In vitro and in vivo activity of aurintricarboxylic acid preparations against Cryptosporidium parvum

Klein, Pavel; Cirioni, Oscar; Giacometti, Andrea; Scalise, Giorgio

OBJECTIVES: The aim of this study was to assess the effect of commercial aurintricarboxylic acid (ATA) against Cryptosporidium parvum. METHODS: The anticryptosporidial effect of ATA was evaluated in vitro using cell culture and double fluorogenic staining, and in vivo in experimentally infected neonatal C57BL/6 mice. Mice were orally treated for 9 consecutive days starting on the day of infection with daily ATA doses of 50 and 100 µmol/kg. Paromomycin (100 mg/kg) was used as a positive control. RESULTS: In both in vitro models, ATA at concentrations of 100 and 10 µmol/L completely inhibited sporozoites within 10 and 60 min, respectively. Viability of oocysts exposed to 100 µmol/L and assessed by flow cytometry and in cell culture was reduced by 65% and 61%, respectively. The treatment of neonatal mice with a daily ATA dose of 100 µmol/kg led to 97–99% inhibition of infection without any observable negative effects on the animals. In comparison, the mean reduction of infection for paromomycin was 79–84%. CONCLUSIONS: ATA exerted high anticryptosporidial activity and should be considered for further study.