Departamento de Medicina Veterinária, Centro de Ciências Agrárias e Engenharias, Universidade Federal do Espírito Santo-UFES, Alegre, ES, Brazil.
Departamento de Medicina Veterinária, Centro de Ciências Agrárias e Engenharias, Universidade Federal do Espírito Santo-UFES, Alegre, ES, Brazil.
J Invertebr Pathol. 2021 Nov;186:107676. doi: 10.1016/j.jip.2021.107676. Epub 2021 Oct 9.
The snail Pseudosuccinea columella participates in the distribution of Fasciola hepatica in the environment by acting as its intermediate host. Therefore, the control of this lymnaeid is one of the ways to prevent hepatic fascioliasis. The objective of this study was to evaluate the susceptibility of P. columella to infective juveniles (IJs) of the entomopathogenic nematode (EPN) Heterorhabditis baujardi in laboratory conditions, as well as to investigate aspects related to the biochemistry and histopathology of snails exposed or not to the EPNs during three weeks. The EPN exposure induced significant reductions in the concentrations of glucose, total proteins and glycogen (gonad-digestive gland complex) in the snails during the onset of the infection, with the levels being restored as the infection progresses. These alterations were accompanied by increased hemolymph activities of aminotransferases and lactate dehydrogenase, as well as the concentrations of uric acid after the first and second weeks of the experiment. The histopathological analyses of the exposed snails revealed cell necrosis at the end of the first week, tissue inflammatory reactions one and two weeks after exposure, and degeneration three weeks afterward in comparison with the unexposed snails. Finally, scanning electronic microscopy revealed proliferation of fibrous connective tissue three weeks after exposure. The results indicate that P. columella is susceptible to H. baujardi. The exposure favored the establishment of a negative energy balance, increased the activity of enzymes related to tissue damages and promoted accumulation of nitrogen compounds in the host snails. Additionally, was observed in P. columella exposed to the EPNs, significant tissue lesions, and demonstrated the strong pathogenic potential of H. baujardi, indicating its possible application for biological control of this snail.
锥实螺参与了环境中肝片吸虫的分布，作为其中间宿主。因此，控制这种扁卷螺是预防肝片吸虫病的方法之一。本研究的目的是评估锥实螺对昆虫病原线虫（EPN）嗜线虫异小杆线虫感染性幼虫（IJs）的易感性，以及在实验室条件下，在感染前、感染后不同时间，研究暴露于或不暴露于 EPN 对蜗牛生物化学和组织病理学的影响。EPN 暴露会导致感染初期，蜗牛体内葡萄糖、总蛋白和糖原（生殖-消化腺复合体）浓度显著降低，随着感染的进展，这些浓度逐渐恢复。这些变化伴随着血淋巴中转氨酶和乳酸脱氢酶活性以及尿酸浓度的增加，这些变化在实验的第一和第二周后发生。暴露组蜗牛的组织病理学分析显示，在感染后第一周末出现细胞坏死，暴露后一到两周出现组织炎症反应，三周后出现组织变性，与未暴露组相比。最后，扫描电子显微镜显示，暴露后三周，纤维结缔组织增生。结果表明，锥实螺易受嗜线虫异小杆线虫的影响。暴露有利于建立负能量平衡，增加与组织损伤相关的酶的活性，并促进宿主蜗牛体内氮化合物的积累。此外，在暴露于 EPN 的锥实螺中观察到显著的组织损伤，表明嗜线虫异小杆线虫具有很强的致病性，这表明其可能用于该种蜗牛的生物防治。
