Análisis moleculares de Trypanosoma cruzi en sangre de caprinos

Mendoza province, in central west Argentina, is considered among the high-risk provinces for vector transmission of Trypanosoma cruzi, the causative agent of Chagas disease. Extensive goat farming is common in large parts of rural Mendoza, and goats may act as a reservoir for this parasite. The objective of this study was to determine infection rates, parasite loads, and seasonal variation of these parameters in T. cruzi infection in goats from rural areas of three departments of Mendoza. A total of 349 peripheral blood samples with EDTA / guanidine were analyzed from goats on 11 farms (three in Lavalle, three in San Carlos, and five in Malargüe department) in spring of 2014, 2015, and 2016; and in fall of 2015 and 2016 (only Malargüe). DNA was extracted using a Phenol: Chloroform: Isoamyl protocol. The detection and quantification of T. cruzi was performed through qPCR amplification using satellite oligonucleotides. Of the 349 blood samples, 267 (77%) were positive, with parasite loads ranging between <0.10 and 10.90 par-eq/mL (median 0.10). In spring, frequencies of infection in the three departments ranged between 86% and 95%, but differences were not significant. Median parasite loads were higher in Lavalle than in the other departments, while those in goats from San Carlos were consistently low. The frequency of infection and parasite loads in Malargüe were significantly higher in spring than in fall. This seasonal variation may have been related to a reduced nutritional status and impaired immune response of goats in spring. In conclusion, the high proportion of positive goats confirms the persistence of T. cruzi in rural Mendoza.

阿根廷中西部之门多萨省，因其作为 Trypanosoma cruzi（克氏锥虫）的媒介传播高风险区域而备受瞩目。克氏锥虫是查加斯病的病原体。在该省的广大农村地区，广泛饲养山羊，而山羊可能成为该寄生虫的储存宿主。本研究的目的是确定来自门多萨省三个部门（拉瓦列、圣卡洛斯和马尔阿尔圭）农村地区的山羊中克氏锥虫感染的感染率、寄生虫负荷以及这些参数的季节性变化。2014年、2015年和2016年春季，以及2015年和2016年秋季（仅马尔阿尔圭），从11个农场（拉瓦列3个、圣卡洛斯3个、马尔阿尔圭5个）的山羊中采集了共计349份EDTA/瓜氨酸抗凝的周围血样本进行分析；DNA的提取采用酚：氯仿：异戊醇协议。通过使用卫星寡核苷酸进行qPCR扩增来检测和量化克氏锥虫。在349份血样中，267份（77%）呈阳性，寄生虫负荷介于<0.10和10.90 par-eq/mL之间（中位数0.10）。在春季，三个部门的感染频率在86%至95%之间，但差异不显著。马尔阿尔圭的寄生虫负荷中位数高于其他部门，而来自圣卡洛斯的山羊的寄生虫负荷一直较低。马尔阿尔圭春季的感染频率和寄生虫负荷显著高于秋季。这种季节性变化可能与春季山羊营养状况下降和免疫功能受损有关。总之，阳性山羊的高比例证实了克氏锥虫在门多萨省农村地区的持续存在。