Schares G, Pantchev N, Barutzki D, Heydorn A O, Bauer C, Conraths F J
Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Seestrasse 55, 16868 Wusterhausen, Germany.
Int J Parasitol. 2005 Dec;35(14):1525-37. doi: 10.1016/j.ijpara.2005.08.008. Epub 2005 Sep 15.
Faecal samples of 24,089 dogs were examined coproscopically in two veterinary laboratories in Germany between March 2001 and October 2004. In 47 dogs, oocysts of 9-14 microm size were found. Their morphology was similar to those of Hammondia heydorni and Neospora caninum. Samples of 28 of these dogs were further examined by inoculation into gerbils: seven isolates induced a specific antibody response against antigens of N. caninum NC-1 tachyzoites. This response suggests that the isolates contained N. caninum. In addition to H. heydorni (12 times isolated), Toxoplasma gondii occysts (twice) and Hammondia hammondi oocysts (twice) were observed in dog faeces. The latter findings suggest that coprophagia with a subsequent intestinal passage by dogs plays a role in the dissemination of coccidian parasites for which cats are definitive hosts. Five of the seven N. caninum (NC-GER2, NC-GER3, NC-GER4, NC-GER5, NC-GER6) and the two T. gondii isolates (TG-dgGER1, TG-dgGER2) were successfully passaged into cell culture and are now available for detailed characterization. In contrast to oocysts of other parasites, N. caninum oocysts were predominantly found between January and April (Fisher exact; P=0.038). In the sera of dogs shedding N. caninum, no reactions against the immunodominant antigens with apparent molecular weights of 19, 29, 30, 33 and 37 kDa of N. caninum tachyzoites were observed 3-5 weeks after shedding. However, the animals recognized a 152-kDa N. caninum antigen. Compared with those identified as H. heydorni, T. gondii or H. hammondi, N. caninum oocyst isolates were significantly smaller in length with the 75th percentiles <or=10.7 microm when measured in concentrated sucrose solution and smaller length-width ratios with the 75th percentiles <or=1.06. It may thus be possible to develop criteria for a preliminary identification of N. caninum in dog faeces based on the oocyst morphology.
2001年3月至2004年10月期间，在德国的两家兽医实验室对24,089只犬的粪便样本进行了粪便显微镜检查。在47只犬中发现了大小为9 - 14微米的卵囊。它们的形态与海氏哈蒙德球虫和犬新孢子虫的卵囊相似。对其中28只犬的样本进一步接种沙土鼠进行检查：7个分离株诱导了针对犬新孢子虫NC - 1速殖子抗原的特异性抗体反应。这种反应表明这些分离株含有犬新孢子虫。除了海氏哈蒙德球虫（分离出12次）外，在犬粪便中还观察到了刚地弓形虫卵囊（2次）和哈蒙德球虫卵囊（2次）。后一发现表明犬通过食粪随后肠道传播在以猫为终末宿主的球虫寄生虫传播中起作用。7个犬新孢子虫分离株中的5个（NC - GER2、NC - GER3、NC - GER4、NC - GER5、NC - GER6）和2个刚地弓形虫分离株（TG - dgGER1、TG - dgGER2）成功传代至细胞培养，现在可用于详细鉴定。与其他寄生虫的卵囊相比，犬新孢子虫卵囊主要在1月至4月间发现（Fisher精确检验；P = 0.038）。在排出犬新孢子虫的犬血清中，在排出后3 - 5周未观察到针对犬新孢子虫速殖子表观分子量为19、29、30、33和37 kDa的免疫显性抗原的反应。然而，这些动物识别一种152 kDa的犬新孢子虫抗原。与鉴定为海氏哈蒙德球虫、刚地弓形虫或哈蒙德球虫的卵囊相比，犬新孢子虫卵囊分离株在浓蔗糖溶液中测量时长度明显更小，第75百分位数≤10.7微米，长宽比也更小，第75百分位数≤1.06。因此，有可能基于卵囊形态制定犬粪便中犬新孢子虫初步鉴定的标准。
