College of Pharmacy, Department of Toxicology, The University of Louisiana at Monroe, 700 University Avenue, Monroe, LA 71209-0470, USA.
Ecotoxicol Environ Saf. 2011 May;74(4):593-9. doi: 10.1016/j.ecoenv.2010.11.009. Epub 2011 Mar 30.
Atrazine (technical and formulation), agricultural runoff containing atrazine, and treated sewage and landfill effluents were evaluated for their potential to modulate antimicrobial activity of Xenopus laevis skin secretions against the chytrid fungus, Batrachochytrium dendrobatidis. This chytrid fungus is implicated in several localized mass mortality events, yet the cause of the susceptibility of amphibians to this newly emergent pathogen is unknown. Antimicrobial peptides secreted from dermal glands are thought to provide critical protection against this pathogen. Chronic exposure of X. laevis larvae to agricultural runoff decreased protein content of collected secretions, while treated wastewater effluents increased protein content. However, the in vitro bioactivity was decreased in treatments with both increased and decreased protein. No differences were observed in protein or bioactivity following laboratory exposures of technical atrazine or a typical atrazine formulation (AAtrex(®) 4L/Top Surf(®)). These findings demonstrate that exposure of an amphibian model to agricultural runoff or effluent from municipal sewage treatment plants and landfills alters peptide production and in vitro activity of protective peptides. Although evidence suggests peptide production and bioactivity is a critical part of amphibian resistance to pathogens such as the chytrid fungus, the implications of observed effects for immunity and infection are not clear.
莠去津（原药和制剂）、含有莠去津的农业径流以及处理过的污水和垃圾渗滤液都被评估了其潜在的调节作用，即调节非洲爪蟾皮肤分泌物对真菌的抗菌活性，这种真菌与几种局部大规模死亡事件有关，但两栖动物易感染这种新出现的病原体的原因尚不清楚。从真皮腺分泌的抗菌肽被认为对这种病原体提供了关键的保护。非洲爪蟾幼虫的慢性暴露于农业径流会降低收集到的分泌物中的蛋白质含量，而处理过的废水则会增加蛋白质含量。然而，在蛋白质含量增加和减少的处理中，体外生物活性都降低了。在实验室暴露于技术莠去津或典型莠去津制剂（AAtrex®4L/Top Surf®）后，没有观察到蛋白质或生物活性的差异。这些发现表明，暴露于农业径流或城市污水处理厂和垃圾填埋场的废水会改变保护肽的产生和体外活性。尽管有证据表明，肽的产生和生物活性是两栖动物抵抗真菌等病原体的关键部分，但观察到的效应对免疫和感染的影响尚不清楚。
