Erban Tomas, Parizkova Kamila, Sopko Bruno, Talacko Pavel, Markovic Martin, Jarosova Jana, Votypka Jan
Proteomics and Metabolomics Laboratory, Crop Research Institute, Drnovska 507/73, Prague 6-Ruzyne CZ-161 06, Czechia.
Department of Parasitology, Faculty of Science, Charles University, Vinicna 1594/7, Prague 2 CZ-128 00, Czechia.
Sci Total Environ. 2023 Dec 20;905:166973. doi: 10.1016/j.scitotenv.2023.166973. Epub 2023 Sep 11.
A challenge in bee protection is to assess the risks of pesticide-pathogen interactions. Lotmaria passim, a ubiquitous unicellular parasite in honey bees, is considered harmful under specific conditions. Imidacloprid causes unpredictable side effects. Research indicates that both L. passim and imidacloprid may affect the physiology, behavior, immunity, microbiome and lifespan of honey bees. We designed cage experiments to test whether the infection of L. passim is affected by a sublethal dose of imidacloprid. Workers collected at the time of emergence were exposed to L. passim and 2.5 μg/L imidacloprid in the coexposure treatment group. First, samples of bees were taken from cages since they were 5 days old and 3 days postinfection, i.e., after finishing an artificial 24 h L. passim infection. Additional bees were collected every two additional days. In addition, bees frozen at the time of emergence and collected from the unexposed group were analyzed. Abdomens were analyzed using qPCR to determine parasite load, while corresponding selected heads were subjected to a label-free proteomic analysis. Our results show that bees are free of L. passim at the time of emergence. Furthermore, imidacloprid considerably increased the prevalence as well as parasite loads in individual bees. This means that imidacloprid facilitates infection, enabling faster parasite spread in a colony and potentially to surrounding colonies. The proteomic analysis of bee heads showed that imidacloprid neutralized the increased transferrin 1 expression by L. passim. Importantly, this promising marker has been previously observed to be upregulated by infections, including gut parasites. This study contributes to understanding the side effects of imidacloprid and demonstrates that a single xenobiotic/pesticide compound can interact with the gut parasite. Our methodology can be used to assess the effects of different compounds on L. passim.
蜜蜂保护面临的一项挑战是评估农药与病原体相互作用的风险。洛氏蜜蜂微孢子虫（Lotmaria passim）是蜜蜂中一种普遍存在的单细胞寄生虫，在特定条件下被认为是有害的。吡虫啉会产生不可预测的副作用。研究表明，洛氏蜜蜂微孢子虫和吡虫啉都可能影响蜜蜂的生理、行为、免疫力、微生物群和寿命。我们设计了笼养实验，以测试亚致死剂量的吡虫啉是否会影响洛氏蜜蜂微孢子虫的感染情况。在共暴露处理组中，将刚羽化时采集的工蜂暴露于洛氏蜜蜂微孢子虫和2.5μg/L的吡虫啉中。首先，从笼子中取出蜜蜂样本，时间分别为它们5日龄时以及感染后3天，即完成人工24小时洛氏蜜蜂微孢子虫感染后。每隔两天再收集额外的蜜蜂。此外，对羽化时冷冻并从未暴露组收集的蜜蜂进行分析。使用定量聚合酶链反应（qPCR）分析腹部以确定寄生虫载量，同时对相应选取的头部进行无标记蛋白质组分析。我们的结果表明，蜜蜂在羽化时没有感染洛氏蜜蜂微孢子虫。此外，吡虫啉显著增加了个体蜜蜂的感染率以及寄生虫载量。这意味着吡虫啉促进了感染，使寄生虫能够在蜂群中更快传播，并有可能传播到周围的蜂群。对蜜蜂头部的蛋白质组分析表明，吡虫啉抵消了洛氏蜜蜂微孢子虫导致的转铁蛋白1表达增加。重要的是，此前已观察到这个有前景的标志物会因包括肠道寄生虫在内的感染而上调。本研究有助于理解吡虫啉的副作用，并证明单一的外源化合物/农药可以与肠道寄生虫相互作用。我们的方法可用于评估不同化合物对洛氏蜜蜂微孢子虫的影响。
