Effects of two anticoccidial drugs, Monensin, Toltrazuril and the mixture of them on Cryptosporidium parvum in vitro

Introduction and objective: cryptosporidium parvum is a protozoan parasite that is a common cause of diarrhea in both animals and humans worldwide. there is no effective specific chemotherapeutic treatment. the aim of this study was to survey and compare the anticryptosporidial effect of two anticoccidial drugs, monensin, toltrazuril and synergic effect on oocysts of c. parvum in vitro.materials and methods: cryptosporidium parvum oocysts were isolated from the fecal samples of calves after purification, stored in hanks balance salt solution at 4°c. they were exposed to different concentrations of the drugs, monensin, toltrazuril and the mixture of them (0, 0.1, 0.5, 1, 10, 20, 60 and 100μg/ml). the effects of the drugs were evaluated by counting the complete oocysts after 24h and 48h incubation at 37°c.results: the results showed a significant decrease in the oocysts number related to the increase in the concentration and exposure time of the drugs. the mixture of two drugs had the highest efficacy on the c. parvum oocysts than each of drugs alone (p <0.001) and monensin in contrast to toltrazuril at the same concentration showed to be more effective (p<0.001). these drugs in all concentrations were effective on c. parvum oocysts, and at100μg/ml had the highest efficacy and at1μg/ml had the least. conclusion: this study showed that two drugs were effective on c. parvum oocysts and monensin was more effective than toltrazuril and the mixture of them was more effective than each of them alone because of their synergism.