Abstract
Gastric cryptosporidiosis caused by Cryptosporidium serpentis has impacted the conservation efforts for the imperiled eastern indigo snake (EIS, Drymarchon couperi). Multiple treatments, including paromomycin, nitazoxanide-azithromycin-rifabutin, clofazimine, curcumin, and hydrogen peroxide gavage, have been investigated and proved ineffective in eliminating the parasite, necessitating further investigation. A novel piperazine-based compound, MMV665917, has been shown to be more effective than paromomycin, nitazoxanide, and clofazimine in treating cryptosporidiosis in mammals. With these promising results, MMV665917 was selected to investigate as a treatment of gastric cryptosporidiosis in EIS. Twelve EIS naturally infected with C. serpentis were randomly divided into two groups of six: Group A and Group B. Group A received 22 mg/kg MMV665917 daily for 7d and Group B received a placebo daily for 7d. All EIS tolerated the treatment with no adverse effects a ppreciated. Success was evaluated by C. serpentis-specific probe hybridization qPCR analysis of gastric lavage performed one, two, and three months following the treatment. Infections persisted following treatment and there was no statistical difference in qPCR CT values between the groups or within the groups for the three months following treatment (F = 0.92, P = 0.525). These findings show that MMV665917 dosed at 22 mg/kg daily for 7d is ineffective in eliminating C. serpentis in EIS and alternative MMV665917 dosing or formulations should be investigated in reptiles.
