Teleost fish embryos are protected by two acellular membranes against particulate pollutants that are present in the water column. These membranes provide an effective barrier preventing particle uptake. In this study, we tested the hypothesis that the adsorption of antimicrobial titanium dioxide nanoparticles onto zebrafish eggs nevertheless harms the developing embryo by disturbing early microbial colonization. Zebrafish eggs were exposed during their first day of development to 2, 5 and 10 mg TiO₂ L⁻¹ (NM-105). Additionally, eggs were exposed to gold nanorods to assess the effectiveness of the eggs’ membranes in preventing particle uptake, localizing these particles by way of two-photon microscopy. This confirmed that particles accumulate onto zebrafish eggs, without any detectable amounts of particles crossing the protective membranes. By way of particle-induced X-ray emission analysis, we inferred that the titanium dioxide particles could cover 25–45 % of the zebrafish egg surface, where the concentrations of sorbed titanium correlated positively with concentrations of potassium and correlated negatively with concentrations of silicon. A combination of imaging and culture-based microbial identification techniques revealed that the adsorbed particles exerted antimicrobial effects, but resulted in an overall increase of microbial abundance, without any change in heterotrophic microbial activity, as inferred based on carbon substrate utilization. This effect persisted upon hatching, since larvae from particle-exposed eggs still comprised higher microbial abundance than larvae that hatched from control eggs. Notably, pathogenic aeromonads tolerated the antimicrobial properties of the nanoparticles. Overall, our results show that the adsorption of suspended antimicrobial nanoparticles on aquatic eggs can have cascading effects across different life stages of oviparous animals. Our study furthermore suggests that aggregation dynamics may occur that could facilitate the dispersal of pathogenic bacteria through aquatic ecosystems.

硬骨鱼的胚胎受到两个无细胞膜的保护，可以防止水柱中存在的颗粒污染物。这些膜提供了防止颗粒吸收的有效屏障。在这项研究中，我们测试了以下假设：抗微生物二氧化钛纳米粒子在斑马鱼卵上的吸附仍然会通过干扰早期微生物定殖而损害发育中的胚胎。斑马鱼卵在发育的第一天就暴露于2、5和10 mg TiO ₂  L ^-1（NM-105）。另外，将卵暴露于金纳米棒以评估卵膜在防止颗粒摄取方面的有效性，并通过双光子显微镜对这些颗粒进行定位。这证实了颗粒积聚在斑马鱼卵上，而没有任何可检测量的颗粒穿过保护膜。通过粒子诱导的X射线发射分析，我们推断二氧化钛粒子可以覆盖斑马鱼卵表面的25–45％，其中吸附的钛的浓度与钾的浓度呈正相关，与硅的浓度呈负相关。 。成像和基于培养物的微生物鉴定技术的结合表明，吸附的颗粒发挥了抗菌作用，但导致微生物丰度总体增加，根据碳底物利​​用率推断，异养微生物活性没有任何变化。孵化后这种效果仍然存在，因为来自暴露于颗粒的卵的幼虫仍然比对照卵孵化的幼虫具有更高的微生物丰度。值得注意的是，致病性气单胞菌耐受纳米颗粒的抗微生物特性。总体而言，我们的结果表明，悬浮的抗菌纳米颗粒在水生鸡蛋上的吸附可在卵生动物的不同生命阶段产生级联效应。我们的研究进一步表明，可能会发生聚集动力学，从而促进病原菌通过水生生态系统扩散。因为来自暴露于颗粒的卵的幼虫仍然比对照卵孵化的幼虫具有更高的微生物丰度。值得注意的是，致病性气单胞菌耐受纳米颗粒的抗微生物特性。总体而言，我们的结果表明，悬浮的抗菌纳米颗粒在水生鸡蛋上的吸附可在卵生动物的不同生命阶段产生级联效应。我们的研究进一步表明，可能会发生聚集动力学，从而促进病原菌通过水生生态系统扩散。因为来自暴露于颗粒的卵的幼虫仍然比对照卵孵化的幼虫具有更高的微生物丰度。值得注意的是，致病性气单胞菌耐受纳米颗粒的抗微生物特性。总体而言，我们的结果表明，悬浮的抗菌纳米颗粒在水生鸡蛋上的吸附可在卵生动物的不同生命阶段产生级联效应。我们的研究进一步表明，可能会发生聚集动力学，从而促进病原菌通过水生生态系统扩散。我们的结果表明，悬浮的抗菌纳米颗粒在水生鸡蛋上的吸附可在卵生动物的不同生命阶段产生级联效应。我们的研究进一步表明，可能会发生聚集动力学，从而促进病原菌通过水生生态系统扩散。我们的结果表明，悬浮的抗菌纳米颗粒在水生鸡蛋上的吸附可在卵生动物的不同生命阶段产生级联效应。我们的研究进一步表明，可能会发生聚集动力学，从而促进病原菌通过水生生态系统扩散。