Mattos Elaine Cristina de, Meira-Strejevitch Cristina da Silva, Marciano Maria Aparecida Moraes, Faccini Cristiane Castro, Lourenço Angela Maria, Pereira-Chioccola Vera Lucia
Centro de Laboratório Regional de Santo André, Instituto Adolfo Lutz, SP, Brazil.
Centro de Parasitologia e Micologia, Instituto Adolfo Lutz, SP, Brazil.
Acta Trop. 2017 Dec;176:311-315. doi: 10.1016/j.actatropica.2017.08.025. Epub 2017 Aug 30.
Chagas disease, caused by Trypanosoma cruzi affects about 6-8 million people worldwide. Although transmission by triatomine insects has been controlled, other means of transmission maintain the infection. These forms of transmission are responsible for introducing Chagas disease in other non-endemic countries of the world. Thus, Chagas disease, nowadays is a worldwide health problem. In Brazil, acai pulp and sugarcane juice have been associated with Chagas disease outbreaks. The difficulties in isolation of the parasite from foods are hampering source tracking which could allow the confirmation of an implicated food commodity in these outbreak investigations. To address this scientific gap, we evaluated the performance of real-time PCR (qPCR) for detecting T. cruzi in acai pulp and sugarcane juice. All experiments were performed with acai pulp and sugarcane juice samples contaminated with different concentrations of T. cruzi. In assays with qPCR, the results showed that the ideal procedure for T. cruzi identification in acai pulp and sugarcane juice consisted of: i. centrifugation; ii. DNA extraction with a commercial kit for stool matrix; and iii. qPCR using a specific molecular marker for T. cruzi. The seeding in LIT medium of experimentally contaminated foods was effective in detecting the parasitic load by qPCR. The efficacy of qPCR was also verified testing food samples crushed with infected Triatomines. In conclusion, this methodology can be used to perform rapid diagnosis in outbreaks, facilitating measures in disease control.
恰加斯病由克氏锥虫引起，全球约有600万至800万人受其影响。尽管锥蝽昆虫传播已得到控制，但其他传播途径仍使感染持续存在。这些传播形式导致恰加斯病在世界其他非流行国家出现。因此，恰加斯病如今是一个全球性的健康问题。在巴西，阿萨伊果肉和甘蔗汁与恰加斯病疫情有关。从食品中分离寄生虫存在困难，这阻碍了源头追踪，而源头追踪有助于在这些疫情调查中确认受牵连的食品。为填补这一科学空白，我们评估了实时荧光定量聚合酶链反应（qPCR）检测阿萨伊果肉和甘蔗汁中克氏锥虫的性能。所有实验均使用被不同浓度克氏锥虫污染的阿萨伊果肉和甘蔗汁样本进行。在qPCR检测中，结果表明，在阿萨伊果肉和甘蔗汁中鉴定克氏锥虫的理想步骤包括：i. 离心；ii. 使用用于粪便样本的商业试剂盒提取DNA；iii. 使用针对克氏锥虫的特异性分子标记进行qPCR。对实验性污染食品接种到LIT培养基中，通过qPCR有效检测到了寄生虫载量。用感染锥蝽碾碎的食品样本进行检测也验证了qPCR的有效性。总之，这种方法可用于疫情中的快速诊断，有助于疾病控制措施的实施。
