Militzer Nina, Pinecki Socias Sophia, Nijhof Ard M
Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany.
Front Microbiol. 2023 Jan 10;13:1050063. doi: 10.3389/fmicb.2022.1050063. eCollection 2022.
Artificial tick feeding systems (ATFS) can be used to study tick biology and tick-pathogen interactions. Due to the long feeding duration of hard ticks, antibiotics are commonly added to the blood meal to prevent the blood from decaying. This may affect the ticks' microbiome, including mutualistic bacteria that play an important role in tick biology. This effect was examined by the consecutive feeding of larvae, nymphs, and adults with and without the supplementation of gentamicin and in parallel on calves. DNA extracted from unfed females was analyzed by 16S rRNA sequencing. The abundance of , and spp. was measured by qPCR in unfed larvae, nymphs, and adults. Larvae and nymphs fed on calves performed significantly better compared to both groups. Adults fed on blood supplemented with gentamicin and B vitamins had a higher detachment proportion and weight compared to the group fed with B vitamins but without gentamicin. The detachment proportion and weights of females did not differ significantly between ticks fed on calves and with gentamicin, but the fecundity was significantly higher in ticks fed on calves. 16S rRNA sequencing showed a higher microbiome species richness in ticks fed on calves compared to ticks fed . A shift in microbiome composition, with . as dominant species in females fed as juveniles on calves and . as the most abundant species in females previously fed was observed. Females fed without gentamicin showed significant lower loads of . M. mitochondrii compared to females fed with gentamicin and ticks fed on calves. spp. were exclusively detected in female ticks fed on cattle by qPCR, but 16S rRNA sequencing results also showed a low abundance in females exposed to gentamicin. In conclusion, the employed feeding method and gentamicin supplementation affected the ticks' microbiome composition and fecundity. Since these changes may have an impact on tick biology and vector competence, they should be taken into account in studies employing ATFS.
人工蜱虫喂养系统（ATFS）可用于研究蜱虫生物学以及蜱虫与病原体的相互作用。由于硬蜱的喂养时间较长，通常会在血餐中添加抗生素以防止血液腐败。这可能会影响蜱虫的微生物群，包括在蜱虫生物学中起重要作用的共生细菌。通过在有和没有补充庆大霉素的情况下连续喂养幼虫、若虫和成虫，并同时在小牛身上进行喂养，来研究这种影响。从未进食的雌性蜱虫中提取的DNA通过16S rRNA测序进行分析。通过qPCR测量未进食的幼虫、若虫和成虫中 、 和 属的丰度。与两组相比，在小牛身上喂养的幼虫和若虫表现明显更好。与喂食维生素B但未添加庆大霉素的组相比，喂食添加庆大霉素和维生素B的血液的成虫具有更高的脱离比例和体重。在小牛身上喂养的蜱虫和添加庆大霉素喂养的蜱虫之间，雌性蜱虫的脱离比例和体重没有显著差异，但在小牛身上喂养的蜱虫的繁殖力明显更高。16S rRNA测序显示，与喂食 的蜱虫相比，在小牛身上喂养的蜱虫的微生物群物种丰富度更高。观察到微生物群组成发生了变化，在小牛身上作为幼虫喂养的雌性蜱虫中， 属为优势物种，而在之前喂食 的雌性蜱虫中， 属是最丰富的物种。未添加庆大霉素喂养的雌性蜱虫显示，与添加庆大霉素喂养的雌性蜱虫和在小牛身上喂养的蜱虫相比， 线粒体菌的负载量显著更低。通过qPCR仅在以牛为食的雌性蜱虫中检测到 属，但16S rRNA测序结果也显示，接触庆大霉素的雌性蜱虫中该属的丰度较低。总之，所采用的喂养方法和庆大霉素补充剂会影响蜱虫的微生物群组成和繁殖力。由于这些变化可能会对蜱虫生物学和传播能力产生影响，因此在使用ATFS的研究中应予以考虑。
