Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts.
Department of Medicine, University of Vermont Larner College of Medicine, Burlington.
J Infect Dis. 2019 Jun 19;220(2):285-293. doi: 10.1093/infdis/jiz105.
Cryptosporidiosis, an enteric protozoon, causes substantial morbidity and mortality associated with diarrhea in children <2 years old in low- to middle-income countries. There is no vaccine and treatments are inadequate. A piperazine-based compound, MMV665917, has in vitro and in vivo efficacy against Cryptosporidium parvum. In this study, we evaluated the efficacy of MMV665917 in gnotobiotic piglets experimentally infected with Cryptosporidium hominis, the species responsible for >75% of diarrhea reported in these children.
Gnotobiotic piglets were orally challenged with C hominis oocysts, and oral treatment with MMV665917 was commenced 3 days after challenge. Oocyst excretion and diarrhea severity were observed daily, and mucosal colonization and lesions were recorded after necropsy.
MMV665917 significantly reduced fecal oocyst excretion, parasite colonization and damage to the intestinal mucosa, and peak diarrheal symptoms, compared with infected untreated controls. A dose of 20 mg/kg twice daily for 7 days was more effective than 10 mg/kg. There were no signs of organ toxicity at either dose, but 20 mg/kg was associated with slightly elevated blood cholesterol and monocytes at euthanasia.
These results demonstrate the effectiveness of this drug against C hominis. Piperazine-derivative MMV665917 may potentially be used to treat human cryptosporidiosis; however, further investigations are required.
隐孢子虫是一种肠道原生动物,在低收入和中等收入国家,会引起<2 岁儿童腹泻相关的大量发病率和死亡率。目前尚无疫苗,治疗方法也不足。一种基于哌嗪的化合物 MMV665917 对微小隐孢子虫具有体外和体内疗效。在这项研究中,我们评估了 MMV665917 在感染微小隐孢子虫的无菌仔猪中的疗效,微小隐孢子虫是这些儿童报告的腹泻的 75%以上的原因。
无菌仔猪经口感染微小隐孢子虫卵囊,在感染后 3 天开始口服 MMV665917 治疗。每天观察卵囊排泄和腹泻严重程度,并在解剖后记录粘膜定植和病变。
与未治疗的感染对照组相比,MMV665917 显著减少了粪便卵囊排泄、寄生虫定植和对肠道粘膜的损伤,以及腹泻症状的峰值。每日两次 20mg/kg 的剂量比 10mg/kg 更有效。两种剂量均无器官毒性迹象,但 20mg/kg 与安乐死时血液胆固醇和单核细胞略有升高有关。
这些结果表明该药物对微小隐孢子虫有效。哌嗪衍生物 MMV665917 可能可用于治疗人类隐孢子虫病;但是,还需要进一步的研究。