Department of Biotechnology, St. Peter's Institute of Higher Education and Research, Avadi, 600 054, Chennai, Tamil Nadu, India.
Division of Biopesticides and Environmental Toxicology, Sri Paramakalyani Centre for Excellence in Environmental Sciences, Manonmaniam Sundaranar University, Alwarkurichi, 627 412, Tirunelveli, Tamil Nadu, India.
Microb Pathog. 2019 Mar;128:281-287. doi: 10.1016/j.micpath.2019.01.014. Epub 2019 Jan 8.
Mosquito that accountable for dispersal of dengue fever is Aedes aegypti Linn. and considered to be a chief vector for dengue especially in South Asian countries. Aspergillus flavus is considered to be wild growing green yellow colonies and synthesis highly regulating aflatoxins (B1, B2, G1 and G2) as a secondary metabolite. Mycotoxins of A. flavus showed its efficacy against III and IV instars of Ae. aegypti with more than 90% mortality at the prominent dosage of 2 × 10 conidia/ml. The proximate lethal concentrations (LC and LC) of mycotoxins against third and fourth instars was 2 × 10 and 2 × 10 respectively. Correspondingly, sub-lethal dosage of mycotoxin A. flavus significantly inhibited the level of α- β-carboxylesterase and SOD activity and upregulated the level of major detoxifying enzymes GST and CYP450. Moreover, sub-lethal dosage also showed higher deterrent and fecundity effects. Gut-histological examination reveals that the A. flavus considerably affected the gut epithelial cells along with the inner gut lumen as compared to the control. The non-target screening of A. flavus against two aquatic predators (A. bouvieri and Tx. splendens) display more than 80% of mortality rate against both the species at the dosage of 2 × 10 (two-fold-higher dosage used in larval assays). Thus the biosafety assessment suggests that A. flavus display higher toxicity against the non-targets and it is not-recommended to apply it directly to the aquatic habitat of dengue mosquito which shares their living space with other beneficial insects.
能传播登革热的蚊子是埃及伊蚊，被认为是登革热的主要传播媒介，尤其是在南亚国家。黄曲霉被认为是野生生长的黄绿色菌落，并合成高度调节的黄曲霉毒素（B1、B2、G1 和 G2）作为次级代谢产物。黄曲霉的真菌毒素对三龄和四龄埃及伊蚊表现出其功效，在突出剂量为 2×10 个分生孢子/ml 时，死亡率超过 90%。真菌毒素对三龄和四龄的近似致死浓度（LC 和 LC）分别为 2×10 和 2×10。相应地，亚致死剂量的黄曲霉真菌毒素显著抑制了α- β-羧酸酯酶和 SOD 活性的水平，并上调了主要解毒酶 GST 和 CYP450 的水平。此外，亚致死剂量还表现出更高的驱避和生殖力效应。肠道组织学检查表明，与对照组相比，黄曲霉对肠道上皮细胞及其内部肠道腔有相当大的影响。非靶标筛选黄曲霉对两种水生捕食者（A. bouvieri 和 Tx. splendens）的影响，在 2×10 的剂量下（在幼虫测定中使用的两倍高剂量），对两种物种的死亡率均超过 80%。因此，生物安全性评估表明，黄曲霉对非靶标表现出更高的毒性，不建议将其直接应用于登革热蚊子的水生栖息地，因为它们与其他有益昆虫共享生活空间。
