Moré G, Pardini L, Basso W, Marín R, Bacigalupe D, Auad G, Venturini L, Venturini M C
Inmunoparasitology and Parasitology Laboratory, Faculty of Veterinary Medicine, National University of La Plata, La Plata, Argentina.
Vet Parasitol. 2008 Aug 1;155(1-2):158-60. doi: 10.1016/j.vetpar.2008.04.003. Epub 2008 Apr 16.
Llamas (Lama glama) are South American camelids described as intermediate hosts of Neospora caninum, Toxoplasma gondii and Sarcocystis aucheniae. Due to the potential role of these protozoan infections as a cause of economic losses, the aim of this study was to determine the seroprevalence for T. gondii, N. caninum and Sarcocystis sp. in llamas from Argentina. Serum samples from 308 llamas (>2 years old) were collected between 2005 and 2007. A total of 55 farms located in six departments of Jujuy province, Argentina were sampled. Presence of antibodies to N. caninum, T. gondii and Sarcocystis sp. was determined by the indirect fluorescent antibody test (IFAT). For Sarcocystis, 2 different bradyzoites-based antigens were prepared using S. aucheniae and S. cruzi. Sera were tested at dilutions 1:25 and 1:50. Antibodies to N. caninum were found in 4.6% serum samples. Fifty percent of departments and 14.5% of farms had positive animals. Antibodies to T. gondii were found in 30% of samples, distributed in 66% of departments and 43.6% of farms. Antibodies to Sarcocystis sp. were detected in 96% of samples and all departments and farms had positive animals, suggesting frequent contact between llamas and canids. Co-infection with N. caninum, T. gondii and Sarcocystis sp. was also recorded. Low seroprevalence of N. caninum in llamas detected in this study could be related to climatic and geographical conditions that limit cattle breeding activity, reducing the source of infection for definitive hosts. Seroprevalence of T. gondii and the positive animal distribution suggest frequent contamination of grass with felid faeces. In conclusion, this is the first report of combined seroprevalence for N. caninum, T. gondii and Sarcocystis sp. in llamas. Further studies are needed to determine the potential role of these protozoan infections as cause of abortion in Argentina as well as presence of these protozoans in llama meat used for human consumption.
美洲驼(小羊驼)是南美洲的骆驼科动物,被描述为犬新孢子虫、刚地弓形虫和奥氏肉孢子虫的中间宿主。由于这些原生动物感染可能造成经济损失,本研究旨在确定阿根廷美洲驼中弓形虫、犬新孢子虫和肉孢子虫属的血清阳性率。2005年至2007年间采集了308头(年龄大于2岁)美洲驼的血清样本。对阿根廷胡胡伊省六个部门的55个养殖场进行了采样。采用间接荧光抗体试验(IFAT)检测犬新孢子虫、弓形虫和肉孢子虫属抗体。对于肉孢子虫,使用奥氏肉孢子虫和克鲁斯肉孢子虫制备了2种不同的基于缓殖子的抗原。血清在1:25和1:50的稀释度下进行检测。在4.6%的血清样本中发现了犬新孢子虫抗体。50%的部门和14.5%的养殖场有阳性动物。在30%的样本中发现了弓形虫抗体,分布在66%的部门和43.6%的养殖场。在96%的样本中检测到肉孢子虫属抗体,所有部门和养殖场都有阳性动物,这表明美洲驼与犬科动物之间频繁接触。还记录到了犬新孢子虫、弓形虫和肉孢子虫属的混合感染。本研究中检测到的美洲驼中犬新孢子虫血清阳性率较低,可能与限制养牛活动的气候和地理条件有关,从而减少了终末宿主的感染源。弓形虫的血清阳性率和阳性动物分布表明草地频繁受到猫科动物粪便的污染。总之,这是关于美洲驼中犬新孢子虫、弓形虫和肉孢子虫属联合血清阳性率的首次报告。需要进一步研究以确定这些原生动物感染在阿根廷作为流产原因以及在供人类食用的美洲驼肉中这些原生动物的存在情况的潜在作用。