Objective To investigate the mutations in the voltage-gated sodium channel（VGSC） gene of Aedes albopictus in the residential habitats of Wuhan, Hubei province, China, and to preliminarily explore the resistance development mechanism of Ae. albopictus in Wuhan. Methods Larvae and pupae of Ae. albopictus were collected from the residential habitats of Wuhan from August to October 2021 and raised to adults in the laboratory. Genomic DNA was extracted form each adult mosquito. The partial VGSC gene fragments were amplified by the polymerase chain reaction and sequenced to analyze the distribution of VGSC genotypes. The genotype distribution at each mutation site of the VGSC gene were compared for female and male mosquitoes by the Chi-square test. Results A total of 238 Ae.albopictus from the residential habitats of Wuhan, including 126 female mosquitoes and 112 male mosquitoes, were analyzed. Mutations were detected at the V1016, I1532, and F1534 loci of the VGSC gene. There were two alleles at the V1016 locus, namely wild-type GTA/V（43.91%） and mutant GGA/G（56.09%）, and three genotypes, i.e., the wild-type homozygote V/V（19.33%）, wild/mutant heterozygote V/G（49.16%）, and mutant homozygote G/G（31.51%）. There were two alleles at the I1532 locus, namely wild-type ATC/I（99.16%） and mutant ACC/T（0.84%）, and two genotypes, i. e.,wild-type homozygote I/I（98.32%） and wild/mutant heterozygote I/T（1.68%）. At the F1534 locus, three alleles, i. e.,wild-type TTC/F（60.72%）, mutant TCC/S（33.19%）, and TGC/C（6.09%）, and five genotypes, i. e., wild-type homozygote F/F（35.30%）, wild/mutant heterozygote F/S（41.60%） and F/C（9.24%）, mutant homozygote S/S（10.92%）,and mutant heterozygote S/C（2.94%）, were detected. No mutant allele was found at the D1763 locus of the VGSC gene,at which only the wild-type allele GAC/D was detected（100%）. There was no significant difference in the genotype distribution at the V1016, I1532, and F1534 loci of the VGSC gene between different sexes of Ae. albopictus（χ~2 =0.198,P=0.656; χ~2=0.014, P=0.905; χ~2 =2.210, P=0.137）. Conclusions The rate of VGSC gene mutation in Ae. albopictus is high in Wuhan, which might be one of the important mechanisms of Ae. albopictus rapidly developing resistance towards pyrethroid insecticides in Wuhan. Anyway, no significant difference was found in VGSC gene mutations between female and male mosquitoes.
目的 监测重庆市重点地区小型兽类携带5种常见鼠媒病原体的流行情况,为指导当地鼠源疾病的防控提供科学依据.方法 2021-2022年,在重庆市中心城区、万州区、涪陵区3个监测点使用笼夜法捕捉小型兽类,提取其肝、脾、肺、肾组织的核酸样本,采用实时荧光定量PCR(qPCR)检测问号钩端螺旋体(钩体)、莫氏立克次体、巴尔通体,反转录实时荧光定量PCR(RT-qPCR)方法检测汉坦病毒及大别班达病毒.运用Excel 2010软件进行数据汇总和整理,SPSS 22.0软件对实验数据进行统计分析,种群构成比、病原体携带率的比较采用x2检验进行统计分析.结果 共捕获小型兽类9种1 188只,其中褐家鼠最多,占比为33.50％,黄胸鼠占比为26.77％,四川短尾鼩占比26.01％,小家鼠占比为9.85％,其余还捕获小泡巨鼠、大足鼠、北社鼠、黑线姬鼠、灰麝鼩,不同监测点的小型兽类种类构成差异有统计学意义(x2=714.786,P＜0.001).所有检测样本中,发现汉城型汉坦病毒阳性4份(只),问号钩体阳性24份(只),巴尔通体阳性8份(只),其余均为阴性.共发现33只小型兽类呈阳性,其中2只黄胸鼠、1只褐家鼠同时携带问号钩体和汉城型汉坦病毒,病原体总体携带率为2.78％,其中汉坦病毒总携带率为0.34％,问号钩体总携带率为2.02％,巴尔通体总携带率为0.67％,3种病原体的携带率差异有统计学意义(x2=18.857,P＜0.001).结论 重庆地区小型兽类中监测到问号钩体、巴尔通体和汉坦病毒,检出阳性较多的小型兽类为褐家鼠、黄胸鼠和四川短尾鼩,主要分布于重庆城区的重点行业和万州区的农村居民区,当地应对鼠源疾病流行及防控予以重点关注.
目的 结合鼠疫疫源地调查和监测工作对青海省海东市小型兽类体表寄生蚤的构成、宿主选择和分布进行调查研究,并应用分子生物学方法对部分常见和疑难蚤种进行分子鉴定,以提高蚤种分类鉴别准确性.方法 应用细胞色素C氧化酶亚基Ⅰ(CO Ⅰ)基因对蚤类进行分子鉴定,并结合传统形态学分类方法综合鉴别蚤类.结果 海东市共发现和记录体表寄生蚤61种(亚种),隶属4总科5科28属.测得4科13属20种计99条蚤CO Ⅰ基因序列片段(约658 bp),种内遗传距离为0.2％～2.9％,种间为3.3％～22.9％,种间距离明显大于种内.结论 系统进化分析显示各蚤种单系的支持率均＞99％,CO Ⅰ基因和传统形态分类方法的结合可以更准确地鉴定海东市蚤类.
蚊媒病毒病的流行传播严重危害公共卫生安全.化学防治蚊虫是控制蚊媒病的有效手段,但世界范围内杀虫剂的过度持续使用造成了蚊虫杀虫剂抗性的发生、发展,对杀虫剂的抗性会影响某些蚊虫对蚊媒病毒的媒介能力.为了评估病媒生物防制过程中杀虫剂抗性对蚊媒病毒传播的影响和风险,已有大量的研究聚焦于媒介蚊虫杀虫剂抗性对其病毒传播能力的影响研究.该文重点对蚊虫媒介能力与杀虫剂抗性的动态关系研究进展,及杀虫剂抗性使媒介能力改变的相关机制分析进行综述,以期为今后抗性研究和病媒控制提供参考.
目的 了解安徽省芜湖市德国小蠊的抗药性水平,为合理用药提供科学依据.方法 2022年3-6月,在芜湖市弋江、镜湖、三山和鸠江区的餐饮店、面包店、宾馆、超市和农贸市场等生境采集试虫,采用药膜法对12种常用杀虫剂进行抗药性生物测定.运用SPSS 22.0软件对数据进行处理和相关性分析.结果 芜湖市德国小蠊对氯菊酯、胺菊酯、氯氰菊酯、溴氰菊酯、顺式氯氰菊酯、高效氯氰菊酯、高效氯氟氰菊酯、残杀威、甲基吡恶磷、乙酰甲胺磷、敌敌畏和毒死蜱的 24h 死亡率,分别为 91.20％、18.40％、91.33％、89.47％、77.85％、92.62％、99.19％、100％、96.85％、100％、76.06％和 99.00％,半数击倒时间(KT50)分别为 32.63、900.61、28.17、30.47、26.60、11.06、1 6.54、17.93、14.13、59.66、27.57和38.21 min.依照死亡率抗性标准,芜湖市德国小蠊对高效氯氟氰菊酯、残杀威、甲基吡恶磷、乙酰甲胺磷、毒死蜱为敏感种群,对氯菊酯、氯氰菊酯、溴氰菊酯、高效氯氰菊酯为可能抗性种群,对胺菊酯、顺式氯氰菊酯和敌敌畏为抗性种群.依照击倒抗性标准,芜湖市德国小蠊对甲基吡恶磷敏感;对高效氯氰菊酯、高效氯氟氰菊酯、残杀威、乙酰甲胺磷、毒死蜱为低度抗性,分别为2.58、3.21、1.39、2.01和1.41倍;对氯菊酯、氯氰菊酯、溴氰菊酯、顺式氯氰菊酯及敌敌畏为中度抗性,分别为6.54、6.39、7.79、5.58和7.14倍;对胺菊酯为极高度抗性(259.54倍).KT50、24 h死亡率与杀虫剂用量间无相关关系(rKT50-杀虫剂使用量=0.045,r24死亡率-杀虫剂使用量=0.141.均P＞0.05):结论 芜湖市德国小蠊对多种杀虫剂产生中、高度抗性,在蜚蠊防制中应结合抗药性监测结果,规范杀虫剂使用,以延缓抗药性的发展.
