Eslami Reza, Karami Mohsen, Gorgani-Firouzjaee Tahmineh, Mirtabar-Darzi Seyedeh Maedeh
Student Research Committee, Babol University of Medical Sciences, Babol, Iran.
Department of Mycology and Parasitology, School of Medicine, Babol University of Medical Sciences, Babol, Iran.
J Parasit Dis. 2024 Dec;48(4):775-781. doi: 10.1007/s12639-024-01707-w. Epub 2024 Jul 23.
Head lice infestation continues to be a major health problem worldwide. In order to solve this problem, frequent use of pediculocides has caused growing resistance among head lice population. This study aims to investigate the presence of the knockdown resistance () mutation in the head lice population in northern Iran. Adult head lice were collected from 115 infested individuals referring to the health centers in different parts of Mazandaran province, northern Iran. 38 samples were randomly selected, and Polymerase chain reaction (PCR) was used to amplify a 332-bp and ⁓ 900-bp fragment of the α-subunit of the voltage-sensitive sodium channel () gene. According to the analysis of a 332-bp fragment of the gene, the frequency of kdr T917I mutation including homozygous susceptible (SS), heterozygous resistant (RS), and homozygous resistant (RR) were 45.83%, 12.5%, and 41.66%, respectively. The total frequency of the resistance allele was 54.16%. The results of the 900-bp fragment of the gene showed two new mutations in the IIS1-2 extracellular loop (H813P) and IIS2 (S825R) and old well-known kdr mutations (M815I-T917I-L920F). The results of Hardy-Weinberg's exact equilibrium test showed that the frequency of genotypes in the studied areas is different from expectations. Moreover, a positive inbreeding coefficient value (F >0) was found in studied areas which indicated an excess of homozygotes. Overall, the results showed a high frequency of resistant alleles in the northern region of the country. Therefore, it is necessary to develop appropriate control programs for the treatment of pediculosis.
头虱感染仍是全球范围内的一个主要健康问题。为了解决这一问题，频繁使用灭虱剂已导致头虱群体产生越来越强的抗药性。本研究旨在调查伊朗北部头虱群体中击倒抗性（kdr）突变的存在情况。从伊朗北部马赞德兰省不同地区前往健康中心就诊的115名受感染个体身上采集成年头虱。随机选取38个样本，采用聚合酶链反应（PCR）扩增电压敏感钠通道（Nav）基因α亚基的一个332 bp和一个约900 bp的片段。根据对Nav基因332 bp片段的分析，kdr T917I突变的频率，包括纯合敏感型（SS）、杂合抗性型（RS）和纯合抗性型（RR）分别为45.83%、12.5%和41.66%。抗性等位基因的总频率为54.16%。Nav基因900 bp片段的结果显示在IIS1-2细胞外环（H813P）和IIS2（S825R）出现了两个新突变以及已知的老的kdr突变（M815I-T917I-L920F）。哈迪-温伯格精确平衡检验的结果表明，研究区域内基因型的频率与预期不同。此外，在研究区域发现了正的近亲繁殖系数值（F>0），这表明纯合子过多。总体而言，结果显示该国北部抗性等位基因的频率很高。因此，有必要制定适当的控制方案来治疗头虱病。
