398a1 mRNA 水平 比参考菌株高 4.9 倍 ，而 cyp4cm1 和 cyp6dn1 显示没有显着差异。我们的研究结果表明，德国C. lectularius 种群中同时存在多种抗性机制 。