Allsopp M T E P, Lewis B D, Penzhorn B L
Onderstepoort Veterinary Institute, Private Bag X5, Onderstepoort 0110, South Africa.
Vet Parasitol. 2007 Sep 1;148(2):130-6. doi: 10.1016/j.vetpar.2007.05.017. Epub 2007 Jun 29.
The intra-erythrocytic parasite Theileria equi is one of two tick-transmitted causative agents of equine piroplasmosis. Piroplasms of T. equi can be transmitted across the equine placenta and once a horse is infected, it appears to remain a lifelong carrier, since anti-theilerial drugs suppress but do not eliminate the parasite. Carrier mares may transmit the organism to their offspring and this may result in abortion or neonatal piroplasmosis, but observations by some researchers suggest that foals may be born as carriers yet remain apparently healthy. Using a T. equi-specific oligonucleotide probe, we have determined that transplacental transmission occurs early in equine foetal development and that carrier mares may give birth to healthy carrier foals. Investigation of parasite levels and the effect of maternal colostrum on the newborn suggests that colostral T. equi antibody may act to suppress parasitaemia in the newborn, reducing the incidence of clinical neonatal piroplasmosis.
红细胞内的寄生虫马泰勒虫是马梨形虫病的两种蜱传播病原体之一。马泰勒虫的梨形虫可通过马胎盘传播，一旦马匹感染，似乎会终生携带，因为抗泰勒虫药物只能抑制而不能消除寄生虫。携带病原体的母马可能会将病原体传染给它们的后代，这可能导致流产或新生马梨形虫病，但一些研究人员的观察表明，马驹可能生来就是携带者，但仍明显健康。使用马泰勒虫特异性寡核苷酸探针，我们已经确定经胎盘传播发生在马胎儿发育的早期，并且携带病原体的母马可能会生下健康的携带病原体的马驹。对寄生虫水平以及母体初乳对新生儿的影响的研究表明，初乳中的马泰勒虫抗体可能会抑制新生儿的寄生虫血症，从而降低临床新生马梨形虫病的发病率。
