Laboratoire de Parasitologie, Ecole Nationale de Médecine Vétérinaire, 2020 Sidi Thabet, Tunisia.
Vet Parasitol. 2010 May 11;169(3-4):241-7. doi: 10.1016/j.vetpar.2010.01.013. Epub 2010 Jan 25.
The present study describes an outbreak of tropical theileriosis cases refractory to buparvaquone treatment, which occurred in a small-size dairy farm in Tunisia. Out of seven treated cows, four died in spite of repeated buparvaquone injections (2.5 and 5 mg kg(-1)) and the monitoring of the affected cows showed no improvement of the course of the disease with a consistent decrease in the haematocrit, the persistence of fever and an increased parasitaemia after treatment. Ticks were fed on a calf experimentally infected with one isolate established in culture from one of the cases and the resultant infected ticks ground up to generate a supernatant infected with the potentially resistant stock. This was used to experimentally infect three calves, and the clinical observations, post-buparvaquone treatment, showed an absence of the usual effect of buparvaquone treatment on the parasite Theileria annulata, such as the rapid decline of schizont index and parasitaemia and a rapid recovery from the disease. These results confirmed for the first time the occurrence of resistance to buparvaquone in the protozoan T. annulata.
本研究描述了突尼斯一个小型奶牛场暴发的热带泰勒虫病病例，这些病例对布帕伐醌治疗有抗性。在接受治疗的七头奶牛中，有四头尽管重复注射了布帕伐醌（2.5 和 5 mg/kg）并监测了受感染的奶牛，但病情仍无改善，血细胞比容持续下降，发热持续存在，治疗后寄生虫血症增加。从其中一个病例的培养物中建立了一个分离株，用该分离株感染了一头小牛，然后用感染的蜱虫研磨产生了一种含有潜在抗性株的上清液。用这种上清液感染了三头小牛，在接受布帕伐醌治疗后的临床观察表明，布帕伐醌对寄生虫环形泰勒虫通常的治疗效果不存在，例如裂殖体指数和寄生虫血症的快速下降，以及疾病的快速恢复。这些结果首次证实了原生动物环形泰勒虫对布帕伐醌的耐药性的发生。
