Characterization of Mycobiota Present in Pediculus humanus capitis (Orden: Anoplura; Family: Pediculidae): Study from Exocuticle, Gut, and Fecal Sources

AbstractHead lice have great medical importance and appear to be the greatest nuisance, amongschool children, where their presence causes itching, different skin reactions, and secondaryinfections. The aim of this work was to characterize the fungal community associated witheggs, and external exocuticle, gut and faeces from adults of Pediculus humanus capitis DeGeer 1767 (Phthiraptera: Pediculidae) using a culture dependent approach. We identified adiverse fungal community associated with P. h. capitis across different isolation sources,including ecto and endomycobiota. These findings support the hypothesis that P. h. capitisserves as a potential reservoir of fungal diversity, both externally and internally. Thebiodiversity index indicated that eggs and female faeces were the isolation sources with themost dominant species. The highest fungal richness and diversity was observed in the eggsamples, followed by the gut and exocuticle of females, suggesting that fungal colonizationmight begin early in the louse life cycle and that eggs may provide a conducivemicroenvironment for mycobiota. The gut compartments of both sexes harbored significantfungal diversity, reflecting ingestion and internal colonization. In contrast, faeces from malelice exhibited the lowest diversity and evenness, suggesting selective survival or excretion offewer species. The principal fungal genera isolated based on abundance were: Candida,Cladosporium, Penicillium, Talaromyces and Cryptococcus. While Candida and Penicilliumwere found in eggs and adult exocuticles, guts and faeces; Cladosporium, the second mostabundant genus, was absent from faeces. Talaromyces was exclusively found in the gut andfaeces of both male and female lice. Overall, our novel findings reveal that P. h. capitisharbors a diverse fungal community, with both common environmental genera andpotentially entomopathogenic species. This underscores the need to further study lice notonly as parasites but also as microecosystems that interact with broader microbialenvironments.摘要 头虱具有重要的医学研究价值，同时也是学龄儿童群体中最令人困扰的寄生虫，其寄生可引发瘙痒、各类皮肤反应及继发感染。本研究采用培养依赖型研究方法，对人头虱（Pediculus humanus capitis DeGeer 1767，虱目：虱科）成虫的虫卵、外体角质层、肠道及粪便相关的真菌群落进行表征。研究团队在不同分离来源的人头虱样本中均鉴定出了多样性丰富的真菌群落，涵盖体表真菌群与体内真菌群。上述研究结果证实了人头虱可作为体表与体内真菌多样性潜在储存库的假说。生物多样性指数分析显示，虫卵与雌性虱粪便为优势物种占比最高的分离样本类型。虫卵样本的真菌丰富度与多样性最高，其次为雌性虱的肠道与外体角质层，这提示真菌定植可能始于虱类生命周期的早期阶段，且虫卵可为真菌群落提供适宜的微环境。雌雄虱的肠道区域均携带丰富的真菌多样性，这反映了真菌的摄入过程与体内定植现象。与之相反，雄性虱的粪便样本呈现出最低的多样性与均匀度，提示存在对少数物种的选择性存活或排泄行为。基于丰度筛选得到的主要真菌属包括：假丝酵母属（Candida）、枝孢霉属（Cladosporium）、青霉属（Penicillium）、塔拉诺伊菌属（Talaromyces）以及隐球菌属（Cryptococcus）。其中假丝酵母属与青霉属可在虫卵、成虫外体表、肠道及粪便样本中检出；丰度排名第二的枝孢霉属则未在粪便样本中被发现。塔拉诺伊菌属仅在雌雄虱的肠道与粪便样本中存在。总体而言，本研究的创新性发现揭示了人头虱携带有多样化的真菌群落，其中既包含常见的环境真菌属，也存在潜在的昆虫病原物种。这一结果强调，未来不仅需要将虱类作为寄生虫进行研究，还需将其视为与更广泛微生物环境相互作用的微生态系统。