Trematodes have complex life cycles with multiple hosts. Biomphalaria snails commonly act as the first intermediate hosts of several species that can affect human and animal health. The specific identification of larval trematodes found in snails is difficult and limited, since the taxonomy of these flukes is based on morphological traits of the adults found in vertebrates. Despite recent advances worldwide, studies aiming at the use of molecular tools for the identification of cercariae found in snails are scarce in the South America. In fact, most studies are focused on Schistosoma mansoni, with few efforts directed towards the identification of larvae of other parasites found in planorbids. When reported, these other parasites are identified as cercarial types, an artificial morphological system of classification. Therefore, alternative strategies for a correct, rapid and inexpensive identification of larval trematodes found in Biomphalaria are needed. This work aimed at developing a methodology capable of distinguishing four important families of trematodes (Clinostomidae, Echinostomatidae, Schistosomatidae and Strigeidae) commonly found infecting species of Biomphalaria. Using the rDNA sequences of 34 species as input for the online tool TipMT, we designed trematode family-specific primers targeting the ITS region optimized to be used in multiplex PCR. The panel of primers identified in this study was effective at the same PCR condition. The specificity of the primers was confirmed, and the PCR sensitivity ranged from 0.1 ng to 1 ag of the DNA of the parasite. This methodology was also effective for the detection of coinfection. Through a simple, fast, accurate, and inexpensive methodology, it is possible to properly identify the trematode families included in this study in a single PCR reaction. A family level identification provides important information about probable hosts, pattern of life cycle and possible impacts that the infection generates in a specific region, thus allowing the design of better control strategies, especially for those infections that have medical and veterinary importance.

吸虫具有多个宿主的复杂生命周期。生物淋病蜗牛通常充当影响人类和动物健康的几种物种的第一个中间宿主。在蜗牛中发现幼虫吸虫的具体鉴定是困难和有限的，因为这些吸虫的分类是基于在脊椎动物中发现的成虫的形态特征。尽管最近在世界范围内取得了进步，但是在南美，针对利用分子工具鉴定蜗牛中尾c的研究很少。实际上，大多数研究都集中在曼氏血吸虫，几乎没有任何努力来鉴定在浮游动物中发现的其他寄生虫的幼虫。报告时，这些其他寄生虫被鉴定为子宫颈类型，这是一种人工形态学分类系统。因此，需要用于正确，快速和廉价地鉴定在Biomphalaria中发现的幼虫吸虫的替代策略。这项工作旨在开发一种方法，该方法能够区分四个常见的吸虫物种（吸虫科，棘皮动物科，血吸虫科和蜘蛛科）。。使用34种rDNA序列作为在线工具TipMT的输入，我们设计了针对ITS区的吸虫家族特异性引物，该引物经优化可用于多重PCR。在这项研究中确定的引物组在相同的PCR条件下有效。证实了引物的特异性，PCR灵敏度为寄生虫DNA的0.1 ng至1 g。该方法对于检测合并感染也有效。通过简单，快速，准确和廉价的方法，有可能在单个PCR反应中正确鉴定本研究中包括的吸虫。家庭级别的标识提供了有关可能的宿主，生命周期模式以及感染在特定区域产生的可能影响的重要信息，